Thorp Air Command - T18.net

Go with new nut plates . At least you know what you are dealing with . You could probably replace them all in less than an hour ? BOOM ! The spinning fan will like it !

RB

yep, I think so too. I appreciate all the input.

Wow,nice looking Spinner install.........!!!!! Dan

I can't take credit for it. Frank built it for me. Once I told him I was gonna use a Saber prop extension, Frank and Saber ( I cant recall the guys name at Saber) called each other and they worked out the spacing details. Then one day spinner bulkheads, prop extension, and a painted spinner with all the hardware arrived in the mail. It was a bolt on application. It was really nice.

Ryan: Not to throw a curve at you ~ you may have:
1. received copy cat / counter fit anchor nuts/ screws.
2. or received poorly inspected (quality assurance / poorly manufactured) parts.
Just to point out ~ copy cat / counter fit parts can be receive from reputable aircraft supply companies. Huge aircraft industry issue.
http://www.almanet.org/code/index.htm

3-4 years ago this was a big problem in the RCAF supply system affecting CC-130 Hercules and CH-146 Griffon Helicopter aircraft systems and sub systems. Traceability documentation from manufacture to installation is now required ~ even at hardware level. The Griffon fleet (Bell 412) DND/ RCAF bought all hardware and parts directly from the OEM. Still non-standard hardware, fittings, couplings and other non-standard parts issued for use / or where originally installed by the OEM.

Nothing surprises me any more with aircraft hardware quality,... fit, form, function,...having seen examples of counter fit parts.
When you said all anchor nut plates failed raised this thought. However it is more likely there was poor QA, poor sample testing for the batch of anchor nuts/ screws you have.

General rules with self locking nuts / anchor nuts:
1. Never chase the treads of a lock nut / anchor nut with a tap to aid bolt/ screw installation. (defeats the locking feature)
2. Self-Locking nuts (with fiber inserts) should be used one time and then replaced.
3. Self locking nuts / anchor nuts should have a run on torque some times called (tare torque, friction torque, drag friction torque or prevailing torque).
A certain amount of torque goes into overcoming the friction of the self-locking feature, with out this friction you do not have a self locking nut.
4. If you can turn by hand a bolt or a screw and it bottoms out in a self locking nut application the self locking nut is not serviceable and needs to be replaced.

_________________
Victor J Thompson
C-GIRQ
In memory of Dad

Victor, that's certainly something to think about from now on. I recall being so happy the way that spinner just magically fit to the plane without me having to do any work (other than screw it on), that Im sure I didn't recognize the nutplates weren't locking the screws like they were supposed to. I should have been more mentally involved during the installation. Lesson learned.