Smash Rocketry New Group Project – The Proton M

[Dr_J]

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 well. Make sure you test well if you decide to use kevlar. It would bind up our cutters.

[edwardModerator]

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 vs epoxy is the field serviceable/replaceable aspect in case something went awry.

Edward

[BEAR]

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. I could drill a small hole into the smaller bolt and secure the ignitor wires thought that hole so they can easily be removed and replaced in the field if continuity is lost.

On your cutter, could you sharpen the cutter so there is a knife edge to cut though the kevlar? I know I have ground blades onto metal tubing or pipe for cutting circles in different materials like hypalon for my rafts. I put down the fabric, put my cutter on the fabric where I want a cut and then I hit it with a mallet. A good clean cut was made. Seems like it should work on kevlar also. Instead of a mallet, you are using rapidly expanding gasses.

[edwardModerator]

Have you tried CD Fasteners in Fort Collins? I have gotten a variety of nylon materials there. If that fails try McMaster Carr

http://www.mcmaster.com/#nylon-set-screws/=ggvr1z

There is really no need for a line cutter to cut kevlar. I use it to cut a zip tie that holds either a deployment bag closed or a loop tied to a bulkhead. The zip ties are strong, cheap, and work well.

Edward

[BEAR]

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 3/8″. I have found nylon bolts on the net up to 5/8″. I also use MSC (mscdirect.com) for parts, tools, etc. They are where I went to get spring steel so I could make my own Estes style engine hooks, any length I want, and .003″ aluminum shim stock where I used it to make laminated aluminum fins that were .030″ thick. There are a couple of others that I am buying from also. I did find steel set screws on the internet, and they had nylon tips, just not the whole thing being nylon. I was avoiding steel and other materials heavier than nylon so that there would not be small pieces of metal flying around. I wish I could find a way to capture the debris so that it does not get scattered all over the place because we know the nylon is not going to decompose. I am starting to lean towards the nylon bolt drilled and tapped, then I can load it and place another nylon bolt in the top so it is secure. Then when I get out to the field, I can remove the top bolt and replace it with one that has ignitors going through the top. I can then insert ignitors and install those bolts. This could help make the units more reliable. (The problem with this is another thing on the check list and another thing to have to do out at the field that takes a little more time. The other side says that as long as the leads or tails are shorted out, it should be a stable device that is not much different than some of my shotgun shells and some I have had in storage for years if not decades and they still fire when I pull the trigger.) You know, failure is not an option.

Ed, I asked you a couple of months ago, I guess, about helping build motors sometime. I am in Wellington and commute to Fort Collins. I would like to learn more about these procedures. I am talking with James Russell about this also. I do not recall a reply from you. If you care to, PM me aobut this. I am serious, and I will carve out a block of time to assist, if you desire.

[smashburn]

For those not attending the launch we’ll be in Longmont working on the Proton this Sat from 10am to ….. Lots to do .. come on out!!

Steve

[James Russell]

We had a productive day today, made some design changes and got a lot of the centering rings cut and got some sanding done.

I also wanted to let all know that Steve’s computer is real sick and he needs to find some good antibiotics or something. It might be a couple of weeks before it will be be let out of quarantine.

I will try to relay to him anything I can.

[BEAR]

Did he go unprotected and pick up a virus? You just can’t go around getting familiar with other computers you do not know without protection!

[James Russell]

Yes, I think you are right, maybe he should double up to be extra safe.

[BEAR]

Or not hook up with strange modems!

I use Iolo System Mechanic, Malwarebytes Anti- Malware, Paretologic XoftSpySE and ESET Nod 32 to protect my systems for what is worth. I also use CC Cleaner and Hitman Pro 3.5. It is a lot but they keep my computers pretty good. I have also found that Internet Explorer slows my computers down so now I am using Mozilla FireFox and I am starting to use other search engines than google.

With some viruses and bugs, they will first attack your anti-virus software so that you can use it or update it to get rid of that stuff; the system mechanic prevents this from happening so that you do not end up wiping your hardrive clean and having to do a clean install. I also have external hardrives that I unplug unless I am backing up my systems so that I can almost always recover.

[Author]

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