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Outdoor Free Flight Forum => Free Flight Scale => Topic started by: Dan Snow on September 25, 2018, 08:31:43 PM



Title: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on September 25, 2018, 08:31:43 PM
I'm half way through the trimming flights on my DHC-1 Chipmunk, and 90% of the way to test flying my DHC-2 Beaver, in spite of distracting myself with scratching together a couple of faux No-Cal. Just waiting on an order from Peck Polymers

Then yesterday I received the most amazing gift!! Thanks to Dave Cowell of Aerowerks, and Paul Bradley of Paul and Ralph Bradley's Model Airplane Hangout, I am the humble recipient of a set of custom laser cut parts for the Pres Bruning DHC-3 Otter found on Paul's website. The wood is excellent quality and the laser cutting is crisp and clean.  I can't wait to get started on it.

Dave and Paul are great examples of the fine people in the sport/hobby of model aeronautics. Their generosity and willingness to help out another modeler is to be applauded.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: OZPAF on September 25, 2018, 08:39:38 PM
It will be hard to not do a great job with that Dan. Amazing support from the Bradleys and Aerowerkes.

John


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on September 26, 2018, 07:56:26 AM
Question for all you guru's out there. This is the side view from the Otter plans.  On the Chipmunk and the Beaver ya'll recommended moving the rear peg forward at least one bay.

Should I contemplate doing the same here? Moving it forward will put approximately 55% of the motor forward of the CG.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: faif2d on September 26, 2018, 01:29:56 PM
I would move forward at least 1/2 a bay but probably 1 full bay would be better.  Look up the use of a rolling rear peg cover.  You can then use up to a 3 or 4 times hook to peg motor and have it unwind well.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Indoorflyer on September 26, 2018, 03:02:16 PM
It's a Pres Bruning design.  He is one of the most prolific modelers (FAC) out there.   Leave it where it is shown. 


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: flydean1 on September 26, 2018, 11:01:50 PM
Forward one bay.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on September 27, 2018, 05:26:13 PM
I admit, I'm like a kid at Christmas! I just couldn't wait any longer so I started on the Otter.  I built the stab, laminated and shaped the cowl and the nose plug, and am attempting to laminate the rudder outline. I don't think this one will work as I think I see a little cracking at the apex of the fin. Maybe it wasn't in the hot water long enough??


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Indoorflyer on September 27, 2018, 07:03:32 PM
It'll be just fine. Once all the structure is in place and covered, not to worry. Those gussets are your friends!

Aerowerkes wood and laser cutting is infinitely better than Dumas, no?

You've inspired me to finish my (now out of production) Thomas Designs Bostonian Beaver kit. Thanks Dan! It's a kit based on the Walt Mooney design.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Balsa Ace on September 27, 2018, 07:05:59 PM
That's a great gift,enjoy the build.

Scott

(https://i.imgur.com/cQ3xQXJ.jpg)

(https://i.imgur.com/BmerN4q.jpg)


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on September 28, 2018, 12:17:25 PM
I have a question Scott, what is a "2 wing flight"?

Not sure what color scheme I will use on the Otter yet.  Paul Bradley has an excellent covering print file for it, just not sure if that's what I want. Will research some other schemes and see.

Made progress on the wings. At the last moment I looked closely at the ribs and realized I needed a 1/32" shim under the leading edge to match it to the curve of the ribs!

(If I don't tell anyone I managed to install one of the strut support ribs upside sown, and had to cut it out and turn it right side up,no one will ever know? Right?)

We have a front about to come through so the next 2-3 days look to be a bit too gusty for test flights, so might as well build.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Balsa Ace on September 28, 2018, 05:46:43 PM
Hi Dan,

 Wings are units within the Royal Canadian Air Force.2 Wing was a Reserve unit in the RCAF that
operated in Toronto.I think they may have transitioned to helicopters when the Otter was
phased out,but I could be wrong.

Scott



Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on September 29, 2018, 03:22:08 PM
Can someone tell me what I'm doing wrong here?!?!?!?  The plans call for the fin outline to be 2 laminations of 1/16"x1/32" balsa around a form, outline supplied.

I have tried twice so far and failed completely both times. First time I poured boiling water over the strips and let them soak for 5 minutes, then slathered them with thinned titebond and very slowly tried to bend them around the form. In spite of this they broke at the apex of the tight radius at the top and bottom of the fin.

Try #2, Got the water boiling and submerged the strips for 10 minutes, then tried the thinned titebond. Again they broke at the apex.

