Replace AN470AD4-6 with bolt or screw?

[rv8ch]

Hi, I would like to replace 5 AN470AD4-6 rivets with appropriate screws or bolts. Would an AN525-832R10 screw be appropriate? Or do I need to bump up to an AN3 bolt? I appreciate your collective wisdom.

[Freemasm]

Unless the hole is reamed specifically for a close tolerance application, you'll loose a little joint strength even though the bolt is stronger in shear (and tension). Not knowing the design basis, there's always a little risk with such. A close tolerance application like a HI-LOK fastener would be a better solution than a regular MS fastener.

Let the dissenting opinions begin.

[airguy]

Why are you wanting to make the change?

[BobTurner]

Originally Posted by Freemasm

Unless the hole is reamed specifically for a close tolerance application, you'll loose a little joint strength even though the bolt is stronger in shear (and tension). Not knowing the design basis, there's always a little risk with such. A close tolerance application like a HI-LOK fastener would be a better solution than a regular MS fastener.

+1
If you're replacing 5 out of 10 (?) I'd run this by Vans'.

[rv8ch]

Originally Posted by airguy

Why are you wanting to make the change?

This will be the third time these parts have been installed - first during the initial build, second when I installed a trutrack-type servo, and now for the GRT servo - I predict that it might happen again, so I'd prefer to not keep drilling out these rivets.

[rocketman1988]

As that appears to be part of a flight control structure, contact with Van?s is recommended...

[j-red]

I'd suspect you're going to be fine from here on out. The footprint of all the modern servo's from Dynon, Garmin, GRT and even the newer trutrak is nearly identical from what I can tell. With this kind of standardization, I doubt you'd ever have to change the mount again.

[rv8ch]

Originally Posted by j-red

I'd suspect you're going to be fine from here on out. The footprint of all the modern servo's from Dynon, Garmin, GRT and even the newer trutrak is nearly identical from what I can tell. With this kind of standardization, I doubt you'd ever have to change the mount again.

You are probably right. I actually thought that when I installed the original trutrak, since they were the industry standard at that time.

I guess I'll go with rivets and keep the fingers crossed!

Thanks everyone for the advice and tips.

[Freemasm]

I assume you?ve already determined #5s won?t meet edge distance. If 4s won?t buck right in the existing holes, another benefit of HI-LOKS is you can get them one or two oversized (in 64ths, I think). Trying to keep your options open. Good luck.

[rv8ch]

Just to close this thread, I just stayed with the AN470AD4-6 rivets specified in the plans. Hopefully this one will last until my grandchildren change it for a flux capacitor powered, mind controlled AP pitch servo.