Modifying Your Lathe V. Buying V. Fabricating

Dan Mosley

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Palm Springs, Ca
The question poped up on me the other day when I was talking with a friend at work about lathe capacities. In particular he was wondering if he bought a older lathe with say 14-16"swiing capacity if it could be modified to accept larger diameter wood to turn - making larger vessels and bowls etc -. I told him im sure it could be but I had never thought about it.
Well it got me thinking about it, and I decided to look into it further. I have a Jet 1642 vairiable speed myself (he is looking to buy) so his question got me thinking more about the possibilities of doing such a modification.

So i stopped by to see a friend of mine that runs a machine shop and asked him the same question. His response was yes it can be by what he called blocking it up and making a custom tool rest to withstand the additional force - it would not be difficult at all to do - However, he mentioned that there would be some concerns above the modifications - such as making sure you have a good strong base which shouldnt be a problem with most well built lathes - suggested using counter weights if necessary (sand bags etc- if needed) - 2hp variable speed would probably be ok but if you have to purchase one to get a 3hp variable speed.

Or another alternative would be is to simply build one to the specifications that I/we wanted and he would help us out with the fabrication. This is the one that has got me thinking about how much fun it could be to have one built.

Soooooo...............anyone out here ever tackled this kind of project ?? ...........blocking yours up ? or building a lathe ???
 
Haven't done it but I've seen both approaches taken by others in the past. Blocking is pretty straightforward - doing it successfully depends on the blocks being fabricated to close tolerances and made of good materials. I've seen both steel and wood blocks used, although I don't think I'd bother doing it with wood.

Building your own lathe can also be done if you have the resources and know-how. Fabricating a steel lathe (like a Oneway or Robust) is definitely doable, but getting the bed true and everything square and lined up is not something for the weekend welder to tackle. They can be made of other materials, too. I remember seeing pics somewhere (was it SMC years ago?) of a guy who built one primarily out of concrete, although I don't recall any details (or if the final product was usable).
 
The concrete project on smc was revived about a year ago and ended up in someone other than the original builders hands and appeared to be working last I saw..

As Vaughn noted the main problems with a fully self built is the details. It can certainly be fine though. My one cousin apparently built a large than can spin up to 60" although I haven't seen it yet...
 
Well im not going to pursue the concrete approach - im going to check deeper into the costs etc- and maybe let him block up mine and make a custom steady rest - as far as the other guy from work he wants to look into building one or buy one and modify it (possibly using the frame as a starting point. I am not totally sure which way he will choose but in the next week or so were going to me meet up with the machine shop friend and discuss it ............................anyway thanks..............maybe somebody has built one but so far i only know one turner that took one and had it redone to his specifications but so far I have not heard back from him..........Ill let ya know how it goes....thanks
 
I believe the reason that some folks have gone the concrete route is that it provides a lot of vibration dampening and weight. I know some machinist's that have done similar tricks with filling voids in machines with concrete or (more common) granite and epoxy. The structural elements are of course still steel or cast.
 
im going to check deeper into the costs

That is the bottom line. As we all know custom made items are made to satisfy wants a lot more than to save money. Custom work is often far more costly than manufactured. It is a decision only the individual can make for himself. Methinks such a modification is not practical and might be more fuss and failures than the effort, and expense, is worth. My tuppence.
 
I think I agree with Frank and personally, I would save my pennies to get the lathe in the size range I want. BUT, if a refurb is something you might want to try, Here's what I would look at. An old powermatic model 90 (12") with a 3 phase motor, not too rare or too expensive (in big lathe terms.) One of the later models with the motor mounted to the base rather than ways. You can raise the headstock with a 4" block of something and drill out for the bolts and cut some of the center out to accommodate the longer belt you will replace. You can raise the tailstock the same way, but a bit more complicated to machine the slide in the ways. You can buy a taller banjo and easily adapt from several companies. You can even (I think) do a direct replacement with a 3520B tailstock and banjo for about $700. Add a VFD and you have an electronic variable speed lathe weighing in at around 700 lbs, 20 inch swing, 40" long for probably around $2000 total. It's up to you to decide if that's better (for you) than a 16/42 jet or Nova lathe in the same price range. It's not quite that simple, but if you want to take it on, you could probably figure out the little stuff. Best of luck and let us know what you decide. PS. lots of info on some of the old woodworking machinery sites. I have an old powermatic 90 sitting next to my Stubby Lathe and have been thinking about doing just this.

Ken Easley
Phoenix - Host to the just completed AAW National Symposium
 
Modifying a older lathe can be hard as many have fixed headstocks that cant be lifted by blocking.

I design and build my own lathes to suit my needs. They are all fabricated from standard steel sections and work just fine, but this is not for every one as a certain level of expertise is needed plus all the gear to do so. I am fortunate to access both and so save myself a considerable amount of money in doing so. I currently have two both will swing around 28-36 inches and the longer bed lathe would be able to do around 5' in length the other is short bed bowl lathe with a 24" bed. All up the cost wouldnt be over $500 and I reckon if I had bought commercially available lathes, say Vicmarc or Stubby it would have set me back $10-15,00 for the pair
 
OK for the curious and Dan who wanted a bit more info. The main image show the lathe before I added a three pulley set up as I only wanted a slightly better speed set up not want to go to the expense of variable speed. This my second lathe designed for the bottoms of bowls and such stuff. The big one will have variable speed when the mods are done.
 

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Thanks for sharing those pics Neil. That's a pretty beefy looking lathe all right! You can also tell that whomever did the welds pretty much knew what they were doing (unlike my welds :eek:).
 
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