Help!!


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: billdennis747 on September 29, 2018, 03:52:25 PM
Strange - it looks like it should be ok. The bottom of the rudder looks worse. Maybe the strips aren't bendy enough. Try pulling the strips around rather than bending them around the form. Or fix them at the apex and pull around forward and back, rather than starting one end. Basswood would be better, soaked in ammonia.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Mefot on September 29, 2018, 03:54:10 PM
First thing. Soak your strips for longer.I like to leave them submerged ( i.e. not floating )  overnight, although a couple of hours can prove sufficient, depending on the density of the wood. Second. Secure your strips at one end of the former and gently pull and tape them around the former. Don't just press them against it and ease them around. The pulling really helps. If the strips aren't limp after soaking them overnight  the wood is too dense/stiff. Third. After taping them to the form, bake them in an oven at 150-200 centigrade. After all this, take them off the former, apply your favourite glue ( 50/50 PVA works well ) and tape them back around the former ( you did wax the former didn't you ? !!! ). Leave for 24 hours and  Bob's your uncle !!!  :)


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Balsa Ace on September 29, 2018, 06:43:30 PM
Royal Canadian Air Force

(https://i.imgur.com/sJUAnYQ.jpg)

(https://i.imgur.com/jdmxSYk.jpg)

US Navy

(https://i.imgur.com/F228H04.jpg)


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on September 29, 2018, 06:52:20 PM
First thing. Soak your strips for longer.I like to leave them submerged ( i.e. not floating )  overnight, although a couple of hours can prove sufficient, depending on the density of the wood. Second. Secure your strips at one end of the former and gently pull and tape them around the former. Don't just press them against it and ease them around. The pulling really helps. If the strips aren't limp after soaking them overnight  the wood is too dense/stiff. Third. After taping them to the form, bake them in an oven at 150-200 centigrade. After all this, take them off the former, apply your favourite glue ( 50/50 PVA works well ) and tape them back around the former ( you did wax the former didn't you ? !!! ). Leave for 24 hours and  Bob's your uncle !!!  :)

150C is around 300F on this side of the pond    BUT BAKE FOR HOW LONG?????  Don't want a crispy kritter when I'm done! :) :)

I tried wrapping it from the apex the second time and almost  immediately it started cracking, but I wasn't trying the pulling trick.  I also checked my wood and I would hazard a guess that the first two times I tried it I was using what looks like B or possibly C grain. I have another sheet that looks more like A grain so I will try the strips from that piece.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Mefot on September 29, 2018, 07:01:36 PM
I should have written 150-200 Fahrenheit. Balsa get's a bit flammable at 200 centigrade  ::)

Twenty to thirty minutes should be enough time in the oven. There's no need to bake it when gluing. Just let it air dry  :)


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on September 29, 2018, 07:33:03 PM
Ah-thank you for clarifying that. I had visions of carbonized balsa!!  :)


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on September 30, 2018, 09:06:52 AM
Well, that was a complete bust! Damn, it has to be me. I am cursed when it comes to forming balsa!  ;D ;D

Everything seemed to work fantastically! When I took the strips out of the water they formed easily around the form with no signs of cracking or splitting. I carefully taped them down, clamped the form together and popped it into a 175F oven for 20 minutes. After letting it cool down for a little bit I un-clamped the form, and then................. totally destroyed the strips trying to get the bleeding tape off!!!  It was my old fumble fingers to blame, I'm sure. I probably used the wrong tape, (scotch) which I'm sure didn't help 

The process works great Mefot, it was my implementation that was off.

I am going to give Paul Bradleys method of heat forming a try. If I screw that up I'm going to build the fuselage next and try again later on the rudder.  ;D


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: flydean1 on September 30, 2018, 09:49:32 AM
Blue painter's tape.  Lowe's, Home Depot, Ace Hardware, Hobby Lobby, Michael's, etc.  We should have told you.  Sorry.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on September 30, 2018, 10:01:48 AM
I tried to use blue painters tape but it wouldn't stick to the form.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on September 30, 2018, 10:48:57 AM
I soaked a 1/16 square strip for about 90 minutes and then used Paul Bradley's technique with s soldering iron, and tah-dah, I have the fin outline done! I used 1/16 rather than 1/32 x 1/16 lamination because I could just envision the carnage with my fat fingers trying it!  :D :D

I will let this dry thoroughly and then figure out how much I need to shim it off of the building board. The rudder has a symmetrical airfoil when viewed from the top. Should be a fun challenge to keep it straight, huh?


