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-   -   Sheber Pitts S1S build (https://www.rcuniverse.com/forum/scratch-building-aircraft-design-3d-cad-174/11219854-sheber-pitts-s1s-build.html)

SplinteredProp 09-06-2012 12:30 PM

Sheber Pitts S1S build
 
1 Attachment(s)
Greetings,

New to the board, and would like to document this build here. If anyone is interested, they are welcome to follow along.

I just got my hands on a set of Andy Sheber 1/3 Pitts S1S plans, so the build is in it's infancy.

So far, I've only made a copy of the plans, cut up the copy to useable sizes, and have made a material list.

This will not be a fast build, since weekends are the only time I can dedicate to building.

Since it is my intention to post a pic with every post (except if answering a question), I will start off with a pic of the plans.

<br type="_moz" />

john josey 09-06-2012 12:50 PM

RE: Sheber Pitts S1S build
 
Hi There,

I built a 1/3 s1s from the toni clark kit a couple of years ago so i'm definatly interested in your build !

                   cheers
                          john

smithcreek 09-06-2012 06:40 PM

RE: Sheber Pitts S1S build
 
Looking forward to this.

SplinteredProp 09-09-2012 06:19 AM

RE: Sheber Pitts S1S build
 
1 Attachment(s)
This plan requires various elements to be laminated to curved shapes, the most complexbeing the horiz stab/elevator (hs/e).

SinceI've never attempted thismethod of construction before, this seemed like the logical place to start.

Pic 1: The plan.

Pic 2: Itracedthe inside line of the perimeter of the hs/e, cut out the pattern, and glued it to doubled up pieces of MDF, which Iscrewed together.


SplinteredProp 09-09-2012 06:21 AM

RE: Sheber Pitts S1S build
 
1 Attachment(s)
<span lang="EN">

Pic 1: The pattern/template after being cut with a band saw and final shaped with a bench belt/disc sander.

Pic 2: I drilled 1" dia holes through the template while they were still screwed together - these will provide places for clamping. I then seperated the 2 template halves, placed packaging tape around the perimeter and screwed then to my workbench.</p></span>

SplinteredProp 09-09-2012 06:28 AM

RE: Sheber Pitts S1S build
 
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I needed a few balsa strips, so Ifashioned a bench mounted balsa stripper.

The plan calls for a final thickness of 5/16, but Icut these to 7/16 to allow me to sand out imperfections and uneven strips.

SplinteredProp 09-09-2012 06:38 AM

RE: Sheber Pitts S1S build
 
1 Attachment(s)
Isoaked the balsa strips for about an hour, then placed them, without glue, around the template. Iwanted to pre-shape the laminate strips before gluing. Ithought this would make the gluing process easier. That also explains the lack of wax paper under the template in the first pic.

After the laminate pieces dried, Iremoved them from the template, placed wax paper under the template, and began gluing the layers together.

Iglued a single layer at a time, allowing approx 30 minutes between layers, for a total of 6 layers, and let dry overnight.

The finished piece ended up being between 13/32 and 7/16 thick, allowing me enough material to sand to a finished 3/8 width.

Overall, I'm pleased with the finished result, considering Ihave never attempted this construction method before.

That's it for this weekend - Today is going to be spent watching football.


SplinteredProp 09-15-2012 03:50 PM

RE: Sheber Pitts S1S build
 
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OK, back to the shop...

The first thing Idid was to cut the HStab TE &amp; Elev LE to the correct size, mark the hinge locations,add 5/16x3/8 backing to the hinge locations, drill them both at the same time on the drill press. Ithen inserted dowels in 4 of the 8 hinge holes to keep everything aligned. (Pic 1)

My shop helper (Pic 2)

acerc 09-15-2012 06:34 PM

RE: Sheber Pitts S1S build
 
I have the plans, cowl, pants, and canopy. Plan to start after the first of the year. So I am subscribed and learnin.

SplinteredProp 09-16-2012 05:08 AM

RE: Sheber Pitts S1S build
 
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Ididn't like how little material there was for the hinges to grab ontoin the elevator, so Iadded more balsa. (Pic 1)

The almost finished stab/elev (pic 2)


SplinteredProp 09-16-2012 05:10 AM

RE: Sheber Pitts S1S build
 
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Rather than use block balsa in areas that require addidtional strength, Imade 3-ply balsa pywood...

SplinteredProp 09-23-2012 06:12 AM

RE: Sheber Pitts S1S build
 
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I cut the Hstab/elev gussets out of 1/8" plywood on the scroll saw &amp;sanded to fit (pic 1)

The finishedH stab/elev (pic 2)


SplinteredProp 09-23-2012 06:22 AM

RE: Sheber Pitts S1S build
 
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I dislike sanding the edges of control surfaces since I feel as though I have little control - especially on this H stab/elev with everything being curved.

So I figured a shaping tool of some kind was needed and made on out of a piece of 1/2" PVC &amp; some self-adhesive sandpaper.


