rotary vacuum adapter design

[Mike Minto]

for any of you have turned your own rotary vacuum adapter from corian (or whatever), can you post some 'plans' or info on how you did it? single/double bearing, must the 'inserted' part meet the spindle that runs thru the headstock, or just half-way or so into the existing handwheel (Jet 1642 in this case). Thanks.

[John Frigillana]

I recently completed my vacuum chuck for my Jet 1642. I made the adapter out of Corian. I was slightly smaller than the diameter of the original knock out hole in the hand wheel. The outside diameter was a little larger than the O.D.. I used double sealed bearings to assure no leaks. I used the nipple side of the brass adapter for the extra length to accept the two bearings. Also put 3 o-rings to seal the shaft of the adapter to the I.D of the hand wheel and a larger one to seal the adapter to the end of the hand wheel. I will post pics.

[Greg Ketell]

Yup, what Keoni did. The only difference is that I only used two o-rings on the body of the shaft. I figured they were there just to hold it in and hold it straight. The o-ring at the base of the shaft is the one that actually does the sealing.

I also put a bead of silicone around the outer edges of the bearing (only one on mine) to help hold it in and to seal any leaks.

GK

I recently completed my vacuum chuck for my Jet 1642. I made the adapter out of Corian. I was slightly smaller than the diameter of the original knock out hole in the hand wheel. The outside diameter was a little larger than the O.D.. I used double sealed bearings to assure no leaks. I used the nipple side of the brass adapter for the extra length to accept the two bearings. Also put 3 o-rings to seal the shaft of the adapter to the I.D of the hand wheel and a larger one to seal the adapter to the end of the hand wheel. I will post pics.

[Tim Rinehart]

Mike,
I fashioned one for my 1642 (when I had it) using a block of maple, with a shouldered hole for a double sealed bearings (2RS). I think the actual size was a R8 (1/2" ID and about 1 1/8" OD). The 1/2" ID works well to take a barbed elbow fitting with 1/4" NPT threads and file enough of the threads to fit inside and hold with JB Weld or equivalent.

The backside of the adapter was drilled with the size of the stem when I removed the handle from the outboard end of the spindle, vs the o-ringed 'opposite but equivalent' that Keoni did.

When I got a 3520, I simply inserted a piece of 1/2" copper tube in the hole on the adapter, glued in place, and slid a small o-ring to help the seal to the 3520. Using a little silicone grease will help the seal, but isn't really all that necessary. I also don't see any advantage in use of threaded rod...as the force of vacuum keeps the adapter engaged during use...and I've not seen any marked losses by not having the adapter 'pulled' up on the spindle.

The first pic is when I first made it for the 1642, and it just had a 3/4" ID (? I think) hole to slip over the outboard end. When I modified it for the 3520, a piece of 1/2" copper pipe fit so well into the outboard end of the 3520 spindle...I decided to fix the pipe to the adapter and just use a small o-ring (not even a tight fit...just a hose washer really is what it is) to seal the gap at the adapter to hand wheel.
Works great, no complaints.
Oh, and I've tried experiments with running a vacuum while turning with a 'test' block attached...and you can try to pull the adapter off...it will move a little..but just keeps wanting to reseat itself, and no big loss of vacuum that I could detect on my gauge.

Good luck and let me know if you need more info.
Tim

[Tim Rinehart]

Ok, I'm an engineer...but not the CAD type. I draw with pencils!
Here's the key dimensions in a cross-section of the adapter I have in pics above.

Material for the adapter can be anything that you have that is 'convenient', in my opinion. This piece isn't under alot of stress...so you don't have to use metal, but corian-like or other composite material would be nice, if nothing else but to look more polished.

If you find that you are getting alot of leakage around the seals on the bearing, it may be that there isn't sufficient grease to prevent leakage. It's pretty easy to pop one of these seals off, add some more grease, and put it back on. I've done it myself, and haven't had any problems getting seal to go back on. Others may have advice as well.

Unfortunately, all bearings aren't alike in terms of performance...though all else seems the same. I wouldn't pay 'top dollar' for these, I think I gave about $6 a piece for the bearings at a local power transmission supply house, and I believe they're either from China or Taiwan. The vast array of online shopping houses have them also.

One last thing that I had to learn difference on...you want Double Sealed...NOT Double Shielded. The shielded bearings are like what you see in most of the lathes for their spindles (at least the Jets and PMs use them). The shield is a metal piece, but doesn't provide as much barrier to air penetration. Double sealed will have a plastic/rubbery kind of barrier on the outsides of the bearing. You'll see a difference if you pull up pics of each type.

Also found that I needed a single sealed bearing to repair spindles on my lawn mower deck (open sides are facing each other to accept grease from connection on spindle housing)... I fought like heck to find supplier of single sealed till someone told me "take one of the sides off to make it a single shielded". Haha, always the obvious.

[Mike Minto]

Excellent...

[Sri Shankar]

Hi all, new member here.
I was looking at all the posts about making a vacuum chuck system. So far I have a Gast pump, but I'm stuck at the adapter level. I can't find a "double sealed bearing" anywhere. Anyone know of a source? Lowe's does not carry any bearings apparently....

Thanks

[allen thunem]

go to msc, or mcmaster carr or enco i fyou have a fastenal close by try them too but they get expensive.
google double sealed bearings

[Rick Hutcheson]

I have a page on my web site how I built mine. Also building vacuum chucks.
http://www.scrollsaws.com/WoodLathe/woodlatheVacuum.htm

[Dennis Nagle]

Great documentation Rick. THanks much.

[Tony Rozendaal]

RotaryCoupler.jpg

Here's something I drew up for my Nova DVR. I bought my bearings from www.vxb.com - I have bought bearings from them for bandsaws and for the headstock on a Grizzly lathe as well.

Wow - this is an old thread isn't it? See the note above between the difference between sealed and shielded bearings.

[James Combs]

Here's something I drew up for my Nova DVR. I bought my bearings from www.vxb.com - I have bought bearings from them for bandsaws and for the headstock on a Grizzly lathe as well.

Wow - this is an old thread isn't it? See the note above between the difference between sealed and shielded bearings.

Yes it is older but still very applicable.

On my 1642 I actually drilled out the aluminum "hand wheel"(if you can call it that) and installed my bearings in it. I rarely use the 2MT feature of the spindle and I use a 1-1/4"-8tpi to 1"-8tpi adapter(with 2MT hole) anyway so if I do get a 2MT device stuck in the spindle I just remove the adapter and knock it out. You can see it here.

Edit: +1 on using www.vxb.com, get all my bearings there, all the way from my lawnmower deck to my Rikon band-saw guides.

[Ron Rutter]

The bearing designation to use is " 2RS " which means rubber seals both sides.