Vacuum Chuck Setup Question

Hello,
I have a PM3520b and a box of Oneway vacuum clamp parts, including adapters, manifold and chuck...and need some help figuring how they go together... I can't find any videos, or even pictures of how this system is installed on the PM lathe. The wheel on the PM is threaded, which I understand was not true on earlier models. So, if anyone has set this up, and could post a picture that would be greatly appreciated! As for the vacuum pump, I was thinking of using my VacuPress pump that I use for veneer work. It is a 6cfm pump, which seems like more than enough. Thanks for the help!
Izzy Charo

Izzy,
I have not seen this system in operation but I'll do the best I can to help you put the pieces together.

Your vacuum pump will be fine.

So, starting from the handwheel side of the headstock spindle, you'll have a vacuum pump pulling air through a hose that goes to a vacuum gauge that connects to a vacuum adpater that fits into a stronghold 3520 A/B Outboard adapter (the hollow headstock spindle carries the vacuum to the other side). On the threaded side of the headstock spindle you have another regular 1 1/4"-8 stronghold adapter that fits in the drum chuck that has the neoprene seal on its rim (between the wood and the chuck cylinder).

Highland Woodworking has some details about what is needed but not much. Go to highlandwoodworking.com and add /oneway8vacuumdrumchuck.aspx and then follow the link in the text to this page /onewaymountingadapterforstrongholdchucks.aspx .

I would be tempted to call Oneway at 800-565-7288. Oneway is usually very helpful and can probably send you a diagram (why they didn't post one on their website is a mystery to me).

Good luck!

By the way, on the heastock threaded spindle side, the standard adapter has a taper that fits into the drum chuck (there may be a set screw at the perimeter of the drum to lock the drum to the adapter) and the adapter taper points away from the headstock. The flat aluminum disc (if you have it) is to protect the neoprene seals during storage and to encourage the right shape of the neoprene.

Quote:

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Originally Posted by Izzy Charo

Hello,
I have a PM3520b and a box of Oneway vacuum clamp parts, including adapters, manifold and chuck...and need some help figuring how they go together... ...

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I got a Oneway vacuum adapter and all the fittings along with a 3520b I bought a few years ago. I have not used the Oneway adapter since it required removing the handwheel to install. Instead, I got a different adapter that fits into the spindle with the handwheel in place.

A suggestion - it might help get useful instruction if you set all the parts you have out on a table and take a photograph or two to post. Perhaps include close up additional photos of certain parts. If I saw what you have, for example, I could tell you if it's the same adapter I have and someone could explain just how to connect everything.

JKJ

Thank you all for the detailed help! I am trying to upload pictures, but the link in the FAQ section on how to upload pictures does not take me to a place with a link to create an album... am I missing something? Thanks again!

Attachment 435969Attachment 435970Attachment 435971
I am attempting to post pictures of the parts...assembled as best I could figure out. Turns out that the wheel shaft on the PM is not threaded, but rather has a slot in it for a set screw. I think the spindle side is not too difficult to figure out; but I think I need an adapter of some sort on the wheel side. The conical part on the threaded rod rotates freely...so that's where my bearings are. I'm not sure what the small aluminum part on the other end of the threaded rod does...Again, many thanks for the help!

Quote:

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Originally Posted by Izzy Charo

I am attempting to post pictures of the parts...assembled as best I could figure out. Turns out that the wheel shaft on the PM is not threaded, but rather has a slot in it for a set screw. I think the spindle side is not too difficult to figure out; but I think I need an adapter of some sort on the wheel side. The conical part on the threaded rod rotates freely...so that's where my bearings are. I'm not sure what the small aluminum part on the other end of the threaded rod does...Again, many thanks for the help!

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I haven't used or even seen one except in pictures, but that looks like it functions similar to the HoldFast vacuum adapter. This is a simple method that works on almost any lathe with a through hole in the headstock spindle.

The tube is a lamp rod or similar rod and is cut to length to fit the lathe. The tube slides through the hole in the headstock spindle so the end with the bearings is on the handwheel side. I'm guessing the aluminum part fits tightly enough into the working 2MT end of the headstock spindle to support and seal that end of the rod. It's hard to tell from the picture but it looks like the rod has a quick connect made for pressurized air instead of a hose barb, but if the plastic tube will slide over it tightly it should work OK. Just connect the vacuum to the manifold, the plastic tube to the hollow rod, and mount the vacuum chuck to the headstock spindle. The valve on the manifold is for bleeding off some of the vacuum as needed to avoid breaking thin or fragile work.

Perhaps someone familiar with this particular adapter knows the details.

I see there are videos on the HoldFast system, such as this one, which show the principle:
https://www.youtube.com/watch?v=3ihTFfcstog

BTW, you only need to make albums if you want to keep photos around.

JKJ

Attachment 436004To hook up a vacuum to the lathe is not that complicated or expensive. The photo shows adapters made for Powermatic 3520B and Nova Comet II lathes to work with a Frugal Vac system. The adapters are inserted in the open end of the drive shaft with fairly close fit (note tape on one) and a "O" ring around the end to improve seal. There is a sealed bearing on the inserted shaft that is epoxied to the wood with a threaded lamp conduit on side to connect the vacuum hose. I use threaded blocks of wood at head stock drive with PVC couplings or pipe to attach foam for the seal to piece. The chuck pieces are made in multiple sizes from 2 to 6" couplings and also a couple a little longer for deeper items. Threaded blocks of flat plates can also be used. IT IS NOT THAT COMPLICATED. The Rikon 70-220 VS purchased recently required a new adapter and it again was easy to make, except the bore was only slightly larger than 3/8" and there I had to build up the lamp nipple that previously had installed wood over to turn down to diameter (like turning a pen).