2.5 inch QDV build

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
Just1ChanceFree
Private
Private
Posts: 9
Joined: Wed Aug 01, 2007 5:12 pm

Thu Nov 19, 2009 7:07 pm

Looks slick tech, nice work. Any chance you measured those o-ring IDs and Widths? I want to be able to calculate your perphral squeeze % to figure out which rings I should buy :P
User avatar
Heimo
Specialist 2
Specialist 2
South Africa
Posts: 243
Joined: Sun Oct 25, 2009 3:02 pm

Sat Nov 28, 2009 4:06 pm

Tech I really like the simplicity of this valve. now I am patiently awaiting updates on this
User avatar
Technician1002
Captain
Captain
Posts: 5189
Joined: Sat Apr 04, 2009 11:10 am

Sat Nov 28, 2009 8:03 pm

Heimo wrote:Tech I really like the simplicity of this valve. now I am patiently awaiting updates on this
Thanks for being patient. It is on hold due to the season. I have a diversion using the following;

Vixen Lights sequencer;
http://www.vixenlights.com/
An Open DMX USB Interface;
http://www.enttec.com/index.php?main_me ... escription
4 of these;
http://www.optimalighting.com/MATRIX-DM ... gory_id=26

and a whole bunch of Christmas lights. :D

When done it should look something like this;
[youtube][/youtube]
Not my show.. I am planning on using that tune. I'll have 16 channels.
:D
User avatar
Heimo
Specialist 2
Specialist 2
South Africa
Posts: 243
Joined: Sun Oct 25, 2009 3:02 pm

Mon Dec 28, 2009 11:42 am

Any updates on this yet?

anyhow As I mentioned before I really like this and I happen to have some spare materials kicking around that would be perfect for this type of gun just smaller since I do not own a compressor

Here is the stuff I am talking about

a small fire extinguisher along with a piece of seamless tubing
Image

the piece of seamless tubing I have, have a high polish on the inside so that is very convenient note the reflection inside the tube due to the polish
the seamless tubing has got a ID of 30mm

Image

I will start a new thread on this if I actually build any thing with it
User avatar
qwerty
Corporal 2
Corporal 2
Posts: 678
Joined: Sun Apr 12, 2009 2:16 am

Mon Dec 28, 2009 12:08 pm

Nothing to do with the thread but where is tech? he hasn't been posting for a while.
I visit occasionally to make unrelated posts.
User avatar
Technician1002
Captain
Captain
Posts: 5189
Joined: Sat Apr 04, 2009 11:10 am

Mon Dec 28, 2009 10:27 pm

qwerty wrote:Nothing to do with the thread but where is tech? he hasn't been posting for a while.
Tech is in full holiday mode.. Cannon is on hold.
:D Happy holidays

Set up stage lights and programmed a light desk for a Christmas Musical, Decorated with Christmas lights, visited relatives, preparing for a New Year's party with noisemakers not in SF guidelines. I have posted once in a while in other threads.
John Conklin
Private
Private
Posts: 12
Joined: Fri Dec 25, 2009 2:53 am
Location: Topeka KS

Thu Jan 07, 2010 6:06 pm

Here are some specs I worked up for an O-ring & piston based on the Dichtomatic O-Ring Handbook:

Pipe size: 2-1/2” (2.469” ID)
O-Ring # 330

Piston OD: 2.439
O-Ring groove diameter: 2.121”
O-Ring groove width: 0.285”

This will meet all the criteria for ring squeeze, compression ratio, extrusion gap, ID/OD interference and gland fill.


Hope this helps!
Just1ChanceFree
Private
Private
Posts: 9
Joined: Wed Aug 01, 2007 5:12 pm

Fri Feb 05, 2010 8:34 pm

Has it really been a month? Gosh I'm slow to respond. Thanks John, that does help! If I'm remembering how to do my math right, that would result in a 1.2% peripheral squeeze. Is that enough to still seal up to around 100psi? The specs I'm looking at recommended a 5% peripheral squeeze. What I'm comparing to is a -326 ring in 2.000" pipe (ID - 1.600, .210 CS, 2.020 OD). I'd love it if the -326 ring would work in 2.000 pipe; else I've have to go up to -327 and just suffer the extra friction :/
John Conklin
Private
Private
Posts: 12
Joined: Fri Dec 25, 2009 2:53 am
Location: Topeka KS

Sat Feb 06, 2010 9:09 am

Just1ChanceFree,

Here's the data for a #330 O-ring in this application:

CYLINDER DIA: 2.469
O-RING NUMBER 330
O-RING I.D.: 2.1
O-RING O.D.: 2.52
O-RING CROSS SECTION: 0.21

ID/OD INTERFERENCE: 1%
INSTALLED O-RING CROSS SECTION: 0.208
EXTRUSION GAP: 0.015 (GAP BETWEEN PISTON & CYLINDER)
GROOVE BASE DIA: 2.121
GLAND HEIGHT: 0.174
GLAND AREA: 0.045
GROOVE DEPTH: 0.159
GROOVE WIDTH: 0.285
COMPRESSION RATIO: 16%

The Dichtomatik O-ring handbook calls for a compression ratio of 5%-30%, so this should work fine.
Also, a piston diameter of 2.439" will give you an extrusion gap of 0.015", and should be good to 500 PSI.

The Dichtomatik O-ring handbook is a really handy reference. Google Dichtomatic and you should have no problem finding it.

John
User avatar
theBOOM
Specialist 3
Specialist 3
Posts: 374
Joined: Wed Jun 03, 2009 10:49 pm
Location: San Antonio, TX

Mon May 03, 2010 11:35 pm

Bit old but, has the build continued or was it stopped for some reason?
User avatar
Technician1002
Captain
Captain
Posts: 5189
Joined: Sat Apr 04, 2009 11:10 am

Mon May 03, 2010 11:56 pm

The build was on hold for the winter, spring gardening, tearing down a house, a move, etc.. Basically life. It should begin construction soon. In the non spudgun discussion is my series of photos of tearing down a house with a logging loader. It's a piece of heavy equipmnet for picking up logs and loading them onto log trucks. I got to run it for a while. This was fun. Last weekend was spent helping a disabled relative and her 3 kids move to another state. That wasn't fun, but did blow another good weekend. Weekend before that was out of state to a grandson's birthday party.

At the birthday party we did bring along the marshmallow cannon and plinked a few cans full of water with marshmallows. :)
Image

Total destruction photos are here for those who like severe damage pictures. :D http://www.spudfiles.com/forums/total-d ... 20791.html

In a couple of weeks is a men's retreat. The cannons were invited. I hope to get some fun launch photos and a video then. I've been wanting to get a good video of a roll of adding machine tape, but have been too busy shooting to take video. With lots of guys, I'll get a chance if the weather is good.

As much fun as spudding is, it is not on the top of the priority list. I get to it when I get time. :roll: Do expect some updates soon. :D

Edit, I was re-reading this entire thread. The delay is pretty much summed up in the first paragraph in my first post on the first page. :D

Edit update; no bump. The men's retreat went well with great weather. Added the paper launches along with a tennis ball hang time, glowstick launch, a full pop can and other videos on my youtube channel. I won't bump this until there is progress to report on the launcher.

Paper launch;
[youtube][/youtube]

Pop can launch
[youtube][/youtube]

Pop can retrieval
[youtube][/youtube]

Tennis ball hang time
[youtube][/youtube]

More on my channel
http://www.youtube.com/user/Technician1002
Post Reply