SpudFiles

POLAND_SPUD wrote:
if the motor winding is burned multimeter would show you that becasue there would be no conductivity (so no reading at all).... if you get results that make sense then try testing the compressor with replaced starting circut (I'll write more about it if it's needed)
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Not all burnouts fail as an open circuit. Some burn the insulation causing some turns to become shorted. In this case a circuit breaker may be tripping before it overheats enough to burn it open. Check the oil for discoloration from the "smoke" and the odor. In a sealed system, smelling the outside won't help. The system needs opened for an odor check. For testing before opening, a clamp around ammeter can be used to check the current. A stalled, stuck, shorted turns, or failed start circuit will show high current that may blow the breaker.

Always check for continuity to the shell of the compressor. If the insulation has become burnt and moisture has entered the system (probable cause) and the oil has become acidic, it becomes slightly conductive and shows up as leakage current. (Ground fault) A GFI outlet can be used to test for this condition as the leakage will trip a GFI outlet.

ITWOST

Instead of the usual spud gun, Ive begun work on a Trebuchet. Expect some fun stuff from that. And better yet its school funded

how much weight are you using?

as far as my cast part, that was actually a pop cap that will be fitted with an air fitting and a spark plug to make a hybrid noise maker.

ramses wrote:how much weight are you using?

Ive got 10lbs in it now, (Firing golf balls) but Im out to buy a junkload of lead shot (or airgun BB's) to increase that weight to about 12 or 13 lbs.

VH_man wrote:

ramses wrote:how much weight are you using?

Ive got 10lbs in it now, (Firing golf balls) but Im out to buy a junkload of lead shot (or airgun BB's) to increase that weight to about 12 or 13 lbs.

I have one that also fires golf balls, but I use around 25lbs of some junk barbell weights.

ITWOST, I played with a lathe for the first time, and made an aluminum piston to slide in a smoothed out 3/4" nipple. When I threaded it in, the pipe compressed, and the piston froze up . I cleaned it up with a dremel, but the o-ringed piston still doesn't move very freely. The valve only seals with the back above 100psi. Does anyone have any potential solutions?? the piston is lubed with motor oil (guy who sold me O-Rings said that would be okay).

A cylinder hone and drill might fix the sliding problem.??

Clean it up, coat the inside with "sharpie" pen or similar, then push the piston in, and then out.

You might be able to lightly coat the inside of the nipple with spray paint if you can't get in with a marker.??

The areas that need attention will have the ink scraped away.

If it's minor, you should be able to use your dremel.

I use grease on all of my pistons. White lithium for PVC, general purpose chassis grease, teflon grease, lithium w/moly and silicone grease all work well with metals, and won't bother the o-ring.

Once you get it sliding, if it still doesn't seal, you'll have to do the "marker ink on the barrel/sanding piston" thing.

ramses wrote:

VH_man wrote:
ITWOST, I played with a lathe for the first time, and made an aluminum piston to slide in a smoothed out 3/4" nipple. When I threaded it in, the pipe compressed, and the piston froze up . I cleaned it up with a dremel, but the o-ringed piston still doesn't move very freely. The valve only seals with the back above 100psi. Does anyone have any potential solutions?? the piston is lubed with motor oil (guy who sold me O-Rings said that would be okay).

I have a thread here on using o rings in air cannons that addresses most of the issues. You may get it to work by buying o rings just large enough to fit in the pipe without the piston, then cutting the piston grooves to fit as shown here.
[youtube][/youtube]

I hope this helps. It works for me. The video shows a piston opened just by shaking the launcher and ends with a hand pulled piston in a 2 inch nipple.

Here is the thread on the subject;
http://www.spudfiles.com/forums/how-to- ... 17899.html

Let us know how this works out for you.

thanks, I will try that. if it doesn't work out today again. we were going to ream?? it, but it didn't fit in the drill press, and we weren't allowed to use the huge, beastly, awesome lathes. Or the milling machines. .

ramses wrote:thanks, I will try that. if it doesn't work out today again. we were going to ream?? it, but it didn't fit in the drill press, and we weren't allowed to use the huge, beastly, awesome lathes. Or the milling machines. .

I don't have a hone or reamer.

The 1 inch wasn't bad, but the 2 inch nipple took a good part of a weekend to get honed enough to seal. I needed several breaks, so it wasn't the entire weekend blown on just sanding. A 3/4 inch nipple shouldn't take much more than an afternoon to get polished up nice.

Edit, removed the youtube link. It is in the above mentioned thread on o rings. See the videos in the o ring thread.

I bet you had a fun weekend!

ramses wrote:I bet you had a fun weekend!

On first test pull when that beast roared and nearly scared me to death, it became very fun. It has been worth it. The cannon kicks a$$ and has been rock solid reliable. It was louder than I ever imagined it to be. My avatar is an apple impact on a 1 L water bottle sitting on the end of a sawhorse. It's the 2 inch valve in action.

My 2 inch nipple is 16 inches long. A shorter one would need less time.

I salvaged a compressor out of a 30-year-old dehumidifier. I plan on using it in conjunction with an A/C compressor to refill paintball CO2 bottle and such. The dehumidifier compressor even has a large fan on the same circuit that I can use for cooling both.

The only thing I'm worried about is that I might blow a fuse using both at the same time. Just starting up the A/C compressor causes the lights to dim.

ITWOST, i tried firing a frozen chili pepper through an old coffee tin, it didn't work.
This did though, me eating chili wings trying to beat the other cats- anyone here like chilis?

ITWOST I made some "changes" to MIKE, The 400 PSI+ marble cannon. It now has a scope. And interchangeable Barrels.

Internally I made the piston nearly 400X more efficient by my calculations (Decreased friction) and now its as powerful at 150 PSI as it was at 400 Before. 400 PSI shots with a marble now actually cause shoulder pain after 2 or more shots

I also Finally got around to fixing JANET, my streamlined sprinkler valve gun. When school gets out Ill fill in the rest of the BONDO work, paint her up and put her in the competition. Its nothing really new but ideas on aesthetics, Which was her main focus.

Also, I Got around to making a sweet target for my marble cannons. its a hanging wok pan. when hit it swings violently and lets out a very satisfying CLANG! It also dents pretty hardcore. I reccomend making one for all you marble cannon people. Its insane.

ITWOST I may soon be getting a high speed camera with all related equipment, And not just any camera, a Vision research v7.3 or a v 12.1!