Drive screw size?

[Kelpro999]

Just wondering if anyone has  dimensions or part number for these drive screws? Causing a preservative or oil bleeding problem during powder coating. It started during a hydrogen baking cycle. Some on hand could complete the gear refinish process sooner. Thanks 

Edited August 7, 2023 by Kelpro999

[RoundTwo]

45 minutes ago, Kelpro999 said:

Just wondering if anyone has  dimensions or part number for these drive screws? Causing a preservative or oil bleeding problem during powder coating. It started during a hydrogen baking cycle. Some on hand could complete the gear refinish process sooner. Thanks 

The part should be available to find in the IPC.

[RLCarter]

Those probably aren’t available, they plug holes used either during the welding process and/or if they coated the inside of the tubing with linseed oil

[PT20J]

7 minutes ago, RLCarter said:

Those probably aren’t available, they plug holes used either during the welding process and/or if they coated the inside of the tubing with linseed oil

Agree. They probably only show up on the manufacturing drawings and BOM. I’d email  Mooney. 

[Kelpro999]

51 minutes ago, RoundTwo said:

The part should be available to find in the IPC.

Common part I was just wondering if someone had already been there done that thing, I’m feeling lazy 

[A64Pilot]

Other aircraft have used pull rivets for this.

OH-58 which is a Bell 206 did in its engine mount, they were Cherry max rivets. On the Thrush fuselage we used small hex socket plugs and used fuel tank sealer in the threads to make sure they didn’t leak.

If you find the correct drive screws I’d still put a drop of fuel tank sealer on it, stuff works really well, can even keep fuel from leaking  

 

[A64Pilot]

If they are for linseed oil, why are there two of them? You only need one to put oil in and drain it out.

[Kelpro999]

15 hours ago, A64Pilot said:

If they are for linseed oil, why are there two of them? You only need one to put oil in and drain it out.

Good question, it’s possible they have a few uses like fixture positioning during build,  weld venting, back gassing, rapid fill/drain phosphate dipping before finishing, preservative application. IDK but today I was able to powder coat by placing the leaking ones  “up” during preheat so they weren’t too much trouble after cleaning the original seeping. Whatever’s in there is staying in there. Still have a few sizes coming from Spruce but won’t need them at this time.

[Fly Boomer]

49 minutes ago, Kelpro999 said:

Good question, it’s possible they have a few uses like fixture positioning during build,  weld venting, back gassing, rapid fill/drain phosphate dipping before finishing, preservative application. IDK but today I was able to powder coat by placing the leaking ones  “up” during preheat so they weren’t too much trouble after cleaning the original seeping. Whatever’s in there is staying in there. Still have a few sizes coming from Spruce but won’t need them at this time.

What makes it a "drive" screw?  What's the difference between a "drive" screw and a regular screw?

[N201MKTurbo]

15 minutes ago, Fly Boomer said:

What makes it a "drive" screw?  What's the difference between a "drive" screw and a regular screw?

Drive screws are put in with a hammer. They are just a common aluminum rivet with knurled shafts. Aside from plugging the tubes, they are used to hold the data plates on out engines.

[Fly Boomer]

17 minutes ago, N201MKTurbo said:

Drive screws are put in with a hammer. They are just a common aluminum rivet with knurled shafts. Aside from plugging the tubes, they are used to hold the data plates on out engines.

Thanks for that.  I just looked it up -- probably should have looked it up before posting.  Here is what one web site says:

Drive screws feature round, unslotted heads, multiple start threads with large helical angles, and an unthreaded pilot point. Similar to nails, hammer drive screws are driven into mating parts with a mallet, hammer, or hammer-drive device for quick and permanent assembly. No tapping threads are required in the mating part, but an undersized predrilled pilot hole is required, and the U-drive screw must be made of harder material than the mating parts.