Old LOC Onyx Rebuild

[mcderek]

I found the first midpower rocket I ever built- a LOC Onyz. It hasn't flown in many years because of cracked fins. My plan is to cut off the fins and rebuild it as a 7 tube fin rocket. While I'm at it I would like to add positive motor retention. The original design is for friction fit. Any suggestions on ways to do it? I have a couple but I'm interested in what other's think. Thanks!

 

[J Blatz]

You don't have much to work with as far as gluing something. These are cheap and effective...


https://locprecision.com/collections/rocket-components/products/z-clip-style-motor-retainer-set

 

[mcderek]

You don't have much to work with as far as gluing something. These are cheap and effective...


https://locprecision.com/collections/rocket-components/products/z-clip-style-motor-retainer-set

Those work great when you have access to the interior to install the T-nuts. I don't in this case unless I'm missing something? Thanks!

 

[J Blatz]

Myself I would drill the appropriate size hole for the the t nut in the centering ring and press the t nut into place with some jb weld.

 

[Art Upton]

Those work great when you have access to the interior to install the T-nuts. I don't in this case unless I'm missing something? Thanks!

I never used T-nuts, just self tapping screws for my Screen Door clips.

 

[David_Stack]

What about retro-fitting brass threaded inserts like these to secure the Z-clip screws?

https://www.woodcraft.com/products/...AYYKSbVNY2c0f8tB7dsaAlyGEALw_wcB&gclsrc=aw.ds

 

[Art Upton]

What about retro-fitting brass threaded inserts like these to secure the Z-clip screws?

https://www.woodcraft.com/products/...AYYKSbVNY2c0f8tB7dsaAlyGEALw_wcB&gclsrc=aw.ds

Those are great for 5.5-8" rockets; when done with all that an Aero-pack would be more slick.

 

[David_Stack]

Those are great for 5.5-8" rockets; when done with all that an Aero-pack would be more slick.

In the case of the OP's Onyx, I don't think there is enough exposed MMT to retro-fit an Aeropack however, hence the Z-clips.

Not sure what screw size would be appropriate for that 3" airframe/29mm motor, but Dubro offers brass threaded inserts down to 4-40...

 

[mcderek]

Thanks for the suggestions. I decided to go with brass threaded inserts. The plan is to use two on opposite sides with a version of kaplow clips. I'll probably add enough ply so that the brass insert is fully engaged. The screws are 6-32's.

 

[RokitFlyr]

Just use a couple of pan head screws into the wood and z clips. It'll be fine.

 

[Hobie1dog]

You should read up on "well nuts" as that is what I use for rall buttons now, or older rockets that have standard launch lugs that have been broken... that way all you have to do with these is to drill a hole, stick the well nut in, put the screw in, use a cordless drill and it pulls the rubber on the backside up against your air frame, and you have a permanent threaded fitting.
https://www.albanycountyfasteners.com/blog/well-nuts-what-are-they-and-how-are-they-used/

 

[mcderek]

You should read up on "well nuts" as that is what I use for rall buttons now, or older rockets that have standard launch lugs that have been broken... that way all you have to do with these is to drill a hole, stick the well nut in, put the screw in, use a cordless drill and it pulls the rubber on the backside up against your air frame, and you have a permanent threaded fitting.
https://www.albanycountyfasteners.com/blog/well-nuts-what-are-they-and-how-are-they-used/

Those are nifty for sure. Thanks for posting the link!

 

[Back_at_it]

Threaded inserts work well. I've used them on a couple of rockets in the past.

I prefer to drill them into the centering ring above the fin tabs so you have additional materials for the insert to bit into. I also recommend that you install the inserts with a touch of epoxy to keep them seated.

Looking forward to your rebuild.