arspievack

Seth,
As you well know, our models are made from much better technology and materials than were WW I aircraft.
I've seen two methods that were used to wrap the end of the rigging after they were looped through the hole or clevis. The usual was just tape that looks like electrical tape but not sure what it was.
The second was strips of linen which were wrapped and then lacquered for "stick" and water proofing.
ars
3155

Sethhunter

Happy New Year!

I finally got to the lower wing today. I thought I'd post a few pics of the undercambered wing tip as I'd never built one this way - I didn't want to laminate a lot of strips and wait for aliphatic resin to dry. So instead, I built the tip using 3/32 balsa sandwiched between 1/64 ply, oriented horizontally. I cut a foam mold to the side profile (using the median chord curvature), cut the balsa and ply pieces to the "planform" (top) profile, then held the bottom ply, balsa, and top ply on the foam shape by hand while gluing it all up with CA. In 10 minutes I had a 3D wing tip. I then spent the next 20 minutes cutting my fingers apart. I can't believe after all these years the glue finally got me!

arspievack

Seth,
Looks good
Here's how I did it. Cut a balsa or foam mold the shape of the tip.
Then cut 3-4 strips of 1/64 ply to the shape of the tip. Soak them in warm water with baking soda in the water.
Cover the mold with saran wrap. Place the strips in a stack on the mold and pin and/or clothes pin everything to the final shape you want. When everything is ok ,lines up and fits the tip of the wing, run the CA along the outer edge. The baking soda water fires it. Your fingers are out of it. Let the water dry over night ( the heat of the CA dries it pretty well. Then the next day do the sanding, cutting and filing to round it up and smooth it. Works great and saves the fingers

ars

Erich_Prinz

Really?

The baking soda acts as an accelerant?

EP

Erich_Prinz

Seth,

I have to admit I was a little surprised. As far along on all the other details of the project, I just assumed everything had been framed out if not already covered!

Looks good and true from the pics.

Erich

arspievack

Yes,
You can use it as powder or make a solution of it. It's great for filling gaps as well.
CAs (there are many different types) are all pH sensative. They can be set at any number of pH settings.
Try it tomorrow., Put a little baking soda between some wood or metal strips, put drop of CA and see what happens.

ars 3155

Sethhunter

Great tip Alan - Thanks!
Yes Erich I usually complete framing before moving on to more details. Maybe because of the protracted timeframe, it's come together in an odd fashion. Anyway, begining to see the light - thinking about the radio and engine!

abufletcher

Seth, what I want to know is when you're going to get around to the REALLY important stuff -- like the teddy bear!

Sethhunter

Actually I've already raided my 6 year old daughter's stuffed animal box. I found a couple of small stuffed bears but they're not quite right. This has to be given some serious thought! (To those not familiar with Fritz Hohn's DIIIa, he had a teddy bear wired to the turtle deck).

abufletcher

I've noticed that vintage teddy bears seem to have a slightly different shape than modern teddy bears. Here's one from the 1920's.

Looks like the aircraft I'll be modeling next year also had a teddy (sitting on the engine). Luckily, Japanese is absolutely awash with little cutsy things like miniature teddy bears!

Sethhunter

Hey everyone - just a quick pic to keep the thread alive!! Actually I think this is the first photo (looking down from the ceiling) with the wings on. My shop now requires an island to support the tail! Now I see why giant scaler's have big shops!! I'm getting lots of exercise ducking under this thing. Final balanced weight projection is 25 lbs, 25 oz/sqft. Running rigging is done. Next up is covering the lower wing, painting the wings and struts, cockpit detail, pilot, engine and radio. I bought some really cute round mirrors from Edmund scientific for the rear-views (not shown). The 4.5" diameter spinner is still under deep consideration; I'm thinking vacuum forming, but need to build a vacuum forming box, buy a lathe to turn a buck, and then or course learn how to v-form. (This a really good excuse to buy some tools for my "big-project" shop). I'm considering using thick (i.e., .375) steel for the backing plate (like a fly wheel) to get some weight as far forward as possible. Anyone see any problems with that idea? I have access to a nice Hardinge lathe to turn it true. Engine I'm considering is the revolution R-50.

Erich_Prinz

WOW!

So the cold winter is good for building!

What's the weight of the Rev and will you need more weight on the nose? I like the idea of a turned backplate for weight - as far forward as possible.

Looks like spring can't get here soon enough!

Erich

abufletcher

Seth, that's just spectacular!!!

arspievack

Seth,
A beautiful site at the end of the tunnel. Here's what I'd suggest.
Get the motor installed and place battery and radio stuff where they belong. Then find the CD with everything placed except the spinner. Make an estimate of what the spinner should weigh, If you need nose weight get one of the comapanies to turn a metal one with a metal back plate to get the weight you need.

If you don't need much weight then just get the metal back plate and make the spinner out of fibre glass/ resin.
Have you ever used the ballon method?
It's easy and quick. Let know if you want instructions
Great work
ars

Sethhunter

Thanks guys!
The vacuum forming idea for the spinner came from one of you (enormously helpful) gentlemen, along with the suggestion to build it with a front plate rather than a backplate, to avoid the "ring of screws" commonly used on Albatros style spinners. (I've been assured the screws are a royal headache to remove each time the engine spins a prop loose!) With a front plate, the spinner cone (however it's made) can be adhered to the plate permanently, and the cone extends back past the prop like a skirt. I suppose in this size range, the prop hub offers enough area to properly (no pun) support the spinner this way. The Pfalz offers the advantage that the spinner has [what looks like] a removable center plug, perfect for inserting a socket driver.

Vacuum forming sounds like an important skill in this hobby that I've always managed to avoid, so I'm up for it (and a lathe would just about finish my woodshop!). Especially since some informal quotes I've gotten suggest a custom one-off machined spinner this size will cost considerably more than the engine. Even a block of Aluminum this big is pretty pricey.

