Hip Pocket Builders' Forum

Outdoor Free Flight Forum => P-30 Class Sport and Competition => Topic started by: Kevin M on January 21, 2021, 09:31:03 AM



Title: Newcomer to P30-advice sought.
Post by: Kevin M on January 21, 2021, 09:31:03 AM
I’m new to P30 and currently building my second. The first was an own-design drawn up after looking at many plans and photos. I made no particular effort to keep it light, I just wanted to get one in the air and develop a feel for it. At the time of building that one my wood stocks were low and I just used what I had. The results were pleasing in that it trimmed out easily and flew very well (the rubber was arranged in six strands) but it was heavy at 69g AUW, and although the cruise and glide were good the climb was soft.

Pleased by its flying qualities aerodynamically, I decided to do a second version, but this time trying to keep the weight lower. The trouble is I am failing to get it down to the minimum (UK) mass, so I’m seeking help from those on here who really know what they are doing with P30.

The pictures show where I am at; the uncovered components as you see them are:
Fuselage (not inc. prop) 13.4g
Wing 12.1g
Tailplane (tissue covered, no dope yet) 3.8g

That lot comes to nearly 30g. The prop shown (Igra) crashes down the scales at 7.7g.
Now we are at 37.7g. A Peck prop would save 2.2g but then I might need nose-weight to balance. Add the shaft, tissue, dope and D/T system and it is clear that I am going to miss the minimum mass target by some margin. It will be considerably lighter than the Mark 1, but I’d like to do better.

So where am I going wrong? Does the basic design have flaws? Is it mainly about wood selection? Any ideas would be most welcome.

The pictures show the Mk 1, then a few views of the Mk 2 in the hope that someone can identify some opportunities to slim it down.

Thanks,

Kevin


Title: Re: Newcomer to P30-advice sought.
Post by: billdennis747 on January 21, 2021, 10:16:42 AM
Kevin, your quoted weights indicate that you already have the all-important milligram balance.
I would be surprised if many P30s are down to 40g. Mine is about 45g, so I might aim for that. If yours is 59g empty, it's a lot. I once entered an experimental contest where the model had to have 10g ballast, and performance was leaden.The model looks fine - no excess material. It took me a long time to realise that I was using wood that was unnecessarily heavy. Have you noticed that you might pick a piece eg for longerons that seems right, only to find that when it is built, it is far too strong? If using 3/32sg for longerons, then 0.9g does for me.


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 21, 2021, 11:07:40 AM
Thank you Bill.

Quote
Have you noticed that you might pick a piece eg for longerons that seems right, only to find that when it is built, it is far too strong?

Frequently, trying to be better at that.

This looks as though it might come out at somewhere between 45 and 50g without rubber, so it's better, but I've read about people having to ballast these. I'll keep at it.


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 21, 2021, 11:27:55 AM
Quote
If using 3/32sq for longerons, then 0.9g does for me.

That's clearly part of the answer, the four sticks i chose were in the 1.3g-1.4g region. I did try to use lighter wood for the uprights and spacers.


Title: Re: Newcomer to P30-advice sought.
Post by: dosco on January 21, 2021, 11:51:05 AM
Nice looking plane!

Am interested to learn how you whittle the mass down with your subsequent versions.

-Dave


Title: Re: Newcomer to P30-advice sought.
Post by: DerekMc on January 21, 2021, 12:11:11 PM
A 45 to 50gm plane can be competitive with the right motor and prop.  I'd go for 6 strand of 1/8" or equivalent.  The long run P30's really need to be close to minimum weight.


Title: Re: Newcomer to P30-advice sought.
Post by: strat-o on January 21, 2021, 12:17:30 PM
I would scrutinize the sheeting areas.  I personally haven't seed a built-up p-30 using sheeting in the wing center section and certainly not in the stabilizer.  Also the nose, while a particular vulnerable area, I think you could still reduce the sheeting there by half.  Go with the lightest prop and don't initially worry about the overall weight distribution of the fuselage until all of the components are complete.  Finally position the wing where it needs to be to get the best CG so that you don't have to add ballast.

Marlin


Title: Re: Newcomer to P30-advice sought.
Post by: gman on January 21, 2021, 12:24:03 PM
Hi Kevin, I agree with everything Strat-o has just said. There's too much balsa about. How's your Mylar covering? Several grams to be saved over tissue.
Gavin


Title: Re: Newcomer to P30-advice sought.
Post by: Red Buzzard on January 21, 2021, 12:29:04 PM
Hi Kevin,

Strat-o just took some of the words out of my mouth. I agree with his "sheet" suggestions and would also look at your tail end in general. Do you really need that slab in the sub-rudder? What about your rudder's anchors to the fuselage and stab platform? But what strikes me is you have done a beautiful job on your nose block, but some of that grace and beauty may not get you to the finish line. You can limit your nose block to a couple of pieces of balsa with a ply backer and Peck nose button if you get right down to it. As Derek suggests, though, you also need something there to complete all five flights on a windy day when you are going to get swept across the field or tumbled upon landing. There's too heavy, just right, and too fragile. The balance is beautiful and 45g. is survivable.

Bill


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 21, 2021, 12:31:03 PM
Thanks very much for the replies, don't know how I'd get on without the resource of this forum.

Quote
I'd go for 6 strand of 1/8" or equivalent.

That's what I will do.

Quote
I would scrutinize the sheeting areas.  I personally haven't seed a built-up p-30 using sheeting in the wing center section and certainly not in the stabilizer.  Also the nose, while a particular vulnerable area, I think you could still reduce the sheeting there by half.  Go with the lightest prop and don't initially worry about the overall weight distribution of the fuselage until all of the components are complete.  Finally position the wing where it needs to be to get the best CG so that you don't have to add ballast.

I'll follow all that advice, thanks. The sheeting is all low density, about 1/20" over the wing c/s and 1/32" over the tail, but I agree, most of it doesn't need to be there at all.

Quote
Am interested to learn how you whittle the mass down with your subsequent versions.

Well I'll keep posting my efforts. I like building, and I'm quite prepared to keep on building more variants until I get somewhere near.


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 21, 2021, 12:33:25 PM
Gosh, good advice coming thick and fast, and all suggestions I will follow. Thank you all.


