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Repairs, Upgrades and things to look for.

The Smithsonian National Air and Space Museum credits the Laser 200 for bringing about a new generation of aerobatic aircraft
Guicensoni
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Re: Repairs, Upgrades and things to look for.

Post by Guicensoni » Wed Oct 26, 2016 7:30 pm

Weight 995lbs, my ailerons are heavy due to the teflon terminals and hinges, thinking about made it of carbon with a carbon spar insted the torque tube... Some idea to share?
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davevon
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Re: Repairs, Upgrades and things to look for.

Post by davevon » Wed Oct 26, 2016 8:08 pm

Your Laser is looking good!

I recently finished going through my torque tube ailerons and removing any potential play and flexibility. I replaced all the spherical rod ends with ball bearing spherical rods ends, all the AN hardware was replaced with NAS bolts also eliminating the castle nuts and cotter pins, I welded a gusset to the aileron belcranks, I shimmed the aileron hinges removing any slop in the hinges and I bonded a carbon tube to the aileron torque drive tube. Definitely made a difference, there is no play in my aileron system now and much less flex. I also rebalanced the ailerons so without the spades or spade arms factored in they are 100% balanced, I had to remove aileron tip weight. You definitely don't want excess weight in the aileron mass balances, it can lead to wing flutter...

I've got the next generation spades on with extra weight to bring them up to the previous spade weight. Still working on reducing the mass in the spades to reduce inertia in the ailerons...

Dave
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The new spade with the extra weight.
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Because of the castle nuts many of the bolts were not tight enough to lock the rod ends in place so they turned on the bolts.
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Weight removed from aileron tip weight.
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Carbon tube on aileron torque drive tube.
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Belcrank gusset with bearing inner race spacer
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Holtzy822
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Re: Repairs, Upgrades and things to look for.

Post by Holtzy822 » Mon Nov 14, 2016 1:51 pm

Quick question, does anyone know if the new plans from york include pushrod ailerons? Hoping to start my laser build before New Years

davevon
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Re: Repairs, Upgrades and things to look for.

Post by davevon » Mon Nov 14, 2016 3:02 pm

There is talk of a new Laser wing from Devin so you may want to hold off on starting the wing :-)

Dave

Holtzy822
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Re: Repairs, Upgrades and things to look for.

Post by Holtzy822 » Mon Nov 14, 2016 4:54 pm

I think it's a composite wing though, I don't know if I trust a early composite wing, think I'm going to stick with the wood wing

davevon
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Re: Repairs, Upgrades and things to look for.

Post by davevon » Mon Nov 14, 2016 6:18 pm

If I were looking at building a wing there's a few things I would do different from my current wing.

• Box spar with carbon caps, lighter, stronger and easier to get the wood.
• Double the nose ribs.
• Minimum 5/8” rib to spar gusset blocks.
• Push rod ailerons.
• 25-28% Displaced aileron hinges. Super Stinker style.
• Long ailerons, I would go another bay longer than my 96” ailerons.
• Constant chord ailerons.
• Narrow hinges with a captured bearing at the root of the aileron to the wing. Maybe 4 hinges per aileron.
• No aileron tip balance weight.
• Fuel in the wing.

If the stock wing is flown hard the nose ribs have a tendency to break loose from the spar.

The ailerons are usually the weak link in a Laser’s performance and feel. The new style ailerons would be lighter in feel and inertia with a higher roll rate and Vne.

I’ve got belly fuel drop tanks, fuel in the wing would make it so much easier to go to distant contests.

All depends on what the goal is :-)

Dave

Guicensoni
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Re: Repairs, Upgrades and things to look for.

Post by Guicensoni » Tue Nov 15, 2016 8:42 pm

Finally flew!!!! Today was the day!!! Al worked perfectly and the plane is great. Only issue was a right roll tendency hands off, no spades yet, with hands on ailerons centered it flyes straight, but when I leave the controit rolls right... any tips instead ailerons adjustments?

davevon
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Re: Repairs, Upgrades and things to look for.

Post by davevon » Tue Nov 15, 2016 10:52 pm

Congratulations!

What kind of ailerons do you have and how are they balanced?

I ask because of possible flutter issues...

How far out of trim is it? Hands off how fast does it roll? How much stick pressure does it take to hold it straight?

I've got mine pretty close
https://youtu.be/Axewnw5BSNU
Dave

moderator edit: embeded video with the Image button

Guicensoni
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Re: Repairs, Upgrades and things to look for.

Post by Guicensoni » Wed Nov 16, 2016 2:07 pm

It requires just a small, or none pressure to de opposite side, just hold it on the middle. Hands off it rolls like 30 degrees per second. My ailerons are balanced with the spades on it, but i flew it without spades. The aileron is 88 inches longer torque tube style.

davevon
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Re: Repairs, Upgrades and things to look for.

Post by davevon » Wed Nov 16, 2016 3:22 pm

According to the Tolve report tip balanced alone ailerons may flutter as low as 160 mph! That's why he came up with the really heavy spade balance. Remember flutter is based on TAS not IAS.

There's where I'm at with my airplane, I want to lower the spade weight as low as possible and maintain a good flutter safety margin. I have my doubts about the results from the Tolve report. To duplicate his test would cost about $30,000! I'm looking at other options to ground test before trying it in the air.

I would try trimming your ailerons with your spades. Sounds like you might need a thin washer difference from side to side.

Dave

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