Search found 11 matches

by akb
Sun Apr 11, 2021 9:42 am
Forum: Pneumatic Cannons
Topic: True formula for flow coefficient
Replies: 6
Views: 3908

Re: True formula for flow coefficient

I designed one launcher using a Deltrol 3/4" QEV and their published Cv feeding a tennis ball barrel (SDR21 2.5). Actual performance was about half of predicted, as I recall (it was a very long time ago). I suspect they measure Cv for exhausting an air cylinder (their intended application), and this...
by akb
Sun Apr 11, 2021 9:30 am
Forum: General How-To & Discussion
Topic: 3D Software
Replies: 19
Views: 12792

Re: 3D Software

OpenSCAD works for me
by akb
Sun Oct 27, 2019 9:39 pm
Forum: Pneumatic Cannons
Topic: DFTV Revisited and 3D Printing Pistons
Replies: 7
Views: 6217

Re: DFTV Revisited and 3D Printing Pistons

Perfect, Thanks!
by akb
Sun Oct 27, 2019 6:01 pm
Forum: Pneumatic Cannons
Topic: DFTV Revisited and 3D Printing Pistons
Replies: 7
Views: 6217

Gas Gun Design Tool

Where can we get the Gas Gun Design Tool these days (GGDT)? It appears that Dave's website has been hacked and points off to some site selling monkey-cactus.

I recall there was an effort to host it here somewhere??
by akb
Thu May 23, 2019 8:04 pm
Forum: Pneumatic Cannons
Topic: DFTV Revisited and 3D Printing Pistons
Replies: 7
Views: 6217

Re: DFTV Revisited and 3D Printing Pistons

https://lh3.googleusercontent.com/5iX8uhmmmDOPlyoaPehaSsdmWAEeoq_kaizpwN23n26AW2E6yZx0Cr6DWcbJk0aedWT4SSTUM0h4ZWdVaurB3Qr4Nc--ZHGdQHc6aIYADk2hOm43zZg38GH8Xteql6MsyTJO5T4-gZUhEHT4T_sXnfuRzF_m36SZ4Dw0QR4Dfhpg1fMwGRzw5X8q8WBWitLrnJMAqd95cVzLEdC26DCv76kIQGnYnd4T1C2xmVGExWFJTvTuhCYu-RC__M42709Sxzc32WDWf...
by akb
Sat May 18, 2019 9:57 am
Forum: Pneumatic Cannons
Topic: DFTV Revisited and 3D Printing Pistons
Replies: 7
Views: 6217

Re: DFTV Revisited and 3D Printing Pistons

Must be a time warp. :) Yes! You have an excellent memory. Going to use it today (G0516). Have a couple Antenna Launchers to finish up. Great design, nice drawing. What CAD tool do you use? Reminds me of the time I did paintball. Another blast from the far past. I wonder at what pressure the tennis ...
by akb
Fri May 17, 2019 10:48 am
Forum: Pneumatic Cannons
Topic: DFTV Revisited and 3D Printing Pistons
Replies: 7
Views: 6217

DFTV Revisited and 3D Printing Pistons

Hi Folks. Been away a very long time. Still making Antenna Launchers, but haven't been on the forum here since 2010, at least in terms of posting. I'm working on a new DFTV (Darn Fast Turbo Valve) design with some 3D printed parts. I see some folks have done printed pistons. I need to do more readin...
by akb
Wed May 05, 2010 7:40 am
Forum: General How-To & Discussion
Topic: GGDT/HGDT Problem
Replies: 15
Views: 5161

Honestly, I've no idea. I've never even seen Windows 7. (OK, so my computer is old) Hi, Dave. Been a long time. My computers are all XP until last week. Bought a new laptop, came with Windoze 7 64 bit. Seems to work fairly well so far. The XP compatibility mode worked for me first try, though each ...
by akb
Tue May 04, 2010 9:41 pm
Forum: General How-To & Discussion
Topic: GGDT/HGDT Problem
Replies: 15
Views: 5161

He wrote them for XP using Visual Basic so they don't play so well with Vista and Windoze 7. I hate to set admin priv when I can avoid it, but XP compatibility should be enough. It works for me. I do have to click through a permission to write on the hard drive, but that is not a big problem. After ...
by akb
Sun May 02, 2010 10:06 pm
Forum: General How-To & Discussion
Topic: GGDT/HGDT Problem
Replies: 15
Views: 5161

I had the same problem on my new Windows 7 machine. I specified to run it in XP mode. Seems to have fixed the problem (have to answer a security screen each time it launches to allow it to access the HD but that's not a big problem). In detail, right click on the ggdt4.6.exe file, select properties,...
by akb
Sun May 02, 2010 7:40 pm
Forum: General How-To & Discussion
Topic: Using GGDT on Linux systems
Replies: 11
Views: 5356

... i actually like CALM better. ... : Wow. Great to hear there are actually some CALM users out there. Apologies for this OT comment. I found it when trying to get GGDT to run on Windoze 7. XP compatibility mode made it work, having the files in the same dir was not enough. Thanks for the tips on ...