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-   -   scale turnbuckles - is there a need? (http://www.rcuniverse.com/forum/rc-scale-aircraft-169/9954683-scale-turnbuckles-there-need.html)

MAJSteve 08-23-2010 03:33 PM

scale turnbuckles - is there a need?
 
I finished my 1/3 scale Balsa USA Sopwith Pup and was puzzled by the lack of turnbuckles and other rigging for this size model. I used the DuBro 1/4 scale turnbuckes, but while they are a very fine product, they really don't look like a scale turnbuckle at all. So my wife suggested that I look into the need for scale turnbuckles and maybe make some up for people.

Anyone interested that could provide me a photo and basic measurements of something they want me to try making?

Steve

abufletcher 08-23-2010 03:43 PM

RE: scale turnbuckles - is there a need?
 
It would be a dream come true. Check out the photo on this page for both photos and drawings of WWI style aircraft turnbuckles:

http://www.flickr.com/photos/landoni...4202028/detail

rmarnold 08-23-2010 04:33 PM

RE: scale turnbuckles - is there a need?
 
Here are two examples that are currently on the market. Although the Kavan examples don't show detailed dimensions, they are very close to half scale. The proctor are about 18% shy of being 1/3 scale size. For 1/3 scale the barrel length would, of course, be 1.33" (3.37 cm). Also in your deliberation, price would need to be a serious consideration. The Proctor items sell for 2 for $10.00. The Kavan M3 is available from www.vogelsang-aeroscale.com for $4.50 ea according to their website. All that said, there are a passel of scale builders that would be interested in a 1/3 scale turnbuckle.

http://www.proctor-enterprises.com/p...rnbuckle-w.jpg
http://www.kavanrc.com/cgi-bin/dpsma...050E_2ehtml_01

Bob

Bundubasher 08-23-2010 04:39 PM

RE: scale turnbuckles - is there a need?
 
Steve, I'm building BUSA pup too - been busy on it since 2002. I've got a lot of pics, let me know what you want and I can email it to you.

What engine are you planning for your Pup?

Cheers
Bundubasher
Basra

MAJSteve 08-23-2010 09:13 PM

RE: scale turnbuckles - is there a need?
 
I spent 3 years in Iraq, so I had a lot of deferred building time pent up when I got back. I got my kit in November and had it framed up by the middle of January. I decided on Stits covering, water-based housepaint and Williams Brothers wheels. I built a scale shock-absorbing landing gear and then got to the rigging issues. The attachment points were copies of the full-scale, in-the-bones Pup in San Diego. I went there and took pictures of what I was interested in.

As has been mentioned at length, the Balsa USA kit isn't all that scale, but it builds well and will fly with a decent 50 gasser. I decided to put a 3W 75US in it and it flys fairly scale, though I did have to put a few pounds of lead in the front.

I used 3/32nd wire to rig the flying and landing wires, and 1/16 wire to rig the control system. BUT, as I mentioned before, clevis' replacing rigging eyes and DuBro turnbuckles don't really do much for a scale appearance. I have a fellow flyer who has a WACO with streamlined wires (at GREAT expense) but I really don't want to go that route right now.

I figured the turnbuckle bodies would be easy to make (I've done a couple for fun) but the eyes and shackles are my next area of concentration.

Steve

MAJSteve 08-23-2010 09:15 PM

RE: scale turnbuckles - is there a need?
 
I've seen those pictures. The one of the old Strutter turnbuckle is a good example of what I'm talking about. I've seen other offerings, but none really fit the bill. I know how to use my TAIG lathe well enough to do the body of the turnbuckle, but those rod ends have me perplexed because they were forged and not machined.

MAJSteve 08-23-2010 09:25 PM

RE: scale turnbuckles - is there a need?
 
I looked at the Proctor offerings, but when you compare them to a full-scale turnbuckle there are a lot of issues. The Kavan ones I hadn't seen but they're closer. From what I could eyeball on my trip to see an in-the-bones Pup in San Diego, there are about 4 basic types (lengths and rod ends) and the Kavan offering would be OK for one of those types. They look very nice though!

I think the biggest ones were almost a foot long including the ends, so half scale would be something like 6 inches! The internal turnbuckles were closer to 4 inches, so 1 1/2 would probably be ok but most people would never see those anyway. The major issue is how to machine the eyes, thimbles, and shackles. I think once I get the basics figured out I can go back to the Air and Space Museum and see if I can make better scale drawings.

Steve

abufletcher 08-23-2010 09:44 PM

RE: scale turnbuckles - is there a need?
 
Question for WWI modelers out there: Do you really use turnbuckles to properly tension rigging...or are they mostly cosmetic? One problem with available model turnbuckles is that they don't really provide much travel.