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 21, 2021, 12:36:47 PM
Gavin - I have hardly used Mylar before, and then under tissue, but I'm very prepared to try new things. Perhaps on the Mk 3.


Title: Re: Newcomer to P30-advice sought.
Post by: DerekMc on January 21, 2021, 12:37:16 PM
What kind of DT are you using?  It looks like stab only?  If so, be prepared to lose it in a thermal.  P30's love to fly and are hard to get out of thermals. A combination of wing and stab DT or pop off wing are the most effective.  Something to think about as you build lighter.  :)


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 21, 2021, 12:48:02 PM
Derek, as drawn this has pop-up stab, but I have been seriously considering pop-off wing, and may well do that on the next one. I found the CB design notes on the pop-off wing for the Boomer on the internet and should be able to adapt it for this.


Title: Re: Newcomer to P30-advice sought.
Post by: DerekMc on January 21, 2021, 12:52:29 PM
Good. The pop off wing is what I use.  The first time you see it in action is wild. It looks like the plane falls apart.  Don't forget a swivel in the line! 


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 21, 2021, 12:58:24 PM
Quote
The first time you see it in action is wild.

Never seen it in action. Do you have any links to video clips of it working?


Title: Re: Newcomer to P30-advice sought.
Post by: DerekMc on January 21, 2021, 01:10:06 PM
Quote
The first time you see it in action is wild.

Never seen it in action. Do you have any links to video clips of it working?

No. The plane is usually far away when it happens!


Title: Re: Newcomer to P30-advice sought.
Post by: calgoddard on January 21, 2021, 01:13:22 PM
Kevin –

Nine replies were posted while I was writing my reply so some of what follows may be redundant.

Your two P-30s look very nice. I see good designs and excellent craftsmanship.

It is difficult to build a P-30 that is reasonably strong and under the 40-gram weight limit in the U.S. rules.  I have done this and the models carry a tiny amount of ballast to bring them slightly over that limit to make them legal.
Unless you are going to use the long motor run approach (4 x 1/8 or 6 x 3/32) a 45-gram P-30 will be very competitive.  A 40-gram P-30 with a long motor run will not perform well unless the conditions are very calm. In the UK, I would think you would need a heavier, studier P-30 with a rapid climb, which takes a 6 x 1/8 rubber motor.

If the 3/32 x 3/32 sticks you cite that weigh 1.3 – 1.4 grams were 36-inches in length, John Barker’s chart indicates that they are 16# and over. That is way too heavy. I would use 0.83 – 1.00-gram sticks for the longerons, at the very most. That translates to 10 – 12# wood.

The uprights and cross-pieces can be lighter 3/32 sticks, e. g. 6 – 8#.

The wing tips on your P-30s could be slimmed down.  You don’t need double ribs at the dihedral breaks.

You may be able to eliminate the sub-fin. Look for a Dutch roll. If that appears, substitute a sheet fin made of light 1/16 sheet balsa with the grain oriented diagonally.  Make the fin the standard size, e. g. by copying the fin of the Majestyk P-30 for example.

The sheeting at the nose can be 1/16 instead of 3/32.

The nose block of your P-30 designs is a bit thick. Use a 9 ½-inch Gizmo Geezer prop assembly, not to save weight, but to enable precise and easy thrust line adjustments and have reliable free-wheeling.
Just as strat-o says, adjust the longitudinal position of the wing to get the CG at the optimum location. Don’t use ballast to set the CG where you want it.
Don’t forget to use a DT or else you won’t have the model very long.

If you want to build a 40-gram P-30 you should use a weight budget and be careful with wood selection.

It is easier to build a strong P-30 to the minimum weight if you use some carbon-fiber spars and/or rib caps and a rolled motor tube. Mylar covering also helps, as it is lighter than tissue. All this is not necessary to win most P-30 contests. Your P-30 at 45 grams can easily win with proper trim and winding.

Attached are pictures of two P-30 models that I built which are each under 40 grams. The one on the left with the green prop has the motor peg under the stab since it uses a 6 x 3/32 rubber motor.  The one on the right has the motor peg ahead of the stab so that it can use a 10 x 1/16 rubber motor. Each has a carbon fiber main spar in the wing. Both of these lightweight P-30 models have a pop-up wing and pop-up stab DT.  A DT which only pops up the stab is too risky when the model is at or near the 40-gram minimum.



Title: Re: Newcomer to P30-advice sought.
Post by: PeeTee on January 21, 2021, 01:13:47 PM
Kevin

Bear in mind that the pop-off wing is being advised by our US chums and they do not fly in such a windy little island as us. I haven't flown P30 for nearly 5 years (haven't flown anything sadly) but Gavin & Don have and they are better able to advise you. As regards props, I recommend trying the Orange props, they have a slightly higher pitch and I converted all my P30s to that type.

Peter


Title: Re: Newcomer to P30-advice sought.
Post by: DerekMc on January 21, 2021, 01:21:55 PM
Kevin

Bear in mind that the pop-off wing is being advised by our US chums and they do not fly in such a windy little island as us.

Peter

Interesting comment. I've flown at the contest wind limit many times with my pop off wing P30 and regular type DT's.  I've chased tumbling airplanes and picked up the parts.  The pop off wing p30 doesn't tumble as much.    It is harder to get out of a tree due to the lanyard so if it leaves the field you could be in trouble.  Balance that with the speed of descent after dt.


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 21, 2021, 01:35:41 PM
Calgoddard, thanks very much for your thought-provoking and comprehensive reply. All of what you say sounds very sensible and I will try to follow your advice.

PeeTee, Orange props? New to me, where do I get them? Interesting thoughts about UK vs. US conditions, and Dereks comments. I'm keen to try it though.



Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 21, 2021, 01:38:51 PM
PS Calgoddard, beautiful models in your pics. Are those the Gizmogeezer props? The blades look quite Peck-like.


Title: Re: Newcomer to P30-advice sought.
Post by: Indoorflyer on January 21, 2021, 01:55:00 PM
what kind of glue are you using?


Title: Re: Newcomer to P30-advice sought.
Post by: DerekMc on January 21, 2021, 01:56:29 PM
Volare Products is a US based source for the orange Chinese props.  I just ordered a few for a bit of testing.

https://volareproducts.com/blog/?product=12-chinese-prop


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 21, 2021, 02:02:26 PM
Indoorflyer, I'm using aliphatic, trying to be frugal with it by applying with a cocktail stick and wiping away any excess.

