Torquing the gear mount bolts
 

I've been using a bicycle beam-type torque wrench, but it's quite impossible to get it between the center section bulkheads to torque the nuts for the landing gear mounts. (page 29-21)

My pal Google led me to this page http://www.myrv10.com/tips/generaltips.html with a great tip on making a torque wrench extension, though the link for the math is dead. (Another request of my pal, and I had my mathematical solution.)

But my "extension" is too short to get to the lower bolts. Heck, I can't even figure how to get a wrench on them, much less torque them.

Thanks for your suggestions.

Jeff

I use click type torque wrenches and I don't recall those nuts being difficult to torque and maybe that's why--I did not use an extension analogous to a long crows foot. If I used anything special it most likely would have been an extension bar like these:

https://craftsman-brand-production.s...12.?1488001225

However, while it is possible I might have used a regular crows foot, I certainly did not fabricate an extension like the ones you are referring to.

Todd,

Maybe I'm not making myself very clear. The gap between the center sections is less than 2 inches, and it's approx. 8 inches from the top of the center sections down to the lower row of nuts.

How does one torque a nut in such a relatively deep and narrow gap?

Sometimes you have to apply torque to the bolt head vs the nut. I'm not an engineer but IMO in this application it's OK to do it that way. If you still prefer to torque the nut, you can use the German method of "Gutentiteenuf". Torquing an AN3 bolt is actually pretty easy to do by feel but I can totally understand that doing it that way might not give you peace of mind, in which case you just have to fab up an extension and do the math to arrive at the proper torque value for the wrench.

Hi Jeff,

I have the CDI wrench from Cleaveland and it just fit over the nuts down in the spar:



Assuming you don't want to purchase another wrench just to fit, as Todd said, sometimes you just have to torque the bolt. I may be misreading your statement above, but if you can't get a wrench on the nut (in order to torque the bolt) how did you even get the nut started? Now I'm a skinny guy, but I remember cramming my (bloody) hands down there as far as I could more times than I could count. Who didn't love section 29!:D

My Craftsman click wrench with a short socket did not want to fit over the bolt heads. A set of cheap sockets I keep in my truck for emergencies provided a socket that was just short enough but I carefully ground about another 1/8" to make it easier to get over the nut. When the nut was hand tight, I pushed it flat to the spar to get the socket over it and then pushed the bolt back before tightening, though I wasn't really worried about 'drawing' the bolt into position. I did worry a little bit that grinding might have removed the temper of the socket but there's so little torque on these nuts it really wasn't a problem.

torque
 

I purchased two different CDI wrenches on amazon. Work great.

Be aware that if you torque the bolt instead of the nut, the final torque value will not be what is set on the wrench due to the drag incurred by the bolt rotating in the hole. The same is true when doing nylon nuts. To get an accurate torque you need to compensate for the resistance of the nylon in the nut...

As for AN3 bolts, it is quite easy to over torque them, 20-25 in-lb is not very much...

I sometimes take advantage of the fact that if your "extension" can be maneuvered to be 90?, no math is necessary.

Shown here as an illustration, though those prop clamp bolts are easily accessible with a normal socket.




A spring scale and a box end wrench can also work, though if you can't on it pull at 12" (for ft lbs) some math is involved.

:D

I'm NOT a skinny guy and couldn't come close to getting a nut on those bolts. Fortunately, my wife has small hands and "delicate" arms. (I dare not call them skinny.:rolleyes:)

A buddy of mine is a car guy and has a garage full of tools. I was able to borrow from him and ended up torquing the bolt instead of the nut. I'm guessing that's the reason (or one reason) for having a washer under the bolt head on the bottom row but not the top.

Thanks!

P.S.
 

Thanks for all of the replies. Got 'em torqued today.

The air in the garage MAY have been a little blue. :p

Tomorrow we'll rivet the 1088 Fwd Fuselage Ribs and call section 29 complete...FINALLY!