Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin (Account/Technical Issues)  |  Contact Global Moderator
September 19, 2021, 01:21:51 PM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with email, password and session length
 
Home Help Search Login Register
Pages: [1] 2 3 4   Go Down
Print
Author Topic: Blast tube for Burdov's P30 Pirate  (Read 5044 times)
0 Members and 1 Guest are viewing this topic.
Sunbeamtiger
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 106

Topic starter


Ignore
« on: September 06, 2010, 03:28:30 PM »

I have just finished building 2 Pirate P30's which are sold by StarLink out of California. Burdov's plans and quality of the parts are great. Even though I have discovered that covering with mylar isn't that easy. Both planes look great from 5 feet away but up close you can see my covering flaws. My only complaint about the kit is I wish Larry at Starlink would throw in the .008/.009 dt spring. I wasted 4 guitar strings before I got a good spring.

Anyhow.....the Pirate body is so small in diameter that I can't seem to come up a inexpensive (cheap) blast tube to use when I'm winding. Does anyone have any ideas on what I can use? I have checked out the home supply stores and the pet shops for a small plastic filter tubes all with no luck. I even find myself scanning store shelves for something that comes packaged in tube.

I need some good suggestions...help.

Mike R. in Indianapolis
Logged

Mike Richardson
Tmat
Titanium Member
*******

Kudos: 69
Offline Offline

Canada Canada

Posts: 2,981




Ignore
« Reply #1 on: September 06, 2010, 03:37:57 PM »

I don't use a blast tube (never have) and now use the external half-tube system for all my rubber models even P-30's. On my Pirate, I found a 1/2" diameter aluminum tube at the hardware store that was the ideal size. Why not use that for a blast tube also?

Tony
Logged

F1B guy...
But don't hold that against me!
Sunbeamtiger
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 106

Topic starter


Ignore
« Reply #2 on: September 06, 2010, 03:50:31 PM »

I don't use a blast tube (never have) and now use the external half-tube system for all my rubber models even P-30's. On my Pirate, I found a 1/2" diameter aluminum tube at the hardware store that was the ideal size. Why not use that for a blast tube also?

Thanks for the reply Tony. I checked the two local box stores by me, Menard's & Lowes and they don't stock aluminum tube that small of diameter but I will keep looking around town, someone has to stock something.

I have a half-tube set up for my F1G that I really haven't used, I can't seem to pull myself away from the old school stuff but I will see if it will fit the Pirate.
Do you have any advice on the triming the Pirate?

Mike
Logged

Mike Richardson
danberry
Gold Member
*****

Kudos: 17
Offline Offline

United States United States

Posts: 987



Ignore
« Reply #3 on: September 06, 2010, 05:42:58 PM »

Look for CPVC pipe. It isn't the regular PVC. More of a light beige color. It has a thinner wall.
Logged
Widdog
Gold Member
*****

Kudos: 13
Offline Offline

United States United States

Posts: 565




Ignore
« Reply #4 on: September 06, 2010, 05:55:03 PM »

Wal Mart sells a “Arrow” that has a 1/2” shaft. I bought one for three dollars. I cut off pieces to use as rear motor mounts. It’s made from Carbon Fiber.
Logged
ram
Gold Member
*****

Kudos: 5
Offline Offline

United States United States

Posts: 259



Ignore
« Reply #5 on: September 06, 2010, 06:31:09 PM »

I bought an 18' golf ball retriever at WalMart several years ago and it provided me a lifetime of thinwall aluminum blast tubes down to 1/2" OD. I think they go for less than $20 and the aluminum is smooth and thin. I think the big end was about 1" OD and there were several sizes in between.

Rey
Logged
Sunbeamtiger
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 106

Topic starter


Ignore
« Reply #6 on: September 06, 2010, 08:00:55 PM »

Look for CPVC pipe. It isn't the regular PVC. More of a light beige color. It has a thinner wall.

Would you believe I looked into that. Menards has a 1/2"x10ft piece on sale for $1.38. Like you said, it beige/tan in color. I thought I had hit pay dirt the other day but nope, it was too large to work.

Thanks for the help....Mike
Logged

Mike Richardson
Sunbeamtiger
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 106

Topic starter


Ignore
« Reply #7 on: September 06, 2010, 08:14:26 PM »

Wal Mart sells a “Arrow” that has a 1/2” shaft. I bought one for three dollars. I cut off pieces to use as rear motor mounts. It’s made from Carbon Fiber.

