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TeamRV8A

Member
All,
Just looking for some advice or information on running a tap through the anchor nuts on the Elev Trim motor access panel. We have found the locking mechanism very tight and are destroying the soft cover screws.
I believe we need a National Fine Tap for these anchor nuts? Has any one had a similar problem, had what type of tap did you use.

Cheers for now

Mark Lees
TEAMRV8A
Downunder
 
Regular tap will work

Most of the nutplates on the RV are either 6-32 or 8-32. P/N will end in -06 or -08. The taps I use are regular Ace Aviation or Home Depot's Aviation Dept. Try to find taps with only two flutes instead of 3 or 4. In my 12 years experience as a machinist they hold up much better. I've tried to tap all nutplates that are going to be difficult to get to like at the edge of floor panels, etc. or any that are for attaching f'glass fairings. I'm concerned with cracking the part when I can't feel the screw seat with the excessive locking feature of the nutplates. Also, some of the fairings (especially the wheels) will be removed more often than others and I don't want to have to replace the screws every second or third time. Hope this helps.
 
TeamRV8A said:
All,
Just looking for some advice or information on running a tap through the anchor nuts on the Elev Trim motor access panel. We have found the locking mechanism very tight and are destroying the soft cover screws.
I believe we need a National Fine Tap for these anchor nuts? Has any one had a similar problem, had what type of tap did you use.

Cheers for now

Mark Lees
TEAMRV8A
Downunder
Click to expand...

If you tap the platenuts, you destroy the ability to lock the screw. You could run a cap screw ( this will make it easier to place and remove) through the platenut a couple of times. This will loosen up the thread a bit. Sometimes the platenuts are squeezed a little too much during manufacture.

Peter
RV9A fuse
 
I second the thought that you don't want to eliminate the self locking feature on something like the elevator trim mount, Your tap will destroy the lock feature.

Here's a better option that retains the self-locking capability but loosens the fit a bit. I run a screw through the anchor nut several time with a bit of boelube. This result in the actual screw going in and STAYING in. I use a discarded screw as my "reamer" and put in new hardware on the final assembly. When using anchor nuts in areas with limited accessability or those affixed to fiberglass, I do the prep runs on the work bench before I attach the nut.

I only tap an anchor nut when the following criteria are both satisfied:

a. The screw doesn't retain a critical item such as a flight control, in other words, does loss of the screw create a hazard either due to loss of the component or through FOD (must be NO);
b. Is the hardware accessable for visual inspection (must be YES).

Jekyll
 
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Anchor nut info

Thanks to all for the feedback.
I agree, we need to be careful not to reduce the effectiveness of the locking ability of the anchor nut. We will also use little Loctite to assist us in the security of the screws.
I did not know of the product Boelube. I currently work on the FA/18 and have never encountered Boelube. Will do a little research to see if have a supplier downunder.

Cheers

Mark
 
I'm not trying to be a wise guy here, but my experience has been that most screws strip because of the wrong size screw driver. Get a good set of Phillips and Reed&Prince screwdrivers and 1/2 your problems will probably go away. When I was fitting my trim servo, elongating the cutouts, etc etc, I must have put that in and out a couple of dozen times, and my screws look brand new.
 
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Boelube

Mark:

Boelube is great stuff. It can be found at Vans and Spruce. It's good for the anchor nut application and for dry lubbing bits for drilling steel amoung other applications. F-18 = Boeing (through some accuisitions), Boelube was developed by BIG B.

Jekyll
 
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