Positioning a heavy Tailstock

[GailInNM]

Over the years my lathes have gotten heavier and more rigid. From a Unimat in the 50's and 60's, through South Bend 9's and 10's in the 70's and 80's, a Nardini Heavy 10 in the 80's and 90's and now a Hardinge clone. With each move up it has been more difficult to position the tailstock accurately. No problem in the early days, but now with the Hardinge clone the stiction of the dovetail ways it was getting more difficult. It has not helped that age of the operator has caused various shoulder ailments either.

I have been pushing the tailstock away from the headstock using the carriage for a long time. To move toward the headstock I would position the carriage next to tailstock and then push the tail stock against the carriage while positioning everything with the carriage hand wheel. Big problem was I could not see where the tool in the tailstock was being positioned as I was too far to the right. All in all it was awkward.

The photos show the solution I came up with. I did not want to drill and tap holes in either the tailstock or the headstock so I used the bolts that retain the way wipers on each. I inserted spacers under these bolts to allow them to be tightened down. In the factory configuration they are only snugged up enough to hold the wipers in position and expand it slightly. A part with two slots in it and holes that match the wiper retaining bolts was made with an oversize 1/8 hole running the length of it. An E-clip is fitted to the rod in left hand slot and that provides a stop for the rod that goes in the 1/8 hole such that when the rod is pushed in it passes through the second slot and when retracted it just clears the second slot.

On the tailstock a block is mounted the same way with a protrusion that engages the second slot on the carriage part. When engaged the rod can be pushed in and lock the tailstock to the carriage. A knob was added to the 1/8 rod and a spring to keep the rod retracted.

Operation is to position the carriage against the tail stock and then push the knob to lock them to each other. Then hand wheel the carriage/tailstock into position. While moving the tension will keep the rod in position, but as soon as the tension is relaxed the sprling disengages them.
Gail in NM

 

[Blogwitch]

Very nice indeed Gail, ingenious too.

All the youngsters need to take note of articles like this, as come the day when eventually, they too will start to lose their strength, but still need to work with their machines.


Bogs

 

[New_Guy]

what a great solution to a big problem nice job Thm:

just a note i heard some people hook up an airline to the tailstock to make it float freely

 

[John S]

I did that some years ago with the tailstock off a big facing lathe. This was that big that for normal work the operator wouldn't even bolt it down !!

I had it lifted off with the crane and drilled four holes front to middle and back to middle with a long drill so they met up in the middle above the two ways, Bunged the front ones up and tapped the rear ones 1/4" gas for air fittings.
Then about 5 or 6 holes were drilled thru the ways to meet up with the cross holes.

Both cross holes were linked and fed from a regulator, it only needed 15 pounds of air for this to be able to be pushed one handed where it was needed, once the air was released it stayed put.

Then had to put a stop on the right hand side of the bed because it has so easy with a hard shove to push the tailstock off the bed !!

John S.

 

[Noitoen]

There is an easier solution if you have compressed air. Usually heavy tailstocks have a lubrication hole that leads to some channels on the lathe's bed. Just put an accessory to connect a small air valve and connect it to the air supply. When you have to move the tailstock just open the air and it will move like an hovercraft with very little effort.

 

[Noitoen]

John was faster than me ;D

 

[GailInNM]

Thank you for the comments everyone.

I had heard of using air to make an air bearing out of the tailstock and thought about doing it. I did not try it for two reasons.

First, the tail stock does not have a lube port of it's own. The carriage and cross slide are connected to a one shot lube system and the tail stock relies on the oil distributed by the carriage on the dovetail for lubrication. That seems to work well enough as oil works it's way through and appears on the tail stock end of bed. So, I would have had to remove the tail stock and drilled passages for the air.

Second, I was concerned about contamination under the tail stock. I do quite a bit of cast iron and you know how much fine dust that makes. No mater how well I clean the dovetail there always is a dark line left at the end of the travel of either the carriage or tail stock. This is a mixture of the lube and fine particulates. My reasoning was that if I set up an air bearing I would lift the tail stock enough for the air to escape under the wipers. Even though this would be less than a 1/1000 of an inch the slurry of oil and particulates would not be blown out of the way and would work their way under the tail stock.

This was the easiest way for me. Ans as it can be undone completely there was no permanent modifications to the lathe. It is only meant to spark ideas for others.

Thank you again for the comments. Lets hear any other ideas.

Gail in NM

 

[doc1955]

I used a Hardinge lathe for many years at work and their tail stocks can some times be a real pain to move with the big flat area the have on top of the ways. This is a very ingenious way of moving. I like the simplicity nice work! I do miss working with that machine though it was a super machine for doing single pointing.
Very nice! :bow: