Hopefully some answers to your questions.....
Kenny asked (
in italics):
I am presently doing the very same thing to my 1642. So many choices... I
was thinking about using a EZ Adapter (79 dollars) or making one for about
10 dollars. If I was to go the route that you took- can you use the punch
out rod with your adapter so to remove the center pin or is there another
way to remove the center pin?
No you can't - to use a knock-out bar to remove things in the Morse taper you must remove the vacuum adapter. In this case the Oneway is likely much easier, since you don't have to unthread anything - just slip the adapter off of the outboard side of the headstock and you're in business.
Is there a reason that you did not choose the less expensive EZ adapter?
Well, my major concern was that the rotating spindle would possibly cause degradation of the seal at the hose connector end. Secondly, I didn't think it a very elegant design to have the weight of the vacuum hose pulling at 90 degrees to the axis of the spindle. The Oneway adapter connection is already at 90 degrees to the spindle axis, so any weight of the hose, etc. is in line with the connector, and likely would not compromise its seal. Although I tend to over-engineer things that I build, I thought this was a major advantage of the Oneway rotary vacuum adaptor.
Pro's / Cons that I have possibly not taken into consideration?
See above - You might also want to have some sort of in-line filter on the vacuum line before it enters the pump - you don't want to suck sawdust and other debris into your vacuum pump. I use sintered metal filters ahead of my pump, and actually filter the "release" air that I let in to the system when I'm "un-chucking" the bowl from the vacuum drum. This may be another example of over-engineering, but one that's designed to protect the pump.
Do you still need a Lamp 3/8" threading rod? if not- what did you put on
the face plate side to secure air tightness?
Nothing. The Oneway vacuum cylinder seals fairly well when threaded on the spindle - even the "stock" faceplate from Jet seals OK too. Some leakage is OK if your vacuum pump can maintain adequate vacuum while you're using the system - remember that to not implode the bowls (especially big ones) you must leak-in air anyway..... so the system does not to be completely airtight. Make sure you do have a good seal at the bowl rim, or at the contact points of a vacuum cylinder.
What type of pump can I use that would not be so expensive for this set up.
I know I can get a Gast for $350 but that is steep.
My friends in our woodworking club often ask where I would get "stuff" since they know that I am particularly "frugal" (read: cheap) and find immense satisfaction in setting up good systems for the least amount of money. I am fortunate that I work at a University, and have our surplus sales operation accessible to me, where I have been able to buy all manner of quality surplus lab-grade equipment that the University sells to the general public on one day each week. My vacuum pump once had an earlier life evacuating the beam tube/sample chamber of an electron microscope, so it's rated for continuous operation - it's an oil-jacketed model, selling new today for $ 2,100; a bit overkill, but very trustworthy! If you are in or near a University town, see if they have such a surplus equipment sales operation - many larger universities do. Short of that, I might recommend a few other places: Vacuum pumps can sometimes be found at Surplus Sales of Nebraska
www.surplussales.com or American Science and Surplus
www.sciplus.com - look for rotary vane types of vacuum pumps, which are the least expensive - you'll want to get a unit that pulls at least 20 inches of mercury (vacuum) and is rated for continuous operation. If the vendor doesn't specify any ratings, call them and ask! it is important that you get a pump with enough capacity. Alternatively you can look on eBay or other auction sites for vacuum pumps. Some folks use salvaged refrigerator compressors for vacuum sources for veneering, etc. but I think I'd avoid these for lathe work (I don't think they're "beefy" enough). There are also venturi-type vacuum sources which generate some decent vacuum (quite suitable for veneering) using air flow from a compressor, but I don't know if I'd advise you to use this for lathe work.
Good luck setting up your vacuum system!
Cheers,
Rob Wallace