Alan - thanks for the suggestion. What is the balloon method??

arspievack

An old method from an old guy.
1) take a block of wood (any kind) put on you lathe and shape the sinner you want. Makr it about 1/8 in too small.
2) When finished drill a hole in the back (cenetred) to accept a heavy post. A dowel works well but a 1 inch diameter at least. Glue it in.
3) Mount the post in your heavy vise with the spinner sticking up, vertical.
4) cover the spinner mold with Saran wrap. You can tie the excess round the post
5) Now drape 3-4 layers of 6 oz. fiberglass cloth over the mold. You can cut pie shaped segemnt from around the bottom edge to get it to lay flat, but you can also just make folds to get it to follow the countour of the mold.
Wear gloves and I used to put a hole in the center of a paper plate to put the post through before mounting it in your vise, to catch all the epoxy glop.
6) Cover each layer of cloth with slow curing epoxy resin and work it in with you hands or a spatula, before adding the next layer of cloth. Be sure to have excess cloth that comes below the edge of the mold. This will be trimmed off later.
NOW COMES THE FUN PART, AND YOU SHOULD PRACTICE ON THE EMPTY MOLD BEFORE YOU TRY IT WITH THE CLOTH AND EPOXY ON THE MOLD. IT TAKES A FEW TRIES TO GET IT RIGHT.
7) BUY SOME LARGE BALLOONS The bigger the better. Blow the balloon up. Then while keeping the air in the balloon by holding the neck closed with your thumb and finger, push the balloon over the mold, slowly letting the air out as you do until you've push the entire balloon over the mold and all the way down around the post. the balloon becomes the female part of the mold.
Take off the gloves which are messy, use your hands to work the epoxy into the cloth by massaging the balloon, then tie the balloon around the post with string , or rubber bands or heavy tape and let the whole thing cure over night.
8) When cured, remove the balloon, mount the post on the lathe and sand it smooth.
Once the mold is almost to shape you can pore epoxy into the nose section in order to drill a tip opening to hold the prop nut.
Try one for practice. If you like the method I'll suggest some ways to make a plug to clod the prop nut hole..
ars

Sethhunter

Alan - What a great idea; I've never heard of the process but it sure cuts the work of making a pristine male mold, casting it, cleaning up the female mold, getting lopsided fiberglass distribution, and on and on. Really, what a compelling and elegant approach. Can't wait to try it! I was thinking of plugging the prop nut hole with something like a fuel tank stopper, but I have a feeling you 've got a much better idea...?!

........thanks

arspievack

an easy one is to cut off the front 1-1.5 in. of the spinner.
Drill a hole in the back and epoxy in a bolt with the same thread as an elongated prop nut,
drill a cross hole through the epoxy tip and the bolt in it and use a prop nut bar to tigthen it in.
ars

Sethhunter

Nice idea especially for a plug that follows the contour of the spinner; in the case of the pfalz, I think the original plug was more like a flat cap; but I might still use your idea of bolting it on rather than a press fit.

Erich_Prinz

Hi All,

I've been working away on tracing the main page for the Jumbo FF scale plans - this isn't complete but couldn't resist sharing it as it's coming along much faster than anticipated. This is largely due to an open source application called InkWell. Of all the apps I've used, this has been by far the most accurate, fast, and simple to use.

This is a trace of plans drawn up by Clint Brooks found on the Small Flying Arts site - all the credit goes to him for the design - especially any errors you find :-)

Erich

ArdChoile

Greetings one and all,

I've just joined the forum and must admit I'm humbled to be in the presence of so much talent and knowledge. I spent several hours last night reading all the postings.

Alan. I remember reading articles on your models when I was growing up a true honour.

Seth. What can I say that hasn't already been said. Your model and detail are second to none and I look forward to seeing more of your progress.

I'm currently gathering as much information as is out there in the hopes that once finished I will have as much as I can get to assist with my project. It's still probably a couple of years off but I hope to build a full size replica of the Pfalz DIII. A hell of a mission but something I have wanted to do since I built my first model 30 odd years ago.

ArdChoile

Question for everyone.

Where do I go to get my hands on Flugsport No.s 20 & 21?

Any assistance would be appreciated.

ArdChoile

Erich_Prinz

.

Welcome to the forum. It's really quite infectious.

Looking forward to seeing the full scale version. Quite an undertaking.

Seth should be getting close to finishing up his project - I expect we'll see some flying photos by summer. Then I'll need to start carving out time to get my small project rolling just so there are some more photos to share.

Erich

Sethhunter

Welcome indeed ArdChoile! I'm afraid I can't help with a source for those publications. Do you think you would use the lamination method to build the fuselage? It would be a great project.

The model is coming along bit by bit. Attached is a photo of the rigging and V strut anchors (prior to adding stitching). The fittings bolt through the wing. Pockets underneath hide the bolts, and are covered with false backing plates.

I've been picking people's minds about engines. In retrospect, I probably would have worked harder to keep the tail light, and widened the fuselage a bit to increase the engine selection (boy those gassers are wide!). I'm leaning towards either the DA or ZDZ 50 cc with wrap-around muffler. Probably the best engine would be the thirsty Moki 2.1, but I think the fuel bill would leave my family eating bread and water!

Anyone know of a source for full-body 1/4 scale WWI pilots? Closest I've seen is the barnstormer from hppilots.

Erich_Prinz

Seth,

How are the wire attach points mounted/anchored to the wing? Just through the rib?

It almost looks like the simply sit on top of the covering but I know better ---

The strut anchors appear to be brass and almost identical to the ones shown in the drawings dated 1918 giving details of the strut attach assmbly.

Erich