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PostPosted: Sun Sep 19, 2004 11:13 pm
by clide
Deemed the "Slider" gun in reference to it's key part, the exhaust valve.

Basically it is a fancy barrel sealing tee valve. The exhaust valve used is a homemade version of McMaster part number 4622K57. In the forward position, the input holes are connected with holes going to the chamber. In the back position, the input holes are isolated and the holes going to the chamber are exhausted to atmosphere. That means input flow is cut off in the same motion that exhaust the pilot chamber. The piston has a built in one way valve for a quick fill without harming performance. If I had a high flow air source available I could get up to .25" input flow, but currently flow is limited by the quick connect fitting. The stock can be pushed into the chamber when the gun is not in use, and I tried my best to give it a fancy paintjob. (3 days ago, waiting 7 days is impossible). I can get about 2 shots off per second. Faster ROF could probably be obtained with an electric 3 way valve instead of the slide valve, but I wanted to stay away from electronics.
OK, pictures say 1000 words so:
<a href="http://members.cox.net/ecyrb/slider/top.jpg">Best view IMO</a>
<a href="http://members.cox.net/ecyrb/slider/right.jpg">Right side</a>
<a href="http://members.cox.net/ecyrb/slider/left.jpg">Left side</a>
<a href="http://members.cox.net/ecyrb/slider/front.jpg">Front</a>
<a href="http://members.cox.net/ecyrb/slider/back.jpg">Back</a>
<a href="http://members.cox.net/ecyrb/slider/grip.jpg">Hand position</a>
<a href="http://members.cox.net/ecyrb/slider/piston%20parts.jpg">Piston with one way valve parts</a>
<a href="http://members.cox.net/ecyrb/slider/slide%20parts.jpg">Two parts from the slide valve</a>
<a href="http://members.cox.net/ecyrb/slider/slide%20assembled.jpg">Slide valve by itself</a>
<a href="http://members.cox.net/ecyrb/slider/slideclosed.jpg">Closed, filling position</a>
<a href="http://members.cox.net/ecyrb/slider/slideopen.jpg">Open, vent/firing position</a>

Anyway, of course I needed a loading system to keep up with the gun. I decided to use paintballs because they are cheap and fit with the scale of the gun. Seems to work fine. I find paint in there sometimes, but I think it is from the 3 year old paintballs, not a problem with the loading. Currently I just use a clip, but I am planning on getting a hopper to work.
<a href="http://members.cox.net/ecyrb/slider/bolt.jpg">Crude paint diagram</a>
<a href="http://members.cox.net/ecyrb/slider/noclip.jpg">Side view, no clip</a>
<a href="http://members.cox.net/ecyrb/slider/barrel%20position1.jpg">Top view, normal position</a>
<a href="http://members.cox.net/ecyrb/slider/barrel%20position2.jpg">Bolt midway through movement</a>
<a href="http://members.cox.net/ecyrb/slider/barrel%20position3.jpg">Closed position</a>
<a href="http://members.cox.net/ecyrb/slider/barreldisassembled.jpg">Inside parts of the loading system</a>Curently I am using a sprinkler valve spring, but I will try to make my own sometime.
<a href="http://members.cox.net/ecyrb/slider/finalwithclip.jpg"> Everything together, view 1</a>
<a href="http://members.cox.net/ecyrb/slider/finalwithclip2.jpg">view 2</a>

<a href="http://members.cox.net/ecyrb/sliderdemo.avi">Video of the gun in action</a> 3MB, encoded with DiVX. Let me know if you have trouble playing it, I can reencode it with something else if people have problems

UPDATE: Animation of the gun provided by GalFisk
http://galfisk.kaaven.net/img/cannons/c ... deauto.gif

PostPosted: Sun Sep 19, 2004 11:28 pm
by Mr.Plow
[:o]

I'm at a loss for words....

badass!

PostPosted: Sun Sep 19, 2004 11:32 pm
by bob-e
<font color="#000000">wow, thats awsome. i think that is now the fastest pneumatic gun ever, now if only i onderstood it. could you please give a deatiled explination of the exhaust valve, because im stumped:?:</font>

PostPosted: Sun Sep 19, 2004 11:34 pm
by clide
Yeah sorry, my description was kinda lame. I will try to draw up a diagram tomorrow. I am too tired ATM

Thanks for the compliments.

PostPosted: Sun Sep 19, 2004 11:36 pm
by plasticex009
Awesome launcher Clide!

If pictures say a thousand words then a video is comparable to a book. Wow, that fires quickly. It seems the balls break in the breech a lot. Have you figured out why this is happening?

PostPosted: Sun Sep 19, 2004 11:41 pm
by clide
I am pretty sure the only reason the some balls are breaking is because they are 3+ years old. I have fired every ball perfectly and still found paint in the loading mechanism. I'll try to pick up some fresh balls sometime this week to make sure that is the case.

PostPosted: Mon Sep 20, 2004 5:53 am
by Melkor
Wow. That is awesome. [:0]

PostPosted: Mon Sep 20, 2004 7:07 am
by GalFisk
^-What those guys said.
That's one of the most awesome guns I've ever seen, the video kicks [donkey]! :p
Looking forward to seeing the diagram.

PostPosted: Mon Sep 20, 2004 7:29 am
by Timmay
you rock.

PostPosted: Mon Sep 20, 2004 8:49 am
by BC Pneumatics
Pure genius. Cant wait for the diagrams. How acurate/fast is it? not the ROF, but the projectile velocity?
I think that if I ever get my curent launcher done (my first real combustion, so i want to do it right!!) I will atemt this with AA batteries, or a strafer. Most likey this.
Amazing work!!!!

--edit-- And god bless you for putting it in .avi Finely a vid I can watch!! Sometimes it seems the world is nothing but a mess of .wmv's out to get me and my precious totem.