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Glenn (gravitywell) Reach on September 30, 2018, 12:40:24 PM
Hi Dan.  I know this is a little late but I use meat tray Styrofoam for my molds.  Its free, tape sticks to it very well and its not bothered by water.  Love the plane and am watching with rapped attention. :)


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on September 30, 2018, 02:37:20 PM
Be fore I forget, I wanted to let folks know:

If you are interested in building one of these birds, contact Dave Cowell at Aerowerks. He is offering a set of laser cut parts for the Otter for $11 plus shipping. Excellent workmanship and balsa quality. Check if he has the new cut files from Paul Bradley yet as Paul made a slight tweak to a couple of the parts.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: skyraider on September 30, 2018, 03:13:22 PM
Nice job, Dan!  And yes, updated cut files already in place.

Skyraider


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 01, 2018, 09:03:27 AM
Sometimes you just have to use a "few" pins to get things to hold still for a minute while you try to find the damn glue bottle that was right beside your elbow two freaking minutes ago!!  ;D

Finally got the fin done and off the board. will let it dry for a day before I cut the rudder off for access to get the stab in place.

Next up, start the fuselage.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: LASTWOODSMAN on October 01, 2018, 09:59:43 AM
Hi Dan.  I am following your build all right!   Yes, I just mailed by order to Dave Cowell for the DHC-3 OTTER - looks like beautifully cut laser parts, and best of all  -   CLEAN BALSA  !!   ie - no laser cut parts numbers, or inked on parts numbers,  in/on the clean balsa.  So I am hoping you can show me how it flies right off of the table !   ;D   ;)

LASTWOODSMAN
Richard


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 01, 2018, 05:01:18 PM
I'm hoping it does fly well Richard. It is a challenging build for someone that hasn't built anything for 20 years, and nothing this delicate for at least 40-50 years. So let's say it is a challenging build for me.

The symmetrical airfoil fin wasn't as tricky as I feared. I asked Paul Bradley a question to clarify one step and took it slow and I believe it came out fine. I have the base frame for the fuselage sides done, it was a little different in that the top and center longerons are on top of the uprights instead of flush with them. I haven't figured out the best approach to start joining the fuselage sides to make sure they stay square and straight along the center-line as I can't really find a good flat section of either top or bottom to pin to the board.  I might make a frame that I can attach right angles to to hold the sides while I glue in the formers. Have to think about this one for a bit.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 03, 2018, 05:30:19 PM
Making a little more progress on the fuselage.  Tried unsuccessfully to solder the landing gear legs yesterday. Was getting pretty frustrated actually, and then DOH!!! Light bulb went off! I wasn't using any soldering flux. After a virtual smack in the head I went looking for my flux, and of course, since I hadn't soldered anything in who knows how long, I was unable to find any. Picked some up this morning, fired up my micro torch and in less than 5 minutes I had completed the landing gear!! Once I clean it up a bit and give it a shot of clear coat it'll be good to go.

Finally got all the formers except for the firewall installed. I need to get the stringers on soon as the formers are very vulnerable right now.

I added the gussets on the uprights supporting the gear legs. A teensy weight penalty, yes, but it gives me a little peace of mind that something more than a 1/16" square is carrying the load! :)


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: OZPAF on October 04, 2018, 09:18:09 AM
Dan I have found that on small models it is possible to make reasonably strong joints with cotton binding and CA as an alternative to soldering. I think I noticed this first on a build of one of Andrew Darby's models. It can be neat and also lighter than solder.
Also I last used common electrical solder with it's own flux on my last UC, over fuse wire binding(36"WS RC Piper Cub ) and it has been more than strong enough.
It will be a nice looking model.

John



Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 05, 2018, 07:12:00 PM
I did that on the tail wheel, the design of which gives me the willies!! The tail wheel is bent from 1/32" music wire, which is then poked through a 1/16" stringer and glued flat along the stringer.  So I cheated a bit. I made that short section from 1/16" x 1/8" and then wrapped a few turns of thread around it.

Anyway, I am rapidly approaching the time to cover and I have decided on a color scheme!!  It's a simple one, but when I saw I said to self. "That's the color scheme I want!!"


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Balsa Ace on October 05, 2018, 07:59:25 PM
That's a sharp looking USN colour scheme,Dan.