WOW.... that sounds like it would do the trick. Awhile back I purchased a carbon arrow at Wal Mart to use a loading stick for a F1B but I don't recal seeing any arrows that large but I will check it out tomorrow.

Thanks for the tip.... Mike
Logged

Mike Richardson
Sunbeamtiger
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 106

Topic starter


Ignore
« Reply #8 on: September 06, 2010, 08:20:09 PM »

I bought an 18' golf ball retriever at WalMart several years ago and it provided me a lifetime of thinwall aluminum blast tubes down to 1/2" OD. I think they go for less than $20 and the aluminum is smooth and thin. I think the big end was about 1" OD and there were several sizes in between.

I'll check into that tomorrow while I'm at Wal Mart, someone else also posted that they sell a large carbon arrow that might do the trick.
Thanks for the help Rey.... Mike
Logged

Mike Richardson
crashcaley
Palladium Member
********

Kudos: 243
Offline Offline

United States United States

Posts: 5,328




Ignore
« Reply #9 on: September 06, 2010, 09:23:39 PM »

Mike, I'd banged my head against a wall trying to locate blast tubes. The guys suggestions are right on. I went to my dinky Wallyworld and looked for the ball retriever pole suggested. Even though this Walmart doesn't carry much in the way of golf equipment, it did have one of these poles that is made of thin walled aluminum. The two smaller diameters may be just what you need. One is 9/16 OD and the other 1/2 OD with the smallest tube being 3/8. I estimate the wall thickness at less than 1/32. Hope this helps you.

Caley
Logged

What's stall speed?  Undecided
Tmat
Titanium Member
*******

Kudos: 69
Offline Offline

Canada Canada

Posts: 2,981




Ignore
« Reply #10 on: September 06, 2010, 10:36:18 PM »

That's a good suggestion for thin walled aluminum tubes.

Mike, a Coupe half tube won't work for P-30 because it is too short. Needs to be twice as long.

As for the Pirate, follow the suggestions on the plan and you should be fine. Right/left for the basic trim. A bit of left stab tilt. And use some wash-in on the right hand wing center panel (about 1/16" to 3/32"). Start with a very slight amount of left rudder offset for the glide. I actually made my rudder into an all-flying fin with a carbon tube as a main shaft mounted in the tailboom (I added some small carbon fiber patches top and bottom to reinforce the tailboom). I can adjust the fin angle. A small rudder tab would work as suggested by the plan but I like screw adjustments whenever possible.

Once the glide circle is set by the rudder offset, adjust the cruise climb turn with right thrust (not too much). Any prop stalling tendencies can be corrected with downthrust. The CG is determined by the burst for locked down models. My CG is a bit too far forward so my Pirate cannot handle the full torque of a 6 strand 1/8" motor wound to 1400 turns. It is just too fast and she becomes a bit loopy. The dilemma is that the CG is ideal to be able to handle windy and turbulent conditions such as I encounter at our main flying site (Base Borden). I could tame the burst by moving the Cg back and reducing the decalage, but I'd lose stability. So I'm faced with two choices:

1) change to a 10 strand (1/16" equivalent to 5 strands of 1/8") motor to reduce the burst torque and leave the CG as is.
2) still use 6 strands and add an auto-stab to get the benefit from the fast burst.

I'm an F1B guy, so I'm going to try the second option.

The last time I flew my Pirate I simply wound to 1100 turns so that the torque stayed at a manageable level and she still got very high and was a pleasure to fly. 5 strands is an option, but the weight needs to be very close to 40 grams. Mine, with the Electronic-timer, radio DT, tracker bug and so on is a bit overweight at 45 grams. I could still fly it on 5 strands, but I'm going to have some fun with an auto stab because that's what I like to do. Play with my models and try and get the most from them.

Some might feel that it is against the spirit of the rules and so forth to be playing with electronic timers, auto surfaces and what not with a beginner's event like P-30. Frankly, I could care less.


Tony
-having fun with a P-30 when I'm not playing with my wakefields...
Logged

F1B guy...
But don't hold that against me!
Sunbeamtiger
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 106

Topic starter


Ignore
« Reply #11 on: September 07, 2010, 08:19:07 AM »

That's a good suggestion for thin walled aluminum tubes.

Mike, a Coupe half tube won't work for P-30 because it is too short. Needs to be twice as long.

