Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 64 users online :: 5 registered, 0 hidden and 59 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], Majestic-12 [Bot], Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Stupid ball bearings don't fit!

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
Sponsored 
  • Author
    Message

Stupid ball bearings don't fit!

Unread postAuthor: JDP12 » Tue May 22, 2007 4:44 pm

Hey all, well i just got my 5/8" ball bearings from mcmaster..and well guess what..they don't fit in my electrical conduit barrel.

Grrr... I don't want to return them and get new ones cuz that'd cost too much, so i need to find a barrel for them, or grind down the balls. I don't want to grind them cuz there'd be impurities so that's off the list..

Well the best thing I've found is 5/8" nominal Type L copper pipe, .667" ID, but i can't find it on any online store!!!

So does anyone know of a pipe i can get in 5/8" or where i can get 5/8" copper??
  • 0

"Some say his pet elephant is pink, and that he has no understanding of "PG rated forum". All we know is, he's called JSR. "
User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Unread postAuthor: mark.f » Tue May 22, 2007 8:45 pm

3/4" type K copper tubing... which you can order off McMaster. :P .652" ID, give or take normal tolerances.
  • 0

User avatar
mark.f
Donating Member
Donating Member
 
Posts: 3464
Joined: Sat May 06, 2006 11:18 am
Country: United States (us)
Reputation: 21

Unread postAuthor: A-98 » Tue May 22, 2007 9:03 pm

did you make sure that the inside of the conduit was 5/8"? like with calipers.
  • 0

There are rules, and then there are hundred dollar bills.
User avatar
A-98
Brigadier General
Brigadier General
 
Posts: 921
Joined: Thu Apr 27, 2006 7:41 pm
Location: Santa Barbara, CA
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Tue May 22, 2007 11:10 pm

Or you could make a 1.5" caliber shotgun :D
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: JDP12 » Wed May 23, 2007 7:15 am

K um no to the shotgun, are you kidding me where can i get Type K copper tubing off of mcmaster, I looked but couldn't find it.

A-98-my dad measured it with a ruler and said it was, but I remeasured it when i found they didn't fit, and it was just a little smaller than .625"..He probably just assumed or something...

EDIT: is this the part number that you are talking about??

50475K24

I only want to make sure cuz the picture they showed, it kinda looked oval shaped..Just want to make sure thanks. I'll probably order it
  • 0

"Some say his pet elephant is pink, and that he has no understanding of "PG rated forum". All we know is, he's called JSR. "
User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Unread postAuthor: mark.f » Wed May 23, 2007 7:20 am

That's it. You were just looking through the actual catalog pages themselves.
  • 0

User avatar
mark.f
Donating Member
Donating Member
 
Posts: 3464
Joined: Sat May 06, 2006 11:18 am
Country: United States (us)
Reputation: 21

Unread postAuthor: JDP12 » Wed May 23, 2007 7:28 am

dangit...okay I guess I'll just order that again... hahaha lol this is great... actually the price isn't too bad though, for 5 feet its only like $19..and I'm makin a 29" barrel so yep..At least I'll have extra :):) Thanks guys
  • 0

"Some say his pet elephant is pink, and that he has no understanding of "PG rated forum". All we know is, he's called JSR. "
User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: jimmy101 » Wed May 23, 2007 12:09 pm

While your ordering from McMaster maybe you should get a micrometer?

You are building pretty specialized stuff, much more advanced than a hunk of starch in a 2" piece of PVC. As you have discovered, a difference of 0.01" makes a difference, the best you can do with even a high quality ruler is perhaps 0.03" (a crappy ruler is probably only good to 0.06"). You really should have a decent micrometer.

Unfortunately, good micrometers cost big $$$, figure $150 at least. So you might have to settle for a plastic one or something a little less than "Nuclear Engineer Grade". McMaster has some dial micrometers that are affordable, like part #'s 8588A12 (plastic, $19), or 2289A42 (steel, $27). I believe both are rated to 0.001" accuracy.

Or, a vernier caliper (no dial) like # 2192A21 (steel, $10.22) or 2272A21 (steel, $23.03).

Most calipers (like those listed above) will read length, OD, ID and depth.

You might also try some surplus places, I got a pretty good one years ago for $20. Also check the local pawn shops and garage sales. If you find a good one buy it, even if it is 50 years old. (Heck 50 year old tools are generally much better than most modern equivalents, and always better than anything you can buy at today's hardware stores.)

If you can, spend enough to get a decent tool. If you take care of it, you'll be using it for the next 50 years.
  • 0

Image

jimmy101
Lieutenant General
Lieutenant General
 
Posts: 3127
Joined: Wed Mar 28, 2007 9:48 am
Location: Greenwood, Indiana
Country: United States (us)
Reputation: 7

Unread postAuthor: jackssmirkingrevenge » Wed May 23, 2007 7:04 pm

jimmy101 wrote:If you can, spend enough to get a decent tool. If you take care of it, you'll be using it for the next 50 years.


here here, a worthwhile investment - I don't understand how I used to get by before i got mine.
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: mark.f » Wed May 23, 2007 8:55 pm

And, a hint... don't get a 4" one. I thought I would never need more than that capacity... until I needed to know the average I.D. of a piece of ~5" square steel tubing for somebody from school. I've got a 6" pair of steel ones now that work great.

EDIT: and sometimes the crappy plastic ones are more expensive than the good steel ones. Take the "General" brand of plastic calipers at Home Depot. Freaking almost thirty bucks, 1/64" accuracy, and cheap nylon plastic to boot.
  • 0

User avatar
mark.f
Donating Member
Donating Member
 
Posts: 3464
Joined: Sat May 06, 2006 11:18 am
Country: United States (us)
Reputation: 21

Return to Pneumatic Cannon Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], Majestic-12 [Bot], Yahoo [Bot]

Reputation System ©'