Finished Long Parts Tumbler

Nice.

How about a bicycle tube - 18" of it or whatever. Use zip ties to squeeze tight.

Mart> Thanks for the help guys... Here's the final final...

Looks nice.

As I had noted, roll on truck bed liner would probably make a good interior coating to both quiet things and give a little traction.

I think trying to make a linear hatch on something that small diameter would be a frustrating experience with lots of leaks.

A tumbler for SCUBA tanks I recently built.

That's what's great about this NG... Everybody is a real problem solver.

You might be onto something with that split idea Carl. I'll have to look into it.

And Pete... Yes, I forgot to mention the spray-on idea you had. I just wasn't quite sure how I was going to get it evenly inside the tube. I learned a little more today... I found rubber end caps that have the stainless bands. I just took off the bands and they work a lot better than the ABS caps. They're easier to get on and off, totally water proof, more quiet, and also provide more friction than you could ever need. In fact, too much friction... They started wearing down the shaft hose. I had to put tape on them to stop the chaffing. They also have these "testing" caps, where they have a cap with a rubber cork below it, and then a screw in the middle to expand the rubber. But those are even with the pipe size, so the whole pipe would be rolling.

I'm not a diver... Why do tanks need to be tumbled?

I also found this pipe insulation tape to put inside. It's like 2" wide foamy stuff with very sticky backing. I actually didn't think it would stay on, but it's was still stuck perfectly after running it 3 hours.

Dave

On Thu, 11 Oct 2007 23:13:40 -0700, with neither quill nor qualm, snipped-for-privacy@aol.com quickly quoth:

What about the liquid rubber dip stuff? Buy 3 cans and pour it in the tube, rotating it while it coats the inside. Pour the rest back into a can and save it for pliers and other tool handles.

I wouldn't think it would have to be perfectly even. At any rate, how about a rag wrapped around a round sponge plug and pulled with a string? Pour in the coating and pull the rag wiper through to distribute. A couple coats in each direction should do the trick.

Those test plugs are probably the best option, though you have to account for the few inches on internal length you loose vs. the end caps.

If a tank gets moisture and resulting corrosion inside you tumble them with an abrasive slurry inside to clean them so they can be fully inspected to be sure the corrosion didn't damage the tank enough to make it unsafe (3,000 PSI for the typical aluminum 80cf tanks = potential big boom).

That's why I think the truck coating would be good, it's designed to bond tightly and is resilient so it should take some abuse.

Ahh... OK, that makes sense.

Yeah, I'll checkout the truck stuff when the tape wears out.

Larry, I did think about the tool rubber stuff. The guy at the store didn't seem to think it would stick enough though. But that other rubber stuff might be an option.

Dave

On Fri, 12 Oct 2007 11:15:42 -0700, with neither quill nor qualm, snipped-for-privacy@aol.com quickly quoth:

Undercoating?

Scuff the inside of the tube to give it some tooth, then clean it thoroughly with a good solvent.

Not undercoating - the bed liners on pickups that are sprayed on. Real nice and tough! Martin

Mart> On Fri, 12 Oct 2007 11:15:42 -0700, with neither quill nor qualm,

Neat, what are you going to use for media? (that's the part that always made me skip any tumbler / vibratory toys..errr tools)

How is your generator doing?

So far so good. It does what I hoped it would do (keep the HVAC and Lights running).

However, if i had to do it again, I'd select a 4cyl engine. With the single cylinder engine running 60hz @ 1800rpm equals 1 power stroke every 4 cycles. The big flywheel helps smooth this out, but my SmartUPS are too "Smart" and see the fluctuating frequency and refuse to switch over to "utility power" when the HVAC is running.

Its not the end of the world, but does require I shut the "data center" down, pull the Smartups out of the loop, and power up the "data center" again... (kinda annoying.) I might look at getting a little 3kw Honda inverter gen to power the "data center"

The alternative of course would be to build a 5 cyl radial Diesel to power the genset :)

I have the same problem with my 2 cylinder Onan DJE. I am not 100% sure why my UPSes do not like it. Could be frequency or could be something else.

I've done a lot of research and I am confident the issue is the slightly fluctuating frequency between power strokes. If I unload the generator, the Ups will switch to utility power over a fairly wide range of frequencies. 58 - 62hz

I think what's happening is the SmartUps has a local oscillator it adjusts to try and match the utility line frequency. Once it's matched the line frequency it references the local oscillator to measure the voltage error on the utility line. The problem arises when the utility line frequency keeps changing, the repetitive change in frequency shows up as a voltage error to the UPS. For instance, you can see the shift in frequency on the O-Scope picture here:

Oh, here's a short list of my "odd" ideas

A) Active rotor power control to modulate the output voltage in real time to fix both voltage AND frequency fluctuations. Not a very efficient fix, but I think it might work.

B) Mechanical weights on the flywheel that extend during a power stroke, and retract during the compression stroke in an attempt to keep the flywheel rpm constant..

C) Various stupid electro-mechanical tricks to make clean 60hz 120vac @ 1.4Kw at the Smartups outlet 1) Rectify to DC, invert back to AC 2) Dc motor powering small generator 3) several large induction motors with massive flywheels attached to line power... For bonus points, enclose flywheels in a vacuum chamber to reduce losses... :)

Jim, thanks for a nice post, I saved it in my archive of notes. It makes total sense. I can live with this issue, but, as you say, it is annoying.

You left out my favorite from that discussion on s.e.d, an elliptical and/or offcenter pulley on the motor to maintain constant generator speed. :-) I know the optimum shape would change with load, but it would look so neat.

-- Regards, Carl Ijames carl dott ijames aat verizon dott net (remove nospm or make the obvious changes before replying)

LOL.. I believe I left it out becuase it made my head hurt thinking about how to implement it!

However, you have made me think that sometimes the most ellegant solution to a problem is not neccisarilly the most enjoyable to implement.. I swear once I find my mill, I'm going to get a copy of

On Oct 17, 10:19 am, James Lerch

The main parts I'm doing are 1/4" aluminum round pieces. For that, I've found that small river pebbles about 1/8" to 3/16" work best. It's filled with 1/3 pebbles and water, plus a little soap. About 2 hours later they're shinny and smooth. I'm sure walnut shells would make them even better. I've tried a couple larger hollow tubes, but it doesn't work as well on those. I think the tubes fill with the media and the weight makes the parts slam down and get small dents from the media. I ended up using pvc shower basin liner inside. I also switched to using screw tight test plugs on the ends instead of caps. I cut the tops off rubber caps and just used the ring sides on the pipe to work as the gripping surface to turn.