As for the Pirate, follow the suggestions on the plan and you should be fine. Right/left for the basic trim. A bit of left stab tilt. And use some wash-in on the right hand wing center panel (about 1/16" to 3/32"). Start with a very slight amount of left rudder offset for the glide. I actually made my rudder into an all-flying fin with a carbon tube as a main shaft mounted in the tailboom (I added some small carbon fiber patches top and bottom to reinforce the tailboom). I can adjust the fin angle. A small rudder tab would work as suggested by the plan but I like screw adjustments whenever possible.

Once the glide circle is set by the rudder offset, adjust the cruise climb turn with right thrust (not too much). Any prop stalling tendencies can be corrected with downthrust. The CG is determined by the burst for locked down models. My CG is a bit too far forward so my Pirate cannot handle the full torque of a 6 strand 1/8" motor wound to 1400 turns. It is just too fast and she becomes a bit loopy. The dilemma is that the CG is ideal to be able to handle windy and turbulent conditions such as I encounter at our main flying site (Base Borden). I could tame the burst by moving the Cg back and reducing the decalage, but I'd lose stability. So I'm faced with two choices:

1) change to a 10 strand (1/16" equivalent to 5 strands of 1/8") motor to reduce the burst torque and leave the CG as is.
2) still use 6 strands and add an auto-stab to get the benefit from the fast burst.

I'm an F1B guy, so I'm going to try the second option.

The last time I flew my Pirate I simply wound to 1100 turns so that the torque stayed at a manageable level and she still got very high and was a pleasure to fly. 5 strands is an option, but the weight needs to be very close to 40 grams. Mine, with the Electronic-timer, radio DT, tracker bug and so on is a bit overweight at 45 grams. I could still fly it on 5 strands, but I'm going to have some fun with an auto stab because that's what I like to do. Play with my models and try and get the most from them.

Some might feel that it is against the spirit of the rules and so forth to be playing with electronic timers, auto surfaces and what not with a beginner's event like P-30. Frankly, I could care less.

Tony
-having fun with a P-30 when I'm not playing with my wakefields...

Thanks for the trim advice Tony, I will keep in it mind.

I am impressed with how light your Pirate came out. Mine came weighed in much different than yours, one at 54 grams and the other at 52 grams. Both are using a viscous timers and those weights do not include the transmitter. I have talked to several others who have built this ship and all have come in the low 50's so whatever you are doing....keep it up, you have the magic touch.

Happy flying....Mike
Logged

Mike Richardson
Sunbeamtiger
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 106

Topic starter


Ignore
« Reply #12 on: September 07, 2010, 08:41:25 AM »

Wal Mart sells a “Arrow” that has a 1/2” shaft. I bought one for three dollars. I cut off pieces to use as rear motor mounts. It’s made from Carbon Fiber.

Thanks for the tip, I will check it out today but I do have to question the 1/2" diameter shaft. Are you sure about that? It seems to me that would be a awful large arrow.

Thanks...Mike
Logged

Mike Richardson
Widdog
Gold Member
*****

Kudos: 13
Offline Offline

United States United States

Posts: 565




Ignore
« Reply #13 on: September 07, 2010, 09:51:27 AM »

I have recently returned to this hobby after a 25 year hiatus. I don’t know the sizes of the Arrow’s but they seem to be pretty handy things to have around.
Logged
Tmat
Titanium Member
*******

Kudos: 69
Offline Offline

Canada Canada

Posts: 2,981




Ignore
« Reply #14 on: September 07, 2010, 10:23:57 AM »

Mike, I'm not sure how you managed to add 10 grams to your model (compared with mine)! What did you cover it with? Mine is covered in 1/4 mil mylar from Aerodyne.

My next one will use a Starlink Kevlar motor tube, but my own design flying surfaces. I will try very hard to come in at the 40 gram minimum weight.

Tony
Logged

F1B guy...
But don't hold that against me!
Tapio Linkosalo
Platinum Member
******

Kudos: 35
Offline Offline

Finland Finland

Posts: 1,338



Ignore
« Reply #15 on: September 07, 2010, 10:36:43 AM »

Tony, how is your back bobbin for P-30 "outside the fuselage" winding? Would a simple bent wire thing do (a U-hook with the arms bent if half-circles to attach to the back peg?).

