What's a doubler?

Ok, I've been reading up on building in preparation for building my first kit after 47 years. I don't believe I know exactly what a doubler is although from long-ago experience I seem to remember that it is two pieces of two pieces of timber, spar, 2x4, etc. glued together to make a more substantial piece.

Is that all there is to it?

This is some new stuff I'm exposing myself to here. Different glues, different materials, different building techniques, etc. We used to cut the parts out of the sheet of balsa and glue and pin the parts down. Now it seems to be drop the parts out of a laser cut sheet, fit everything together and then apply thin CA to the joints. Is that typical now?

I guess a book or tape on kit building might be helpful. Does anyone have any tips, suggestions or sources for "tapes"?

Harlan

Reply to
H Davis
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Depends what you are building. "Stick build" kits still require plans and pins. Only thing is instead of using wax paper as in the days of Ambroid and Sigment, one uses clear plastic wrap.

A better forum for answers might be

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There are others.

Reply to
High Plains Thumper

When I think of a "doubler" it is usually a part that is the same shape as the forward part of the fuse and it is glued to the fuse half to double the thickness and add strength. Same in other areas of the craft. It used to be balsa, but many times now says it's light ply.

Yep mk

Reply to
MK

H Davis wrote:

Harlan there are some books at Amazon.com some of these are used which will save you some money. To avoid confusion with these wonderful laser kit is to read the instruction sheet which details the part numbers. There are no numbers on the laser parts like the old printed method that you had to cut out. Use a find ball point pen to mark the number on each part before you punch them out or use mailing labels cut to about 1/2 inch square or smaller and stick them to the part. Then you don't have to sand the ink off. Good old carpenters glue, titebond II, elmers is better than the instant glues. Give you time to move the parts around. Use small ball dress pins or t-pins to pin your parts. The instruction books give you a plan that is progressive. Meaning from step one to the last plus tips along the way. Elmers carpenters glue should be water resistant. Yes it takes a while to let the glue dry but you can be working on other parts while one project dries. If you don't mark the parts ahead before punching them out you will be very frustrated. I also use small trays wing parts with wing parts, fuselage, tail pieces all in separate small trays. Should you lose a part use tracing paper to copy the lost part from the plans or break one, use tracing paper. Cut out the tracing of the part and use a glue stick to place on a piece of scrap of the same dimension. I still use wax paper, however as mentioned clear food wraps works great and you can see your lines much easier. Doc Ferguson

Reply to
Doc Ferguson

Harlan, You should also be aware that there are at least two 'levels' or tiers of laser cutting. I didn't become aware of this until just recently. I had assumed that 'laser cut' was synonymous with the perfect fitting, tab-and-slot, lock-together format you find in top end kits like Stevens Aeromodels etc. But it's not. There are 'short kits' bllled as laser cut, which do not follow the above format. They're simply laser cut in lieu of "die crunched" or your having to cut them out yourself. No effort is made to provide perfect snap-together fitting.

Bill(oc88)

Reply to
Bill Sheppard

Yes! These are the kinds of tips and comments I need before I mess this up entirely on my first shot. Thanks, HPT, MK, Doc and Bill! Guess I have some additional reading to do, too.

Harlan

Reply to
H Davis

Even better than that is the clear backing off of the Monokote you put on your last airplane's wings.

Reply to
Robert Reynolds

Take a look at some of the ARFs out there, they are really nice. Some of mine have lasted years. With ARFs you can be flying in no time, with some help. If you want to build, or even learn to fly, join a club and ask around. The club members will be happy to suggest planes, engines, radio equipment, etc. Don

Reply to
Don and Marion

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I'm just catching up with this thread, Harlan, so forgive me if the question has already been answered.

A doubler is often used in the fuselage. It is a technique of "doubling" the size of the balsa wood in particular areas of the fuselage (sometimes used in the wing too) by adding another thickness (usually) of the same material as the fuselage side to an area that is exposed to higher stress levels than the rest of the fuselage/wing/whatever. For instance, normally, in the older kits of yesteryear, they would cut out two pieces of sheet stock balsa from

1/8" or 3/16" balsa that copied the front of the fuselage's side panels. The "doublers" were then relieved of extra material to allow for insetting the firewall, the top or bottom fuselage sheeting, etc. These were always glued "inside" of the model by glueing them to the sides of the fuselage in their interior. I hope that made sense.

A variation upon the doubler for a long while was the use of a very thin plywood to construct the doubler from, instead of another thickness of the original fuselage side material. Stabilizer stations were also doubled too, to add more glueing surface area and rigidity to that portion of the fuselage.

Ed Cregger

Reply to
Ed Cregger

Ed, thanks for the explanation. Yep, it makes perfect sense and seems to fit into a memory from long ago.

