• Guest, Help us understand what we can do better in future. Click Here!

Re-align main shaft

#1
I have an old Delta Milwaukee wood turing lathe that has a slight wobble in the main shaft of the head stock. This wobble, although slight, transfers exponentially to the piece being turned the longer the piece is. My question for anyone in the group (I’m also a new member - just) is there anyone who could either take the wobble out on there metal lathe or cut me a new shaft. Very willing to pay whatever costs there might be incurred. Also realizing that the shaft would have to be viewed before a decision is made. Currently have the headstock off of the bed. Thank you.
 

DPittman

Active Member
#2
I have an old Delta Milwaukee wood turing lathe that has a slight wobble in the main shaft of the head stock. This wobble, although slight, transfers exponentially to the piece being turned the longer the piece is. My question for anyone in the group (I’m also a new member - just) is there anyone who could either take the wobble out on there metal lathe or cut me a new shaft. Very willing to pay whatever costs there might be incurred. Also realizing that the shaft would have to be viewed before a decision is made. Currently have the headstock off of the bed. Thank you.
Is the wobble because of the shaft (bent/defect) or could it be bearings/misbalance somewhere?
 

RobinHood

Active Member
Premium Member
#6
This wobble, although slight, transfers exponentially to the piece being turned the longer the piece is.
So you are turning with the work piece held in a chuck or on a faceplate, not between centers? It could be that your chuck/faceplate register is not running true. Or some chips have found their way between the chuck/faceplate and the register. The spindle may be fine.

Unless the spindle is made from really cheap/thin material, i would think that it would take a lot to bend it. Wood dust can find its way into the tiniest cavities, like past a seal into the bearings... so if you can, take out the bearings and inspect them.

Are they taper roller bearings? If yes, you may have to re-adjust the preload as things may have gotten a bit slack over the years.

You have any pictures of the headstock/spindle arrangement?
 
#7
The four stage pulley that has power transferred to it from the electric motor (it is on the left side if the headstock obviously) has a distinct wobble. I have a One Way Talon chuck & the wobble on the chuck is less pronounced than on the pulley, but still there. If I can figure out how to send a picture I will. Thanks for the reply.
 
#8
The four stage pulley that has power transferred to it from the electric motor (it is on the left side if the headstock obviously) has a distinct wobble. I have a One Way Talon chuck & the wobble on the chuck is less pronounced than on the pulley, but still there. If I can figure out how to send a picture I will. Thanks for the reply.
The shaft did have a cut in it when I had new bearing caps fabricated a number of years ago & that cut wasn’t removed I don’t believe. I’ll take it apart and hopefully provide you with some more details in pictures & print. Wondering if the pulley could be out of alignment & that vibration is transferring downline.
 
#9
J
The shaft did have a cut in it when I had new bearing caps fabricated a number of years ago & that cut wasn’t removed I don’t believe. I’ll take it apart and hopefully provide you with some more details in pictures & print. Wondering if the pulley could be out of alignment & that vibration is transferring downline.
Just took the pulley off and the shaft cut has been repaired, but very poorly. As I spin the shaft you can visually detect a wobble/out of roundness. I don’t have a dial indicator so cannot tell how much it is, but there shouldn’t be an amount that I can visually detect it with the naked eye. I would say a new shaft is in order, plus the right hand threads of the shaft for the Talon chuck seat minimally into the chuck. I feel the chuck should have more threads holding it, i.e. more threads = greater holding aka surface area. Any suggestions. Could you cut a new shaft or know of someone in the group who could or are there any online areas I could go to that might have this shaft? Thanks in advance for your suggestions.
 
#10
Here are the pictures taken recently of the headstock and damaged main shaft.
 

Attachments

John Conroy

Well-Known Member
Premium Member
#11
The old girl is pretty beat up! It looks like it would be fairly easy to make a new shaft if the old one was available to take measurements from. It looks like it may use 2 tapered roller bearings to support the shaft, and maybe has shims under the end covers to control bearing pre-load? Is it hollow all the way through? Is the bolt pulley mangled on it's inside diameter also? I'm assuming the short end with the right hand thread supports the chuck?
 