I have been recluctant to take up outside the fuselage -winding in F1B, as I seldom blow motors, and I feel that I get a slight edge in the flyoffs by being able to wind fast inside the fuselage. However, my recent experience with digital torque meter for F1D was so promising, that I feel like I'd need to setup such equipment also for outdoor models, and measuring the torque at the peg does not work with model wings on. Actually it would work best with only the half tube. So maybe I'll try with a P-30 first, and if it works, then move over to F1B....
Logged
Tmat
Titanium Member
*******

Kudos: 69
Offline Offline

Canada Canada

Posts: 2,981




Ignore
« Reply #16 on: September 07, 2010, 11:36:53 AM »

Tapio,

I did not make a typical hook and roller type of rear bobbin for my P-30. I just used a simple Delrin bobbin (I'll take a photo tonight of the whole set-up) at the rear which fits inside the motor tube, and is captured in a slot in the half tube. You have to remove the rear peg to install the motor (slide the half tube inside the motor tube, lineup the rear bobbin with the hole, and push the peg through). A wire hook might be fine for P-30. I might try and make an aluminum hook that is small enough for P-30.

I break motors in F1B from time to time (I broke 3 this past weekend and spectacularly!). Sometimes, even a new motor will break unexpectedly well under full turns. Who knows why? (Maybe a flaw in the rubber at that point?). I pull all my motors to near 36 kg when breaking in to try and avoid this, but still some motors will break. Eventually, the model will be damaged. There are other advantages to half tubes as I'm sure you know. You can have several motors installed and ready to wind at a moments notice. And you can very quickly wind another motor and change the tired motor after waiting for a thermal for a long time. You can't do this with a conventional wind-in-the-model system nearly as fast. You could also wind several motors (as Andriukov does) to see if you can get a really good wind (technique matters as you know) and then chose the best. The list goes on and on.

And finally, if you are not breaking motors, some F1B flyers would argue that you are not winding hard enough! Grin

Tony
Logged

F1B guy...
But don't hold that against me!
Tapio Linkosalo
Platinum Member
******

Kudos: 35
Offline Offline

Finland Finland

Posts: 1,338



Ignore
« Reply #17 on: September 07, 2010, 12:52:38 PM »

Just thought that a bobbin that you could twist and pull into location would be more convenient, quick to use, than a bobbin that you need to hook up with an ordinary peg (and the rubber band to hold the peg in place)....

Yup, I'm aware of the advantages of winding outside the fuselage, but still claim that there might be some benefit to be able to launch quickly at the start of the fly-off round. Also I have heard that if you do not break motors you do not wind tight enough. There is also a version that if you do not break a few strands you do not wind tight enough. For me, I think that as my motors stay together for the flight, but most often break a strand or two on the next flight on the same motor (a trim flight), that is winding tight enough. If I broke strands during that contest flight, I would loose some torque for that climb already...
Logged
Sunbeamtiger
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 106

Topic starter


Ignore
« Reply #18 on: September 07, 2010, 01:10:25 PM »

Mike, I'm not sure how you managed to add 10 grams to your model (compared with mine)! What did you cover it with? Mine is covered in 1/4 mil mylar from Aerodyne.

My next one will use a Starlink Kevlar motor tube, but my own design flying surfaces. I will try very hard to come in at the 40 gram minimum weight.

Beats me Tony, heck.... maybe my scale is off but I doubt it. The viscous timer is only a gram so that's not it. As for the covering I use 1/2mil mylar on the wing and 1/4mil on the tail. The mylar came from Lee Campel who gets it from FAI Supply.

I suppose one good thing for me is that I don't have to add ballast to bring up to legal specs.

Good luck on your new design......happy thermals.
Mike
Logged

Mike Richardson
Sunbeamtiger
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 106

Topic starter


Ignore
« Reply #19 on: September 07, 2010, 01:20:03 PM »

I bought an 18' golf ball retriever at WalMart several years ago and it provided me a lifetime of thinwall aluminum blast tubes down to 1/2" OD. I think they go for less than $20 and the aluminum is smooth and thin. I think the big end was about 1" OD and there were several sizes in between.

Rey,

I hit WallyWorld today and found the ball retriever you told me about and it is going to work out great for me. Not only for the small P30 body but for other planes too. Oh.... what's even better, the price was $11.98 plus tax.

Thanks Rey....you put a smile on my face.