Derek, thanks, I'll check their website.


Title: Re: Newcomer to P30-advice sought.
Post by: calgoddard on January 21, 2021, 02:09:18 PM
Thank you for the complement Kevin.

Here is a picture of the orange Chinese prop. It has a larger hub bore than the Peck prop and may need to be bushed. No alterations to the prop are allowed under the P-30 rules except bushing, adding weight to one blade for balancing, and removing flashing.

The approximately 9 1/2-inch diameter orange Chinese prop costs $2 (US) from Volare Products.

The Gizmo Geezer prop is re-pitched to a higher pitch so that its P/D is 1.25 I believe.  Long ago the powers that be ruled this alteration to be legal under the P-30 rules.

I used Peck style P-30 props on my lightweight P-30 models because they had the lower pitch I wanted for the thinner (longer) 6 x 3/32 and 10 x 1/16 rubber motors.

The green prop was super light as I recall so I used it.  

I have tried pretty much every legal P-30 prop. I have read the detailed technical analysis in FFQ re the prop choices.  I think I have eight flyable P-30 models.  I have tried flying the same P-30 with different props.  So far I cannot discern an appreciable difference in flight duration.  There is one prop in my collection that may be legal which I have not tried. It is no longer available as far as I know.  

My friend Stan Buddenbohm flies his P-30 with the Czech (IGRA) prop and he is pretty much unbeatable in the P-30 event except perhaps occasionally by Don DeLoach. The plan for DeLoach's Polecat MK 10 P-30 appears to show the Peck prop.  I think these two fliers would both be pretty much unbeatable in the P-30 event regardless of which prop that they flew with.

Be aware that Stan and Don could both beat me flying your P-30 design at 45 grams.  

I might pull off a lucky victory if their models flew into a downdraft.

Have fun Kevin.



Title: Re: Newcomer to P30-advice sought.
Post by: DerekMc on January 21, 2021, 02:31:30 PM
If I remember correctly Stan B's record setting P30 wasn't that close to minimum weight.  Something to think about for sure.  And it used Boron to strengthen the stab.  I'd include Clint Brooks with Stan and Don. 


Title: Re: Newcomer to P30-advice sought.
Post by: billdennis747 on January 21, 2021, 02:33:50 PM
...and use Ezewind lube (Aeromodeller) for extra duration.


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 21, 2021, 03:21:54 PM
Quote
...and use Ezewind lube (Aeromodeller) for extra duration.

Will I get more duration the more I use? May need several grams of it.....


Title: Re: Newcomer to P30-advice sought.
Post by: DerekMc on January 21, 2021, 03:33:15 PM
Quote
...and use Ezewind lube (Aeromodeller) for extra duration.

Will I get more duration the more I use? May need several grams of it.....

AMA P30 rules state the lubed motor must weigh 10 grams or less so you don't want to use lot's of lube. My motors are weighed to 9.7 grams and then lubed.  They end up up around 9.95 grams.  I use 10k -15k wt. silicone lubricant. 

The ezewind lube looks interesting and I see there is a write up on it in the latest Aeromodeller.


Title: Re: Newcomer to P30-advice sought.
Post by: atesus on January 21, 2021, 03:46:27 PM
Excellent recommendations from everyone. I will add a couple more of mine. You may consider slimming down the fuselage a little and also using 1/32" ribs and/or lighter wood in the outer wing panels. I suspect the weight reduction may not be significant but since you're literally working on shaving grams so everything helps :). I do agree with the strategy of reducing the weight wherever it can be done and then moving the wing to balance the plane at the end. My P-30s have a movable pylon, which I glue in place once I'm satisfied with the performance. Not sure what kind of DT you'll use but if you're going to use a viscous timer, or an electronic timer, that is a good bit of weight which you may shift around for optimizing the wing location.

Handsome design, I like it a lot.
--Ates


Title: Re: Newcomer to P30-advice sought.
Post by: OZPAF on January 22, 2021, 12:44:10 AM
Another late edition to all these good suggestions Kevin.I like the 2 spar approach for your wing as it tends to induce a slight bit of washout at the tips and also turbulates the front of the airfoil however perhaps the spars may be reduced in size - definitely in the tips - say 3 square?

It's a nice looking model and deserves a bit of development!

Good luck with it.

John.



Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 22, 2021, 09:23:17 AM
Today I have been trying to incorporate some of the above helpful suggestions; some others will have to wait for the next version.

Most of the fuselage sheeting has been removed, a saving of 0.66g. Most of that was at the front end, removing the bits where the fins attach only yielded 01.g, but it all adds up.

I made a new shorter nose-block and left off the ply facing, used a shorter brass tube bearing for a total saving of 1.34g, certainly worth having.

The c/s sheeting on the horizontal stab only came to 0.08g, so I’ll leave it on this one but not bother with it on the next, similarly with the wing c/s sheet.

I managed some trivial savings with some minor wood removal from both fins.

My fuselage is now down to 11.3g, so 2.1g saved. On the next one using 1g vs. 1.4g sticks for the longerons would save another 1.2-1.5g, and I could use even lighter stock for uprights and cross-pieces than I did on this (when balsa becomes available again here). Thanks to your advice I think I am on the right track.

Do people generally use 18swg (.048”/1.22mm) prop shafts on these?


Title: Re: Newcomer to P30-advice sought.
Post by: lincoln on January 22, 2021, 11:24:52 AM
You might try moving the motor peg forward if you're worried about nose weight. Maybe this would allow a lighter prop. Coupe d'Hiver models have the peg quite far forward, but they don't use heavy plastic props.

If it was my model, I'd put something over that nasty wire up front before flying it. Or else use a finish that's blood-proof.


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 22, 2021, 11:43:42 AM
Lincoln, the Mk 1 balanced without nose weight; this one will be lighter up front but also hopefully at the back too. The current plan is to complete the model and adjust the wing position a little if necessary to balance it. At the moment the rubber distribution about the C.G. is roughly 46/54.

Yes, my Coupe has the peg at the wing TE.


