I'd like to use a Williams Brother's Le Rhone kit and make it spin with the prop. How would I do this? Also is there some SECURE but still scale way to attach a wooden propeller?

Don't like to dampen ideas, but I think you have a problem. It will fly apart. A full scale LeRhone turned how many rpm? 2400? If you spin up a glued together plastic model on your engine it will not last long. And even if you could keep it together, you would end up with a huge torque reaction.

What might work is to install ball bearings inside the Williams engine and let it freewheel behind the spinning prop. Creatively add some "baffles" that act as a prop and the motor will spin. And hopefully not fly apart.

I seem to remember seeing somewhere (in one of the mags) that modellers had figured out ways to make radial engines turn in flight for a more scale appearance. But I see how it would be hard to have the engine travel at the same speed as the propeller. Maybe your suggestion of making the false engine free-spinning (like a pinwheel) might work. I'll give it some thought.

There is a review in the May issue of Flying Scale Models 2002, showing Peter McDermott´s
incredible 1/3-scale Sopwith Snipe in detail. The model include a dummy Bentley BR2 engine
that spins with the Laser 360 twin installed.
I believe the dummy rotates at the same speed as the engine, as Peter says it will not quit
without a cut-off valve when idling at 800rpm.

Here's a thread with a guy who has a giant scale DH-2 and is doing the same thing you're talking about (posts #36 and 39). I'm sure if you PM him he'll give you the details.

http://www.rcuniverse.com/forum/m_15..._2/key_/tm.htm

Hi all,
The dummy rotary on my DH2 spins on a ball race on the propshaft. The prop only turns at 4200 (still too quick for scale, but what the hell) but the drag, or slip, of the bearing, combined with the aerodynamic drag of the dummy motor itself, slows the Rotary down to I guess about 1700 rpm, about right. I would be slightly hesitant to spin a Williams kit at anything like this speed, as they are reasonably heavy when completed. Mine is constructed around a Paxolin 'spider' (with 9 legs!) onto which the bearing mounts. The cylinders are cast in polyurathane foam, to get the basic shell and fins, and attached to the spider using expanding foam to fill the cylinder and secure the spider. Each finger of the spider is drilled to accept a couple of cross pins, which once surrounded in squirty foam is very secure. The crankcase is made from blue foam, covered in paper for smooth finish. Again, the crankcase is crossdrilled and pegged to the spider, secured this time with epoxy. The key to the success of the rotary is the fact that it is very light, the heaviest part of the whole thing is the bearing and housing. It spins very easily, although no matter how fast you spin it by hand, it wont do more than 10 or so revolutions, due to the drag of the cylinders. When designing the system for the DH2, I intended to have the dummy engine bearing on the housing for the shaft, and not on the shaft at all, feeling that the motor would spin too fast, with dire results. I was going to blow the motor round with the exhaust gasses, as I had used that system before on a smaller Fokker, but the exhaust on the Fokker was right next to the dummy, so it was easier. Doing it this way means there is definately no extra load on the model engine, and the rotary engine can be sped up or slowed down dependant on how close the exhaust is.
The exhaust is much further away on the DH, and there is a former, speed reducer and shaft in the way, so it was not to be done the way I had before. Another problem with a coventional plane with a rotary at the front, is balancing. It is usually neccessary to move the model engine back a bit, to make way for the dummy in front. This, on most WW1 planes, takes the heavy bit closer to the Cg which means you need more weight at the front to keep the balance point in the same place, so the model will be quite a lot heavier, no matter how light the dummy rotary is. A compomise is to only have the front half of the rotary, and using a model engine with the bits at the back, so it can be closer to the front. I am due to have the motor out of the DH quite soon so I will post pics of the whole 'kit and kaboodle' when I do.
Hope this helps, Ian.

as to the scale prop question, the sept 03 issue of model aviation magazine has a quick blurp about a scale ww1 hub it looks great and they give contact info to order. it says you can get them from balsa usa or the designer directly. his name is Ralph Vannaman and i show an e mail of [email protected] or write him at 2301 13th ave menominee MI 49858. the hub looks good and the price in the mag says 24.95 plus shipping.


in another issue i read about making a scale looking prop basically by taking a wooden prop stripping the finnish of of it, sanding the tips round and restaining it a darker, more realistic color. in that article it even had contact info for ww1 era prop decals that can be applied to your new ww1 prop. i guess it goes without saying that if you do this then the new prop and your balancer will get to know eath other real well. i just wish i could remember which issue i read that in to pass it along too.

That was the RC Giants column in the January 2004 issue of Model Aviation.

Here is a birch prop from Clark Industries. Since its all birch and not the Mehogany and Walnut like the Full scale I had to stain and streak it . I still need to make the hub but, it does look like the full scale prop. Not perfect but atleast convincing.. BobH.

idigbo, your plane, from what I can see, looks great! Could you post some additional pictures of it? Thanks BobH.

Here you go Bob, the DH passed its final inspection today so test flying can begin very soon, but not soon enough for me!! (and I am a very happy camper!)
Ian.

Excellent!!!! I hope if flies as well as it looks. Please keep us posted after the Maiden flight. Good luck with it.. and thanks for the pictures. BobH.

beautiful plane. Nice job! Damn! - look at all them wires.