[Buwaro]

I went ahead and measure up two different valves. One will come all the way to the rear end and replace the end cap. The other stops just short of the end cap so that you could put a stock on. Without the end cap, the Dump chamber volume is .714"^3, and the dump chamber for the spool that replaces the end cap is .984"^3. How do I figure out what pressure these two spools will operate at?

[M98custom1212]

If you want send me the dimensions. I will model this up in a CAD program.

[Buwaro]

Originally Posted by M98custom1212

If you want send me the dimensions. I will model this up in a CAD program.

I have some of them right now, Still working out everything. I have to work some of the things out still. Right now I am just trying to figure out if I should do the fill length or stop it short so it can be hidden inside with the end cap.

[ironyusa]

Originally Posted by Buwaro

I went ahead and measure up two different valves. One will come all the way to the rear end and replace the end cap. The other stops just short of the end cap so that you could put a stock on. Without the end cap, the Dump chamber volume is .714"^3, and the dump chamber for the spool that replaces the end cap is .984"^3. How do I figure out what pressure these two spools will operate at?

Unfortunately, the math isn't that straight forward. I'm not sure volume does what you think in the overall picture. The valve itself is going to be the determining factor as well as some other key factors (choked flow, volume offset, etc.). Honestly, you're best off to use something as a baseline. Both seem small to me based on what I see, so my complete guess is somewhere around the 325ish range.

[Buwaro]

Just a little update. Beginning stages of learning how to run a lathe. I started to turn my 1" round stock aluminum down to .9800, but I am not extremely good with getting everything set up just right, so I will have to do some more this weekend.

[PMace (Banned)]

I'm following with anticipation! This is very interesting stuff and would like to continue to see updates, thank you!

[Buwaro]

Nothing new yet. I need to get some new bits and tools for the lathe at work before I can get anything really done.

[Buwaro]

I finally have an update. I got a lot of work done this weekend. I actually have more parts than this finished, but I don't have picture of them yet. I should have an update on those by friday. So here is whats going on so far.

Here is the bolt.



The bolt sits in a brass housing



Then everything goes into, for now, a steel housing since we don't have the proper tool for me to make an aluminum one.


Everything is slip fit, sealed with orings and the body of the gun holds it all together. I have most of the ram housing together, but had to put everything up before I got to take pictures of it. I can do projects at work, just can't be doing them when the boss comes in.

[GhostJedai]

Looking great. Good job, so far.

[Buwaro]

Thanks. I have to rework the piston housing when I go in on Wednesday. I didn't like the way it came out. I'll hopefully have some more pictures by Friday.

[Buwaro]

This is the final design I have worked out after beginning actually manufacturing and assembling this. I might have to make some changes for the final product, but the double spool allows me to cut the stroke almost in half. Let me know what you guys think.

[1cheeselova]

wow that's actually a very great design... It has the benefit of having the firing chamber as close to the ball as possible while not having a bolt guide

[Buwaro]

Originally Posted by 1cheeselova

wow that's actually a very great design... It has the benefit of having the firing chamber as close to the ball as possible while not having a bolt guide

I am just happy to be actually making something again. I actually have a 2 way ram ebolt setup for this gun, but I haven't been doing anything with it since I have started this concept. It will be much better than the ebolt if it works properly.

[Buwaro]

I made some changes, and realized I messed up the piston housing last night. I need to add about .4000 to the piston housing and removed about .4000 from the can so it will still fit in the gun, but here is essentially what it will look like. If I have time tonight I will finish the piston housing and begin work on the actual piston/spool

I added an o-ring to the end of the bolt so it will slide in the body.




I also made it so the brass piece doesn't just slide into the can as a whole. I cut the can into two pieces and used bearing mount to hold the brass piece into the front piece.




Here it is mocked up in the gun. The stroke is right around 1". Much shorter than the standard 1.8"

[ironyusa]

Just a minor detail, but ideally you want the firing chamber cutoff right before the main valve is opened. Otherwise you limit the refill time of the main chamber.

[Buwaro]

Originally Posted by ironyusa

Just a minor detail, but ideally you want the firing chamber cutoff right before the main valve is opened. Otherwise you limit the refill time of the main chamber.

That is pretty much what I am going for. The dump chamber will be a tiny bit away from opening as the fill side closes. I still have to work out those exact measurements. A lot of this has been trial and error on the lathe and then assembling. I don't really have the drawings to scale, and most of it is figuring everything out after I have already started to put it together.

[Massriot]

very interesting. posting so I can keep up to date with this.

[Buwaro]

It's alive!

[ironyusa]

Let us know when you get it over a chrono and where your pressure landed. Very cool though.

[Buwaro]

Originally Posted by ironyusa

Let us know when you get it over a chrono and where your pressure landed. Very cool though.

Thanks. I have to work out some kinks first, but I should be able to actually test it soon.

[the_kwa]

way cool project