Title: Re: Newcomer to P30-advice sought.
Post by: dosco on January 22, 2021, 12:08:20 PM
Lincoln, the Mk 1 balanced without nose weight; this one will be lighter up front but also hopefully at the back too. The current plan is to complete the model and adjust the wing position a little if necessary to balance it. At the moment the rubber distribution about the C.G. is roughly 46/54.

Yes, my Coupe has the peg at the wing TE.

Kevin:
If I understood your description correctly (quite possible I did not) ... you mentioned removal of several widgets of noseweight, as well as plans to keep several widgets of tail weight.

While the suggestions here have indicated you should place the wing "at the end of building" so as to achieve a natural state of balance (and avoid addition of noseweight), wouldn't you want to seek to eliminate the tail weight (due to lever arm considerations)? I'm not sure I see the need for keeping the sheeting on the horizontal stab.

Anyhow, probably nitpicking, as you indicated that sheeting = 0.08g.

Regards-
Dave


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 22, 2021, 12:18:22 PM
Quote
I'm not sure I see the need for keeping the sheeting on the horizontal stab.

Laziness. It won't be there on the next stab.

No, just trying to keep it light everywhere and hope the balance works out somewhere near.


Title: Re: Newcomer to P30-advice sought.
Post by: gman on January 22, 2021, 01:52:08 PM
Hi Kevin, if you're interested in Orange plastic P30 props you might try..
https://www.ebay.co.uk/itm/5pcs-Orange-Plastic-9-5-17mm-Hub-Thick-RC-Airplane-Propellers-Vanes/362791382206?hash=item54780d2cbe:g:9agAAOSw7XFf8pa0
regards wire gauge, 18swg will be fine for a P30, maybe make your "Gray Hooks" from 22swg. It's about saving a little bit of weight wherever you can.
Gavin



Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 22, 2021, 01:58:35 PM
Thank you Gavin. I'll look into that source, and I would have gone for 18 swg for the Gray hook, good to know it can be lighter.


Title: Re: Newcomer to P30-advice sought.
Post by: calgoddard on January 22, 2021, 05:41:36 PM
Kevin -

For P-30 models the standard prop shaft diameter that I use is .047-inches.

Do yourself a favor and install a 9 ½-inch Gizmo Geezer prop assembly on the current P-30 you are building. It will provide three distinct advantages:

1)   Precision thrust line adjustments that are easy to make;
2)   Reliable free-wheeling of the prop during the glide; and
3)   Avoidance of rubber motor bunching and CG shifting where the prop hook-to-motor peg distance is substantially less than the length of the rubber motor.

Normally no. 3 is not a factor in P-30 as the typical prop hook-to-motor peg distance is set up to accommodate a 6 x 1/8-inch rubber motor that is approximately 19-inches long.  
Someone mentioned moving the motor peg in the fuselage of the P-30 you are building forward to improve the moment arm.  If you are going to use a shorter 15-inch prop hook-to-motor peg distance, for example, a 19-inch rubber motor might bunch in the rear toward the later part of the motor run, causing a stall.  Or it might bunch in the front, causing a dive.

Like everything else in free flight, shortening the motor hook-to-motor peg distance is a trade-off.  You either have to use a braided rubber motor or a spring tensioner, like the Gizmo Geezer prop assembly includes, if you substantially shorten the prop hook-to-motor peg distance. The spring tensioner in the Gizmo Geezer prop assembly will leave you with about 50 or so unused turns, and that is why the rubber motor will not go slack and bunch.  However, those unused turns would have very little torque and would not increase the flight time very much.

Personally, I wouldn’t use a short motor hook-to-motor peg distance in a P-30. If it provided a significant benefit, others would already be doing it.

Motor bunching becomes a big problem with scale models where the rubber motor can be 2X, 3X or even 4X the prop hook-to-motor peg distance in order to get a reasonably long motor run.

I am aware of two extreme P-30 designs that use a very short motor hook-to-motor peg distance. Each has a rubber motor with more than six strands of 1/8 rubber. One uses a 14 x 1/8-inch rubber motor and a 1:4 gear drive. The other uses -a 10 x 1/8 rubber motor that is wound to a ridiculous launch torque. The gear drive is inefficient and trimming a P-30 to launch at 20+ inch-ounces is not a viable strategy in my opinion.

Keep up the good work.  Your P-30 is a very good looking design.


Title: Re: Newcomer to P30-advice sought.
Post by: calgoddard on January 22, 2021, 05:46:29 PM
Kevin -

The motor peg holes in your sheet balsa wood uprights will quickly wear and the motor peg will have a sloppy fit. These uprights may fail as the holes enlarge and/or the motor peg may dislodge. Each such failure can cause major damage to the fuselage of your model.

You need to glue two ½-inch x ½-inch squares of 1/64 plywood over the inside surfaces of your motor peg uprights. Reinforcing the motor peg holes is standard practice in constructing balsa wood model airplanes.

Pre-drill holes in the center of these squares that are the same size as the OD of your motor peg. White glue, carpenters glue, or nitrocellulose cement (e.g., Duco brand) should be used to glue the plywood squares to the inside of the uprights. Don’t use CA for this purpose. The former types of glues will give you time to adjust the location of the small squares. Use the motor peg to align the holes in the squares with the holes in the uprights.  Pull the motor peg out of the squares while the glue is still uncured, taking care that the position of the squares does not change.

On my P-30 models that have a rolled sheet balsa fuselage, I boil the squares in water and form them over a forming mandrel so that they conform when glued to the outside of the fuselage. It’s not practical to glue these reinforcements on the inside of a sheet balsa wood tubular fuselage.

Switch to a 1/8-inch OD Aluminum tube for a motor peg for your P-30.  It looks like you are using a larger diameter motor peg like 3/16-inch which is overkill.



Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 22, 2021, 06:09:48 PM
Thanks Calgoddard, all good thoughts. My plan is to use 6 strands of 1/8" with the motor length you see. I always do .4mm ply around those holes, I like your idea for making them fit on curved fuselages. You are right about them being sized for a 3/16" tube.I have been used to stronger motors recently than these use. I will reduce to 1/8"


Title: Re: Newcomer to P30-advice sought.
Post by: gman on January 23, 2021, 10:06:16 AM
I would have gone for 18 swg for the Gray hook, good to know it can be lighter.
Hi Kevin, now I see that you're using 6x1/8th for the motor then maybe 20swg for the hook, I use 22swg on 10x1/16th or lighter. Best is to try it and see. Do keep the hook nice and "compact" though, big open loops will distort even on these small motors, and weigh more!
As if all this weight chasing isn't enough don't forget there's 3.5g of tracker....
Gavin


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 23, 2021, 11:14:49 AM
Quote
don't forget there's 3.5g of tracker....

