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-   -   Exclusiv Modellbau 50% Pitts S1 (http://www.rcuniverse.com/forum/giant-scale-aircraft-3d-aerobatic-110/6173200-exclusiv-modellbau-50%25-pitts-s1.html)

tobba 07-30-2007 04:25 AM

Exclusiv Modellbau 50% Pitts S1
 
I am building an Exclusiv Modellbau 50% Pitts S1. I plan to use RC Universe as a build record for myself and would welcome input from anyone interested.

Clearing enough space to begin was a job in itself. Like most I don't get enough time to spend modeling - a young family make sure of that! So lets just say, it won't be a quick, but hopefully an enjoyable experience.

The fit out spec will be as follows:

- Exclusiv Modellbau 50% Pitts S1
- 3W212cs
- BMB Can mufflers
- JR 8711's throughout.
- Powerbox champion and batteries.

Started on the tail surfaces - will post images soon.






japan3d 07-31-2007 09:32 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
It is a Big Plane!!! Check out the one on my website.

tobba 08-01-2007 03:30 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
You are not wrong! Great site. Thanks.

tobba 08-09-2007 04:08 PM

RE: Exclusiv Modellbau 50% Pitts S1
 
1 Attachment(s)
Here's the first pics. Work on elevators complete.

- Made horns out of carbon plate.
- Dubro monster clevises
- Lunsford 3mm Titanium turnbuckles
- Used spruce rib caps on horn rib
- in set carbon tube into leading edge of surface to help distrubute load.
- Running 1 x DS8711 on each.

RTK 08-09-2007 11:11 PM

RE: Exclusiv Modellbau 50% Pitts S1
 
Looks very nice. One question, are you going to put something around the horns to make the covering stick or will it be completely sheeted??

tobba 08-10-2007 03:45 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
Yep - 2 x 1/16 ply triangles either side of the spruce ribs. Thanks. On to the tailplane...

tobba 09-28-2007 03:22 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
1 Attachment(s)
Work complete on tailplanes.

Used Carbon plate for the servo mount. Used light plastic sheet as a large servo bay cover. JR horns, Dubro monster links with 3mm Titanium turnbuckles. Planning a 1/16 ply root cap to add some strength. Most of the strength seems to come from the flying wires as the tubes are relatively short and are not supported at their ends. Good fun and easy building. Enjoying it!

Still to fit covering triangles around the horns.

On to the fuse.

T

tobba 09-29-2007 07:11 PM

RE: Exclusiv Modellbau 50% Pitts S1
 
1 Attachment(s)
This aircraft is big!

A quick test fit of fuse parts and thinking about a few updrades around the engine bay area. Possibly a fabricated aluminum mount for the 3W212. I'm not comfortable with this engine hanging off an 1/8th lite ply engine box... no matter how much glass you throw at it. The 1/4 inch firewall also seems a little under done for a 200cc engine. Looking to make it 1/2 inch and add a fair bit of grunt around joints etc. Maybe some aluminum angle with screws and a fair bit of 1" triangle balsa and epoxy. I believe there is a balance between being super light and lasting the distance.

Other option is a composite version like the image attached for the 212. This is part of a kit and I doubt they will supply as an accessory separately.

Does any know of anyone doing composite engine mounts or the like?

T

tobba 10-08-2007 03:51 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
1 Attachment(s)
I had a few problems laminating the curved leading and trailing edges of the surfaces. I have attached a few pics of a way out if anyone is having the same issue as it ended up working well. I found that using water to bend the wood weakened the PVA joints dramatically and made it difficult to get accurate, strong no-gap joints when wrapping the laminated sheets around the surface frames themselves. Endless pinning as per instruction didn't seem to help much.

I made templates from 25mm MDF or custom board traced directly from the lite-ply surface frames and cut them out accurately with a bandsaw. I attached thin tape to the template on the cut edge to stop any glue sticking. I used alphatic resin, no water and whole lot of masking to to pull the strips down to meet the template. Once dry they are super strong and stay in perfect shape. No gaps or bad joints and they fitted perfectly to the frames.

This took a little work and cost an extra $30 for wood and a pile of masking tape but i believe gave a far superior result. Templates were cut for all surfaces. One for the fin, rudder, elevator and tail plane.

cheers Craig

wifpwcf 10-08-2007 07:24 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
nice plane craig ...i will be keeping my eye on this thread,
thanks for doing the build on rcu;)
cheers glen

Hooked-On-RC 10-08-2007 09:13 PM

RE: Exclusiv Modellbau 50% Pitts S1
 

Quote:

ORIGINAL: tobba

I made templates from 25mm MDF or custom board traced directly from the lite-ply surface frames and cut them out accurately with a bandsaw. I attached thin tape to the template on the cut edge to stop any glue sticking. I used alphatic resin, no water and whole lot of masking to to pull the strips down to meet the template. Once dry they are super strong and stay in perfect shape. No gaps or bad joints and they fitted perfectly to the frames.

This took a little work and cost an extra $30 for wood and a pile of masking tape but i believe gave a far superior result. Templates were cut for all surfaces. One for the fin, rudder, elevator and tail plane.

cheers Craig

For future reference, in lieu of a "whole lot of masking tape", you can purchase things called band clamps, basically they are nylon web clamp in various lengths and will wrap around the outside of whatever surface you are trying to shape to. I used them once to make a port hole window for a door on a boat and they worked like a charm. They also help keep the wood in alignment. Just for future reference.
Cheers
hooked

fokker fan 10-09-2007 04:02 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
Pretty impressive. Where abouts in NZ are you? I wouldn't mind seeing this fly when it's finished if your not too far away.

tobba 10-09-2007 04:37 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
Thanks for the tip - sounds interesting. Still have the wing tips to do so may give these a go.

tobba 10-09-2007 04:42 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
I'm in Auckland - It will be a while away but keep in touch. Not really in a huge rush, keen to enjoy the build. From all reports it should be impressive!

