bobripley

Hello,

I built the VK/Proctor DR.I a couple years ago. On that project I used a Satio 56 mounted with the head positioned at 7:00. That engine turned out to be perfect for this model and the Williams Brothers LaRhone hid it well. He is a link to that part of the build if you are interested.

http://www.rcscalebuilder.com/forum/...18&PN=1&TPN=29

TFF

I really like your stabilizer.

abufletcher

Bob, thanks for the link. I remember looking through at least some of the pages of your thread some time ago. Outstanding detailing. What were the advantages of the 7:00 mounting?

How does the weight of 16g (0.56oz) on the stab (not including the elevator) compare to the weight on the stab on the VK DrI? This seems light to me, but I need a frame of reference.

vonJaerschky

My Feedback: (3)

Thanks Abu. I did a build thread [link=http://www.rcgroups.com/forums/showthread.php?t=593151&highlight=dreidecker]here[/link] , and there is video [link=http://www.bengco.net/guest/videos/1sixthDr1_small.wmv]here[/link] (best to right click and "save as"). It's really a great flying airplane and never fails to draw attention at the field.

abufletcher

Wow! So many DrI threads to go through! [:@][:@] The thing about triplanes is that they've been modeled again and again in all scales, from kits and scratch-built, in IC and electric, in sport scale and "rivet-counter" scale, and in every conceivable color scheme. The Aerodrome kit (at 1/6 scale) looks great. The 1/3 scale GTM DrI is a stunner. And the BUSA DrI offers a great sport version in 1/4 scale.

So really the only thing you can do is enjoy your own build. And enjoy being a member of the DrI Club. For me, this build is all about learning about how the actual triplane was constructed. I'll be consulting Achim Engel's full-scale build the whole way. Of course, I don't plan include every single bolt, but I want to at least know what I'm leaving off.

abufletcher

Since this build is all about trying new things, VonJ, I notice that you covered your 1/6 scale DrI with Polyspan and dope. I don't know anything about polyspan. What's it like? The Guillow's models of my youth were all silkspan and headache inducing dope from little jars from the hobby shop. Since I started RC it's been only solartex. I had planned on covering the DrI in Solartex Natural. But I like the idea of covering the rear fuselage and/ flight surfaces with something lighter.

Also what's a good source for nitrate dope?

Trev

Hey Don, glad you decided to go ahead with the Dr1! That looks amazing, I don't think you can go much more scale! Using bamboo for the structure seems an excellent idea! I'd say with your select choice of lightweight materials you'd hardly run into any tail-heavy issues.
Do you think it would be possible to get a similarly durable 1/6 scale airframe with hardwood dowel (or does the 3mm snap too easily)??

How are you going to anchor the internal rigging (what material and will it be threaded through the gussets?), also any ideas yet on the wings (you mentioned wire TE's)
I'm probably getting a little ahead with my curiosity, its just this is exactly the sort of approach I'd hope to take for future builds! Great stuff!

Trev

why not add another layer of bamboo to the inside of each of the main fuse longerons? Could have them terminate before the cockpit where it'd be visible. At least you'd have 4 x 3+3 mm attachment points

abufletcher

I think hardwood dowel should work just fine. In fact, in my informal weight tests the dowel was bit lighter than the bamboo. And as far as it snapping, if you heat it to bend into shape so that it's not in tension, it should be fine.

I found some kevlar thread at a fishing shop. It goes through the gussets and wraps about the bamboo in several long continuous lines. Then it's just "tied off" with CA.

I'd like to try an authentic box spar of scale side and build the ribs as per the full scale (to be slipped on). I don't want to do standard model construction with ribs placed down on spars. I'm also contemplating copying your EIII method of 1mm ply ribs instead of balsa. It looked great on your EIII.

abufletcher

It's certainly an approach suited to life in small town Japan!

vonJaerschky

My Feedback: (3)

I love polyspan. I have had better success with polyspan than any other covering. It is a woven polyester material, and has a texture similair to silkspan. It has no adhesive, so you need to brush some onto the model framework (such as Sig Stix-it or Balsaloc) and then iron it on. They the covering is shrunk wit heat. After that, it takes about 3 or 4 coats of clear nitrate to seal it, and then you can paint. Once polyspan is on, shrunk, and doped, it stays tight forever. I've never had it wrinkle, and that includes the flat black painted portion of the horizontal stab on the Dr.1 sitting in the sun. It has also stayed firmly attached to the bottom of the undercambered airfoil on my C.III and Gotha G.IV. The final finish has a slightly textured look. It isn't like the weave of a fabric, but it looks very good.

Dope can certainly be a stinky situation. I only use it when I can open the garage door wide open, and I use a good respirator when I am spraying it. I get my dope from a source here in Canada, and I know they don't ship outside of Canada and the USA, so I can't help you out there.

abufletcher

I must admit that I like the fabric-like texture of solartex. Seems just right for WWI aircraft. Plus it's way cool that you can tear strips of solartex to simulate "rough edge" rib tapes. Note, however that it only tears straight in ONE direction (along the line of the bolt).

abufletcher

Here's the stab, Mark II. You probably can't see much difference but it's more scale in a number of ways including thickness and sharpness of the leading edge. The leading edge is made of 1.8mm aluminum tube with 1.2mm music wire inside. For the main structure I used 4mm stock and dowel instead of the 5mm. All in all, the weight savings here and the weigh to the metal leading edge about canceled out.