Yikes!

I'll try 20 sag, thanks.

K


Title: Re: Newcomer to P30-advice sought.
Post by: flydean1 on January 23, 2021, 09:54:28 PM
Derek,

Re: pop-off wing DT.

I'm kind of curious as to where you fasten the line between the wing and the end of the fuselage?  On my grandson's Souper 30 about a dozen or more years ago, we fastened the line to the DT break on the right side.  there were a couple over-sized gussets for an anchor point.  Some said he should have put it on the wing tip.  Only used it once and it was so far away, I couldn't see how well it worked.  Got the model back as he was under it with his chase bike.

We were careful to route the dt line across the top of the stab and it had very little slack.  It seemed that if it was under the stab, the line would probably damage the stab when the wing popped off.

Still, maybe the tip would be better as the usually slightly heavier tip rib would be sufficient and not make a huge gusset necessary.


Title: Re: Newcomer to P30-advice sought.
Post by: DerekMc on January 26, 2021, 12:48:05 PM
Dean I'll post a few pictures of the dt line attachments and swivel when I get back home. It will be in early February. 


Title: Re: Newcomer to P30-advice sought.
Post by: flydean1 on January 26, 2021, 06:37:29 PM
Thanks Derek, that's soon enough.  Building my Jetstream first.


Title: Re: Newcomer to P30-advice sought.
Post by: atesus on January 26, 2021, 07:05:04 PM
Derek,

Re: pop-off wing DT.

I'm kind of curious as to where you fasten the line between the wing and the end of the fuselage?  On my grandson's Souper 30 about a dozen or more years ago, we fastened the line to the DT break on the right side.  there were a couple over-sized gussets for an anchor point.  Some said he should have put it on the wing tip.  Only used it once and it was so far away, I couldn't see how well it worked.  Got the model back as he was under it with his chase bike.

We were careful to route the dt line across the top of the stab and it had very little slack.  It seemed that if it was under the stab, the line would probably damage the stab when the wing popped off.

Still, maybe the tip would be better as the usually slightly heavier tip rib would be sufficient and not make a huge gusset necessary.

Although not a P-30, I used pop-off wing DT on my late Square Bird with great effectiveness. It brought the model down so fast that on that one day, I took my eyes off of the model for a moment, and it had already fallen out of the sky and I lost it  ;D.

The DT line went from the TE at the wingtip to a hard-point at the tail. A swivel was included in the line. Although the photos don't clearly show it -particularly after the requisite compression- the line was routed above the stab for the reasons you also mentioned. Keeping the line just long enough makes sure that the line cannot move under the stab in flight. Another concern was the wing potentially hitting the fin but in practice that turned out to be a non-issue. Once the wing pops off, the nose quickly dives, and the wing flies upwards so the separation of the two pieces is very fast. I had a video clip where I was able to see this clearly, but I couldn't locate it. If I find it I'll post. I found this video (link below) which shows the DT operation towards the end.

https://youtu.be/TBe_axZQHGo

Best,
--Ates


Title: Re: Newcomer to P30-advice sought.
Post by: calgoddard on January 27, 2021, 12:14:21 PM
If you employ a pop-off wing DT in a P-30, one end of the line should be connected to a first swivel connector mounted in one wing tip, midway between the LE and the TE.  The other end of the line should be connected to a second swivel connector mounted in the rear end of the fuselage.  The line should be 10# monofilament fishing line and should have a length that is only slightly larger than the distance between the connectors.  The line should run over the top of the stab when the model is launched. The swivel connectors are the type that are typically used as part of a rod and reel fishing line set up.

I am not a fan of the pop-off wing DT as the fuselage comes in very hard, nose down. This can lead to a bent prop shaft and/or broken fuselage if your flying field has a hard pack dirt surface with no vegetation, such as one experiences at Lost Hills, California and Eloy, Arizona. The grassy flying fields of the UK would present no risk of such damage if a pop-off wing DT were used.

I prefer use of a combination pop-up wing and pop-up stab DT on a P-30.  The model descends gently in a horizontal orientation.  See the end of the video at this link:

https://www.youtube.com/watch?v=L10YLPjZq38

Details of the pop-up wing and pop-up stab DT set-up are provided in the instructions for the excellent P-30 kits sold by CB Model Designs.
 
I have attached a picture of my P-30 model that I am flying in the video. This model has no moving surfaces except for the DT.
 
Note that the P-30 in the video is flying with a 6 x 3/32 rubber motor.  It DT’s early, with the prop still being driven, and when the model is still climbing.  Even though this P-30 was only launched with 1,500 turns at only 3 inch-ounces of torque, the flight would have easily been over two minutes had the DT not triggered early.  I could probably wind the same rubber motor to 2,000+ turns and perhaps 4-5 inch-ounces of torque before breaking. I might be able to wind this motor to 6-inch ounces of torque, but that would be pushing the envelope.

Note that use of a 6/32-inch rubber motor in a P-30 necessitates the motor peg being located under the stabilizer. This leads to challenges in mounting the model on a winding stooge.  Use of a thinner rubber motor in a P-30 gives you a long motor run. However, the model must be very close to the 40-gram minimum to get a good climb.  Also, lightweight P-30 models like the one in the video only perform well in calm conditions.  In the UK, I would fly a sturdier 45-gram P-30 with a 6 x 1/8-inch rubber motor.


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 27, 2021, 01:52:44 PM
Calgoddard, I'm keeping notes of your excellent advice and experience of P30. I'll investigate the pop-up wing and stab system.

Quote
In the UK, I would fly a sturdier 45-gram P-30 with a 6 x 1/8-inch rubber motor.

Pleased to hear you say that because that is what i planned, although I was wondering about 3/32. I'll now stick to 6 X 1/8" (albeit my model that started this thread looks like it is going to finish at 48g or 49g; hopefully the next will make 45).


