Replicraft

Drorso · 9 October 2011, 01:18 PM

Hi All,

I finally got the Replicraft plans for the Sopwith Pup. It's been a while since I started to ask you guys questions, and many thanks for the answers. Now the decision has been made, the plans are here, so let's get to work.

I am going to build a full size replica, authentic as much as I can. The major modifications will be:

1. Engine - I'll use the Rotec R2800
2. Brakes - I'll operate from a paved 1000 ft runway, I must have brakes
3. Tailwheel - same as above
4. Machine gun - anybody has a vickers for sale? I guess not...

so I'll put a dummy

First questions I have in mind for those who have built or are building a Sopwith replica from Replicraft plans:

1. Fittings - the bill of materials for almost all fittings states MS. What type of metal is it and where can I get it?
2. The wing spars have lightening routers giving them a H shape in part of them. How do I do that? would it add considerably to the total weight if I don't do that?

Thanks, Dror.

Avro Avian · 9 October 2011, 03:54 PM

Hi Dror,

1. Your best bet would be to contact Leatherhead on this forum. He is having all the steel fittings laser cut. This will save you an enormous amount of time and hassle.
2. The search function on this forum is your friend. Have a look at John MacKenzie's threads, Butch's SPAD thread for starters. There is so much valuable information on this forum.

'14-'18aviationcollector · 9 October 2011, 04:03 PM

Hi Dror,

MS is mild steel. You will need to cut the hollow sections out of the wing spars, and all other areas as specified, since every gram of extra weight will affect the flying qualities. The power to weight ratio is very marginal, particularly for the Pup. A little bit of extra weight and you won't be able to get it off the ground!

To hollow the spars you will need the correct router bit, guides for the sides and ramps for the ends.

Regards,

David.

RobW · 10 October 2011, 12:55 AM

It may be helpful for you to get a copy of John Gaertner's videos "This old Airplane"... He does a good job of explaining how to work with wood, set up jigs, etc...

Blue Swallow Aircraft

Rob

Dogtail2 · 10 October 2011, 12:58 AM

Hi Dror

Looking forward to seeing your progress.

Mild steel sheet is available at any metal supplier but the exact spec on the drawings is a bit vague. Some parts are shown as MS spec S3 but not sure what this is exactly.
You could use 4130 but will have to be careful about cracks when bending the tight radii. Also brazing with 4130 will need extra care.
Mild steel S510 or S514 will probably suit most jobs.

There are routing pictures on Nick's Snipe thread and my Camel thread.

Drorso · 10 October 2011, 01:44 AM

Thanks for the info about the MS. I'll see what I can get here.

Another question is about the wood. It is specified as spruce, and I intend to order it all from "Aircraft Spruce". Are there any special specifications and different types of spruce, or one type only?

Thanks, Dror.

Dogtail2 · 10 October 2011, 02:04 AM

Just make sure you specify 'spar stock' when you order for your spars.

Omega · 13 October 2011, 04:28 PM

[QUOTE=Drorso;593561]Hi All,

4. Machine gun - anybody has a vickers for sale? I guess not...

so I'll put a dummy

If you are in the US PM me.

Koz

Dart · 13 October 2011, 05:35 PM

[Rubbing hands together in excitement]

Ooooh, a Pup from scratch! Can't wait to follow your progress!

And please know that the group of folks here are supremely helpful in every way that you need assistance.

Butch · 13 October 2011, 05:40 PM

For a supply of spar stock, try Wick's Aircraft Supply. They are small enough to entertain custom orders.
As to routing spars, I have seen measurements of four pounds per spar on a Skybolt. Eight spars, that adds up. The routing is very simple. Look at MLCS for router bits, a core box cutter should work.
Pete