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chenyingying
07:40:19 Mon
Jan 9 2017

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jlgg
03:04:29 Mon
Jan 11 2016

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Tbkahuna
23:25:42 Mon
Nov 23 2009

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Marching on... 2600 psi pressure test...

My scuba tank was down to 2600 psi, but I was able to shield the valve in case of a rupture for an air test. It held 2600 psi for about 30 minutes. There wasn't even a tiny leak, so I am happy about that.

TBK

  
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Tbkahuna
12:27:57 Mon
Nov 23 2009

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Re: Caselman, anyone?

Cutting the 1/8" NPT threads in the air chamber caused me a small headache. I drilled the hole and reamed it with a tapered reamer before tapping. The depth of that hole is limited by the depth and diameter you can drill without going through the other side of the air chamber. As a result, my tapered reamer barely removed any metal at the top. I could grind the tapered reamer down, but it is the only one I have for 1/8" NPT and I will need it for other things. I made the hole as deep as I dared, but still need to get a little more clearance by drilling out a little more on the inside (down the length of the tube) at that end. I have a 3/16" of 1/4" hole at the very end, of the air tube, but will make it a little bigger. That should add a little clearance for the reamer and tap.

It holds pressure to 1000 psi so far, but I would like to get one or more additional turns on the fitting just to be sure.

TBK
[1 edits; Last edit by Tbkahuna at 12:51:58 Mon Nov 23 2009]

  
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Tbkahuna
03:19:03 Mon
Nov 23 2009

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First Pressure Test a Success

The o-ring is working fine. I have tested it to 500 psi, then to 1000 psi for about 10 minutes each with not a single bubble. I need to set up a better containment area to test it at higher pressures.

TBK

  
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Tbkahuna
22:41:27 Sun
Nov 22 2009

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Re: Caselman, anyone?

The o ring fit seems to work ok. I cut the 10 degree taper about .010" deeper into the air chamber. It goes together very smoothly.

I need to drill and tap the air inlet and I will be able to do my preliminary tests with air. I intend to strength and leak test it with vegetable oil to about 2 times the working pressure.

TBK

  
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Tbkahuna
21:06:29 Sun
Nov 22 2009

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Re: Caselman, anyone?

Here is a picture of the valve body, air chamber, valve and stem.

I spent a while trying to decide on the need for changes to the o-ring setup shown in the drawings. It should be an #015 O-ring, 9/16" ID, 11/16" OD. I considered building the valve body longer than required so I could drill and tap the back of it for a pressure connection to test so I could test the o-ring seal and valve body and air chamber integrity. I skipped that, but now wish I would have allowed for that. I can still test it prior to welding the valve body to the receiver.

Once I get this one to run, I may incorporate some other ideas into the valve body and air chamber design. I want to be able to use various air chamber lengths without having to machine new air chambers. On a mini lathe, it takes a while!!

TBK


[1 edits; Last edit by Tbkahuna at 21:47:08 Sun Nov 22 2009]

  
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Tbkahuna
06:32:17 Sun
Nov 22 2009

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Re: Caselman, anyone?

One of the things I didn't like about the valve setup is that the valve body is welded to the receiver tube, and the air chamber section screws on to it. That would be fine, but there is an attachment to the air chamber from the storage tank. That means you have to locate the input hole and pipe threads correctly when the valve is threaded together.

If it doesn't seal against the o-ring, it will take a while to get those surfaces mated and sealing while maintaining the orentation of the air chamber to the valve body welded to the receiver.

If anyone else is making a Caselman, you'll want to consider that.

TBK

  
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Tbkahuna
06:27:10 Sun
Nov 22 2009

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Re: Caselman, anyone?

I whittled the valve body out of a piece of steel tonight. The little lathe had the big chuck on it when I started cutting the threads. It doesn't have enough low speed torque to cut threads with the much heavier chuck, so I did it by hand. It took a while longer, but the threads mate up very well to the air chamber. I have a little more finish work to do on the inside of the valve body.

  
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Tbkahuna
00:01:36 Tue
Nov 17 2009

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Re: Caselman, anyone?

AMD65,

I sent you an email.

The diameters aren't critical, but the various parts need to fit inside each other. You could easily make the valve body (air chamber) wall thicknesses a little bigger.

