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All Springer/NP/PCP Air Gun Discussion General => Machine Shop Talk & AG Parts Machining => Show us your Custom Airgun Parts (TRICKS-N-TIPS) => Topic started by: darkcharisma on March 16, 2020, 03:51:27 AM
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Well. i spent about 3 days on and off taking 1 hour break from two 4 hour sessions each day. and look at what i made.
its a Rainstorm valve made to be modded for 257 cal.
the original valve seems to be okay. i used 1144 to replaced the unknown valve material. since i have done some modding and cutting thin oring grooves into the valve body. i did not want to take a chance so i went overboard and overkill.
its not done yet but making a counter sunk throat and poppet fitted with 2mm stem is easily done in a day. ill have to fit that onto a busy schedule, the wife almost killed me so ill have to do airgun stuff on the weekends from now on.
i have made threaded parts using taps and dies on 1144 before so i have confidence in having nice threads. No doubt its super nice threads and way faster than changing gears on the lathe for a specific thread.
1145 is a PIA if you dont know how to take care of it. I gave it plenty of silicon oil after rinsing with tap water. it rusted where ever it wasn't polished overnight! so i polished it inside and out! I may need to treat it with some kind of coating, but don't know which is good.
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It's a nice looking part. 1144 or 1145?
I am curious about the 3 days bit though...
Al
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I am curious about the 3 days bit though...
Al
Only three days? Some of us, for a variety of reasons, work rather slowly.
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its 1144. mistyped on one of the paragraph.
back when i first started. something like this would have took me more than a week with errors. zero big error on this one.
it took me 1 hour to true and zero. 2-3 hours to cut the profile from 1.5" to .885... i didnt have 1" 1144. i take .010 passes sometimes .005 passes.
drill, boring and reaming that took forever. i worked until its 5am first night.
Lots of run offs and re-zero and truing, thats easily 1/2 to 1 hour each truing. cutting the grooves, man that took forever, there is no such thing as going too slow on grooving...0.02 increments to avoid chatter and tool breaks. final profile and cutting the thread with hand dies took more than a couple of hours and polishing alone took 2 hours with 500 grit, 1000 grit, 2000 grit then 3000 grit...and thats going fast.
this is how i built patience btw. i would rather go slow to save from parts breaking...
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What type of lathe did you use ?
I must be spoiled from using big high power rigs.
.100” would be my usual roughing cut.
Your work looks really good.
Charles
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whoa...i would dream of having .100 rough cuts! the little guys dream big. i use grizzlys 7x12 mini lathe, its too underpowered. i could have saved alot of time if i have one of the bigger lathes...
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Wasn't meant as criticism, merely curious regarding the lathe/methods. Have never run a 7" lathe, but...any lathe is better than no lathe at all. 8)
Al
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true that, any lathe is better than no lathe. ill take all the criticisms too btw, constructive or not. ;D
i am really wanting to get a bigger lathe now.
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got some more pics to show off.
the valve and barrel ports are 7mm. the throat is .310 and is removable if one decides to upgrade. stem stays at 2mm
the poppet is peak and set up to seal against the counter sunk throat. no leaks.
with the stock spring and stock light hammer. i got this RS to shoot 94 grains at 787fps for 129fpe max. its a cliff for 5 shots from 200bar to 150 bar. i was anticipating 150fpe so its shy 21fpe.
made a linear magazine for it out of delrin but no detents install yet, waiting on parts. short slugs will fall into the port but with a magazine it cycles smooth.
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Very well done .. Part looks fantastic !!
Being your that dedicated to improving the power, you may want to do away with a conventional poppet and go with something more balanced / reduced opening force ?
Just a share of info you may not have seen previous ...
Along these design lines. You can use a solid metal poppet head in a soft seat material .. or make the poppet head from Peek / Glass delrin .. or sleeve the metal poppet in either using on a hard seat.
Poppet can be an opposing into the intake side held thimble or inverted with Thimble on backside of poppet.
Your into this now ... why not really GO FOR IT 8)
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Your into this now ... why not really GO FOR IT 8)
You are speaking directly to my soul.
I don’t think making a balance chamber is difficult but a couple of days worth of shop time.
But I don’t know if there is a known ratio of the chamber volume to valve throat that is best for power and efficiency? Do you have a couple of suggestions given your experience?
I am trying to wrap this project up next week when the 257420 mold arrives. maybe I can squeeze in a couple of valve mods before then.
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Your into this now ... why not really GO FOR IT 8)
You are speaking directly to my soul.
I don’t think making a balance chamber is difficult but a couple of days worth of shop time.
But I don’t know if there is a known ratio of the chamber volume to valve throat that is best for power and efficiency? Do you have a couple of suggestions given your experience?
I am trying to wrap this project up next week when the 257420 mold arrives. maybe I can squeeze in a couple of valve mods before then.
50/50 is safe and very effective, tho on my personal ones fabricated closer to 60/40 because I like & use really light hammers along with SSG devices where I can control the opening forces better than a free flight heavy hammer or non SSG configuration.
A lot of my modified valves use valve throats of .280" and have poppet heads sealing it in the .330/.350" range and have balance chamber at .250"
The JSAR valves also a .280 throat have @ .340" poppets and @ .210" balance
Hollow valve stems are a trouble spot so you can also drill an @ .048-.052" vent hole next to stem and get the same effect. * Picture shows this, tho was an R&R poppet and hole was too large ! Idea of th vent alternative to stem hole still holds true tho. * ONLY with the inverted design having the cup on back of poppet and thimble on intake grate. as shown in 2nd pic which uses a 006 size buna QUAD ring.
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Thanks for the pictures and details, I’ll make an attempt.
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Any news on your balanced valve attempt? I've been thinking of making one but I just can't figure out a simple way of attaching the rod to the valve block.
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i have not had time to start it.
you can cut a small groove inside to fit a retaining C clip ring. Not to the block but the removable piece that has exhaust hole