Plus there were a number of small but annoying flaws with the Mark I (for example, it wasn't 100% symmetrical, much to my surprise). Now on to the elevator. I need to use the same "filled aluminum tube" method on the TE so it matches the stab. I also thought about the idea of filling the tube with 90min epoxy inserted with a syringe and then bent to shape.

Teus

Outstanding.............. [sm=thumbup.gif]

bobripley

Hello Abu,

I mounted the Satio 56 at the 7:00 postion because at 12:00 and 9:00 the muffler routing would have been a problem. The 9:00 placement was great for the exhaust system but the head would stick through cowl. At the 6:00 I would have a problem again with the muffler so the 7:00 worked out the best.

Rip

abufletcher

The "inverted at 45 degrees" is the solution I decided on from my Fokker EIII and the dummy hide it perfectly and the exhaust was nicely placed between the legs. According to my photoshop tests (which could be off by a smidge) the Saito 56 should fit under the cowl I have but I won't be sure until and I can actually test fit the engine.

BTW, I went over to RCSB and logged in but couldn't find your thread. The link only took me to the login page, which then took me to the forum discussion main page. There's some great building going on over on RCSB but the interface always gets in the way.

abufletcher

Another quickie materials weight comparison for equal lengths:

4mm aluminum tubing: 4.5g
1.5mm aluminum tubing filled with 1.2mm music wire: 4.0g
3mm bamboo dowel: 1.5g
1.5mm aluminum tubing by itself: 1g

The filled 1.5mm tubing has the advantage of being scale at 1/6 size. The bamboo is the most flexible and resistant (so maybe a good choice for the rudder). I'll start with a filled tubing rudder to match the stab/elevator but if I need to remake one after a nose-over, I'll go with bamboo.

abufletcher

Following Del's fine instructions on his GTM DrI thread, I was able to make this teeny strap hinge. This is as small as I can make it with the tools available. I need three of these for the elevator, two for the rudder, and either four or six for the ailerons.

TFF

That is a great hinge. You are giving me an inferiority complex on my VK.

bobripley

Abu,

See if this gets you to where you want to go. http://www.rcscalebuilder.com/forum/...18&PN=1&TPN=45 Otherwise, log on to RCScalebuilder.com, go to Proctor Enterprises under the KITS section. My build was a while ago so you need to go to page to on the list of posts to get my Dr.I build titled oddly enough, "Fokker Dr.I build".

abufletcher

I have no doubt that the finished VK Triplane will look every bit a good as my scratch-built one, and possibly fly better. Bob's VK DrI is as spectacular as any model can be. As I mentioned above, this build isn't about reproducing a "every rivet and bolt" but rather learning about how the original Dr.I was built. For example, I hadn't realized that the elevator only has three hinges, two out by the spar locations and one in the middle, under the rudder. And while I've played around with strap hinges in the past, I never before really understood how they went together. They're really not that hard to make once you figure it out and get the jig and tools ready.

abufletcher

Bob, thanks, that got me there. That's a stunning build and looks like a gold-mine of information.

VonJ, do you think the Aerodrome DrI could be easily adapted to IC power? (That's a strange question to be asking!)

The following thread had some good info on WWI hinges.

http://www.rcuniverse.com/forum/m_20...tm.htm#2084638

abufletcher

Once I figured out the "production process" for the hinges, each one takes about 5min. The steps are:

1. Cut off a section of brass tubing a bit wider than the strap you'll be using.
2. Smooth off the edges of the tube.
3. Cut a length of the strap material (also brass) and fold it around a dowel.
4. Put the strap over the wooden fixture shown in the photo and clamp in place.
5. Cut two slots in the top of the strap (going about 3/4 of the way through the dowel)
6. Move the strap over to the slot that was cut in the fixture.
7. Use a rounded off file to tap the center piece of the strap down into the slot, forming a loop.
8. Remove from fixture and insert brass tube.
9. Add a small drop of CA around the strap loop (or solder, but at this scale CA seems fine).
10. Drill the bolt hole through the strap ends.
11. Trim and round off the ends of the strap.

Voila!

smcouch77

Beautiful job on the hinges! I think you may have the worlds first "Lighter than Air" DR1
Steve

abufletcher

And here's the matching elevator. This might, however, be altogether too delicate for a flying model. I'll be reinforcing each rib connection with a "weld" of JB Weld which might also add a bit of lateral strength, but it seems pretty flexible right at the moment. Of course with a pull-pull cable system the cable itself keeps the halves straight, but we'll just have to see how it seems after it's covered. If need be, I'll make another using more traditional construction techniques. The entire elevator and stab currently weighs 35.5g (1.25oz) with the three brass hinges.

Bear in mind that the stab of the DrI does have supporting braces on the bottom.

Hmmm...I wonder about adding small gussets to the underside of the elevator where the ribs join the TE. [sm=50_50.gif]