650 hrs
There are a couple of things I forgot to mention in previous entries. One is an item that was very handy in removing the coating that is on the chrome moly tubing. When I was stripping the coating off for painting I began by using acetone and a scotchbrite pad. The scotchbrite loaded up very quickly. I then found a fine 180 grit open mesh sanding medium. It looks like window screen with grit bonded to it. This worked great for the first pass taking the bulk of the coating off the tubing. As it loaded up the stripped off materal just fell out of the sanding cloth. The followup was with the scotchbrite. Acetone does help but it is very nasty stuff, it can go right through your skin. It is also extremely flammable. I found the open mesh cloth in rolls in the plumbing section of the local building supply store.
When fabricating the foot rests I saw that the prints spec a radius for the bend. To make this I ground the radius on a piece of steel and place dowel pins as stops in the steel strip so that the bend is at a consistent distance from the edge of the material. I placed the steel radius die and the aluminum blank in a large vise and proceeded to beat the crap out of the Aluminum blank with a rawhide faced, split head hammer until it was at a 90 degree angle. It was crude but effective method to bend the .090 Aluminum.
When making the control horns for the trim tabs I first bent them with a press brake. There was cracking on the backside of the bend. I only have 1 die set so controlling the radius is difficult. The horns are made from 6061-T6 aluminum. They required a radius that is 3 times the material thickness. Rather than using the heavy hammer technique I opted for the rubber die method to form the radius bend in the control horn.
Some time back I had a project that needed a complex shape on a sheet metal piece. I made up a holder for a 2x2x4 inch block of 90A durometer urethane rubber. This became the female die. It will form the metal to the male die without stretching it. For the trim tab control horn bend, the male die is simply a steel rod welded on edge. The correct size urethane block for this particular application would be about 3/4 inch but I used what I had and it worked just fine.
A good bracket and a bad one is pictured here. The cracking is plainly visible on the bracket on the right.
I used the same rubber die to form the straps for the strap hinges. There were holes drilled in the bend area so the material strength varied along the bend as well. With the urethane die the bend was at a constant radius. For the 180 degree bend I had to press the material on both sides and then the center of the bend. The die is only 4 inches long so it would not have been long enough to be used on the foot rests.
The canopy has arrived and it is sitting on the rug in the spare bedroom. I decided to go against the advice of everyone that I spoke with about the canopy and make a tip up rather than a slider. It will be easier, faster and less costly to make. I can always change it if I find I don't like it. Come to think of it, I have not seen a sliding canopy on an Extra or an MX2; I wonder why? At the price of those planes it can't be cost.
I spoke with Doug Dodge about a canopy. He was replacing a tip up one on a One Design for a customer with a slider. I became second in line to buy the old canopy, the first guy took it. Oh well, so much for that. He tells me he has used a Starlite canopy on the One Designs. He also mentioned Airplane Plastics in Tipp City OH as a source. Their phone number is 937-669-2677, they don't have a website. They also make a One Design canopy per print. I ordered the light smoke canopy and it is nice.
A couple of items mentioned as a reminder to myself and info for anyone else is the adhesive to bond the canopy to the aluminum should be 3M Scoch-Weld 2216. This is a 2 part flexible epoxy with a room temperature cure. The other thing is that it takes a special drill bit to properly drill through acrylic plastics. Craftics makes and sells these bits, their Pro Series Plasdrills. They have a 60 degree point and 0 degree rake. They are not recommended for metal or wood. Metal drill bits will not work as they are made to bite into the metal as they are pushed into it. If they are used on acrylics they will chip and cause other damage to the plastic.
The wing spar was set flat and level on a pair of adjustable stands. A steel wire was stretched above it on center and plumbobs were hung from the wire. This gave me a vertical and center visual reference. I then attached the end ribs to the spar with epoxy and fine wire staples.
After they were installed perpendicular to the spar and the epoxy had set for a day I proceeded to install the rear spars and long ribs. You can see the plumbob above the center of the rear spar junction.
The rear spars were tied together in the center to eliminate any twist in the wing during assembly. Temporary diagonal bracing was also added to hold the ribs square to the main spar during assembly.
When fabricating the foot rests I saw that the prints spec a radius for the bend. To make this I ground the radius on a piece of steel and place dowel pins as stops in the steel strip so that the bend is at a consistent distance from the edge of the material. I placed the steel radius die and the aluminum blank in a large vise and proceeded to beat the crap out of the Aluminum blank with a rawhide faced, split head hammer until it was at a 90 degree angle. It was crude but effective method to bend the .090 Aluminum.
When making the control horns for the trim tabs I first bent them with a press brake. There was cracking on the backside of the bend. I only have 1 die set so controlling the radius is difficult. The horns are made from 6061-T6 aluminum. They required a radius that is 3 times the material thickness. Rather than using the heavy hammer technique I opted for the rubber die method to form the radius bend in the control horn.
Some time back I had a project that needed a complex shape on a sheet metal piece. I made up a holder for a 2x2x4 inch block of 90A durometer urethane rubber. This became the female die. It will form the metal to the male die without stretching it. For the trim tab control horn bend, the male die is simply a steel rod welded on edge. The correct size urethane block for this particular application would be about 3/4 inch but I used what I had and it worked just fine.
A good bracket and a bad one is pictured here. The cracking is plainly visible on the bracket on the right.
I used the same rubber die to form the straps for the strap hinges. There were holes drilled in the bend area so the material strength varied along the bend as well. With the urethane die the bend was at a constant radius. For the 180 degree bend I had to press the material on both sides and then the center of the bend. The die is only 4 inches long so it would not have been long enough to be used on the foot rests.
The canopy has arrived and it is sitting on the rug in the spare bedroom. I decided to go against the advice of everyone that I spoke with about the canopy and make a tip up rather than a slider. It will be easier, faster and less costly to make. I can always change it if I find I don't like it. Come to think of it, I have not seen a sliding canopy on an Extra or an MX2; I wonder why? At the price of those planes it can't be cost.
I spoke with Doug Dodge about a canopy. He was replacing a tip up one on a One Design for a customer with a slider. I became second in line to buy the old canopy, the first guy took it. Oh well, so much for that. He tells me he has used a Starlite canopy on the One Designs. He also mentioned Airplane Plastics in Tipp City OH as a source. Their phone number is 937-669-2677, they don't have a website. They also make a One Design canopy per print. I ordered the light smoke canopy and it is nice.
A couple of items mentioned as a reminder to myself and info for anyone else is the adhesive to bond the canopy to the aluminum should be 3M Scoch-Weld 2216. This is a 2 part flexible epoxy with a room temperature cure. The other thing is that it takes a special drill bit to properly drill through acrylic plastics. Craftics makes and sells these bits, their Pro Series Plasdrills. They have a 60 degree point and 0 degree rake. They are not recommended for metal or wood. Metal drill bits will not work as they are made to bite into the metal as they are pushed into it. If they are used on acrylics they will chip and cause other damage to the plastic.
The wing spar was set flat and level on a pair of adjustable stands. A steel wire was stretched above it on center and plumbobs were hung from the wire. This gave me a vertical and center visual reference. I then attached the end ribs to the spar with epoxy and fine wire staples.
After they were installed perpendicular to the spar and the epoxy had set for a day I proceeded to install the rear spars and long ribs. You can see the plumbob above the center of the rear spar junction.
The rear spars were tied together in the center to eliminate any twist in the wing during assembly. Temporary diagonal bracing was also added to hold the ribs square to the main spar during assembly.
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