vacuum chuck testing

Not sure where the rotary valve is specifically on your site. I check the links off woodstuff.htm but didn't spot it.

Derek

alt.binaries.pictures.woodworking

Greg G.

Hi mac

It would be easier for us if you put it on your website.

I have been to the abpw and nothing yet, the last pic. from you is a stitched up platter, don.t know how long ago you posted that ?? it is right in the last page, 10 pictures or so from the end.

Leo.. that is one of the pictures that were posted this morning...

I'll try to put some on my site, but when you do web pages all day, it's hard to get enthusiastic about them at night...

Damn good thing I didn't go into OBY/GN!! Mac

Hi Mac

They just showed up, the pictures that is.

Looks good, you used a plastic end cap over the bearings I think ?? with the brass elbow in it. What you use for the inside, into the spindle, copper/steel pipe or something else ??

Nice small clear bulb filter, makes it easy to see if anything is in there, and you have a bleeder valve on the front side I suppose, can't see it in the picture.

Next chapter in your quest for more round wood .

Have fun and take care Leo Van Der Loo

My first attempt, which Bill Noble warned me would wear out quickly, was simply a compressor quick disconnect, and it wore out pretty quickly..*g* I lasted long enough to try a few chuck designs, though..

The 2nd try was a PVC joiner section with a bearing in each end, but I found that 2 bearing aren't needed... all you need is yo isolate the handwheel from the vacuum fitting...

I threaded the inside of the spindle to fit a brass gas fitting, then used an adapter to get the thread size up to the inside diameter of the bearing.. I think it was .625".. I put the fitting in the lathe chuck and tapered the threads off the larger end of the fitting with a file, then used thick CA and a jam fit to fasten it to the bearing...

I picked an end cap that was slightly too small for the outside of the bearing, put it in the chuck and widened the end at a taper with a sharp mini-skew...

While I had the cap in the chuck I drilled a 5/16 hole in the end of the cap for the compression elbow..

It's still not a GOOD valve, but it works and has no leaks so far... It would be MUCH more time efficient to just buy a complete system or have Bill make one up, but it wouldn't be nearly as much fun.. *g*

Mac

Hi Mac

You say it's still not a good valve, I don't agree, it does not leak, it works, and it is KISS, what more doe you want ??? A tool that works is a good tool. Yes the quick connect/disconnect is not made for that kind of swiveling, even I could have told you that , but they sure are nice to have, so you are able to take a part, piece,gun,tool, and switch for another or just take it off and store. Time and efficient, Oh, well that would mean I would have to go and buy my turnings, noooooooh I'm having to much fun.

Have fun and take care, and thanks for sharing. Leo Van Der Loo

I think the weak part is the pvc cap super-glued to the bearing.. it's on a stress point.. The swivel relieves a bit of the stress, but until I support the quick disconnect to the pump or something, there is still downward pressure on the cap.. My original idea was to put the hole for the vac fitting on the side of the cap, but it was easier to drill the end..

I forgot that it was hooked up today until I was putting Shellawax on a pen blank.. the vac fittings were NOT happy about 3,000 rpm!

the quick connect lasted quite a while, long enough for several tests... which let me get the theory down and make a couple of good chucks before I had to concentrate on getting the vacuum TO the chuck..

I never failed, I just learned several ways that vac chucks don't work.. *g* Mac

That is an interesting valve you have there. I have been giving some thought recently to trying this out. How much vacuum is needed to make this type of chuck work, assuming you dont have any leaks?

Would one of these work well?

Hi Jimbo

The venturi vacuum system work very well, drawback to the ones I'm familiar with is they are very noisy, and use an very large amount of air, they are very good for use with high flammable material, in our case emptying gas fuel tanks that had a leak or where there was a problem with the fuel pumps and tanks had to be taken down. The vacuum systems used on the wood lathe have always some leakage, through the wood and or bearings, so in order to have a high vacuum for small turnings you would have to run an let say 10 hp compressor to keep up with the venturi, not a problem if you have lots of compressed air, but not very economical for a home workshop IMO. I happen to have a venturi from an evacuation setup that was scrapped and I rescued the venturi, gauges and valves, I even gave it a try on my lathe, but thought better of it and use a small compressor instead.

Have fun and take care Leo Van Der Loo

I really have no idea if those would work, Jimbo.. sounds like Leo has the scoop on them, though...

I'm running about 10 on the vacuum gauge right now, but I sanded the bottom on one bowl with the first valve and it was holding fine at about 5.. I hesitate to say "5 pounds", as I'm not sure if the correct term is pound, inch, etc...

I'm totally new at this and if it wasn't for Bill Noble's used pump and accessories and his advice, I never would/could of tried it..

Mac

If I find anything interesting I will post back. Thanks for your input.

Jimbo