There shouldn't be a problem with cycling hollow points. For expansion, it will depend on the hollow point design and the velocity. I don't expect a high velocity, so the expansion would be limited. At 60 ft-lbs or so soft lead will deform, but won't be like a bullet from a centerfire cartridge. Even at 200 or so ft-lbs, the expansion will be limited for a small hollow point cavity. Yes, a large open cavity will deform, but the penetration may not be very good since the energy levels are low compared to cartridge guns. You will be using pure lead or slightly alloyed bullets, not copper jacketed bullets like found for centerfire rounds.


  
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Tbkahuna
23:50:16 Mon
Nov 16 2009

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Re: Caselman, anyone?

I don't sell it as a kit. However, I did send a material list out to a few people at one time. It was a big help getting all the metal in front of me. It was just my list for purchasing the metal, and had enough extra so I could machine it. I'll see if I have that in electronic format. I may have already posted it here, too.

Tbkahuna

  
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gotcha12
21:39:01 Thu
Sep 24 2009

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Re: Caselman, anyone?

do you sell it in a kit thanks
please email me back
robbenline@yahoo.com

  
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caselmanproject
23:27:08 Sat
Jul 11 2009

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Re: Caselman, anyone?

whats new Tbk ?

  
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AMD65
17:37:09 Sun
Jun 28 2009

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Re: Caselman, anyone?

Hi Guys

I've been following this thread for a while and I have a few ideas/questions.

I want to use a .45 acp barrel and lighter .45 tips since they can be bought bulk as reloading components. I figure since the .45 doesn't go much faster than 1100fps, the power shouldn't be a problem.

Is this do-able? I want to thicken all the steel by a few mm and use a 20''-ish bull barrel. I'm not a huge fan of the Thompson look and I'll feel a little safer letting off compressed gas with thicker steel. I don't have the tools so I'm going to have this made for me.

Oh and will hollow points cycle in the mechanism and expand with this thing?

  
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caselmanproject
15:25:07 Wed
Jun 24 2009

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Re: Caselman, anyone?

nothing new?:rolleyes:

  
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caselmanproject
22:51:26 Sun
Apr 26 2009

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Re: Caselman, anyone?

I'm hurry to see the suite :smile:

  
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Tbkahuna
15:46:24 Fri
Mar 27 2009

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Re: Caselman, anyone?

Nothing major to update. I haven't had any time in the shop for the last month. I hope to soon, though.

I did just get my TIG welder delivered, so once I get set up, I can start putting it all together.

TBK

  
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caselmanproject
22:22:42 Mon
Mar 23 2009

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Re: Caselman, anyone?

whats new Tbk ?

  
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Tbkahuna
13:41:21 Mon
Feb 23 2009

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Re: Caselman, anyone?

I wound all of the springs using tempered music wire. It is a high carbon steel, ASTM 228 specification. It is common music wire that comes in a roll. I unwound about 30 or 40% more than needed, let it uncoil, and went right to winding. I got mine from Enco.

http://www.use-enco.com/CGI/INSRIT?PMAKA=325-4175&PMPXNO=5810375&PARTPG=INLMK3

I also use shorter, straightened, 3 foot lengths that I have from model airplane building, and it works well, too.

The barrel I am using for the first version is a barrel liner that I got from Track of the Wolf. It is the 32-20 barrel. It is 1/2" outside diameter, .305" bore, .312" groove. I don't know the actual material, but I cleaned up the saw cut end on the lathe and it was pretty soft. It won't be welded in my application.

http://www.trackofthewolf.com/(S(p5lkir55rzktokiotnf5i045))/categories/tableList.aspx?catID=14&subID=142&styleID=483

TBK


  
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caselmanproject
21:47:50 Sat
Feb 21 2009

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Re: Caselman, anyone?

which type steel you used for the barrel ?, and the spring?

  
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caselmanproject
14:31:20 Sat
Feb 14 2009

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Re: Caselman, anyone?

Quote: Tbkahuna at 12:52:31 Sat Feb 14 2009


Initially, I am just going to use a high pressure quick disconnect like on other pre-charged airguns or paintball tanks. That way I can use an external air tank to test fire. Once the gun works ok, I will make any changes to match the original Caselman.