Rgds Craig

Aastan 11-29-2007 05:46 PM

RE: Exclusiv Modellbau 50% Pitts S1
 
Tobba,

I am thinking about purchasing this kit, great work so far. Since your using 8711 servos, are you going to mod the wings to operate on 1 each surface (aileron)?

Aastan

tobba 11-30-2007 01:53 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
Hi Aastan

I am planning to run 8711's. The model only calls for 1 servo per surface on the wings as standard. ie: 4 8711's in total.

I have been on a go slow with the Pitts. I brought a Rookie Mkll jet a month or so ago and am keen to get it flying for xmas.

I highly recommend the kit - the quality is second to none and the crew at Exclusiv Modellbau are very helpful. Don't expect detailed plans or a manual but the kit comes with a CD full of build imagery which makes life easy.

All the best,

Craig.

tobba 03-18-2009 02:53 PM

RE: Exclusiv Modellbau 50% Pitts S1
 
Back live on this project. Distracted with a BVM Mig and a PCM Me-109.

Back at it, and working on the fuse. Pics soon.

Craig.

awesome 03-20-2009 07:30 PM

RE: Exclusiv Modellbau 50% Pitts S1
 
Tobba , nice job mate! I have the EMHW Challenger 2 version that i've been building. Embarrased to say for how long. Done all the rear empennage and the two bottom wings. Still got the top wings and fuz to go. Really nice kit 'eh? When i did the strips i used Windex to soak the strips in and Titebond glue. The ammonia in the windex made the balsa strips be able to be bent into a 4inch circle! Too late for you perhaps , but mate grab a strip and give it a try. Will be watching this build for sure!
Cheers ,Leon.

tobba 03-21-2009 12:44 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
Thanks Leon. Yep great kit. Feels a little flimsy in a few places for me. I'm keen to build it to last for a while vs being super, super light. Awesome kit though and the parts fit is brilliant. Other articles I have read do say once the fuse is finished its solid as a rock. Will post a few more shots soon. Hope they get you enthused!

Cheers.

tobba 03-21-2009 02:04 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
1 Attachment(s)
A few fuse shots... excuse the mess. No time to build let alone clean.

awesome 03-21-2009 06:56 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
Craig , what do you think about running some carbon fibre with some of the fuz stringers? I was wondering how strong it would be vs just using the wood supplied , talking about the stringers from canopy back , lower. Also , have you built your upper wings yet? Trying to get my head around the built in anhedral of the upper wings and how the spruce strips that you build on are arranged. All i have really is the CD , the manual is all in german , tried google translator on a couple of pages but i reckon i'm better off asking here.
Cheers , Leon.

tobba 03-21-2009 01:01 PM

RE: Exclusiv Modellbau 50% Pitts S1
 
Leon, Funny you mention carbon stringers. I am planning to use 6mm carbon tube for the stringers on the rear upper deck. The skin is incredible thin, 1/64ish ply and I don't believe the 5mm square balsa stringers recommended are strong enough. I have had some pain testing fitting the 2 side stringers, they don't seem to fit that well and I have managed to break one at one of the former notch points just trying to test fit it. I was contemplating using 3mm carbon tube running the full length on the outside edge. of the stringer. This would give it good strength, be light and make a nice even platform for the covering to adhere to.

I haven't looked at the wings yet. Will probably start with the bottoms to make sure the balsa diecut surrounds on the fuse fit the wing properly being fitting them. I have had a look at the wing imagery on the CD and seen how the root end of the stringers seem to be raised when building which seemed a little strange. Will have a better look and come back to you. Have you seen the RC Universe challenger link at - some really good info:

http://www.rcuniverse.com/forum/m_38...llenger/tm.htm

Cheers.

awesome 03-21-2009 08:45 PM

RE: Exclusiv Modellbau 50% Pitts S1
 
Thanks for the link. Yep , already read that one , but thanks anyway. Also noticed in your pics that your stabs have phenolic tubes , mine has brass tube with piano wire pins.
Must be an upgrade or the Pitts may be different than the Challenger? Are you planning on making the stab incidence adjustable? Was thinking this might be the go with mine.
If you want i can post some pics of my build so far , but don't really want to butt in on your build thread.
Thanks Craig , Leon.

tobba 03-22-2009 01:21 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
Leon. Got for it, love to see you build shots. What do you think about the carbon ideas I mentioned?

I like the idea of an adjustable stab. I may look at machining up a aluminum housing that can be adjusted with a couple of cap scrwws from a hatch through the bottom.

awesome 03-22-2009 08:19 AM

RE: Exclusiv Modellbau 50% Pitts S1
 
No worries Craig , cheers for the thumbs up on the piccies. I'll get the camera out and take some shots of what i've done so far. Man , though i have to admit , i'm getting sick of wing building , probably why it's taking so long. Still got two top ones to go before i get onto the fuz. Have a 3w212 b4 i bought new from Model Design to power it , it's not the CS like yours just the plain jane model. Bought their headers and cans for it as well , wish i didn't. Crap header design and sounds like a sewing machine. Going to try to run 4 tuned pipes instead , should wake it up. Sounds cool idling with open exhausts though. I drag it out once in a while and start it up just to listen to it. Couldn't interest you in the cans and exhaust?:) Cans would be fine if had different design headers. Looks like we're on the same frequency on the carbon for the fuz stringers , great minds think alike , eh?:)
Cheers from OZ , Leon.


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