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 27, 2021, 03:17:20 PM
It seems the more I get into this , the more questions I have.

Sometime back in this thread Atesus suggested my fuselage could be slimmer; true. The reason it isn't is because the cross-sections at the nose and motor peg are designed to accommodate my blast tube, and then I designed a low-drag body around that. But do people usually wind their motors outside the model with built-up P30 fuselages? Sorry if this is a basic question, but I've never seen a P30 flown live, only video, and they don't show the winding!


Title: Re: Newcomer to P30-advice sought.
Post by: atesus on January 27, 2021, 05:20:02 PM
I seldomly see people winding P-30 motors outside. Maybe it's just not common where I am (in CA).

I use a piece of clear plastic aquarium tubing for a winding tube for a 6x 1/8" motor. The tube is quite slim at 9/16" ID. It has quite a thin wall so OD is not much larger. I got it long time ago at Volare Products. I don't see it on their web site any longer though. I also recently ordered the item below but have not cut it to size to use it yet. My main motivation to buy the new tube was that the older one is no longer straight.

https://www.amazon.com/gp/product/B000OMHJAS/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1



Title: Re: Newcomer to P30-advice sought.
Post by: calgoddard on January 27, 2021, 06:49:09 PM
Kevin -

Few fliers wind P-30 rubber motors outside the model.  I have done it but you have to make your own half tube. Then you need two stooges, one to wind the motor and one to hold the airplane. So I usually wind my P-30 models using a blast tube.

Winding outside the model is customary in flying high-tech F1B and F1G models. The people who fly those models wind very, very hard and do not want a motor to explode inside the model.  High-tech F1B and F1G models have super strong fuselages made of exotic materials like Kevlar, so I am not sure a blast tube would even be needed in winding them.  However, extracting a highly wound blown motor from a fuselage in the heat of world-class competition needs to be avoided. Also I have heard that world-class F1B fliers will wind two motors before an official flight for that flight. They have a wound spare ready to insert into the model in case the first one explodes near the end of a round.

The clear plastic tubing from Amazon is too thick and heavy.

Item 470 from Arcata Pet Supplies has just the right OD and ID:

https://www.arcatapet.com/sresult.cfm  

I prefer very thin walled Aluminum tubing for my blast tubes but have a very hard time finding it, even from our big suppliers like McMaster-Carr.

It is easier to machine the bayonet lock on the rear end of the blast tube in the Aluminum tubing than it is on plastic tubing. Use a Dremel and a file. Remove all sharp edges or else you will nick your rubber motors. A bayonet lock couples the end of the blast tube to the motor peg and prevents the blast tube from creeping forward.  One of my mentor's recently told me that you can avoid blast tube creep by wrapping a sufficient amount of tape around the blast tube to create a friction fit at the front end of the fuselage.

Atesus - we met in Perris, California a few years ago.  I have enjoyed your videos. Maybe we can see each other at a contest some day at Waegell Field in Sacramento after I get my vaccinations. You have some really nice models and know how to fly them well. I live in northern Nevada.



Title: Re: Newcomer to P30-advice sought.
Post by: atesus on January 27, 2021, 08:13:22 PM
Atesus - we met in Perris, California a few years ago.  I have enjoyed your videos. Maybe we can see each other at a contest some day at Waegell Field in Sacramento after I get my vaccinations. You have some really nice models and know how to fly them well. I live in northern Nevada.
I didn't realize you live in Nevada. I'm looking forward to seeing you at Waegell. The first contest on the NCFFC calendar is approaching quickly. It's the SGMA Spring Bash on Sat, Feb 27th (Sun 28th is the backup day). I'm planning to go.
Best,
--Ates


Title: Re: Newcomer to P30-advice sought.
Post by: calgoddard on January 27, 2021, 08:17:33 PM
Atesus -

I will miss the contest at Waegell Field at the end of February, 2021. I probably won't have full vaccinations by then.

Maybe I can make the June contest.

Thanks for telling me about the SGMA Spring Bash.


Title: Re: Newcomer to P30-advice sought.
Post by: cvasecuk on January 28, 2021, 05:39:14 AM
In UK, I use 20mm conduit from B&Q. Very cheap.
Ron


Title: Re: Newcomer to P30-advice sought.
Post by: PeeTee on January 28, 2021, 07:30:38 AM
I too use the 20mm conduit you can buy from hardware stores. The white stuff has lasted me for 20 odd years and is still going strong!

Peter


Title: Re: Newcomer to P30-advice sought.
Post by: Tapio Linkosalo on January 28, 2021, 07:37:04 AM
Re: winding outside the model. I have been considering moving to that, have laminated a half-tube from carbon and 3D-printed the rear bobbins to use. But have not had the time to try that out yet.

I would not need to do that to avoid model breaking if the motor blasts, as I use kevlar tube for motor tube and it can withstand the breakage. But taking the broken motor out of the tube is  unpleasant (and if it jumps to the read tube it may get tangled with the fuse line. But most of all, keeping the model in the stooge in windy days gets the model thrown around pretty bad, so I'd be happier to store the model in the tent while winding, and only insert the wound motor still in wind shelter after winding, and only after that expose the model to the elements.
   


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 28, 2021, 10:37:55 AM
Quote
I too use the 20mm conduit you can buy from hardware stores

I've got 20 mm conduit too, which is effectively governing the fuselage cross-section. Calgoddard's stuff is a little slimmer, may let me reduce it a bit.

Quote
keeping the model in the stooge in windy days gets the model thrown around pretty bad, so I'd be happier to store the model in the tent while winding

An interesting thought Tapio, windy days are common even in the summer here nowadays.

Well this one is finished, ca. 48.5 g. I know I can do better on the next simply by better selection of wood, particularly longerons, but also wing LE and inner panel main spar. Many thanks to you all for setting me on the right path. I have no doubt I will have more questions when I start the Mk 3....


Title: Re: Newcomer to P30-advice sought.
Post by: calgoddard on January 28, 2021, 11:28:59 AM
Kevin -

Your Mk 2 looks really nice. Your craftsmanship is excellent.

Don't worry about the weight of this P-30.  Fly it and have fun. It should do well in the windy conditions in the UK.

When you build Mk 3, trying slimming down the fuselage a bit as someone else mentioned.  Also, more careful wood selection should save a few grams.