Also what's really needed on most of the British aircraft are actually fork ends, rather than turnbuckles for the rigging.

MAJSteve 08-23-2010 10:14 PM

RE: scale turnbuckles - is there a need?
 
On my Pup they're definetly functional. They're there to hold the lower wing tight to the fuselage and connect the upper and lower wings together.

There are two 3/32" flying wires and two 3/32" landing wires, interplane strut cross bracing wires, and cabane strut cross bracing wires on 3 of the 4 sides. All of them have turnbuckles, so you have 6 on each wing, and 6 in the cabanes. Right there that puts you at 18 turnbuckles so you see why I think making them would be something people would be interested in IF the prices were reasonable.

Since you only have to have one turnbuckle per wire, the other end should terminate in a fork or a shackle with a pin and safety wire through it. So, to complete each wire, you'd need 1 turnbuckle, two eyes, two forks, 4 wire thimbles, 2 pins and some safety wire to wrap the wires to the thimbles and safety the turnbuckle.

abufletcher 08-23-2010 10:38 PM

RE: scale turnbuckles - is there a need?
 
There are two sorts of functionalities involved. First, the turnbuckle needs to be at least as strong as the cable or wire. On some of the smaller "model ship" turnbuckles with very small threaded ends this can be a problem. Although with proper safety wiring they are probably ok. But if someone could create static "non-adjustable" turnbuckles it would still be able to satisfy this level of functionality.

The second type of functionality is adjustability. But I'm really wondering how many modelers actually need this. That is, do you (all) actually attach the wires and THEN adjust the tension with the turnbuckles. The way Mick Reeves does the flying wires on his models they end up being fixed in length once set and can removed for transport. So in a sense, the turnbuckles (or rather fork ends) only need to be adjusted once.

So I wonder if there isn't some other way to make turnbuckles adjustable without resorting to threaded eyes.

TFF 08-24-2010 12:31 AM

RE: scale turnbuckles - is there a need?
 
Mick Reeves has the right idea of getting the length right and making it release instead of twiddling with the turnbuckles every time you mess with the plane. A plane with real flying wires may come apart every 20 years or so, and like any threaded part, it will wear out if done and undone a bunch. The most airframes should be flexible enough to be able to get the mount pin in to hold the wire.

Teus 08-24-2010 01:40 AM

RE: scale turnbuckles - is there a need?
 
1 Attachment(s)
I also started to make my own turnbuckles so I can make them to the scale I want. The examples in the photos are my first attemp and are approx 1/4 scale.

MAJSteve 08-24-2010 03:02 AM

RE: scale turnbuckles - is there a need?
 
Now THAT's what I'm talking about. Very nice work and gave me some ideas on for the eye and yolk. Certainly better looking than the DuBros'. What did you use for a reference for the profiles?


Teus 08-24-2010 04:33 AM

RE: scale turnbuckles - is there a need?
 
I used photos for reference and estimated the sizes a bit. They are not true scale but scale a like and fully functional with left and right thread.

cocobear 08-24-2010 06:59 AM

RE: scale turnbuckles - is there a need?
 
TFF, try this some time. When the wire is properly tensioned, saftey wire the reverse thread end and nut the "normal" end. To assemble or disassemble, loosen the nut and unwind the wire from the saftey side, to assemble, wind up th wire, set it on the stud and let go, tighten the nut and your done. If you make it hard to do, the plane will never come out once the novelty wears off. BTW, MAJSteve, no streamlined wires on most WW1 stuff. I found making turnbuckles to be a drag after the first couple.

DJ

TFF 08-24-2010 08:44 AM

RE: scale turnbuckles - is there a need?
 
Those are some nice turnbuckles. DJ I will work with your idea; your right, you dont want the plane to be a pain to get out to fly.

mcjustis 08-24-2010 09:03 AM

RE: scale turnbuckles - is there a need?
 
1 Attachment(s)
Here's a picture of a turnbuckle I'm thinking of producing. I have a few questions before I go to the trouble and expense of making several hundred of these. What would you be willing to pay, is there really a market for these? I don't claim any ownership of the one in the picture, I didn't make that one. But will be making several hundred more just like it...(hopefully). The ends are 416 stainless steel with a 4-40 thread , and the center is brass. About 9/16" (.562") of useful travel. Just a quick run of the numbers show it'd support somewhere around 200 lbs. I know what I'd have to have out of them to be worth my while. Anybody have any idea what they'd pay for something like that? Just curious.
Thanks,
Martin

abufletcher 08-24-2010 09:10 AM

RE: scale turnbuckles - is there a need?
 
