Questions about turning new custom spindle for older WT wood lathe, best material?

Hello all, this is my first post in a very long time on this forum. I have a great 60-70 year-old Walker Turner mechanical variable speed 36" x 12" inboard/outboard lathe( original spindle diameter is 1" OA). This old spindle has always had a bit of annoying run out, and though I rebuilt the head with new bearings a few years back, it didn't help the issue much. Now that I'm not (quite) a poor as I used to be and going to be using the wood lathe more often, I've decided to collect a full set of Teknatool Supernova chuck bodies so I don't have to change the four jaws every time I have a different diameter work piece to work on. This sparked the idea that I turn my own spindle for the WT with the mating chuck threads single-point turned into the spindle itself, as opposed to using one of the Nova inserts that the company provides to adapt different brand lathes to their chuck bodies (I have a SB 9C that should easily handle this project once I'm past the learning curve. My questions are: What specific material is best to turn the spindle from, and has anyone gone so far as to actually single-point Teknatool's proprietary threading to eliminate the need for an adaptor (which could conceivably eliminate whatever minute run out the adaptor adds). In a perfect world, I'd like to be able to spin on and off these chucks at will without any fuss. Thanks in advance for any help!

McMaster carr has ETD 150 material
I use it alot for onesie twosie stuff

Or use McMaster-Carr

I like it for most one off items...

FWIW I much prefer 4140 prehard for spindles and such. And it has a lot less stress in it than "stressproof". Harder tougher, finishes more nicely too. The 1144 may have a slight advantage for threading- the chips come out in crumbles and short pieces rather than long tough strings. 1144 is a nice material to thread. But the problem is that 1144 gets most of its properties from cold working/rolling. So when they "stress relieve" it, it ends up softer, and still has stress in it, if you cut deep sections, transitions, or bore it, e.g. It is a common spindle material. I just think 4140 prehard has much better properties and is not much more difficult to work, except the stringy threads.

smt

Rather than worry about the material to make this spindle out of first determine if the threads in the Technatool Supernova chucks are based on the inch or metric system. Seems like they have an adapter that you must use to fit the chuck to a 1-8TPI spindle. You might have to make the spindle on a lathe that can cut metric threads.

I looked at their site and you can get them with a M33x3.5 thread, which requires that you be able to cut metric threads. Can't tell if the adapter models have the same thread, only way is to get one and measure it. If you can't cut metric, I'm sure you can find someone who can.

I also like 4140 PH for spindles, but 1144 Stressproof would probably be just fine.

I periodically do runs of replacement spindles for Powermatic 45 and 90 woodworking lathes. I'd agree on the 4140 PH being a good material. I make mine out of ETD 150 which really is a 4100 series steel with some additional additions that just make it turn great with nice finish. It's a bit more money than 4140 PH but frankly the cost of material for a woodworking lathe spindle is pretty minimal. I turn my spindles on a CNC lathe and then grind both the OD and the ID. I would NOT use stressproof for a spindle. Stressproof is an easy metal to turn and I use it for a lot of parts, but a spindle deserves a little higher grade of steel. A lot of work goes into a spindle, so why not use the BEST material, not the easiest to turn? In my CNC lathe however I don't even notice the difference between stressproof and 4140. The chips fly off equally well.

Turning a lathe spindle as a one off on a manual lathe and hitting the tolerances for the bearing journals is a pretty time consuming project. The through hole is long, and I assume you have an ID taper for a morse two or three center. As a machine tool builder I have gaging for bearing dimensioning and taper gages for the morse taper. All things that make a one off challenging for the tool deprived.

All very good thoughts, guys. I have to say that making a one-off spindle from scratch is seeming more and more onerous. I may have thought of a possible work around the boring/threading/MT hurdles by altering an existing larger/longer lathe spindle to fit my needs, that is if I can find one that fits the bill. Then there's still the matter of exactly mating with the bearing surfaces as you mentioned. The guy who sold me this lathe did a midnight job on the original spindle by prick punch upsetting the already worn mating surfaces on the original spindle so they would grab. I expect this is the root cause of my run out now. I'd thought about sizing the current spindle down to the next available higher bearing Inside diameter, but that seems like a waste of time. Thanks for your input. your comments are opening other rusty doors in my mind.

Machine tool spindles can be ground in situ. Would that work for you?

Wow, I totally got way from this due to some health issues last year, but now the project is being "mother of inventioned" again. Making a new spindle seems outside my tool (skill) set, and I'm wondering if anyone here would consider taking this project on as a paying gig. the parts explosion for the head stock is here: http://vintagemachinery.org/pubs/808/1773.pdf and I'm willing to discuss making several of these, so I can maybe sell a few on Ebay to help defray expenses for getting mine done. This machine has a nice Reeves Drive, and is a solid performer, so I don't want to replace it with a modern machine. I'm calling around to local shops, but the grinding and/or 2MT boring seems to be putting folks off. Anyone reading this have a compass bearing to point me towards?

What if you get it made without the Morse taper. And then thread the chuck on and take the old spindle cut off the portion with the taper and hold that in the chuck to drive your spur center? Would that work?


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Can you find a suitable donor #2 or bump up to #3 MT solid socket to machine into a spindle?

Some are soft for machining. This is just an example - the tail end is hard and would need ground or hard turned; but the nose end is soft enough to thread.

SL2-5 2 Morse Taper(hole)-5 Morse Taper(shank) Extension Socket

stepping up to 3MT, a longer and possible larger OD option:

SL3-5 3 Morse Taper(hole)-5 Morse Taper(shank) Extension Socket

They don't list OD's, and pics are merely "representational of similar products". You would have to call to see if the OD is large enough to turn the nose details. New shoulder need not be exactly as large as original.

smt

While precisely boring a Morse taper can be tricky, it is easy to bore it close to spec and finish with a reamer.

I'm 17 with only about a year of experience on a metal lathe and my only threading experience is once on outside 1-8 and one inside cut thread at 1 1/8-8 I think best not to offer to make your Spindle because I don't know exactly how well I could keep the tolerances. About how much runout do you have currently?


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I have an older WT wood lathe. When rebuilding it I discovered that the ball bearings had a non standard bore. There was only one source for those bearings. If you can, modify the spindle so it takes standard bearings.

I can make it for you email me @[email protected]


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