Mount the viscous timer button closer to the nose, but not so close that you cannot freely grip the sheeted part of the fuselage when inserting the nose block. You always want as much weight forward as possible.  This allows you to move the wing forward.  Greater separation between the wing and the stab is almost always desirable.

As I mentioned before, determine if you really need the sub-fin.  While it looks great, it probably adds at least one or two grams, and those are added at the end of the tail boom, exactly where you don't want unnecessary weight. If you notice that Mk 3 exhibits a Dutch roll without a sub-fin, you can increase the size of the fin on the top or attach a sub-fin.  A Dutch roll is characterized by a sort of corkscrew motion of the tail or a wagging of the tail.  Too much fin can also induce spiral instability.  The McCombs book probably has formulas for figuring out the optimum fin area for your design.  

While I am on the subject, the McCombs book is considered the go-to treatise on building and trimming free flight model airplanes. While the focus of this book is scale free flight model aircraft many of the principles explained in the book apply to sport models, like P-30.  The full title is "Making Scale Model Airplanes Fly."  The author is William F. McCombs.  It only comes in an ancient typed format with hand drawn sketches.  The last I know you have to order a copy from an individual.  The cover of my copy lists the following person and address:  Susan Creamer, 1925 Clark Trail, Grand Prairie, Texas, USA 75052.

William McCombs was an early mentor of Don DeLoach who is one of the preeminent free flight masters in the US.  Mr. McCombs was a Princeton educated Senior engineer for Vought Aircraft.  


Title: Re: Newcomer to P30-advice sought.
Post by: Red Buzzard on January 28, 2021, 12:17:28 PM
Wow, Kevin,

Down from 69 g.!! You win the prize. Fly it. Now is when you start watching and picking air as your model will survive at that weight. Nice design and as others have said great workmanship. May still be a couple of grams in the nose block, but then your wing moves back. Combine that with a re-imagined sub rudder.

Great stuff.

Bill


Title: Re: Newcomer to P30-advice sought.
Post by: PeeTee on January 28, 2021, 12:50:47 PM
Have a look at the Teachers Pet by John O'Donnell, it has the fin above and below the centre section. Having said that, I prefer the fin above but JOD won lots of comps with that design.

Peter


Title: Re: Newcomer to P30-advice sought.
Post by: billdennis747 on January 28, 2021, 01:21:06 PM
Have a look at the Teachers Pet by John O'Donnell, it has the fin above and below the centre section. Having said that, I prefer the fin above but JOD won lots of comps with that design.
I suspect John was the major factor. I've got a TP but the underfin hasn't won for me yet!
All I would add to the debate is that I watched John spending ages fixing a broken underfin


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 28, 2021, 01:42:31 PM
Quote
All I would add to the debate is that I watched John spending ages fixing a broken underfin

A good enough reason to remove it then. I put it there because my DLGs have that arrangement, as do nearly all others, and I like the way it looks, but I'll probably dispense with it on the next.


Title: Re: Newcomer to P30-advice sought.
Post by: atesus on January 28, 2021, 02:15:25 PM
Quote
All I would add to the debate is that I watched John spending ages fixing a broken underfin

A good enough reason to remove it then. I put it there because my DLGs have that arrangement, as do nearly all others, and I like the way it looks, but I'll probably dispense with it on the next.

I fully agree with the comments on the subfin. I too love the looks of it, but the only way I found to make sure that it didn't break at each landing of my XL-56 involved adding more weight at the tail. I'm stuck with it because it is in the original design.

Your design has very pleasant lines. Great weight reduction too, congrats!


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 30, 2021, 09:42:54 AM
Thank you for the nice comments and thoughts for development.

The leaner, meaner Mk. III is underway. The fuselage design has been slimmed a bit, all unnecessary sheeting has gone. The ventral fin has been dispensed with, the remaining dorsal fin has had the area increased a bit to compensate, but there is a net reduction in area. Hope the new fin is big enough, it "feels" as though it is. One of the main culprits on the Mk II was the density of the longeron wood I used, I've managed to find just enough approx. 1g sticks for this one. I don't have any lighter 3/32 sq. left, so most of the uprights and cross-pieces have been changed to 1/16 x 3/32", stripped from some reasonably light 1/16" sheet.

Pics show the design changes and how it looks so far. All of the changes are in response to suggestions made on here. If anyone has any more suggestions, please chip in before I get too far...


Title: Re: Newcomer to P30-advice sought.
Post by: Yak 52 on January 30, 2021, 10:53:05 AM
That's a really attractive P30  8)

I put it there because my DLGs have that arrangement...

One reason why DLG's have this is because they have to cope with massive yawing forces in a discus launch. Mounting the fin centrally (ie a sub fin) gives aerodynamic balance and helps avoid turning this yaw force into torsional twist of the boom.

I'm fairly sure you'd get a slight drag reduction with a slightly larger single fin on your latest iteration since there will be some interference drag around each of the root/fuselage areas. A DLG won't have this since the boom is so skinny at this point.


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 30, 2021, 11:10:10 AM
Thanks Yak52, true, there also used to be a theory that ventral fins helped mitigate roll moments due to slipstream effects on the power burst on rubber models once. They are also quite common on tow-line gliders, but I'm not sure what the theory is there. They look cool though!


Title: Re: Newcomer to P30-advice sought.
Post by: Yak 52 on January 30, 2021, 11:22:02 AM
Yes, that's the theory. I suspect any spiral slipstream effect is a very minor with everything else that's going on though. I'm afraid I'm no expert on rubber duration (listen to Peetee instead  ;))

I understand that in towline gliders having the fin area low helps stability on the line. I think Hepcat wrote about this at some point...


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 30, 2021, 11:38:22 AM
Quote
I suspect any spiral slipstream effect is a very minor with everything else that's going on though

I think you are probably right. I think sometimes there are features of a successful model that get copied widely, whether or not that feature was a reason for the success of the original.


Title: Re: Newcomer to P30-advice sought.
Post by: calgoddard on January 30, 2021, 03:29:14 PM
Kevin –

McCombs put forth the formula listed below in his book that he says will give a fairly reasonable estimate for the tail size for a free flight model.  He says the ideal size for the vertical tail means less drag and weight, easier trimming, less sensitivity to inadvertent warps and no spiral instability troubles.  However, McCombs also says you can really only determine the “ideal size” by flying.  

