I need help!

Does anyone know where I can find good plans for a Comet?
I was looking for something around 100" span. It isn't exactly giant scale, but I post this everywhere I can...

All I came up with so far is a kit from Bob Dively models (too small) and a free plan from the web from a fellow named Colletti(don't like the plan).

Thanks in advance for any help.

Check these links out. They are about plans available from australia. The first link is related to the construction and the second link is where you would purchase the plans from. Other than the free plans you mentioned, this is all I've seen.

http://www.scad.com.au/rcaero/constructart/DH88/
http://www.airbornemagazine.com.au/i...5_01_page3.gif

Go to this page and then find the Comet. They have up to 1/4 scale 132"


Clevaland

There is a German Magazine plans site that offers one at about 8' span. The site is in German, but you can muddle through it. I tried to e-mail them to enquire about ordering these plans myself, but I had no reply. Since then, a fellow here at RCU posted an e-mail address that he said they will reply to in English, but I haven't tried it yet. Here's the web site: www.vth.de/modellbau/default.htm you'll have to look for the "store" or "shop" button, and go from there.
The e-mail is: [email protected]
As you will see, the fellow that designed this model has designed many of the giant scale models in their range, which tells me he must be a decent designer. The plans are only $20 euro, so about the same in USD....quite reasonable, I'd say.
Good luck, and please let me know what you find out, as I'd still like to get a set of these plans myself...thanks!

Cheers, Nigel

PS If you can't find the plans, give me your e-mail address, and I'll e-mail a direct link to the plans page with the Comet.

Thanks Nigel

I have just ordered a set of plans.
I think those are the ones I have been looking for...I sure hope so.

I really don't see why you had problems with ordering. I had no problems at all...only took me about 2 minutes. Of course, I'm from Belgium, which is next to Germany...Maybe that has something to do with it.
Total price including S&H is 25,- Euro...I would say that is very resonable.

The plans should arrive within a few days...I'll let you know how they are.

Thanks, I'm very curious to find out what you think. If you like what you see, I'll order a set for myself.

Cheers, Nigel

My set of plans from VTH in Germany has just arrived...

This is going to be the one!

Yo, Nigel, check your e-mail...

Yo, Rudeboy....check your e-mail as well!

Cheers, Nigel

I went to the german web site and was unable to locate the plans, but for the price I think I would like to buy them and put in my long waiting to be built list. Can soemone help me?
Sparky

Elmshoot, send me an e-mail or private message, and let me have your e-mail address. Then I can send you the web page you are looking for. I have sent them an e-mail, enquiring about purchasing a set of the Comet plans last night, but I haven't heard anything yet. Rudeboy says there very nice....I'm sold!

Cheers, Nigel

Well I guess knowing german can be a help here...

DH-88 Comet

Try this one, it should be the first plan listed at the top of the page.

Have fun with it.

Nigel, I was wrong about only the gear covers being GF...The engine cowls and the tail plane fairings are also GF.

But you can work around that without too much trouble. There's actually quite a bit of room available forward of the firewall, so a wooden cowl is an option...

Rudeboy,
Making cowls out of wood doesn't scare me off, but they do tend to suffer from eventual oil soaking and they don't generally fare as well to the rigors of gear up landings or the model tipping onto it's nose. I've made enough cowl and wheel pant moulds now that I wouldn't hesitate in making the cowls out of glass...maybe even the whole engine nacelle, and certainly the gear doors. We'll see once the plans get here. Actually, if both of us build this model, it would make even more sense to make moulds. Perhaps there might be others that would be interested as well. what do you think?
I have a Super Tigre 2500, and an O.S. 120 four stroke on hand, so I have a choice of which way to go for power. Either way I'd only have to buy one more engine. I'm already leaning towards the four stroke. mind you, I'm getting a little ahead of myself as I haven't even seen the drawings yet! Have you given any thought as to what you might power it with?

Nigel

Well the plans show a very rugged construction...a bit too rugged in some places to my preferences. The wings are covered completely with 1/64" plywood for instance.

The advertised weight is 21 pounds. If one takes care when building and doesn't cover the entire plane with glass, this weight is probably achievable.

