Modified Etac-Reg
Well because my new lathe is a little late on showing up I figured I would make another etac-reg with a collar for more volume. Can’t make what I will make until the new lathe shows up in the next couple of weeks. I made this one about .187 wider to see how much difference it makes. All I know is that my new .22 condor I built shoots kodiaks in the 970’s with a standard etac-reg and 2500 psi reg. With modified etac-reg and 2000 psi reg it shoots in the mid 960’s to low 970’s. I have the 2000 on a 53 ci tank and the 2500 on a 62 ci tank. I get more shots with the 2000 reg on the 53ci tank. I will pressure test this one to 4500 psi in a bucket of water after I weld it together tomorrow. It is .180 on the top and the sides are .140 thick. The most it will see is 2500 psi and I don’t think I will need more than my 2300 psi to get the .25 kodiaks to 950 fps or so. Going to go down to 1800 psi for the .22 I think.
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Nice weld…. ( I did industrial non-destructive testing with magnetic particle, dye penetrants, ultrasonics and gamma radiography for 10 years)
😯 Ouch!!! 😯
I use a 1/2″ end mill and slot the top and bottom. It is all done and it is cooling off. Have to change out the burst disc on my reg to 5000 psi so I can pressure test it. I was playinyg with the valve you sold me and I had a little accident in the lathe with it. Was able to fix it and now it’s just cosmetic. Here are the pic’s.
I believe you are correct AG1, a few well placed holes drilled perpendicular to the major axis… 😉
Dyotat100 – How do you open up the base unit into your ring ?
He said screwy because they were better than his… 😆 😆 😆
😀 Didn’t mean screwy numbers, like that, but screwy numbers in that the shot count went up as the reg pressure went down. 😀
Because you were increasing the volume.
Well here’s the $64,000 question:
What is the volume of air at what starting pressure is normally released from a standard hammer striking the top hat without a regulator ?
A reverse way to figure this is how much air does it take to push a pellet at a given velocity ?
Is any of this info available anywhere ?
I think I found a spreadsheet awhile back (but deleted it) from a guy in Germany who calculated the air needed to push a pellet in different barrel sizes (in theory) ?
Screwy numbers? Those are good numbers and I’m trying to get great numbers. I’m trying to get as close to unregulated numbers with a reg at the same pressure I can. I will see how much closer this gets it. I have a new version I will build with new lathe that I hope will do it. If not I will settle for as close as I can get.
Let me understand what you are doing. You have the long body and you drill holes in it or something to use the cavity of the collar, which you weld on, to increase the volume post-regulator ?
Now I understand why you posted those screwy number and shot counts for the past modified adapters. It is all based al increased volume post-regulator.
Whew, for a second I thought I was losing my mind… 😆
Yes the valve showed up. Thanks. That is the valve in the pics. I did this a while ago for my .25 with good results.
I take it the Condor valve showed up? 😀
Did you make something similar to this before? Or did someone else weld a ring to an Etac to increase the volume?
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Ok it turned out even better than I thought. I tested it to 4269 psi and no problems. I had to play with the reg to get it to not regulate and when I did I somehow messed up my shim stack. So after playing with it for a while I settled on 1800psi instesd of the 2300 psi it was. Well the collar works. 1800 psi on my .25 with 25.4 g JSB’s it is now shooting in the mid 960’s. It shot around 940 with 2000 psi reg before. I took 80 shots on 62 ci tank with only 22 fps spread. I get a little creep in the reg so that is why 1 shot that was 973 fps and the rest were in the 960’s until the very end.
Hi 973
Low 951
Avg 963
Spread 22
Std D 3