Scott


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 06, 2018, 08:46:44 AM
Thanks. I'm trying to find the other picture I came across that had the outer third of each wing panel red as well.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: DavidJP on October 06, 2018, 05:51:12 PM
You need suitable wood for laminations but of course you will have released that.  I find that cracks and creates can be avoided if having soaked the timber as you have done  and applied the glue placing it against the former you ease it round the bends with a piece of suitable sized scrap balsa slightly thicker the the strips used for the laminations.  It is a case of pushing and pressing and sliding really - can't think of a better description. Basically the balsa spreads the load and keeps the laminations in contact with the former rather than they being allowed to crack and spring away as you bend them.  When you try it I think you will soon get the knack!


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: OZPAF on October 06, 2018, 08:21:38 PM
That's a very good point David. I seem to remember a very old bit of advice to maintain tension on the strips while forming them around the form. Your approach would seem much better.

John


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: DavidJP on October 07, 2018, 08:59:08 AM
Thank you John.  It was provoked by a technique you use in bookbinding to ease leather round the spine etc.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 07, 2018, 06:58:48 PM
Worked on some of the scale bits yesterday and today. Exhaust fairings, cowl intake duct, landing gear attachment fairings. Gave them a coat of white so they don't stick out like the proverbial sore thumb.  Got the wheels sanded and painted and glued the hub in place.

Then I had an "Aw Krap!" moment. Very minor in the long run, but it does make a fair bit of extra work for me.  My original plan was to cover the fuselage and then glue the cowl block on.  But instead, after sanding the fuselage to get it ready for covering, I went and glued the cowl on!  Didn't realize it until after the glue was dried.  I figure if I wrap a layer of painters tape around the cowl, I can cover right up to it, and trim the covering back with a razor


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 08, 2018, 05:52:13 PM
Starting the covering. Just over an hour to get this much done.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 09, 2018, 12:29:28 PM
Finished the covering on the fuselage this morning!


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 09, 2018, 04:28:40 PM
Spent about 3 hours in total on the fuselage today. Finished and shrunk the covering, then spent some time adding the scale bits to it. I still need to tape the door outlines and install the windshield and then it'll be ready for the wings and tail feathers.

Covering the fuselage I discovered why, now that I'm at the age of having sometimers, that if I need to do things in a certain order I need to write a list. My plan was to glue the clear plastic for the side windows to the inside of the fuselage window panels before adding the panels to the fuselage frame. But if I did that I thought, it would make it very, very difficult to trim the tissue away from the window openings. So I revised the plan to cut the plastic into small enough pieces that I could glue them to the backside between the fuselage uprights, and glue them in after I had covered the sides and trimmed to openings, but BEFORE i covered the top!  Great plan, right?  Well, it was, until I forgot the windows until AFTER I had covered the top, and bottom, and every side, of the fuselage! ARGH!

Oh well, my passengers will enjoy fresh air during their flights!!


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: PaulBrad on October 10, 2018, 10:55:18 PM
Looking good Dan.

When I built my model from that plan I did install the side window plastic before covering the fuselage. Before covering I applied a thin coat of rubber cement to the plastic. The side tissue panels were then applied while the rubber cement was still wet. The rubber cement made sure the tissue was adhered to the plastic and provided a protective layer. After water shrinking the tissue I applied several thin coats of clear dope. This is where the protective quality of the rubber cement came into action. Once the dope had dried, I carefully cut each window panel using a fresh knife blade. When each panel was cut, the tissue was teased up at one edge with the tip of my knife. The tissue pulled away from the plastic very neatly. The result was nicely framed windows with no edges.

Paul Bradley


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 11, 2018, 07:54:35 AM
Thanks Paul. Next challenge is the markings. I was going to try printing them on tissue but my printer picked now to run out of ink so that'll have to wait until I get some more.


Wings are on, as are tail feathers, just need to install the wing struts, which I have to remake as the first once mysteriously came out 5/" too short. I measured them several times holding the wing in place, but after gluing the wings in place discovered the shortage. Hmmmm, the measure twice cut once doesn't seem to work if everything isn't in the right place!!  :D


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Balsa Ace on October 11, 2018, 05:36:57 PM
Top Notch work,Dan.

Scott


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 11, 2018, 06:25:11 PM
Well, here it is, minus only the US NAVY markings. Registration number 424.  As soon as I get our printer running again I'll see if I can get tissue printing to work.

Trying something new for me on this model.Since I had to separate the rudder and fin to install the stab, I re-attached the rudder using two soft .04" wires. That way I can quickly make adjustments if needed. Then once it's set i can put a dab or two of silicone to held the setting.

