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Sep 30, 2014, 05:07 AM
No RTF flies like your own SB
mperaltaoz's Avatar
Thread OP
Build Log

The Beast (or kind of)


Update: it flies great!
Final version of the plans in Sketchup attached below.

The Beast Scratch Build (3 min 40 sec)


Hi All,

I'm building a Spirit of Pitts following some balsa plans I found in this thread.
Similar to that thread, I'm planning to modify the plane as I go (move top wing aft, change elevator) to make it look and hopefully fly like The Beast.
Of course the paint scheme will also be like The Beast

Build materials will be as usual... XPS foam, plywood and CF rods.
I've got the power plant already from another plane of mine, and I reckon it will pull this bird unlimited vertical (it was pulling my Gee Bee Z unlimited vertical before).

Here are the specs:
Wingspan 1100mm
Weight 1500 g AUW
Battery 4S 2200mAh
Motor Turnigy 790kv (715Watts)
Propeller 13x6

Construction method is my preferred one after many scratch builds:
- Solid wings cut with airfoil template and hot wire
- Skeleton fuselage with thin skins for complex/round areas

Photos below.
Last edited by mperaltaoz; Jan 08, 2015 at 06:49 AM.
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Sep 30, 2014, 05:58 AM
Registered User
Love the Pitts. Your build looks good so far.
You must have very fine grained XPS. Every time I try to cut the XPS I can get my hands on, it just doesn't work out.
Could you post a close-up of the XPS you use so I can see the grain?
I'd like to try it with CF tubes for strength (since it's so freakin' light, it might be worth the head-ache).
Sep 30, 2014, 07:59 AM
No RTF flies like your own SB
mperaltaoz's Avatar
Thread OP
I've got 2 types of XPS: green and yellowish

Both of the are quite dense, with the yellow one being denser and a bit heavier.

I have built other planes with the green XPS foam using ribs and skins method and they turned to be quite light (around 800g including paint, WBPU, LG and electronics).

I'm building this one with the yellow one and solid wings, so I'm expecting the weight to be around 1000g.

I took some pictures of the green foam below. The close ups for the yellow one you can see them in the previous post (wing profile).
Sep 30, 2014, 08:30 AM
Registered User
Quote:
Originally Posted by mperaltaoz
I've got 2 types of XPS: green and yellowish

Both of the are quite dense, with the yellow one being denser and a bit heavier.

I have built other planes with the green XPS foam using ribs and skins method and they turned to be quite light (around 800g including paint, WBPU, LG and electronics).

I'm building this one with the yellow one and solid wings, so I'm expecting the weight to be around 1000g.

I took some pictures of the green foam below. The close ups for the yellow one you can see them in the previous post (wing profile).
Thanks for the pics. Yeah my XPS is just not fine grained enough. I'll hunt around for some with the same density as yours.
Oct 20, 2014, 06:09 AM
No RTF flies like your own SB
mperaltaoz's Avatar
Thread OP
For the ones interested in this build... this is still work in progress.
I've been busy with the Gee Bee Z (repainting and finish), but I've resumed activities now.
I'm making some design decisions as I go, and I've modified the plans to move the top wing aft by 24mm.
Here are some close up pictures.
Oct 27, 2014, 09:07 PM
No RTF flies like your own SB
mperaltaoz's Avatar
Thread OP
The interwing struts proved more difficult than expected, but it think I've got them under control now.
I had to cut them shorter a couple of times as I stuffed up the template I printed from Sketchup.
Anyway, it all looks good now.
Oct 28, 2014, 05:58 AM
No RTF flies like your own SB
mperaltaoz's Avatar
Thread OP
Skins in progress
Nov 08, 2014, 06:52 PM
No RTF flies like your own SB
mperaltaoz's Avatar
Thread OP
Skins complete. Looking like a plane now
Nov 09, 2014, 01:41 PM
This is kid stuff.
Mazzepa1's Avatar
Beautiful work all around. The wings in particular, almost works of art.

Respect.
Nov 09, 2014, 03:02 PM
No RTF flies like your own SB
mperaltaoz's Avatar
Thread OP
Thank you.
Yeah I'm pretty happy with those wings...
I have been building hollow wings (ribs and skins) for a while but recently changed my approach to solid wings cut with profile templates.
Solid wings are a bit heavier but a lot more sturdy and easier to repair in the event of a mishap... And a lot quicker to build!
Nov 10, 2014, 05:00 AM
No RTF flies like your own SB
mperaltaoz's Avatar
Thread OP
Cowl complete. Preparing fuselage for paint job.
Nov 10, 2014, 06:11 AM
Registered User
Great build so far. Any possibility you'd share your sketchup plans ?
Nov 10, 2014, 07:20 AM
No RTF flies like your own SB
mperaltaoz's Avatar
Thread OP
Sure. They are still work in progress as I haven't had time to clean them up and remove the original balsa plans.
As a result, the file is 200MB+ and hence not possible to attach here.
However, you can access the WIP copy on this link: https://www.dropbox.com/s/jz18fvbnnf...Pitts.skp?dl=0

Note: I've modified the following things to make it closer to the Hangar 9 Beast:
- Moved top wing 24 mm aft (aligning tips with bottom wing)
- Shortened the cockpit
- Modified the horizontal stab/elevator
Nov 12, 2014, 10:36 AM
Registered User
limmacslim's Avatar
Subscribed! I normally build simple flat foamies & was nosing around looking for ideas for a full fuselage, your Pitts looks fantastic! Looking forward to seeing her fly .
Nov 12, 2014, 11:15 AM
Warbirds Lover
Dreamcatcher's Avatar
Hello !
Great design, i take a seat and watch the next steps with interest

cheers !


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