On a 21 pound plane you don't need two ST 2500's. Also fuel consumption will be very high, so you'll need a big tank...
A couple of 1.20 4-strokes would do the job more then adequately. If only 21 pounds, the plane would go almost vertical with 2 1.20's...
I'm thinking of Laser or Saito 1.20's.
How about a couple of RCV 1.20's? With these you could turn these nice scale props...there's room for 20" props on the plane (according to the plans).

About the cowls: if there are more people building the plane it would sure make sense if one of us made a nice set of moulds. I haven't got much experience making female moulds though. For the one piece job I usually make a foam plug, cover it with glass and remove the foam afterwards...

Nigel,

I just read on a folder included with the plans about building and flying big models and written by the designer Peter Kriz, that GF parts for his models can be ordered.

I'll dig out my best german and give them a call next week...

Rudeboy,
Elmshoot has expressed an interest in the cowls as well. Maybe you could ask Peter Kriz if he would give us a better price if we were to order three sets of cowls? If for some reason we cannot get the cowls from him, and assuming I like the plans well enough to proceed, I may just volunteer to make the plugs & moulds for the cowls. Like I said earlier, it might be worth making moulds for the engine nacelles as well....we'll see.
Like you, for my scratch built scale models, I usually glass over foam then take out the foam also.
I don't have any scale drawings handy at the moment so could you tell me: Would it be correct to assume that the left and right cowls on the Comet are identical? So only one cowl mould is required? My memory tells me they are the same...of course, my memory has played all sorts of tricks on me before!
The other thing that I'm curious about is if the wing is designed as a one piece unit, or two, or even three pieces?
As for the 1/64" ply wing skins....it would certainly be easy enough to use an airfoil program to print out new ribs that allow for thicker, balsa sheeting, if that was a better way to go. It would be interesting to know the weight difference between the 1/64" ply and say, 3/32" balsa. I think I'll go and find out this morning.
I'm pleased that the retractable landing gear details are shown on the plans. I think building the gear would be fun. My father sells Graupner motors, so he may even have the retract motors in stock.

Cheers, Nigel

Here is what I have discovered:

After looking at the scale drawings, it would appear that if the cowls on the model are to scale, then there will have to be a left and right cowl mould made.

I have worked out the wing area to be 1223.86 sq. in, so at 21 lbs, we get a wing loading of 39.5 ozs per sq ft. That's much heavier than I would be happy with! Rudeboy, you are right about having to loose some weight from somewhere!
I also made a weight comparison between 1/64" ply, and 7lb stock 3/32" balsa: 1/64" ply = 1.31 ozs per sq ft. 3/32" balsa = .875 oz per sq ft. If you sheet the wing with 7lb stock, 3/32" balsa sheeting instead of 1/64" ply, you will save 7.4 ozs, or almost 1/2 lb. That brings our wing loading down by 1 oz, to 38.5 ozs per sq ft. It helps, but it's still not enough!

Nigel

I nominate Monocoupe for the "Mind the grams and it will take care of the ounces" award!

I think my free flight background is showing...

Nigel

My preference in building this thing would be a 3 piece wing with glassed 1/16 sheeting.
Do you think a pair of YS .91's would deliver the mail? I also have a Webra 1.20 but I thing the ys's are as powerful. Then the jump would be to a Saito 1.50 as far as my inventory goes. I will also us the Jomar/EMS electronic prop sync so I could go with a mixed displacement engine set up or even a Webra 1.20 and Saito 1.50 as the master, would that sound wierd or what!
Sparky

Well, the wing is a three piece unit, but the center part including the two engines is fixed to the fuse... We'll need a big van...Fortunately I've got one...and a trailer if needed...but then again, you guys are on the other side of the Atlantic...

Judging by the plans, the wing centerpiece could be separated from the fuse if one really wanted to. The plane would get heavier though...

The plywood wing covering isn't a problem I think...(if you don't glass the whole plane). As this will not be my "every day of the week" plane, I won't bother to glass the plane. This will be my showpiece! Durability is not an issue for me on this thing...
The wings have TINY (balsa) spars on the plans, so the skins are ply to take all the forces...a bit like those F3D all glass planes, but then in balsa and ply...It should work and converting the wings to a real spruce spar and balsa skin wouldn't give you that much of an advantage weight-wise I think. Ply skins are much easier (lighter) to finish then balsa skins. (You don't need to glass them...)
But that's up to the builders discretion...

