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Spindle Adaptor Question

Joined
Dec 16, 2019
Messages
48
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15
Location
Tallahassee, FL
I am thinking of upgrading to a full size lathe (Jet 1640) and want to be able to use my existing 1" x 8 tpi chucks and accessories including vacuum chucks.

Most of the adaptors I see do not have a hole through them. Is there some reason that they do have a through hole for a vacuum line or knock out bar?

I assume the adaptors are made from pretty hard material and would be difficult to drill. Is that the case?
 
You could drill the adapter on your lathe. Pack the MT of the lathe spindle with a paper towel and use a normal HSS drill bit. Leave a little room so that the drill doesn't contact the paper towel. Blow the debris out of the spindle from the opposite end when finished, be sure it is clean. Low speed and cutting oil will help. Make sure that the adapter seats and runs true first, if it doesn't return it. I doubt that any of the adapters are hardened enough that a HHS bit won't drill. I can't think of any reason you would need a hole large enough to pass a knock-out bar.
 
Bulldog Chucks has some adaptors that are not solid, at least they look to be.

https://chucksplus.com/accessories.php
I can't tell from the picture or the description on that site whether the "1 1/4"x 8 tpi to 1"x 8 tpi Spindle Conversion Adapter" is or isn't solid.

I did find the Easy Wood Tools CA125 - 1-1/4" x 8 TPI Easy Spindle Adapter that appears to. Grizzly carries it and I am emailing their tech support to verify.
 
You could drill the adapter on your lathe. Pack the MT of the lathe spindle with a paper towel and use a normal HSS drill bit. Leave a little room so that the drill doesn't contact the paper towel. Blow the debris out of the spindle from the opposite end when finished, be sure it is clean. Low speed and cutting oil will help. Make sure that the adapter seats and runs true first, if it doesn't return it. I doubt that any of the adapters are hardened enough that a HHS bit won't drill. I can't think of any reason you would need a hole large enough to pass a knock-out bar.
The way my vacuum chucks are currently set up they require a 3/8 hole through the spindle.
 
Not sure what vacuum chucks you have. Just guessing you are running a rod through the spindle. Depending what full size lathe you get, most do not require a rod. Just install the appropriate rotary adapter. Many turners make their vacuum chucks from PVC and attach to a faceplate or use a Beall tap. I think trying to save the vacuum chucks is more trouble than it is worth. I do have the One Way vacuum chucks that I really like.
 
Not sure what vacuum chucks you have. Just guessing you are running a rod through the spindle. Depending what full size lathe you get, most do not require a rod. Just install the appropriate rotary adapter. Many turners make their vacuum chucks from PVC and attach to a faceplate or use a Beall tap. I think trying to save the vacuum chucks is more trouble than it is worth. I do have the One Way vacuum chucks that I really like.
I am using the Frugal Vacuum Chuck System pump, tube, and bearings. I made the chucks using 1" 8 tpi nuts and a variety of pipe and materials. I bought a box of 1" nuts. I could start over and make all new ones with the larger size thread nuts. I still need an adapter if I want to make use of my existing chucks, so why not get one that lets me use the vacuum ones too.
 
I have several adapters with through holes which I use with vacuum chucks.
I have vacuum chucks with 1 1/4 x 8 threads and 33 x 3.5m threads

I know my 33 x3.5 m to 1 1/4 x 8 And my 1x8 to 33 x3.5m has a through hole.
I will have to check the other I have.
 
I am using the Frugal Vacuum Chuck System pump, tube, and bearings. I made the chucks using 1" 8 tpi nuts and a variety of pipe and materials. I bought a box of 1" nuts. I could start over and make all new ones with the larger size thread nuts. I still need an adapter if I want to make use of my existing chucks, so why not get one that lets me use the vacuum ones too.

Pete, I understand your desire to use what you have. I had a PM 90 and needed to use the rod with that lathe. When I bought ny Laguna 18-36 I bought their vacuum adapter that screwed into the hand wheel. That was so, so much better. When I got my Robust I made an adapter for the Robust using the Laguna adapter. It uses o-rings and pushes into the hand wheel. Life is better without having to use the rod for vacuum chucking. I do recommend you look at getting a rotary adapter regardless of what chucks you use.
 
