Classic Valve spring packs

[wthomas333]

I have been working on this some more and am pretty close to having a good, reasonably priced (if you buy enough quantity from the right places) rebuildable spring pack.

I have these 2 “prototypes“ that I have successfully tested in my Minimag and Micromag with both Lvl7 and Lvl10 bolts.

Only real difference is how they are captured on the end. As you can see one is a C-clip, the other is a roll pin. I am waiting on some orings to test out instead of the c-clip. It’s a bit of a bear to take off and the oring would only be there to keep the washers from sliding off when you remove the spring pack. But it has to be just the right size because the center post does stick up slightly into the bottom of the piston, so everything needs to be just the right size as to not interfere with it or make contact with it in any way. I was gonna try using a similar post as the stock one but I wanted to try and make one that can be disassembled and rebuilt.

Also going to change out the copper washer with another one I found that is closer in size to the stock AGD washer and should have a little better fit.

Want to do more testing over the next few weeks. Have a personal and a work trip over the next few weeks that are gonna slow me down a bit though. Once I get these completely finished up, I will post up all the info and parts I used that seemed to work out the best and since I now have quite a few parts on hand, I will probably sell some here on MCB. Not looking to make money, just recoup costs.

[Alexndl]

I would be interested in 2 spring pack when they will be available

[superman]

awesome. I think the c-clip option is probably the better one. I would be happy to buy multiple assuming all works out.

[Shane-O]

A C clip would be best in my opinion. Keep in mind these could also be used for many old AA secondary regs. Nice work.
Also, a SS washer or steel washer would probably be better, I can see the copper bending or warping under pressure.

[rawbutter]

Actually I wonder if copper is better than stainless steel. That washer is sandwiched between the spring pack and the regulator piston. It's under a lot of pressure, but it's just compression. Would copper soften that contact?

[Shane-O]

We use a copper washer as a crush seal on brakelines. So I would think it could deform and change the spring rating, or just break off after time.

[wthomas333]

The c-clip option is a cleaner look. I do prefer it as well. The posts with a C-clip groove are slightly more expensive, but not prohibitively so.

The copper washer is pretty beefy, probably would have been just fine. The biggest issue was the ID was slightly off making it a bit loose. I wanted something that fit a little better. The new washer I am waiting for is steel and that is the one I plan on using.

[FredMnkyDad10]

Great work. I am also down to buying some.

[alpha_q_up]

Good job, when you get situated and iron out any issues, I'd be interested in a couple to have for my spare parts box

[rawbutter]

Awesome. I'm so glad someone finally figured this out.

Have you told Tim about this?

[wthomas333]

Not yet, I previously bought just a small amount of parts to make the few I have. I wanted to get some more parts in and test a few more units to make sure they are all uniform and working properly. I can also see if there is any noticeable difference between a steel washer or the copper one. I’m thinking probably not enough difference that I would be able to tell.

[wthomas333]

Have more parts on order. Should be enough to initially put together 50 or so spring packs. I will likely be selling them around $20 shipped for the first one and then $15 for each additional. That’ll pretty much pay for the parts and my time for assembly. You might see them for a few more bucks on eBay as expected.

Looking like end of June as one of the parts is on back order.

[wthomas333]

Still working on them, but will have some available very soon. I wanted to continue testing a few of them after they sat in the gun compressed for at least a week or two. So far so good. The washers I used might have a little bit more spring rate than the original, but obviously I don’t know for certain. These are slightly longer than an original spring pack and I am using 30 washers as opposed to the 27 that come on a stock piece.

I am using an oring to capture the washers. It’s fits nicely and I picked a little more durable oring than a standard buna. The c-clip would not work with this particular pin. Made the top too wide to fit into the bottom of the piston. I am still searching for one that will work, but for now the oring works fine.
Long story short, the washers I purchased in the bulk purchase ended up having an ID that was a little on the large side of the tolerance range and the pins I originally purchased had a OD that was a little on the small side. So they didn’t fit together well, too much play. If there is too much play then the washers don’t sit nicely on top of each other, they kinda slide to one side or the other. So I tracked down a different pin with a slightly larger OD and it works great with these washers. I could have bought more washers from the original source, like on the first 2 ones above, but the overall price would have more than doubled.

The spring packs have plenty of adjustment in either direction and I can get velocities from low 200s all the way up to 330+ with at least another turn available on the adjustment. Once I get around 260 or so it only takes the smallest amount of adjustment to get it up in the 280-290 range. Probably a 1/16 of a turn at most. I am sure other setups will be different, but so far that is my experience with both of the test guns. One is Lvl10, the other Lvl7. They seem to be a little more sensitive than an original spring pack.

[superman]

I wonder if that quick change in velocity is the result of a higher spring rate. Maybe dropping down some will offer a larger range of adjustment in that 270-300 area. Either way man awesome work.


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[wthomas333]

That would definitely take some extra testing and I am not opposed to that and likely with continue to fool around with different washers and configurations. I had zero knowledge of Belleville washers or how they worked and these 2 little charts sum it up best for me and doing amateur work with these things.

But, from my understanding, making the stack shorter doesn’t matter as far as force applied, only changes the amount of deflection available, at least with this particular stack. You have to change the configuration of the stack. I obviously tried to mirror the stock spring pack as closely as possible when shopping for parts and therefore we have a parallel-series stack with 2 washers in parallel. And putting 3 washers in parallel would definitely be too stiff, and a series stack of only one washer would be too light with these particular washers.

The bottom chart talks about load vs deflection trend (linear,pro,regressive). That is likely what I will play with a little more as I believe this spring pack just has linear load vs deflection since it’s the same top to bottom. If I change the configuration of the stack I might get something that is a little more forgiving. Nice thing is that if I do happen to figure something different out, you can just pop off the oring and sort your washers the same way and put it back together.

[wthomas333]

Have some complete. I know some of you already chimed in as wanting some of these so I will set some apart. The others will go up for sale in a normal BST thread. If they sell relatively quickly and there seems to be more demand, I will put in another order for some more parts. It doesn’t look like much, but that was a bag of 1500 Belleville washers. I have about 45 available.

Once people get a chance to install and use them, I would appreciate any feedback. I have already put in a couple orders for some possible alternative components, not that there is anything wrong with these, but I had some other ideas I wanted to test out.

Hopefully this helps some folks get those classic valves back up and running. I have tested several and have one installed in my Minimag that I have tested everyday for about 2 weeks. It seems to be working well, but obviously only long term use with thousands of shots will determine how durable these really are.

[Levi]

Great work! I'm down for a couple of these.

[wthomas333]

For those of you that maybe want to build your own, or just for posterity's sake. Buy these parts from McMaster and you can build your own for about $26-$27 a piece if you buy enough washers to build up all 5 pins that come in the pack. If you just want to build one, it will run you about $60. FYI. These are the same parts I used for the 2 'prototypes', not the same as the ones I am selling.

Clevis Pin https://www.mcmaster.com/92735A120/
Belleville washer https://www.mcmaster.com/9712K58/
Washer https://www.mcmaster.com/90474A164/
O-ring or C clip https://www.mcmaster.com/1295N114/ OR https://www.mcmaster.com/97414A615/