Av = N x Aw x b/Lv

Where:

Av is the vertical tail size in square inches

N is a numerical factor from a chart that lists different types of free flight models (it is .033 for
              an outdoor rubber duration model)

Aw is the wing area in square inches

b is the wingspan in inches

Lv is the distance in inches from the CG aft to the “center of the tail” (apparently the center of
             the vertical tail)

I have read that a sub-fin can be beneficial during the power phase in countering roll. I prefer to rely on thrust line adjustments to handle this trimming issue.


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on January 31, 2021, 03:08:22 AM
Calgoddard

Thanks, using that formula the "ideal" fin area comes out at 10.1 sq. in. for my model. I took Lv to be from C.G. to fin A.C.

My fin as drawn comes out at 11.1 sq. in. including the fuselage bit below it, whether McCombs followed the convention of including that bit I don't know. If he didn't mine comes out at 8.5 sq. in. So mine is in the ballpark.

As he says this gives a starting point, but the formula, in its coefficient, makes fixed assumptions about several factors e.g. keel area distribution and fin CL-alpha characteristics. My Mk 1 has good directional and spiral stability, and as has been mentioned a larger single fin brings some efficiency gain, so it seemed O.K. to accept something slightly less than the total fin area of the ventral-dorsal arrangement.

It doesn't take long to make a new fin if this isn't right, but it is good to have a starting point.


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on February 06, 2021, 01:27:22 PM
My progress continues....

The pictures show the Mk. III with the woodwork complete. It appears that this one is 4 to 5g less than the Mk. II was at the same stage. so I have hopes of a sub-45g model at the moment. We'll see, the covering and finishing process always adds more than I think it will. Fingers crossed.


Title: Re: Newcomer to P30-advice sought.
Post by: DerekMc on February 06, 2021, 04:37:02 PM
Nice!


Title: Re: Newcomer to P30-advice sought.
Post by: Red Buzzard on February 07, 2021, 01:19:14 PM
Kevin,

Now that looks pretty airy!

Bill


Title: Re: Newcomer to P30-advice sought.
Post by: calgoddard on February 10, 2021, 08:58:10 PM
Kevin -

I have several comments.

Your piano is very nice.

I really like the bottle of wine.

Your Mk. III is coming along beautifully. Let me reiterate that your craftsmanship is excellent.

I always have a back-up model ready to fly at any contest. Usually my competitors don't.  I have won contests with back-up models used for second and/or third official flights. You need a back-up model in case the first model has flown OOS and not been recovered. You also need a back up model when the first model has been damaged on an official flight. Repairs during a contest are not advisable as usually they take up too much valuable time and/or there is insufficient time for trim flights and you don't know how the model will perform after repairs unless they are extremely minor.  I have also beaten other competitors because they did not have a back-up model. They probably would have beaten me if they had a back-up model.

Oh and I forgot to mention, I have had airplanes land in the water on an official flight, which necessitates flying a different model for the next official flight. Balsa wood absorbs water - who knew? See the attached picture. You can see that the stab of this model pivoted to its UP position so the viscous timer controlled DT triggered, but alas, this model (Buddenbohm Air Shark P-30) landed in a flood canal. It is only filled with water a few weeks out of the year in the semi-arid place where we fly. I am going to switch to RDT for my better models (e.g. F1G) so I can semi-control where they land.

Winning isn't everything but it beats losing.

So you will have two back-up models for any P-30 contest. Bravo!

Kevin - It would be nice if I could fly with you in the UK. I would bring one of my 45 gram P-30's (plus a back-up 45 gram P-30) to fly in your breezy conditions. I have been to the UK a few times but only as a tourist. Lovely country. I have a picture of me at Stonehenge standing next to one of the sarsens before they kept everyone away. My AUW was 10 Kg less at the time. I can put my planes on a diet when I build them.  



Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on February 11, 2021, 03:17:19 AM
calgoddard, Red Buzzard and DerekMc

Thanks for the encouraging comments.

Calg, your model looks very forlorn taking its swim. Back-ups should be useful, you don't have to land in water to get wet models here! One of the advantages of tissue on mylar covering.

Quote
It would be nice if I could fly with you in the UK.

Let's hope that will be allowed in the not too distant future...



Title: Re: Newcomer to P30-advice sought.
Post by: OZPAF on February 11, 2021, 07:41:49 PM
A well balanced and attractive design - carefully and skillfully built. Well done Kevin.

Good luck with it and definitely never fly it without a DT!

John


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on February 12, 2021, 04:13:49 AM
Thank you John.

Quote
definitely never fly it without a DT!

No, in fact I intend to fit wing and stab D/T on the next one.


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on February 13, 2021, 08:35:19 AM
Well, the Mk. III is now complete. It came out at 43.6g in the end-and could be 1.8g less with my lightest prop fitted. In truth it could do with a little more dope for U.K. conditions, nevertheless I'm quite pleased.


Title: Re: Newcomer to P30-advice sought.
Post by: calgoddard on February 13, 2021, 09:11:24 AM
Very nice!


Title: Re: Newcomer to P30-advice sought.
Post by: Red Buzzard on February 13, 2021, 12:12:14 PM
Kevin,

Yay! What a nice result. A little more dope would be good for puncture and hangar rash protection. Besides it only gets lighter with time and evaporation. Trimming and repairs will gradually round out your real competition weight and it will be right in there with others. Go get some good air!

RB


Title: Re: Newcomer to P30-advice sought.
Post by: vintagemike on February 13, 2021, 12:56:15 PM
Nice model


Title: Re: Newcomer to P30-advice sought.
Post by: OZPAF on February 15, 2021, 07:10:47 PM
It looks even better covered Kevin. To my eyes it has a bit of Bill Dean influence in the wing/tail tips - the wing particularly with the nice taper from the last rib to the tip.

Happy flying.

John


Title: Re: Newcomer to P30-advice sought.
Post by: Kevin M on February 16, 2021, 06:57:58 AM
Thanks for the kind comments.

Quote
To my eyes it has a bit of Bill Dean influence in the wing/tail tips

Not deliberately John, but I did build an Ace last year so perhaps something stuck subconsciously.