DIY lathe way grinding?

So I bought this lathe. It was a good deal. Not as good as I first thought. When I got it set up and was leveling it I noticed wear by
the headstock that I should have noticed before. Like before I paid the guy. The guy who sold it was completely honest about the condition of the lathe, I just missed some stuff. The lathe is a JET copy of a 15 x 60 Clausing-Colchester. Because everything else on the machine is in pretty good shape I am considering several different options to make the ways better. The ways are hardened, hard enough that a file just skitters across instead of cutting. But not so hard that they can't be scraped with a carbide scraper. I know because I got out my scraper and tried. But still hard enough that the job would take a lot of time and my wrists already hurt enough. And I have never scraped vee ways, only flat. But I do have that Machine Tool Reconditioning book. Another option is to remove everything from the ways casting and bring it to a grinder who can do the work. This would take a lot of time, probably 20 hours, to remove and replace everything. Another option might be to make a mount for my Dumore tool post grinder and just grind the ways in place. This would require making the tailstock ways as good as possible first and then making some sort of mount for the Dumore grinder. So the first requirement would be to level the tailstock ways after making sure that all the way surfaces are flat. Then mount the grinder to the bottom half of the tailstock and just slide it along to perform the grinding. I'm sure I could come up with some sort of feed device so the the grinder would always be fed along at the same rate. I would for sure need to scrape in the bottom half of the tailstock to the ways if this method is going to work at all. I see a problem though and that is I don't know how to make sure that the tailstock ways remain parallel to the axis of the spindle. I suppose I could put a two inch diameter rod in the chuck that extends just a little over ten inches, indicate it to less than .0001" TIR, put my .0005" in 10.0" level on it, level it, then check the tailstock ways to see if they are level. Anybody done this? Anybody tried and failed? Any opinions? Thanks, Eric
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@whidbey.com wrote:

I faced the same problem on a 15" Sheldon lathe. That one was actually quite a bit harder, a carbide scraper blade would not even scratch the surface!
First step (and you may actually be able to just use the lathe after doing this) is to rig a toolpost grinder to the tailstock base and tow it down the bed with a small gear motor. I cut a piece of large angle, like 3 x 3" and drilled some holes. I mounted the angle on the base of the tailstock, and then mounted the lathe's own compound swivel/slide assembly on the angle. Then, I mounted the toolpost grinder onto the compound rest. This made a pretty neat adjustable fixture for bringing the grinding wheel down to the bed. I used a really big cup wheel to grind the ways. See http://pico-systems.com/sheldon.html
for a picture of the grinding process. I then went on further refining the process with Cratex muslin-bonded wheels and straightedges, essentially doing what you do for hand scraping, but using an air die grinder to bring down the high spots.
But, if the tailstock ways are in good shape, you may be able to clean up the main ways pretty quickly with the grinder trick and just leave it at that.
Jon
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Thanks for the reply Jon. So you actually did what I am considering. It seems to me that if I can check the tailstock ways, and if they are in good enough condition, then I can probably grind the ways. My grinder will of course need to be able to handle a big enough cup wheel. I'll see what Dumore says. Eric
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@whidbey.com wrote:

Yup, I did it! The self-grinding can be done in a weekend. But, it wasn't GOOD ENOUGH for me, OH NO! I had to go FURTHER! I spent the next 20 months or so trying to make it better. After a few false starts that ended up making it worse, I did assemble the tools and techniques to do better, but I have NO IDEA if it was actually worth it.
The problem was that my bed was deep flame hardened, and flame hardening will warp any surface, even a 1500 Lb lathe bed. So, the bed had at least a 0.003" sag in the middle from the hardening process.
As for the grinder, I ran it at the slowest speed, and when I first mounted the wheel, it vibrated some. The angle bracket/compound rest allowed me to dress the wheel, and when that was done, the wheel ran smoothly.
Jon
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Greetings Jon, Whether I do the job myself or send the ways off I still need to take a lot of stuff off of the machine. I have sent emails out for bids on the job but have found only one place fairly close. Every place else is hundreds of miles away. So since I'm taking stuff anyway I'll check the tailstock ways and if they are OK then I'll try grinding. The grinder you used appears to be a Themac. I have a Dumore. I have used both and I am sure my Dumore will handle a cup wheel as big as the one you used. It looks like the only machining that needs to be done to mount the grinder is to drill a couple holes in the tailstock base, a couple matching holes in an angle plate, and then one big hole and 4 tapped holes to mount the compound slide to the angle plate. So it looks like about 4 hours machining and assembling in order to try out the grinding. I am still not sure how to make sure the tailstock ways are parallel to the spindle axis except with a level and the best levels I have are graduated to .0005" per 10". If the grinding doesn't turn out to work well I can always finish stripping stuff and send the bed out. I am pretty sure I won't make things worse. I am a competent machinist at least if not a machine rebuilder. You certainly did a good job on your machine. Cheers, Eric Eric
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@whidbey.com wrote:

Yes, that's right.

Remove the headstock. On most lathes, both tailstock and main ways run the entire length of the bed, and the headstock usually sits on the tailstock ways. All ways are ground parallel in one setup. So, if the main ways are re-ground parallel to the tailstock ways, and you then remount the headstock on the ways, everything SHOULD be perfectly parallel again.
Jon
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
jon_banquer wrote:

Oh, I learned a LOT on that project, that's for sure! The lathe is a very fine machine, and I get this big grin every time I use it.
Jon
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/29/2014 11:19 PM, Jon Elson wrote:

I remember that move - thanks for the memories - and of those of Fitch!
I have a Sheldon myself. Chrome ways. As new as when brought home in '52.
Martin
Martin
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@whidbey.com fired this volley in

Eric, I think it's a fool's errand (not calling you a fool, that's just a figure of speech).
How many times will you need to grind the ways on a lathe? Do you _really_ need to spend 40 hours making up special tools you'll only use once, ever?
Strip it down, and have it ground by someone with the right equipment.
Lloyd
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/30/2014 6:19 AM, Lloyd E. Sponenburgh wrote:

+1
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 30 Dec 2014 05:19:22 -0600, Lloyd E. Sponenburgh wrote:

Well, three or four times, since you'll mess up the first time(s).

+1
--

Tim Wescott
Wescott Design Services
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.