Thread: Tail stock question - cast v's welded

G'day Guys,

I have a query about tail stocks, be it for a wood lathe or metal lathe.

What is the advantage and disadvantage of cast of welded steel?

There are a couple of other questions but may raise as separate posts to deal with each one at a time.

Thanks


Dave the turning cowboy

turning wood into art

Cast absorbs more vibration and being cast are generally have more mass so are harder to get vibrating in the first place. That's not to say that a properly designed fabricated T/S would not work but cast is probably the material of choice.

Michael

can I buy a block of cast and have it machined, what is the best option for a custom job .... I dont want to spend heaps as I have nothing to spend at the moment but the time will come where I need to


Dave the turning cowboy

turning wood into art

First off, a block of cast can certainly be machined.
If you are looking for something for a metal lathe then I'd be trying to go the cast route. However, if this is for a wood lathe then fabricated would be lots cheaper and probably just as good. With metal we are concerned with taking comparatively smaller piece of material off, so the less vibration the better. On a wood lathe probably +/- 0.5mm is fine (and it will be sanded afterwards) so the change in surface finish due to vibration would be negligible.

Michael

You could do a little from column A and a little from column B...get some cast sections of bar and round and some cast iron rods, weld one up that way. Ive not seen a lot of cast sections for sale, so itd likely be something youd have to hunt a little for, depends on how motivated you are for those vibration absorbing properties.

Thanks guys, that gives me something to go on.

Can cast be welded? I was always under the impression that welding cast was not a good idea. Excuse my ignorance on the metal work front ... It is something I would like to learn more about and dabble in at some point.


Dave the turning cowboy

turning wood into art

Cast can be welded but it is something that is avoided as it can be really tricky to get right and cast will crack like anything if subjected to enough tensile force (uneven cooling for example).
Try it out as fabricated and go to cast if it doesn't work well enough for you.

Michael

Dave I made a tail stock for my wood lathe out of 150 X 75 x 6mm channel. Welded a 10mm piece of flat with a piece of 3mm flat to slide up and down the ways with just enough clearance. The spindle was turned (on a metal lathe) and threaded to take the moving spindle with a Singer Sewing Machine wheel fixed on the end. It was bored to No 2 Morse Taper to take accessories. It has been working well for more that 30 years.

As mentioned, the tensile loads can play havoc with it. Welding cast involves cast rods, which look like they make a bloody mess of everything (but underneath, it usually goes well) and a lot of pre and post heating. Usually once the post heating is done, youd wrap it in a glass blanket to slow the cooling to help keep it under control.

Originally Posted by DaveTTC

Thanks guys, that gives me something to go on.

Can cast be welded? I was always under the impression that welding cast was not a good idea. Excuse my ignorance on the metal work front ... It is something I would like to learn more about and dabble in at some point.


Dave the turning cowboy

turning wood into art

You guys are awesome ...

chambezio, you sound like my kind of guy, good bit of repurposing going on there and fabrication


Dave the turning cowboy

turning wood into art

If it's for a wood lathe, I'd fabricate from steel sections. Not like anyone uses 'wood lathe' and 'accuracy' in the same sentence without a 'lacks' somewhere included.....

If it's for a metal lathe, forget making one altogether. I wrote a lot more, but 'forget it' is the executive summary.....

PDW

If I had to build a small or lightweight tailstock (eg wood lathe) I would consider doweling and screwing together pieces of heavy steel bar. That would avoid the whole issue of weld stress.

If it was for a metal lathe I would try to find one close in size and make it fit.

If you have an existing cast iron one that needs repair, it can be welded by someone who knows their stuff. I had a cracked one successfully welded in Adelaide.

Carving a tailstock from a solid lump of cast iron bar sounds like the most expensive and time-consuming option to me.

I second the "forget cast iron" motion.
I am a boilermaker who has welded more than my fair share of cast iron with a great deal of success if I may say so. Having said that, there is not enough money in the world to make me contemplate making a tailstock from cast iron sections, welded together and then machined. I can just imagine the new words in the English vocabulary created when your machinist hits a pocket of exceptionally hard material created by the welding process. If my first born was on the line and I absolutely had to do it, braze welding would probably be my approach for a number of reasons.
A good, chunky steel tailstock could be made for a fraction of the cost, (cast iron bar is not cheap), and I would challenge anyone to find fault with its properties in that application.

great food for thought ... it has helped me think out the issue more.

If I can get another carriage for the bars (it is a two round bar bed) I could have a flat machined on the top of the carriage and customise an existing tailstock to suit. By far could be the easiest if I can source another carriage

It is a wood lathe but if I were able to use it for some steel too that would be great

Dave the turning cowboy

turning wood into art

Originally Posted by chambezio

Dave I made a tail stock for my wood lathe out of 150 X 75 x 6mm channel. Welded a 10mm piece of flat with a piece of 3mm flat to slide up and down the ways with just enough clearance. The spindle was turned (on a metal lathe) and threaded to take the moving spindle with a Singer Sewing Machine wheel fixed on the end. It was bored to No 2 Morse Taper to take accessories. It has been working well for more that 30 years.

We have an old cast iron lathe at our mens shed that has no tailstock and your description is more or less what I had in mind to replace it.