Quote:

ORIGINAL: cocobear
BTW, MAJSteve, no streamlined wires on most WW1 stuff.
??? [sm=50_50.gif] Didn't MOST British aircraft use the flat (streamlined) RAF "wire." Certainly all the Sopwiths did. And the SE5s.

abufletcher 08-24-2010 09:17 AM

RE: scale turnbuckles - is there a need?
 
Quote:

ORIGINAL: mcjustis
Here's a picture of a turnbuckle I'm thinking of producing. I have a few questions before I go to the trouble and expense of making several hundred of these. What would you be willing to pay, is there really a market for these?
The shape looks good but it seems a little on the largish size even for 1/3 scale. In terms of usability, there's the question of whether modelers really need turnbuckles with two eye ends or with clevis ends (or some other type).

BobH 08-24-2010 09:19 AM

RE: scale turnbuckles - is there a need?
 
Yep Don, you are correct. My Camel and SE5 both have flat wires. Not sure they are streamlined but definately flat per the full scale. There is a variety of fasteners used by UK WWI aircraft. Some don't use turnbuckles at all. The adjustment is part of the landing/flying wires.

The SE5 uses attachments just like shown on the Bristol picture that Don posted.

TFF 08-24-2010 10:11 AM

RE: scale turnbuckles - is there a need?
 
The British wires have always been made at Bruntons. Think of it as top secret advantage of WW1; the Germans did not know the advantage. Until recently, Bruntons was low tech. The guy, ( and I mean 1)who made these wires, retired, he who had made them sense WW2, and they had to figure out again. It had turned into a sideline business that is why no tech advances. That guy learned from the WW1 guys. The big customers are homebuilt airplanes and F1 race cars. Back in the 90's there was a real panic on wires.

mcjustis 08-24-2010 10:21 AM

RE: scale turnbuckles - is there a need?
 

Quote:

ORIGINAL: abufletcher

In terms of usability, there's the question of whether modelers really need turnbuckles with two eye ends or with clevis ends (or some other type).


This has a clevis end on one end and round eye on the other.

Martin


MAJSteve 08-24-2010 12:41 PM

RE: scale turnbuckles - is there a need?
 
Nice work, especially on the eyes. How did you work that profile on the machine? I don't know whether to start with hex or flat stock and then mill/turn the threaded end down to size. The egg-shaped ends have me a little puzzled. I don't think filing to shape would be the most efficient way for production runs!

Price - well, you can look at it two ways. Those who are SEVERE scale modelers would probably be very interested if you made them as exact replicas of their specific airplane's ends and turnbuckles. They're already spending probably $200 for the flat flying wires (at least), so it might be a "custom" job for each one. For the masses (like me) probably 20% more than the DuBros cost. But, the other side of the coin is whether the builder is truely satisfied with the look of a regular clevis on the end or a couple of what look like hardware store eyebolts on the turnbuckle.

Right now I have hardware store cable (and I can live with that) but those chrome turnbuckles and chrome clevises on the ends don't really satisfy me at all. The guy that has the WACO with streamlined wires has to take them completely off for transport and he has regular clevises and on a $10,000 plane he doesn't feel that's a good quality approach. On mine, the wires are permanently attached to the fuse and the wires are easy to wrap up in coils for transport. Then I just unwind them and put the clevises through their attachment points, secure them with fuel tubing keepers (though the Sullivan clips would look nicer). It still takes me about 30 minutes to rig and retention the wires. That's why I think an end that is secured with something like a hitch pin and clip would be a snap.

The wings could be supported to take off the load and then the pins taken out with the turnbuckle left alone.

MAJSteve 08-24-2010 12:49 PM

RE: scale turnbuckles - is there a need?
 
My limited research indicated that with the early planes, especially those with doubled wires, cables were used. As things developed, they changed to single streamlined wires. However, the many varients of each model could have had either on the Pup (at least). The example at the Air and Space Museum isn't an original airframe, but rather built from blueprints, so they had one example with streamlined wires. I was unable to get very close to the plane and didn't have a tripod so my pics didn't really have a measurable scale I could use for the sizes of the wires and fittings.

What I did realize after seeing the rigging was that every cable end had a thimble with the wire end wrapped back and then the wrapped end covered in strips of heavily waxed cloth.

I think making the thimbles is another headache to come unless I can measure the loop on the fullsize and see if I can either bend tubing into an eye and then cut off the outside of the tubing OR just coat the whole end in solder and sand the solder off the outside radius.

MAJSteve 08-24-2010 12:59 PM

RE: scale turnbuckles - is there a need?
 
Wouldn't it be great to see how these flat and streamlined wires were produced. Make you wonder if they were rolled (probably) or drawn through a die (or dies). I could envision that the ends were threaded first, then the ends put into a mandrel and the rest of the wire shaped, but there would be some stretching of the material during the process. Makes ya think, doesn't it?


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