Mike
Logged

Mike Richardson
Sunbeamtiger
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 106

Topic starter


Ignore
« Reply #20 on: September 07, 2010, 01:24:51 PM »

Mike, I'd banged my head against a wall trying to locate blast tubes. The guys suggestions are right on. I went to my dinky Wallyworld and looked for the ball retriever pole suggested. Even though this Walmart doesn't carry much in the way of golf equipment, it did have one of these poles that is made of thin walled aluminum. The two smaller diameters may be just what you need. One is 9/16 OD and the other 1/2 OD with the smallest tube being 3/8. I estimate the wall thickness at less than 1/32. Hope this helps you.

Caley, I took Rey's and yours advice and stopped at WallyWorld and today picked up one of those golf ball retrievers and what a great idea you guys had. This will take care of my Pirate and several planes too.

Mike
Logged

Mike Richardson
Tmat
Titanium Member
*******

Kudos: 69
Offline Offline

Canada Canada

Posts: 2,981




Ignore
« Reply #21 on: September 07, 2010, 02:07:46 PM »

Mike, glad you found a good source for the small aluminum tubes. 1/2 mil mylar is considered heavy for P-30. It is what I'd use on an F1B!

Tapio, I don't need a rubber band to secure the rear peg when you use a rear bobbin. The bobbin prevents any side loads on the peg, so it stays put always.

I actually saw Gorban wind his model for a fly-off without the half tube (rubber in the fuselage) while he used the half tube all day for the rounds. My only explanation was that he wanted to be able to get away quickly. As it turned out he had to wait for a thermal and by then the half-tube guys were waiting too...

But the point is taken.

Tony
Logged

F1B guy...
But don't hold that against me!
crashcaley
Palladium Member
********

Kudos: 243
Offline Offline

United States United States

Posts: 5,328




Ignore
« Reply #22 on: September 07, 2010, 02:13:21 PM »

Mike, I'm happy that you're pleased with the aluminum pole. It takes a bit of doing to get it apart, but is worth the effort. I'm using one for my Gypsy Wakefield and another for my Gollywock.
Logged

What's stall speed?  Undecided
Tapio Linkosalo
Platinum Member
******

Kudos: 35
Offline Offline

Finland Finland

Posts: 1,338



Ignore
« Reply #23 on: September 07, 2010, 02:33:58 PM »

Quote
Tapio, I don't need a rubber band to secure the rear peg when you use a rear bobbin. The bobbin prevents any side loads on the peg, so it stays put always.

Ok.

Quote
I actually saw Gorban wind his model for a fly-off without the half tube (rubber in the fuselage) while he used the half tube all day for the rounds. My only explanation was that he wanted to be able to get away quickly. As it turned out he had to wait for a thermal and by then the half-tube guys were waiting too...

But then, the fly-off is the time when you really need to get every joule out of the rubber, to wind it to 99% of breaking load. So if you learn to do it with precise torque meter for the rounds, I think you do not want to risk breaking the motor into the model by winding by "feel" for the fly-off.

So I guess I still need to find a way to measure torque while winding the motor within the model... For F1B at least.
Logged
Tmat
Titanium Member
*******

Kudos: 69
Offline Offline

Canada Canada

Posts: 2,981




Ignore
« Reply #24 on: September 07, 2010, 04:12:29 PM »

Tapio,

Whether you need every last Joule for the flyoff depends on the time of day that the fly-off is being held. For an early morning fly-off that will be timed all the way to the ground, in still conditions, a half tube is almost a necessity as you will be winding to near max and could break a motor. Being ready to fly right at the start is not as important as having the maximum amount of energy available to get to over 100 meters.

However, for fly-off rounds that take place right after the 7 rounds are over (ie: late afternoon) there are still thermals present. Thus it is far more important WHEN you fly, then having every last Joule of energy. I see this happen all the time. Guys are trying to get every last oogajoule out of their rubber and are breaking motors and wasting time. Meanwhile, they missed the one and only thermal during the ten minute window! What was the point of that?

Early afternoon fly-off rounds are tactical rounds and should be flown accordingly. I think a good plan is to wind a first motor rapidly to "high safe" turns (without breaking danger) and "park" the motor in a model. If a thermal is present, fly that model. If not, wind another and park that motor. If it breaks, no big deal you already have a back-up. I use two winding stooges now (1 for the model and 1 for the 1/2 tube) and I'm thinking about swapping the model stooge head for another 1/2 tube stooge unit so that I can wind two motors with no delay if one breaks. Sounds crazy, but tactics suggest that time is important in a short fly-off window.

Tony
Logged

F1B guy...
But don't hold that against me!
Pages: [1] 2 3 4   Go Up
Print
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!