Search found 746 matches

by mobile chernobyl
Tue Oct 25, 2016 11:23 pm
Forum: Pneumatic Cannons
Topic: Arrow gun: Barrel length vs fps question.
Replies: 18
Views: 2200

Re: Arrow gun: Barrel length vs fps question.

Good point @mrfoo Here's a cutaway view of a modern spear gun: http://www.nauticexpo.com/prod/imersion/product-22356-405649.html And another view of the stages of a typical spear gun from rest to arrow launched: http://aquatech1.narod.ru/pneumatic.gif I think the arrow sealing against the barrel wit...
by mobile chernobyl
Wed Oct 19, 2016 10:47 am
Forum: Pneumatic Cannons
Topic: Arrow gun: Barrel length vs fps question.
Replies: 18
Views: 2200

Re: Arrow gun: Barrel length vs fps question.

I would think actually that the shaft just creates a larger 'dead space' area - as the entire barrel is empty in the beginning - and the volume only increases to approximately 2x that dead space up to the point of arrow leaving the barrel. This would create a softer acceleration curve - which may be...
by mobile chernobyl
Tue Sep 13, 2016 3:57 pm
Forum: Pneumatic Cannons
Topic: Jöerg Sprave's Pneumatic Arrow Shooter
Replies: 3
Views: 1049

Re: Jöerg Sprave's Pneumatic Arrow Shooter

Joerg was a fairly active member here - could probably bring him back on here for discussion if you had any questions if you send him a private message!

http://www.spudfiles.com/joergs-u13549/
by mobile chernobyl
Tue Aug 16, 2016 7:53 pm
Forum: General How-To & Discussion
Topic: Is spudding dead?
Replies: 102
Views: 27477

Re: Is spudding dead?

This is a relevant point, for many people this hobby is indeed a way to shoot things when you're too young to own a "proper" gun, or otherwise prevented from doing so legally. I'm definitely in both realms. It is certainly nice to be able to buy off the shelf stuff and put holes in stuff up to 1/2"...
by mobile chernobyl
Mon Jun 27, 2016 12:36 pm
Forum: General How-To & Discussion
Topic: Frisbee launcher
Replies: 7
Views: 985

Re: Frisbee launcher

What's a reference size you want it to be, and a reference weight? Good place to start!
by mobile chernobyl
Mon Jun 27, 2016 10:24 am
Forum: General How-To & Discussion
Topic: Frisbee launcher
Replies: 7
Views: 985

Re: Frisbee launcher

The clay pigeon setup usually imparts spin from the arm - As the arm rotates, the frisbee/pigeon will move outwards along it from the centrifugal force. The arms usually have a little rubber U-shaped channel that the outer edge of the disc can maintain contact with. This is how the disc starts spinn...
by mobile chernobyl
Wed Jun 22, 2016 10:33 pm
Forum: Off-Topic Hobbies
Topic: Anybody else going to IREC next week?
Replies: 3
Views: 1418

Re: Anybody else going to IREC next week?

Nice pictures! Any interesting CATO's or were they mostly all succseful launches? Looks like one in there possibly late stage.

Any interesting rocket chemistries? See some interesting colors in some of the pictures
by mobile chernobyl
Tue Jun 14, 2016 8:52 pm
Forum: General How-To & Discussion
Topic: Frisbee launcher
Replies: 7
Views: 985

Re: Frisbee launcher

This guy has made a pneumatic clay pigeon launcher - you can probably abstract an idea from his basic mechanism:
by mobile chernobyl
Tue Jun 14, 2016 8:49 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: BFG #7
Replies: 57
Views: 7510

Re: Semi automatic ideas?

Check out the 'Autococker' paintball mechanism:
http://www.zdspb.com/media/tech/animati ... er_wgp.gif

Tons of other paintball based semi-automatic ideas here:
http://www.zdspb.com/tech/misc/animations.html
by mobile chernobyl
Thu May 19, 2016 10:20 am
Forum: General How-To & Discussion
Topic: Is spudding dead?
Replies: 102
Views: 27477

Re: Is spudding dead?

...You could make this site a whole lot more popular by having step by step tutorials on the front page with immediate results... I think there was one time in this site's history that they tried to promote posts from the build log - sort of make a different project a 'featured' one every week. Spu...
by mobile chernobyl
Mon Apr 25, 2016 10:38 pm
Forum: Off-Topic Hobbies
Topic: "Offtopic-posts-topic" NSFW
Replies: 6630
Views: 266912

Re: "Offtopic-posts-topic" NSFW

Nice work!

Got a close up of that rear disc mount? And I'm guessing you had to get a disc compatible rear wheel (hub)?

I always wanted to build a cool steel framed city beater bike - they're pretty common now but weren't always haha.
by mobile chernobyl
Tue Mar 01, 2016 4:03 pm
Forum: Combustion Cannons
Topic: Noise cannon for RC planes
Replies: 162
Views: 20921

Re: Noise cannon for RC planes

Just noticed this thread pop up to the main page again - all I can say is WOW! Great progress! Love seeing more work done in the field of detonations! :D :D Good luck in your future ventures - Do you have a picture of how the noise maker is installed in/on the RC plane? And what is your theory/hypot...
by mobile chernobyl
Fri Jan 15, 2016 6:32 pm
Forum: Hybrid Cannons
Topic: Automatic Piston Hybrid Cannon Design
Replies: 27
Views: 5412

Re: Automatic Piston Hybrid Cannon Design

What you are describing is precisely the conclusion Utron came to - and if you view the Defense document below - you can see their solution!

(It will automatically start downloading a pdf file when you click it - it's worth a thorough read through!)

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA462130
by mobile chernobyl
Fri Oct 30, 2015 1:28 pm
Forum: Combustion Cannons
Topic: Noise cannon for RC planes
Replies: 162
Views: 20921

Re: Noise cannon for RC planes

Futterama wrote:Hi Shyasuna!

"it seems like your tube is shorter and bigger in diameter than mine."
That is interesting :lol:
by mobile chernobyl
Thu Oct 29, 2015 1:17 pm
Forum: General How-To & Discussion
Topic: Modeling software for CNC (Mach3)
Replies: 8
Views: 1223

Re: Modeling software for CNC (Mach3)

Mastercam, however you choose to obtain it, is very friendly with SolidWorks. I've used the two together for CNC Lathe, Mill and EDM (no... not the music lol). And I don't consider myself an expert by any means - it's just a reallllly good tool path program that ties into SolidWorks really well and ...