TBK

Probably for the same reason it is put this part.
[1 edits; Last edit by caselmanproject at 14:31:42 Sat Feb 14 2009]

  
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Tbkahuna
12:52:31 Sat
Feb 14 2009

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Re: Caselman, anyone?

Caselmanproject,

You asked about the differences in the connections to the valve.

I have seen the second picture on the web, as well as some others showing parts made by the same person. In one of those pictures you could see a part made as an apparent improvement on the sheet metal spring guide that goes inside the valve. It was full diameter and had grooves in it for o-rings. Unfortunately, that wouldn't allow air to pass through the valve body. I think that person just didn't understand how the valve works.

Based on that, I am guessing that the person didn't have access to the high pressure fittings shown in your first picture and was trying something else. I am not familiar with that particular fitting, but since it is barbed for a hose attachment, it is probably not good for 3000 psi. However, that setup would be useful for testing and playing around with the valve using shop air at 120 psi or so.

Initially, I am just going to use a high pressure quick disconnect like on other pre-charged airguns or paintball tanks. That way I can use an external air tank to test fire. Once the gun works ok, I will make any changes to match the original Caselman.

TBK


  
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Tbkahuna
12:27:13 Sat
Feb 14 2009

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Re: Caselman, anyone?

I didn't think a conventional magazine like shown in your pictures would work with the Caselman so I didn't go that route. The bolt with an o-ring on the end would have to push the bullet through the lips on the magazine and into the chamber without cutting or deforming the the o-ring. Because the magazine spring is pushing up, there would always be a force pushing the bolt into the feed lips. I also looked at just usng a much smaller diameter pin to push bullets out of the magazine, but didn't think I would be able to get enough blowback force with the open magazine in the path of the air and bolt when it blow back.

I am thinking of making some changes to allow a little bit of air to flow back to the front of the 3/4" diameter section on the bolt to help it recock, especially at lower pressure. Increasing the annular space between the bolt probe and the bolt would do that.

I wish it would work, but I couldn't figure out how to reliably do it. If you do, let me know.

  
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caselmanproject
16:04:39 Fri
Feb 13 2009

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Re: Caselman, anyone?

I have a picture of the firing valve , that on the SMG , one of the parts differs from much.You know why?




  
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caselmanproject
15:51:51 Fri
Feb 13 2009

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Re: Caselman, anyone?

Two types of magazine which could perhaps be appropriate???:ohwell:






  
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caselmanproject
15:33:28 Fri
Feb 13 2009

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Re: Caselman, anyone?

I am in a hurry to see the result.

Another picture that I have .







[3 edits; Last edit by caselmanproject at 15:41:52 Fri Feb 13 2009]

  
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Tbkahuna
00:12:08 Fri
Feb 13 2009

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Re: Caselman, anyone?

I don't think of it as improving performance, but it should make a lot of the build work easier, and I have always had good luck getting something round to feed through a magazine since its orientation is always the same. If everything works, then I can decide if I want or need to use something other than round lead balls. Also, with this, a caliber change will be easy to do. I think that would be great!

I am building the valve, now, and once that and the mags are done I will be finishing up the fire control group operation and will be ready to fire with an external tank hooked to the the valve with a braided hose. I want to get the thing to fire and run, then will decide on a final tank type and attachment. I am strongly leaning towards an external tank and a wooden stock, but don't know how it will work with lower pressure and the pressure drop of a longer hose.

It's fun to see something like this come together out of just a pile of steel!

TBK

  
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caselmanproject
23:46:26 Thu
Feb 12 2009

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Re: Caselman, anyone?

Interesting, you thinks improving the performance ?

  
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Tbkahuna
18:42:41 Wed
Feb 11 2009

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Re: Caselman, anyone?

I have designed a different magazine and feed system for feeding lead balls. I have built and tested a short version of it and it seems to work. I am waiting for some more steel and tubing to make a full-length version. I will post pictures when it is done.


TBK

  
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caselmanproject
00:50:03 Wed
Feb 11 2009

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Re: Caselman, anyone?

A pre-heating would be preferable, if not the welding should contain a nickel alloy to reduce the tension, afterwards, if I remember. an income with 200 degrees during 2 hours.

  
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