Are you getting a larger lathe to make larger pieces? Without tailstock support? If so I’d recommend replacing your chucks with one that take a 1-1/4 x 8tpi spindle or whatever larger spindle you get. The length created by a 1-1/4 down to 1” thread is ok for smaller turnings but not ok with large turnings a 16” swing is capable of. I have one I use but only for small light stuff.
 
Are you getting a larger lathe to make larger pieces? Without tailstock support? If so I’d recommend replacing your chucks with one that take a 1-1/4 x 8tpi spindle or whatever larger spindle you get. The length created by a 1-1/4 down to 1” thread is ok for smaller turnings but not ok with large turnings a 16” swing is capable of. I have one I use but only for small light stuff.
Yes I plan to get a larger chuck with the larger spindle thread, but I'd like to be able to mull over the purchase a while and use what I have in the mean time. That way I am more likely to give it enough thought and actually buy the right thing. Also I am sure there will be many small projects where my little chucks will actually be preferable.

BTW, good point about the length of the adapter. I was mostly only considering the smaller diameter and after you pointed it out I can imagine the extra unsupported length being an even bigger deal.
 
Many turners end up with more than one lathe over time and the 1x8 spindle is very common followed by the 1-1/4x8 spindle. The spindle adapters come in handy when using the larger lathes with your smaller sized accessories. Over time most turners end up with an assortment of accessories that allow them to work on any project that comes along. You can always use these extra tools as your trading inventory as the cost/value of tools and equipment usually hold their value over time.
 
I was able to drill a Penn State adapter on my Powermatic lathe without any trouble. Joe Kaufman's advice about keeping debris out of the spindle is right on.
 
Okay, so I am finding the spindle adapter to be okay for now, but really don't like it for use with my existing vacuum chucks for a few reasons. My original vacuum chucks were made using some 1" 8 tpi nuts (I got a good deal on a box of them so they were cheap because the box had been in stock forever and was battered and shop worn). Since I am making new vacuum chucks anyway I looked at buying some 1-1/4"-8 nuts, but found it cheaper to just buy a 1-1/4-8 Beall tap. My plan is to make new vacuum chucks from hard wood (some also include some metal or PVC pipe) , cut the threads, harden them with CA glue and recut them. I plan to use the same bearings and flexible rod from the Frugal system as I have been using.
 
Pete,

Delrin is a reasonably priced durable polymer that is easily turned and threaded on a wood lathe, many machinists use Delrin for a lot of different applications for tooling. A polymer would be a stable material that would hold its shape and not change its shape like wood does if the moisture content changes. The only drawback to Delrin is you can not glue it to another surface it has to be screwed or bolted with a mechanical means of joining it to other components. PVC can be turned on a lathe and you can glue it to other materials but it does not have the same strength or durability as Delrin however many turners still use it for making vacuum chucks. A hard wood will work for your needs if you seal the wood after turning it to the shape you need this will help maintain the shape over time. Make sure your hard woods are dry that you intend to use to make your vacuum chuck with, if not you will end up having to true the chuck up when it changes moisture content over time.
 
A hard wood will work for your needs if you seal the wood after turning it to the shape you need this will help maintain the shape over time. Make sure your hard woods are dry that you intend to use to make your vacuum chuck with, if not you will end up having to true the chuck up when it changes moisture content over time.
I have had pretty good luck with using wood in combination with aluminum tube (I salvaged some nice 3" or so aluminum). I have some more of that aluminum. I assume PVC would work similarly and is readily available in many other diameters if I need that.

My shop is pretty constant as far as temperature and humidity and I used wood that was pretty stable and did seal the wood so I haven't found any need for re-truing the chucks once made and trued once, but I have sometimes tweaked the shape a bit to better fit a particular project.
 
I made my vacuum chucks out of 6/4 hard maple ... threaded them with a Beall 1-1/4" x 8 tpi tap, cut a grove for schedule 40 PVC. I used 5-minute epoxy to secure the PVC to the wood and sealed the inside of the chuck with epoxy. I use Rubber Chucky seals.

I abandoned the lamp rod that came with my Frugal system, and went with a Rotary Vacuum Chuck Adapter from Craft Supplies USA.
 
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