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Old Nov 19, 2012, 05:23 AM
ulpilotrmh
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USA, FL, Tavares
Joined Sep 2010
313 Posts
Anyway, the first two pics show the progress from yesterday. The last pic is of washers I punched out of the side of a milk bottle. They will go between the horizontal and vertical stabs. I have used this material in the past and it is very slipery stuff in low thrust/low rpm applications. Will probably only need 4, but made a bunch in case of loss.
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Old Nov 21, 2012, 10:53 AM
ulpilotrmh
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USA, FL, Tavares
Joined Sep 2010
313 Posts
Nothing done since the last post. I need 4/40 "T" nuts to put in the firewall for the motor mount. They're on order from Mcmaster Carr and may be in today's mail. Then I can epoxy the firewall to the fuse and start planking. I did get some planks cut out with the modified balsa stripper. Pics as soon as I get started on the planking.
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Old Dec 26, 2012, 07:51 AM
ulpilotrmh
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USA, FL, Tavares
Joined Sep 2010
313 Posts
Long time no post.

I have the left wing panel framed and sanded and noticed I've messed up again. The top sheeting ahead of the front spar is to be left off until the center section fairing is fitted in place. I'll have to carefully remove this sheeting, but will wait until I have the right wing framed.
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Old Jan 08, 2013, 08:30 AM
ulpilotrmh
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USA, FL, Tavares
Joined Sep 2010
313 Posts
While waiting for the epoxy and glue to cure on the wing center section I decided to replace the solid rudder with a built up one. I wasn't looking forward to sanding away half the rudder's thickness in order to taper it as shown on the plan. I decided on a laminated TE with a 1/4' square LE. The TE is made up of two 1/16" x 3/32" strips. the ribs are 3/32 thick and tapered from 1/4" AT THE le to 3/32" at the TE.

Russ
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Old Jan 08, 2013, 01:20 PM
ulpilotrmh
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USA, FL, Tavares
Joined Sep 2010
313 Posts
Here's today's output. The rudder is considerably lighter than the original would have been and is nicely tapered due to the way it was built. Now I need to design and cut out a control horn from fiberglas sheet.

Russ
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Old Jan 10, 2013, 07:37 AM
ulpilotrmh
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USA, FL, Tavares
Joined Sep 2010
313 Posts
The rudder, vertical and horizontal stab have been coated with thinned nitrate dope. I love the smell of nitrate dope in the morning, it smells like progress.

Covering will be Polyspan sealed with dope and I plan to use the red and white color scheme and pattern shown on the 1945 plans.

Russ
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Old Jan 10, 2013, 07:53 AM
ulpilotrmh
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USA, FL, Tavares
Joined Sep 2010
313 Posts
Oh, I discovered I can't use the hinges I planned to use because of the boom interfering with the placement of the hinges, I'll be using Blenderm surgical tape instead. This stuff is easy to apply, seems to remain flexible forever and stays put. Also I added cypress blocks in the rudder and full-flying horizontal stab as a place to attach standard nylon control horns.

Russ
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Old Jan 10, 2013, 09:51 AM
ulpilotrmh
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USA, FL, Tavares
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In researching how polyspan is to be applied, I'm told there is a difference in the texture of the two sides of the stuff. The "shiny" side is to be the upper surface of the part. I cannot detect a difference in the two sides of the rolled Polyspan I recieved. Does anyone know if the "shiny" side is on the outside of the roll, or toward the inside? Also does this stuff have a "Grain?" If so, does the grain run along the length of the Pollyspan or the width?

Russ
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Old Jan 12, 2013, 09:47 AM
ulpilotrmh
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USA, FL, Tavares
Joined Sep 2010
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Well, now I can supply answers to the questions in my last post, thanks to the guys at BMRJ Models. The surface of the polyspan that is to be the outer surface of the part to be covered is on the outside of the roll. The Polyspan from BMRJ Models does have a "Grain", and it runs along the length of the rolled Polyspan.

I love the way this stuff goes on. I followed the instructions found on BMRJ's webb site. I had to use all the techniques shown in the instructions but there were no difficulties. I think this stuff is now my favorite covering, especially for Old Timers.
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Old Jan 14, 2013, 04:59 AM
ulpilotrmh
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USA, FL, Tavares
Joined Sep 2010
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The flying stab is covered as well as the rudder. I had a self induced problem with the stab that I managed to fix, but failed to take any pics of the process.

When I had the right and left halves of the stab framed up I should have pinned them down to the board while installing the rods and tubes for the pivots. I must have been in too much of a hurry and epoxied each side separately, trusting that the holes in each of the four drilled ribs were in good alignment. But no, they were off a noticeable amount. I was afraid this might cause a bit of a roll problem in the trim of the plane.

How can I fix this, build a new stab, or try to fix the one I have? Long story short, I decided to see if I could fix what I have.

Since the stab was ready for covering, I had to remove the top and bottom sheeting and the center section ribs. One of the brass tubes is epoxied to the spar and it was impossible to remove it without wrecking the spar. I had saved the balsa sheet the spar came from and used a part of it so scarff in a new section. I made paper patterns from the ribs on the left stab and made two replacements for the left stab. I added the sheeting on the bottom of the stab and pinned both sides to the board aligned against a straight edge and epoxied new tubes to the ribs and spar. Replaced the sheeting on the top surface, sanded and all was good again.

Russ
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Old Jan 16, 2013, 11:08 AM
ulpilotrmh
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USA, FL, Tavares
Joined Sep 2010
313 Posts
Now I have a tricky problem to solve. According to the plan, the wing seat is carved or milled out of a slab of balsa and is to incorporate the dihedral, all well and good, except the under chamber is ignored. I didn't care for the idea of the wing resting only on the leading and trailing edges. I want the wing to bear all across the bottom of the centersection in the wing seat area.

I determined that the underchamber is 1/8" "deep" and cut two pieces of 1/8" balsa to match the outside contour of the seat. This will be carefully sanded down to a straight line between the leading and trailing edges using the light weight sanding block shown under the wing.
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Old Jan 16, 2013, 11:14 AM
ulpilotrmh
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USA, FL, Tavares
Joined Sep 2010
313 Posts
Now I have a tricky problem to solve. According to the plan the wing seat is carved or milled out of a slab of balsa and is to incorporate the dihedral, all well and good, except the under chamber is ignored. I didn't care for the idea of the wing resting only on the leading and trailing edges. I want the wing to bear all across the bottom.

I determined that the underchamber is 1/8" "deep" and cut two pieces of 1/8" balsa to match the outside contour of the seat. This will be carefully sanded down to the under surface of the centersection using the light weight sanding block shown under the wing.
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Old Jan 17, 2013, 10:02 AM
ulpilotrmh
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USA, FL, Tavares
Joined Sep 2010
313 Posts
Sanded the wing seat using the sanding block shown in the last post. I sprayed 3M Spray Adhesive on the pad and 100 grit paper. I placed wide painter's tape around the seat to protect the sheeting and had the seat sanded flat with the dihedral angle in just a few minutes. It's a pretty good fit to the wing and will be improved with silicone sealer later.
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Old Jan 19, 2013, 11:40 AM
ulpilotrmh
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USA, FL, Tavares
Joined Sep 2010
313 Posts
I've been thinking (I know, not necessarily a good thing) and have come to the conclusion that I cannot complete the wing fairing and blend the nose to the "Pod" to my satisfaction. What I'm gonna do is switch to a modified Thermic 70 fuse with the "Stick" type construction. I'll use the T72 wing and full flying Horizontal Stab that I have. This should be a piece of cake. I'll start a new build log as soon as I have a set of plans for the T70.

Russ
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