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Thanks Ed, for the reminders about those two sources. I like McMaster-Carr and use them, and I was on the phone to CD Fasteners (have them programmed in my phone) just yesterday morning; the largest nylon bolts they have are…   Read more»

Have you tried CD Fasteners in Fort Collins? I have gotten a variety of nylon materials there. If that fails try McMaster Carrhttp://www.mcmaster.com/#nylon-set-screws/=ggvr1zThere is really no need for a line cutter to cut kevlar. I use it to cut a…   Read more»

Ed, that is a good idea. It seems that if I needed to, I could tap the top of the bolt, and then screw a smaller bolt into the hole, since I am having difficulties in finding nylon set screws….   Read more»

My cutter went poof when I tried to cut even the thinnest of kevlar. I use them in tandem to cut through the zip ties – that way I have a backup.My only reasoning for using a 1/4″ nylon plug…   Read more»

That is very interesting and gives insight. Thank you for sharing this with us. I would like to express the same with Edward in regards to his sharing his line cutter also.There is a line cutter on that link as…   Read more»

That is very interesting and gives insight. Thank you for sharing this with us.I would like to express the same with Edward in regards to his sharing his line cutter also.

Great project. Fun to read. A long time ago I made these pyro-bolts:The brass part has an undercut. The stainless bolts are just igniter holders. The advantage of the brass is that they are relatively strong before breaking. Here is…   Read more»

Your call. I see it as a different rocket, different weights, different aerodynamically induced stresses, different number of bolts, different configurations, new wheel. Where do you start? You can make everything identical to Kevin’s and still have to make it…   Read more»

There is not a lot of wheel to invent here. The photos and the description almost says it all. Just need to know which size to work with so we can figure out the stress tolerances. When you think about…   Read more»

There is not a lot of wheel to invent here. The photos and the description almost says it all. Just need to know which size to work with so we can figure out the stress tolerances. When you think about…   Read more»

Steve, I presume the dimensions in your drawing are meters?yea .. that’s the original drawing we started with. We will vary slightly but close to that.Still waiting for Kevin to get back with details .. but it may be 3/8″…   Read more»

Steve, I presume the dimensions in your drawing are meters?

What size bolts did they use? The picture looks like a 3/8 X4″. I was thinking of something at least 2″ long, 1 1/2′ for two pieces of 3/4″ plywood and a 1/2″ for the nut. Easy to get longer,…   Read more»

Here are, more or less, the 3 Proton Stages.will extend the 3rd stage a little.Booster is 60″, stage 2 is 48″ and stage 3 is around 72″. I plan to add fin and motor mounts to the 3rd stage for…   Read more»

No, Adrian, I do not. I was preparing to order some. If you are coming to the launch Saturday, I would be happy to take some from you. Since we live probably about 70 to 80 miles apart, the only…   Read more»

No, Adrian, I do not. I was preparing to order some. If you are coming to the launch Saturday, I would be happy to take some from you. Since we live probably about 70 to 80 miles apart, the only…   Read more»

For the bolted interface, I would suggest to design it so that the airframe tube of each section is butted up against each other and the nylon bolts just preload that interface. That way, as long as the preload from…   Read more»

Thanks for the input Ed. For my prototype testing this weekend, I was not going to use epoxy at all. I was planning on drilling about a 1/4″ hole from the hex head end, drilling down about 2″ and tap…   Read more»

I can give you a few tips on something similar to the bolts. I built a parachute reefing/ line cutter mechanism off of something that Tony A. posted.http://tqc.yuku.com/reply/32555/2010-Balls-project#reply-32555Post #27 is a picture of what I have.It is 1/2″ OD aluminum,…   Read more»

Steve, I was going to get some nylon bolts, drill a hole in the hex head, then scribe the circumference 1 1/2″ down from the head on the outside, in the threads. I was thinking of placing powder and two…   Read more»