InfernalDesigns

Luckily OPRV's are cheap and readily available Mcmaster PN 9889K15 would seem to be a good candidate at $9.19 and a 50 psi blow off pressure. This is conjunction with a throttle valve than can be locked could mean a nice safe blaster with adjustable performance.

I had a bit of free time after a meeting with a Client ended early. I managed to get some time to work on the grip. Again I am working in HDPE because I have it readily available and I have the machining parameters well defined.

Today I spent a bit of time in Solidworks and a short while and a humongous pile of plastic swarf later I had the 2 halves of a grip. I also made a GitHub Repository so that anyone who is so inclined can Fork it and work on the project. GITHUB REPOSITORY

The idea was to make it a bit sleeker by adding the pockets for some polycarbonate sheet for supporting the trigger without having to do 2 sided milling. 2 Sided milling is possible, but making the fixtures is a pain so I decided to make the grip in 2 halves. I also made the opening in the catch square to improve compatibility. After talking With Koree, I decided that the bushings were probably unnecessary and eliminated them from the design.

What program did you use to set up the tool paths? I currently use MasterCam X5. If you could send me a compatible file type, I would be interested in working on the design as well.

Right now I am using MakerCam or HSM Express depending on I am doing. I know that they are not the best programs, but they are cheap and capable enough to work for a smaller operation like I run here.

it seems that the main complaint about safety is the use of a homemade pressure tank. What about if they used a commercial tank meant to take deal with compressed air? AndyMark.com has them for $14 http://www.andymark....t-p/am-2649.htm they are by no means the best or cheapest supplier, but they are easy to deal with. Toss an over pressure relief valve and gauge into the system and you will end up with a relatively safe set up for not much more than building everything out of PVC pipe.

I really like this idea and it is a good way for people to get access to very nice rainbow catches. However, I strongly advise using something like polycarbonate instead of HDPE. I know you might have easier access to HDPE, but in my experience it hasn't held up as well as polycarbonate. I know that MIG has had success with HDPE, but if you are able to get polycarbonate, I would use it.

I can get my hands on almost any material. I am just prototyping right now. Polycarbonate is $20-30 for a 12x12x0.5inch sheet while I buy 24x24x0.5 inch HDPE cutting boards from a restaurant supply store for $9. This lets me cut all day and cost less than I spent on lunch. I like working with HDPE for prototyping because it is cheap, strong, very impact resistant, holds threads well, and I can machine it very easily. I very well may end up using polycarbonate for a final version of this, but I am going to explore other options as well.