Eccentric cam wing assembly tools

Steve Bralla used to make and sell tools used to help align the wing spar pin bushings during assembly. He contacted me recently and said he had lost access to the machine shop. He graciously offered me the opportunity to take over the product line, and I am now in production. I will add them to my website shortly (www.mmfabrication.com) If you need one, please contact me through the website.

And a big "Thank You" to Steve!

On Sunday, October 30, 2016 at 9:24:13 AM UTC-7, wrote:
Steve Bralla used to make and sell tools used to help align the wing spar pin bushings during assembly. He contacted me recently and said he had lost access to the machine shop. He graciously offered me the opportunity to take over the product line, and I am now in production. I will add them to my website shortly (www.mmfabrication.com) If you need one, please contact me through the website.

And a big "Thank You" to Steve!

Mark, In 2002, I bought one from Spindleburger that shipped with my trailer.. I made my own "improved" version and sold the one I bought.

Mine was made of black Delrin (as is the original) with the reinforcement a pressed in stainless steel pin. I made the outer large diameter a bit longer and have that cross drilled at 0 - 60 - 120 degrees for 6 handle hole options total, though the handle is rarely used. The 3 cross drilled holes provide plenty of purchase for turning to assist initial pin alignment.

On the face of the handle portion, in line with the eccentric end of the tool, I drilled a small dimple, filled with white paint, it shows where the eccentric is when the tool is fully inserted. This proved to be invaluable when using the tool to show which way the wing needs to be moved.

best,

bumper

This is a fun thread to read. "How many engineers does it take to ..."?? I say that with many smiley-face emoticons.

FWIW, the simple taper pin that my friend made works 10 times out of 10 with my -29. It's just a delrin pin with a solid handle at 90 degrees to the major axis of the pin. If the wing bushing are misaligned by a few mm, the pin pulls the wings together. If they are misaligned by more than that, it's time to make sure a) the flap handle was in -2 or so and b) the stick was more or less neutral and c) the divebrake handle was at the forward 1/4 or so of travel.

P3

Steve's tool is a bit undersized on the 20 & 27. No problem on the
20 because there's a reasonable taper at the end of the pins –
not so on the 27 where there's only a rounded corner with a tight
radius; so you have to be really fussy lining up to get the first pin
in.

I would love a pin that's ground off at the end so there's only a
few degrees of arc. Then you could rotate to find if the next hole
is high or low. Fingers are not straight enough.

As for marks, I filed a flat spot where the cylinders line up, and a
notch at the maximum difference.

I find that feel works better than vision on a promising soaring
day because my eyes don't adapt quickly to under the turtledeck
when the sun's out.

Bumper- Thanks for the tips. I think the reinforcing pin is a good idea on the pins with a small eccentric. The witness mark on the face is also something I will consider incorporating.

Now that I am going into production, can RAS readers help me by sending me the diameter of their main spar pins? I'd like to set up a glider database so I can anticipate the demand.

Thanks. I can be emailed at: info (at) mmfabrication (dot) com

On Sunday, October 30, 2016 at 9:24:13 AM UTC-7, wrote:
Steve Bralla used to make and sell tools used to help align the wing spar pin bushings during assembly. He contacted me recently and said he had lost access to the machine shop. He graciously offered me the opportunity to take over the product line, and I am now in production. I will add them to my website shortly (www.mmfabrication.com) If you need one, please contact me through the website.

And a big "Thank You" to Steve!

Mark,
I've been using Steve's alignment tool for several years now on my ASW 20. I love it however I'd like to suggest an improvement. I suggest installing a large Hex head (use a standard bolt/wrench size) on the end. Instead of using the sliding handle/pin which sometimes is awkward, the Hex end would allow the use of a ratcheting wrench. Easier to turn and more leverage!
Hope that helps,
Dan Rihn

Dan- The only problem with that is the bolthead would try to unscrew if turned counterclockwise. Schempp-Hirth provided a rigging tool with the Arcus that has an allen head bolt inset in the face of the tool and we ran into that issue.

If you only turn it clockwise, it isn't a problem. I might incorporate that idea if people request it.

On Monday, October 31, 2016 at 8:57:02 AM UTC-7, wrote:
Dan- The only problem with that is the bolthead would try to unscrew if turned counterclockwise. Schempp-Hirth provided a rigging tool with the Arcus that has an allen head bolt inset in the face of the tool and we ran into that issue.

If you only turn it clockwise, it isn't a problem. I might incorporate that idea if people request it.

Sorry, I should have been more clear, I didn't mean to use a threaded bolt per say. I agree it would have to be a "solid" installation that could be turned either way and not unscrew.
It would be a nice option. It's a great tool.
Good luck,
Dan

glue the bolt into the threads.

On Monday, October 31, 2016 at 10:41:14 AM UTC-7, Jonathan St. Cloud wrote:
glue the bolt into the threads.

Should it take that much effort to require a ratchet?
For a Schleicher, the hex key used for the tail works in the holes of the Bralla/MM or Cobra wing alignment tools. Sometimes turning the tool by hand is sufficient.
The dump handle should be in the closed position. From experience, ASW27/G29 is more difficult with the valve handle in the open position. Using excess force with a Schempp dump valve misalignment may end in tears.
Jim