As for the cowls, they could be the same left and right (maybe not 100% scale, not sure, but I'm going to Great Brittain this summer to take pictures of the real thing to make sure)...The complete engine nacelles however can't (due to the "v" of the wing). It isn't that hard to build those nacelles out of wood though, as the form aft of the cowls isn't too complicated and there isn't much "stuffing" to do since the tank is located in the fuse... The 13/64" (5 mm) ply nacelle bulkheads are needed to take the forces of the landing gear anyway...

As for the weight issue, I don't think that wing loading is a problem providing you don't step over the 21 pound mark too much. The plans show a semi-symmetrical 9% airfoil at a 1.5° incidence with the engines at 3° downthrust.
Even a couple of .90 four strokes would do the job at this weight I think (with a little less down thrust), but I would like the power reserve of the 1.20's...
Two different brands and displacement engines would sound weird I think...it is the first time I have heard of such a setup...I'll go with identical (new) engines.

Elmshoot, I don't know if you intended a pun, but the Comets were indeed used for mail service after the race...

I have a van as well. I have owned no other type of vehicle since 1988, when I realised that being able to carry more or bigger airplanes was far more important than going fast, or looking cool! I figure that the center section and stab should be about 29" span, which isn't too bad for transport. Still, you're right about it not being an everyday flyer!
I'm currently building a 1/4 scale Lockheed Vega, and just the stab spans 42" I never thought I'd end up building such large models that I'd have to make the stab in two pieces!
You're right about not needing to glass the wing if the ply sheeting is used. I think I'd consider dope and light silkspan.
I see what you mean about about having to use heavier spars if you were to use balsa sheeting, and not saving much weight. That's the benefit of having the plans in front of you!
I have the Harry Robinson scale drawings from MAP in England, and they are very detaied, and I highly recommend them. The drawing shows an RAF 34 airfoil set at 0 deg, 54', which I have never been able to figure out!
I hope to hear from the plans service early next week...or at all since I had no reply on the first try!

Cheers, Nigel

Hi there.

You guys might have seen this already but I thought I would place a link to pictures of the real thing.

I have a couple of great pictures that I can't remember where they came from. I you would like to see them send me an EM.

RSN

http://warbirdsovernewzealand.com/Gu...etRacer-02.jpg

http://www.stewart50.freeserve.co.uk/main/sc/start.htm

Steve Holland's 50% scale Comet at Cosford 2001.

You European guys have probably seen this one at some of the meets.

Damn, I didn't know he went with the scale landing skeg on that thing. I'm going with the tail wheel on mine! So mine will be a 1/4 scale model of the full size replica of the original.


Hey anyone use any of the Cleveland plans before? I was told that the 1/4 scale plans are not really designed as a 1/4 scale plane but are a rubber powered plane like the Guillow kits blow up to where it is 1/4 size. Man if they are I guess I'll be burning up my miter box cutting stringers after I spend months cutting out formers!

cloudniner, I'd like those pictures so I'll send you an e-mail. Thanks for posting the other links. One day I hope to go to England and take in as many aircraft museums as possible. Shuttleworth being at the top of the list.
Countryboy, thanks for the Cosford pics. Certainly an impressive model at 50%!
AmishWarlord, yes, the Cleveland plans are pretty much stick and tissue free flight designs enlarged to various sizes. It is my understanding that Cleveland scale plans had a pretty good reputation for being quite accurate, compared to others of that era. I also understand that some of the designs are closer to being used "as is" than others depending on the size of the original drawing. Wy own personal experience was with an enlargement of a Stinson Gullwing to 1/5 scale. While nicely drawn, it was IMO going to require a fair amount of re-engineering to make it practical to build at that size. Not to totally knock them, as they are very nice in their own right, however I would prefer to buy a plan of more modern design if it were available for the aircraft I wanted to model. I was browsing their site the other day, and found that they do have some interesting and obscure aircraft in their range. I'm considering picking up a few of them at smaller scales, to use as reference material in drawing my own plans down the road.
I expect the 1/4 scale Comet enlargements are going to be pricey!
I hope this helps.

Cheers, Nigel