SplinteredProp 09-23-2012 06:23 AM

RE: Sheber Pitts S1S build
 
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The finished result after using the PVC sander &amp; finishing with some 220 grit.

SplinteredProp 09-23-2012 06:26 AM

RE: Sheber Pitts S1S build
 
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Ithen cut the elevator away from the H stab, and rounded the elev LE the same way Idid the other edges.

Iwant to minimize the gap between the elevator &amp; H stab, so in order to do that, Ineeded to make the TE of the H stab concave.

Another tool was needed, and this time a pencil &amp; piece of sticky sandpaper was used.

SplinteredProp 09-23-2012 06:27 AM

RE: Sheber Pitts S1S build
 
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The finished result.

SplinteredProp 09-23-2012 06:33 AM

RE: Sheber Pitts S1S build
 
Iwould love to hinge this thing before covering, but Iam unsure how Iwould do that....any tips would be greatly appreciated...

acerc 10-09-2012 10:51 AM

RE: Sheber Pitts S1S build
 
http://www3.towerhobbies.com/cgi-bin...LXES25&amp;P=7   Might be helpfull

SplinteredProp 10-11-2012 06:49 AM

RE: Sheber Pitts S1S build
 
1 Attachment(s)
Well, after a shop disaster which resulted in the destruction of the stab &amp; elevator, I had to start from scratch &amp; rebuild.

I took this opportunity to make some changes to the stab/elev. In my opinion they are improvements - things that I thought of after building the first stab/elev.

Pic 1 shows the new stab/elev.

Pic 2 shows 1/16" plywood inlays at the points where the flying wires will be attached. These should make a more stable area of attachement.

Pic 3 shows how I reinforced the leading edge of the stab with plywood gussets. I figured this couldn't hurt since this is one of the areas where the airplane is held during engine run-ups.

I also doubled up the balsa on the trailing edge of the stab &amp; leading edge of the elevators to provide strength &amp; a better gluing rea for the hinges.<br type="_moz" />

R/C Art 10-13-2012 06:28 PM

RE: Sheber Pitts S1S build
 


ORIGINAL: acerc

I have the plans, cowl, pants, and canopy. Plan to start after the first of the year. So I am subscribed and learnin.
I also have the same items but don't know when I will ever get to the actual build. I am subscribed, too.

acerc 10-14-2012 05:21 AM

RE: Sheber Pitts S1S build
 
http://www3.towerhobbies.com/cgi-bin...LXES25&amp;P=7

SP did you give the above link a look in regard's to the hinging?

R/C Art 10-14-2012 05:50 AM

RE: Sheber Pitts S1S build
 


ORIGINAL: SplinteredProp

<span lang=''EN''>

Pic 1: The pattern/template after being cut with a band saw and final shaped with a bench belt/disc sander.

Pic 2: I drilled 1'' dia holes through the template while they were still screwed together - these will provide places for clamping. I then seperated the 2 template halves, placed packaging tape around the perimeter and screwed then to my workbench.</p></span>
I have laminated outlines on several projects over the years but never thought about drilling holes around the perimeter and using clamps. Sheer GENIUS! I will use this technique in the future for sure. (I have sent you a PM)

SplinteredProp 10-15-2012 02:12 AM

RE: Sheber Pitts S1S build
 


ORIGINAL: acerc

http://www3.towerhobbies.com/cgi-bin...LXES25&amp;P=7

SP did you give the above link a look in regard's to the hinging?

Yes Idid, thanks for the link. The hinge pockets are worth considering, but I'm not sure I'm going to go that route.


SplinteredProp 10-15-2012 02:14 AM

RE: Sheber Pitts S1S build
 


ORIGINAL: R/C Art

I have laminated outlines on several projects over the years but never thought about drilling holes around the perimeter and using clamps. Sheer GENIUS! I will use this technique in the future for sure. (I have sent you a PM)
Ican't take credit for being a genius. I've seen that method on this site and copied it. But it is a forehead-slapping type of an idea...

SplinteredProp 10-15-2012 06:38 AM

RE: Sheber Pitts S1S build
 
1 Attachment(s)
Well, didn't get too much done this weekend, as I chose to spend a lot of time flying instead

I did work on the upper wing ribs, and in studying the plans, I really didn't like the spar arrangement as shown. In Pic 1, you can see where the main spars (1) are shown as 1/4" x 1/4" balsa, and not located at the thickest part of the rib.

I chose to add 3/8" x 1/4" basswood main spars as shown on my rib template in Pic 2 (1). A also decided to use 2 1/4" x 1/4" TE spars in lieu of the 1/4" x 1/2" spar drawn on the detail (2). I wasn't confident that I could cut accurate rectangular holes in the ribs.

I spray-glued the modified detail onto 1/8" plywood, and cut on the bandsaw. I then glued sandpaper onto the backside of the template to prevent it from moving while cutting the ribs.<br type="_moz" />


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