Any recommendations for a starting motor? The only rubber I currently have is 3/32" Tan FAI


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: skyraider on October 11, 2018, 06:50:36 PM
Nice job Dan! Gotta love that color scheme. It really stands out. Hope
you had some fun building it.  Looking forward to your flight reports soon.

Skyraider


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: OZPAF on October 11, 2018, 06:52:29 PM
That has turned out well Dan.

John


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: MKelly on October 11, 2018, 08:06:17 PM
Very nice Dan, look forward to hearing how it flies.

Mike


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: tom arnold on October 11, 2018, 09:10:00 PM
 My humble suggestion for motor size is based on the prop diameter. An 8" Peck prop needs 4-6 strands of 1/8th rubber (1/2" to 3/4" of combined rubber strand width). For a 7" Peck prop, a motor from 2-4 strands of 1/8th rubber (1/4" to 1/2" of combined rubber width). I can't think of anything other than multiples of 1/8th as 5th grade math can make me look like an idiot. Whatever number of strands of 3/32 reaches those parameters would work. Other guys, I am sure, have different rules of thumb. Good luck in any case.....great looking flyer.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 27, 2018, 04:04:36 PM
Good news! The Otter is completely finished, and I have made a couple of short test glides in the back yard. First one showed slight tail heavy, second was a bit better and third was good. All were straight ahead no sign of turning. I put in 30-40 winds and got a pronounced left turn. Not really a diving turn, but a very definite turn. Need a lot more room than my back yard to go further, plus I need to figure out how to keep the ring on my motor from slipping off the hook on the prop shaft.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Balsa Ace on October 27, 2018, 04:12:02 PM
She's a beauty. :)


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: MKelly on October 27, 2018, 06:30:34 PM
Looks very nice Dan, good luck with the flights.  Search for "reverse S-hook" for a possible solution to your motor hook difficulties.  Several folks recommended these to me and I've become a convert.

Mike


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: jdincau on October 27, 2018, 06:40:09 PM
U tube video on how to make a reverse S hook

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


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: flydean1 on October 27, 2018, 07:14:22 PM
Dan,

From another post, it seems you are using a hard ring on the front of the motor bound in place with thread.  A reverse "S"  hook doesn't work very well with this.  Better to pair the reverse "S" hook with a common rubber "O" ring.  For models the size of your Otter. A 3/32 X 1/4-3/8 inch "O" ring would work well.  Make it easier to handle the motor when hooking on the prop, and it will wind around the hook just like the motor.

Most hardware stores have them in quantity, they are very inexpensive.

Also, you need to use a winding tube.  Even if you do not wind the rubber hard, the motors will eventually fail and destroy all your careful work.

The Otter looks really great!


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 27, 2018, 08:15:53 PM
I will look for the o-rings tomorrow.  FYI for those looking for small split rings I found a package of 120 each 3/16" and 1/4" split rings in the jewelry craft section at a local Walmart for less than $3.00


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 28, 2018, 10:12:44 AM
OOPS!!

This is why you DO NOT test fly in a small back yard!!  I knew better but did it anyway as I was anxious to try out the trim tabs I had added to the tail feathers. They worked so well it went straighter and farther than expected until the table got in the way.

Thankfully the  wing popped off clean, (Hmm apparently the glue joint was not as good as I thought it was??) with no structural damage. A bit of glue and it's ready to go again.

No more test flights of outdoor models in the back yard!!


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: DavidJP on October 28, 2018, 12:27:24 PM
You are certainly turning out some very nice models Dan..... and nice to see the enthusiasm continues. 

I have long been curious about the term "back yard" which in some cases seems in America to embrace quite large area that we would call garden or a small yard.  But I think you do not go in for gardens like us limeys - with little flowers shrubs a lawn garden gnomes and goldfish?  All of which are very model aeroplane unfriendly.     


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: Dan Snow on October 28, 2018, 02:37:11 PM
Our backyard is about 30'x80'. On the edges are a couple of bushes, a charcoal grill/smoker, a couple of tables and a chain link fence closing off a 10'x30' space for growing vegetables. So not really big enough for much more than a moderately sized indoor model.


Title: Re: I'm going to build a DHC-3 Otter, because of a very generous Gift!
Post by: DavidJP on October 29, 2018, 06:44:10 AM
Handy size for maintenance - and about twice the size of some gardens here........ but for my part what ever the size of the area you choose to use it never seems big enough....  but at least you do not have a pond!