#13
The old girl is pretty beat up! It looks like it would be fairly easy to make a new shaft if the old one was available to take measurements from. It looks like it may use 2 tapered roller bearings to support the shaft, and maybe has shims under the end covers to control bearing pre-load? Is it hollow all the way through? Is the bolt pulley mangled on it's inside diameter also? I'm assuming the short end with the right hand thread supports the chuck?
Yes the shaft is hollow through the middle and it takes a morse taper (#2 I believe). The 4 stage pulley doesn't appear to be mangled in anyway and fit tightly onto the left hand side of the shaft. the rights side with the short threads does indeed hold the chuck. The other end has left hand threads. I do not have an adapter to attach my Talon Chuck to left hand threads for larger turnings. I will check with Oneway if they make an adapter. Thanks again for all of your support so far - wonderful!
 
#14
Looking at this info it may have a Morse taper inside the spindle shaft also?

http://thewoodknack.blogspot.com/2016/05/how-to-buy-vintage-lathe.html

Have you checked eBay for used ones?

https://www.ebay.ca/itm/Delta-Homec...h=item4686c633ec:g:lKYAAOSwQqJbqM9T:rk:4:pf:0

This one looks like it may be correct for your lathe and appears to be in good condition.
I did check eBay, but obviously you had better luck. I also checked Craigslist, but as this was the first time there I was overwhelmed with the various locations i.e. cities to check from - wondered if there was an overall search function on that site that would narrow it down like on OWWN metalworking classifieds when you type in South Bend lathes that is all that comes up.

That shaft does appear to be like mine, but in much better condition. I'll take mine out and use my digital callipers to acquire dimensions such as length, outside and inside diameters etc. Will get back to you.
 

RobinHood

Active Member
Premium Member
#15
Hi Tom, that shaft does look in poor condition. Like John Conroy suggest, it might be time to get a good used one.
As far as making a new one: it can be done.
Just speaking for myself, my biggest challenge would be to drill the hole all the way through the shaft as it requires some pretty long drill bits, or drill from each end i suppose. The rest seems straight forward.
 

RobinHood

Active Member
Premium Member
#16
Your lathe looks like the one in this video...


At approx 1:40 you can see the flat on the spindle where the step pulley set screws engage. From your pictures, it looks like this flat has been welded over / is missing and the set screws engage directly on the round shaft. Filling in an area that large could lead to enough distortion during the welding process, hence the runout you see visually.

It almost looks like your pulley spun on the spindle at one time and marred the shaft badly. Probably because the set screws came loose. I would put two set screws in each hole if you have enough threads, or if not, use some blue locktite to better secure them upon reassembly.
 
#17
Your lathe looks like the one in this video...


At approx 1:40 you can see the flat on the spindle where the step pulley set screws engage. From your pictures, it looks like this flat has been welded over / is missing and the set screws engage directly on the round shaft. Filling in an area that large could lead to enough distortion during the welding process, hence the runout you see visually.

It almost looks like your pulley spun on the spindle at one time and marred the shaft badly. Probably because the set screws came loose. I would put two set screws in each hole if you have enough threads, or if not, use some blue locktite to better secure them upon reassembly.
Wow that looks exactly like mine, Thank you SO MUCH for locating that video. What also was interesting is the pulley in the video had indexing holes to match up with the indexing pin on the back side of the head stock. My four step pulley does not as it's not the original pulley, but was supplied by my friend a number of years ago as he had it laying around and it is very heavy solid steel (not the pot metal ones usually seen in Princess Auto, Canadian Tire etc.) and it provides (I think) a bit of a flywheel effect because of its heft. Now that I see that indexed pulley I'm on the hunt for one of those too. My existing pulley only has one Allen set screw hole, but I'm sure another could be drilled and tapped fairly easily, but if I can locate an indexed pulley we're off to the races. I'm so glad I found this forum and you guys who've responded - Thank you Thank you Thank you!
 
#18
I ordered the spindle/main shaft from the eBay link you sent. Should be here between the 18th & 24th. Thanks for the tip. Looked for an indexed pulley, but was unable to locate on eBay. This is something that could probably be done with a metal lathe - drilling the appropriate accurate hole to match up with the indexing pin. Not going to worry about it as so far in it's use I haven't needed that feature. Will let you know when it comes in. Thanks again to all of you who assisted with this task.
 

RobinHood

Active Member
Premium Member
#19
Great to hear that you made progress in getting your machine back into good repair.

Let us know if you need further help - like with drilling indexing holes into your existing pulley in case you can’t find an original one.