Page 3 of 7
Posted: Sat Aug 11, 2012 4:09 am
by Fire Buster
You should use a good and perfect shaft....
Posted: Sat Aug 11, 2012 4:17 am
by airpress
I don't know what you mean with perfect shaft?
Posted: Sat Aug 11, 2012 1:24 pm
by airpress
Can you see the difference between 2" threads and 3"?
I've reduced the pilot to 3/4" and maybe I will use a QEV to pilot it. But I have to find one first.
I've send some mails to different pipe suppliers and I hope that the can sell 3" pipes in 1m.
Something else.
I was just thinking about the rubber sealing face. Is it possibly that the seat could be cutted in the rubber? With the forces from the pressure and area(cm²). Since the seatpipe is a 2" pipe with 3mm walls. I will use 5mm rubber.
I ask this because when I get acces to 3" steel pipes I will use more pressure.

Posted: Sat Aug 11, 2012 4:49 pm
by MrCrowley
airpress wrote:
Something else.
I was just thinking about the rubber sealing face. Is it possibly that the seat could be cutted in the rubber? With the forces from the pressure and area(cm²). Since the seatpipe is a 2" pipe with 3mm walls. I will use 5mm rubber.
I like to think I have a bit of experience in this area as I've dealt with numerous sealing faces being destroyed by piston bounce in my piston hybrid.
There's been one type of rubber that has successfully held up, rubber from a boat trailer roller. I'm not sure if you have any boating stores near you, but here they sell these for about $10 up to 4" in diameter. Simply cut off the bit you need and bolt it to your piston. They come in all shapes and sizes, but generally you can find them like this:
The rubber is very hard, it doesn't compress noticeably at all.
Posted: Sun Aug 12, 2012 1:04 pm
by airpress
Thanks for the tip Mr Crowley! I will see what I can do. Since we haven't got any boat stores here nearby. But I will test it first with the rubber I have laying around here. If it continuously fails, then I have to find something else.
Today I get my "hole saw" to drill a hole that has the exact diameter of the 2" pipe.
Tomorrow I will weld the pipe in the bushing.
Posted: Mon Aug 13, 2012 1:09 am
by Crna Legija
feck that would have taken a bit to drill
Posted: Mon Aug 13, 2012 11:38 am
by airpress
I've added frequently some cutting oil to the saw. It helped much with cutting it.
Btw: pipe succesfully welded in the bushing. I've screwed some fittings together for piloting.
Posted: Mon Aug 13, 2012 3:02 pm
by silentkill12345
this thing is gonna be so amazing!! dude i love it

are you from belgium?
Posted: Mon Aug 13, 2012 3:50 pm
by MrCrowley
Did you cut that hole so you could push that 2" barrel nipple through, weld it in place, and use it as the seat where the piston seals against?
Can't think of any other reasons why you would need to modify that bushing.
Posted: Mon Aug 13, 2012 6:32 pm
by PotatoEnemy17
Just Curious-Is there a difference between piston valves and quick exhaust valves?
Posted: Tue Aug 14, 2012 3:09 am
by airpress
MrCrowley wrote:Did you cut that hole so you could push that 2" barrel nipple through, weld it in place, and use it as the seat where the piston seals against?
Can't think of any other reasons why you would need to modify that bushing.
Indeed, thats the reason like you said why I needed to modify that bushing. I did the same with the 2" piston valve.
silentkill12345 Yep, i'm from belgium.
Update: 16u30
Finished the piloting area, except the manometer
Pïpe succesfully welded in the bushing. I need to shorten the pipe.

Posted: Tue Aug 14, 2012 12:43 pm
by airpress
I like it!
The piston is ready, the only thing I have to do is cutting the rubber and mounting it on the piston side.
Mr crowley, i've found some hard rubber in my local store.
piston inside the nipple
other side
btw: i've found the correct word for the material i'm using for the pistons
It's called Nylon.
Posted: Tue Aug 14, 2012 12:55 pm
by ACE_Tomato_Co.
Nice valve. Heavy duty. Did you turn the nylon piston on a lathe?
Posted: Tue Aug 14, 2012 2:11 pm
by silentkill12345
so nice, thats gonna give a punch when you fire it :p i should mount it on a cart
(dacht het wel

had het gehoord in je filmpje)
Posted: Wed Aug 15, 2012 3:43 am
by airpress
Thanx!
ACE_Tomato_Co. wrote:Nice valve. Heavy duty. Did you turn the nylon piston on a lathe?
The piston was 0.5mm to big in diameter. I sanded it on a "sanding table".
Piston ready for use. You see that the rubbers is a little bit wobbly. It is later sandend in the shape of the piston itself. I cutted the rubber a little bit larger and then sanded it.
This afternoon:
- screwing the pilot together
- shorten the seat pipe
- screw the chamber in the elbow, I had left over some 75mm pvc pipe, I will use it untill I have found a 3" metal chamber
- and finally testing