Good old photobucket carnt see pics
I decided to see if I could improve upon my 21mm TX tune , I know that Jon Budds short port is worth some power so took it to the extreme and made a comp tube end plug to take a 21mm sleeve and provide a 4mm long port using a single breech seal , this increased the spring room considerably, and knowing that a longer spring can be softer and less stressed I also installed a spring guide fixed into the trigger block.This worked well with my original ally piston , the short port allows a much lighter piston to be used without it bouncing, so again went to extreme on spring room and made a very short skirtless piston hoping the rear guide would support the rear , it didn't , the fit of the trigger block in the action is pants so the guide pitched upwards when the screw was tightened , causing friction on the piston.
So came up with a design of full piston( using an x ring to seal) that along with the short port and fixed guide give me an extra 18 mm of spring room .
The gun shoots nicely with very little recoil and is a little softer to shoot, I will attempt to put pictures up to illustrate , and bring it to the bash
https://goo.gl/photos/TQKtWy5jVeq6Vxo28 last picture shows longer spring now used over original
https://goo.gl/photos/1tXjJDGg1Fuv9VdW8 failed skirtless piston
https://goo.gl/photos/Jo5yDFt9nLWZCTQ99 components showing piston design
https://goo.gl/photos/4nQyFpp7ey1hSLQm8 power plant
https://goo.gl/photos/XtUGEfJeLKTCLXZL7 trial short piston to see if the design works
Last edited by NickG; 05-08-2017 at 07:46 AM.
Good old photobucket carnt see pics
Thats weird I have tested them and they work for me .
sounds good mate, I like it. Spring room really helps guns shoot nice; I think that's why sleaved HW80s and Pro Elites are so soft...
Photobucket has blocked third party hosting for everyone BTW, so no-one will be able to see the pics - you need to use another provider
Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.
ok will try flicker
So you're coming to The Bash, Nick?
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THE BOINGER BASH AT QUIGLEY HOLLOW. MAKING GREAT MEMORIES SINCE 15th JUNE, 2013.
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good work nick .
are you making the end cap from scratch ?
just wondered why you kept with the hex
oh yeah
thought about boring the trigger block , to get a bit MORE spring room ?
hows the spring clearance to the inside of the piston tube ?
and
could you go lots longer on the rear guide ?
get it shooting , and start counting the shots for us
Last edited by hmangphilly; 05-08-2017 at 10:08 AM.
Had to do the cap from scratch to get the room, made the hex so i could get it out , it only has loctite on the liner diameter, next one is only having the thread in the liner and just loctite into the tube , no hex one thread ,easier.I have a 19.8 mm ream for the piston bore , so around 1mm clearance it doesn't bind , The x ring gives a little extra power to the o ring as you run them with less crush.
I have the shorter spring version in my target gun and its holding up, hoping this one is the answer so its going in .