Harlan

Reply to
H Davis

Yeah, Don, I have several ARFs and I like them, but I'd like to try building a couple of planes again. Actually, I liked Bruce Tharpe's Venture 60 plane and it only comes in kit form, so I really need to learn the new techniques of building. Plus, all my other "stick kits" were for static models, and this one is going to fly, so I'm interested in building for stress, as well. Then, too, its supposed to be winter up here in Illinois, so I figured I'd be locked in the house for a few months and wouldn't be able to fly, and I haven't been at this long enough to have make repairable mistakes. The one plane I put into the ground went in pretty hard, so its beyond repair.

I'll probably build a simpler plane for practice before I tackle the Venture.

Thanks for taking the time to reply.

Harlan

Reply to
H Davis

Halan,

If you live in upper Illinois, you should be very close to Tower Hobbies

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in Champaign IL. Take a good look at their web-site. They have something for every level of building or ARF models. Join their Super Saver Club and earn big discounts and save postage if you order enough. I plan my orders to get the best discounts. I can't tell you everything I ordered before the Christmas rush, but I have enough to keep me busy all winter. After several orders, I got enough in discounts to pay for another RC plane.

I got a very nice Christmas check from my daughter, so I bought the 'Cessna Skylane 182 ARF' (62-1/2" wingspan). It will be flown with a O.S.FS-52,

4-stroke engine, and a Futaba 7CAP radio. This will be my Sunday flyer.

I'm a single senior and I've built many stick planes in my lifetime. Now I just assemble and fly them.

MERRY CHRISTMAS to everyone, all over the world. ________________________________ Earl Scherzinger 'AMA' #40329

Reply to
Earl Scherzinger

Merry Christmas, Earl!

You know, its a constant amazement to me that Champaign, IL has become the hobby supply capital of the world. I went to college there and had no inkling that anything like that was taking place. As a point of fact, it probably had only a hobby shop back then. I guess Tower is the leading hobby supplier in the country, but it looks like Horizon trying to catch up. Competition is a wonderful thing for those of us who buy that stuff.

The only problem with having Tower in Illinois is the state sales tax. If I plan to buy via mail-order, I'll buy elsewhere if I can find it cheaper. I also like to make sure my LHS gets a bit of business, too. I seldom seem to buy enough at one time to take advantage of the discounts offered by Tower. When I first started in this hobby, it was a different story, of course. Now its kind of interesting to find the bargains, and its easy to do with a tool like the internet.

By the way, those of you who are looking for good prices on extensions, y-splitters and a bunch of other things might want to check out the following link. I have no connection with them, but I like a company that charges me a buck for shipping an order of up to $30.

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Have a great Christmas and a 2007 that allows you to recover from any spin you might be in.

Harlan

Reply to
H Davis

Harlan, Built a Venture 60 from BTE and just have to comment. It was the BEST kit I've ever built (out of maybe 20 now?). The wood is top notch. The plans and instructions are well put together and easy to follow. Most kits I build I hit at least a couple points where I don't understand or can't read the plans or whatever and I get bogged down for hours or days before I have researched and re-asssured myself that the way I'm going to glue that next part or whatever is correct. I built my V60 in no time flat. Didn't take me much longer than some ARF assemblies I've done and the results were wonderful. The quality wood (I've never seen such good quality wood in a kit) and hand shaped parts fit together so well you can test fit complex assemblies and they hold together with almost zero glue... not that there is much in the way of complexity! I wouldn't worry about doing other kits first if you have ANY experience with kit building at all you will not have any trouble with the V60 kit. The only trouble is you will be spoiled and likely get frustrated with the wood quality and fit of your next kit! The V60 was the most fun I ever had BUILDING a model. It's just a joy to work with such quality. Go for it, you'll like it!

Jack

P.S. I have never met Bruce Tharpe and have no interest in his products other than promoting good quality when I see it.

Reply to
Jack Sallade

Thanks for the encouragement, Jack. After your comments, I think I will just jump in and start it. Sounds like I made an excellent choice.

Harlan

Reply to
H Davis

IIRC, Tharpe was the kit designer for one of the big companies (Sig, perhaps?) who decided he could do a better job on his own. A friend who's an aeronautical engineer (ex-Lockheed Skunk Works) stopped by to visit Tharpe's business and came away saying that his kits were really well-engineered. Google around and you'll find similar comments to Jack's, so yeah, just read the instructions all the way through first, then go for it!

Geoff

Reply to
Geoff Sanders

I believe he designed the Four * 40. No introduction to that model is needed.

And I believe Tharpe says the Venture is an IMPROVEMENT over that hugely-successful design.

I have heard nothing but great things about BTE kits. I've looked at them at the WRAM show and was very close to buying one, but never did.

Good flying, desmobob

Reply to
Robert Scott

Jeez, guys, I can't believe no one even said it before this- the group is slipping a little bit it seems-

A doubler is simply that which doubles!! It ain't that difficult- Paul, Brea, CA

Reply to
Paul Ryan

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