Plastic Rivets vs. screws in LOC Bruiser

[EBurg]

I'm starting a build for my L2 certification flight with a LOC Bruiser (PK-88). I'd like to make it possible to disassemble for transport and am looking at either plastic rivets or aluminum screws to attach the forward airframe tube to the coupler. I'm leaning to 4 plastic rivets like Apogee sells (https://www.apogeerockets.com/Build...s?zenid=1bd4622d7f6a1bd0fb5812c7601f6734) due to the cardboard tube construction, but wondering if I should go ahead and design it for the 6-32 aluminum fasteners instead (https://www.apogeerockets.com/Build...s-3-pk?zenid=1bd4622d7f6a1bd0fb5812c7601f6734).

I'm realizing the forward airframe doesn't take a lot of load, but don't want to shear through the coupler with the metal screws.

 

[Nick@JET]

Alum screws are very clean once done, Plastic rivets are very easy to drill and install, used in my LOC Magnum 5.5" level 2 and will be in my L3.

Most people will not reuse the rivets, also when remove is easy to scratch the paint, so I put a clear sticker on the BT under where the rivet head sits.

 

[dixontj93060]

...easy to scratch the paint, so I put a clear sticker on the BT under where the rivet head sits.

That is such a good idea! I'm stealing it!

 

[cherokeej]

Once the holes are drilled and the rivets fitted, take it all apart and soak the holes in the paper with thin CA. Let it cure, and lightly sand. Toughens up the paper.

 

[neond7]

Use the plastic rivets. You can get them MUCH cheaper from McMaster Carr. Here is the part number and description:

91020A218 Nylon Click-lock Shank Rivet, .163" Hole Dia, .177"-.217" Material Thk, Black

 

[Bat-mite]

Use the plastic rivets. You can get them MUCH cheaper from McMaster Carr. Here is the part number and description:

91020A218 Nylon Click-lock Shank Rivet, .163" Hole Dia, .177"-.217" Material Thk, Black

Or Grainger, if you have one near you. Pick up in store and save shipping.

 

[ksaves2]

Can substitute 2-56 buttonhead screws for the plastic pin if desired. On FG rockets another way to deal with it is drill straight through and tap for whatever screw size you'll be using. If the FG coupler is thick, might just get away with tapping with the
appropriate thread and be done. Would need to be careful so's not to strip out the threads. There is a backup though. Can use PEM nuts on the inside of the coupler/ebay tube. Carefully lay some J&B and plant the PEM nut with a screw that's been treated with oil. I haven't had a screw get stuck after three nosecones. Ebay/upper bay tubes would be the same. Kurt

 

[JDcluster]

I use 10-24 machine screws.
Plastic rivets never seem to want to come out when you want them to....
I stopped using them 18+ years ago.


JD

 

[Banzai88]

Those Apogee aluminum thingys are cool, but over priced for the functionality that you get, altuough they do have a very nice countersink that you can't really get any other way. You can get enough conventional hardware to do dozens of rockets for the same price . Also, the ones you referenced require thickness of the body tube and coupler combined to be over .120. You can do the very same thing by inverting standard t nuts and stainless screws and a washer. Better yet, use PEM nuts since you'll be epoxying anyway.

I've only ever used PEMs for fiberglass rockets and as my plastic rivet holes start to go funky, I'm converting them to nuts and screws, too. Countersinking to get a flush fit is tricky, but for the security and ease, I'm willing to give up a few feet or feet per second.

If you're going to use the plastic rivets, CAing the holes works well for a time, or you can reinforce them by epoxying a .005 brass plate on the inside the same way that people use it for shear pin inserts. That's worked pretty well for me.

 

[KenRico]

Or Grainger, if you have one near you. Pick up in store and save shipping.

GMTA - I do that for 1/4 inch 4-40 nylon stand-offs and 1/4 - 20 aluminum all thread..

They closed the branch close to work..now have to drive across town for pick up..will try some rivets like you suggested .

Kenny

 

[NateLowrie]

GMTA - I do that for 1/4 inch 4-40 nylon stand-offs and 1/4 - 20 aluminum all thread..

They closed the branch close to work..now have to drive across town for pick up..will try some rivets like you suggested .

Kenny

PEM nuts. Drill your holes and soak the hole with CA before you press in. After you press in use some epoxy around the nut as extra insurance.

The main problem I have with plastic rivets is they are a pain in the butt to remove.