plastic rivets

I got some of these recently -
https://www.apogeerockets.com/Building_Supplies/Misc_Hardware/Removable_Plastic_Rivets

I am thinking that I should use them similar to shear pins, only where they do not shear. That is, three or four, depending on size and weight. Is that the correct line of thinking for this product, or is there another strategy?

I use them all the time for other than shear pins. I use them to hold main chute tube to av-bay couples.

I use them to hold payload sections (camera bays) together. The only caveat is that the body tube needs to be stout enough so that they don't wallow out the hole and make it larger.

crossfire said:

I use them all the time for other than shear pins. I use them to hold main chute tube to av-bay couples.

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Sorry, I did not mean that I was going to use them to shear, but rather that I would locate them in the same way and fashion. Does that seem like the correct number and location to use?

I use 3-4 on a 4" FG tube. Never had any problems.

watermelonman said:

Sorry, I did not mean that I was going to use them to shear, but rather that I would locate them in the same way and fashion. Does that seem like the correct number and location to use?

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Just use the same number as you have fins, if you have 3 fins line up the rivets with them (keeps a nice looking line on the airframe), many people use them for keeping sections of airframe attached to couplers etc. I prefer using button head screws myself, since we are not trying to use them as shear pins. The only place I use shear pins (2-56 nylon screws) is at the nose cone to airframe joint where I want separation at ejection.

I used one instead of three while ground testing a few weeks ago. Given enough pressure, they do indeed shear ><. Normally though, yea I use them for this.

DizWolf said:

I used one instead of three while ground testing a few weeks ago. Given enough pressure, they do indeed shear ><. Normally though, yea I use them for this.

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:rofl: , and you of all people. Sorry if my humor is misplaced.

Oh no. I deserve it. I as thinking ok sweet this thing is good to go, walk over to pick it up and the NC is attached to the payload and the sad rivet is laying there cut in half.

To make it worse my next test wasn't enough BP and it sat and burned everything in the payload bay as I tried to pull all three rivers out. Thankfully I use dummy para cord and old tshirts for ground tests.

So I went with two grams of BP. One way or another that chutes hitting air.

Does McMaster sell these?

cwbullet said:

Does McMaster sell these?

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Yes

jeff2space said:

Yes

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Thanks. I found them. I had trouble finding them today.

So far I have found that most of the stuff everybody says "McMaster Carr has it", you can usually get locally at your local Home Depot, Lowes, or the best place in my area is Ace Hardware (they have a full aisle of Hillman Fasteners, the only things I can't seem to find locally are the closed eye-bolts and nylon 2-56 screws. I also have a Fastenal, a Tacoma Screw and two or three other specialty bolt places local. 1010 and 1015 rail I can order from Grainger and have it shipped to their local store (or Amazon for less). Plastic Rivets iirc can be gotten at many autoparts stores in the body fasteners section.

I have never used them. The only things I use are 3x6-32 machine screws threaded into the tube. Never had a failure.

You can get 100 rivets from amazon for about 10 bucks. Just have to determine the right size. Seems to me screws would work just as good or better in some instances. 100 screws (2-56x1/2 inch) for shear pins about the same price (3/32" for like 6 bucks but they seem short). Never thought to check auto parts store for rivets but the ones around here overcharge for most things.
Mike

You know what? I've used plastic rivets to secure tubes to the ebay but I've found out a little secret. Use a 2-56 buttonhead screw instead of the plastic "head". I've seen people use cut off nails too.

Now here is the kicker. With fiberglass tubing with say a relatively thick coupler, just drill and tap the hole for a 2-56 or 4-40 size screw and screw the danged thing in. I'm finding it's a viable option instead of dealing with the plastic rivets.

Yes, the plastic rivets are better for cardboard tubed DD projects and I use 'em there. It's worth investing in an appropriate tap and drill set to drill and tap holes. Fiberglass holds the threads pretty well and just don't over-tighten. Kurt

I use them. Have the 6mm type in the UK. Got them off eBay. Using them on Bluetube which is very tight. Holding body tube either side of an Av bay.

Have also used them to hold a 4" nose cone. No issue as it hit 590mph.