Standard Modern 12x30

[jstem4]

Hi, i'm new to the forum, and this is my first post.

I bought back in November a SM utilathe 12x30 that was in rough condition, I've been fixing it since then. I rebuilt the feed gear box and the saddle, changed to gear rack and a couple of other things. The lathe works but i noticed some pretty bad wear on the bed way, about 0.015'' the maximum, I mesured quickly yesterday with a dial on the saddle reaching underneath the bed, on the surface where the gib's plate slides. I also have a lot of play up and down on the saddle. 0.015'' is a lot and the lathe will never be anything close to precise. I'm debating on to selling it or trying to re-grind it. I didn't pay much for the lathe, with all the parts i'm in on it for about 700$.

Did anyone have had their lathe re-grinded? Anyone have experience with a standard modern lathe re-grinding?

I haven't taken anything apart on the lathe yet to regrind it but from what i can see i think i can have the bed re-grinded all the way even underneath the headstock, yes everything is going to be lower but am I right to assume the this is going to be the easiest way to have the headstock and tailstock line up again?

I'm located in Quebec, does anyone know of somewhere in the eastern Canada that regrind lathe beds?


Thanks

Julien

 

[YYCHM]

Welcome from Calgary.

 

[Susquatch]

Hi Julien! Welcome from South Western Ontario (near Chatham).

Although that is a lot of wear, it may not be as bad as you think. Vertical movement of a tool post due to worn ways doesn't translate 1:1 with cutting geometry. It could be much much less depending on the diameter of the part you are cutting.

Most machinists are aware of the wear and play in their machines and take it into account by compensating for it while they are machining. Some excellent work is quite possible that way.

But if you are determined to do it, I seem to recall that our member @Rauce in Toronto sent a bed away to the USA to be reground and was happy with the work they did. If he doesn't see your request, you might send him a PM and ask him directly.

 

[Brent H]

@jstem4 - above is a simple scetch of the utilathe. You can adjust the gibs to tighten up your clearance. I stoned my ways to remove any burs and then adjusted the (3) gib plate to take out most of the play. It takes some time but well worth it.

 

[TorontoBuilder]

Hi, i'm new to the forum, and this is my first post.

I bought back in November a SM utilathe 12x30 that was in rough condition, I've been fixing it since then. I rebuilt the feed gear box and the saddle, changed to gear rack and a couple of other things. The lathe works but i noticed some pretty bad wear on the bed way, about 0.015'' the maximum, I mesured quickly yesterday with a dial on the saddle reaching underneath the bed, on the surface where the gib's plate slides. I also have a lot of play up and down on the saddle. 0.015'' is a lot and the lathe will never be anything close to precise. I'm debating on to selling it or trying to re-grind it. I didn't pay much for the lathe, with all the parts i'm in on it for about 700$.

Did anyone have had their lathe re-grinded? Anyone have experience with a standard modern lathe re-grinding?

I haven't taken anything apart on the lathe yet to regrind it but from what i can see i think i can have the bed re-grinded all the way even underneath the headstock, yes everything is going to be lower but am I right to assume the this is going to be the easiest way to have the headstock and tailstock line up again?

I'm located in Quebec, does anyone know of somewhere in the eastern Canada that regrind lathe beds?


Thanks

Julien

welcome Julien.

I think there was a guy in Kingston who allegedly grinds lathes, but I've never been able to connect with him.

IIRC Rauce sent his lathe to pennsylvania to be ground

 

[jstem4]

Hi Julien! Welcome from South Western Ontario (near Chatham).

Although that is a lot of wear, it may not be as bad as you think. Vertical movement of a tool post due to worn ways doesn't translate 1:1 with cutting geometry. It could be much much less depending on the diameter of the part you are cutting.

Most machinists are aware of the wear and play in their machines and take it into account by compensating for it while they are machining. Some excellent work is quite possible that way.

But if you are determined to do it, I seem to recall that our member @Rauce in Toronto sent a bed away to the USA to be reground and was happy with the work they did. If he doesn't see your request, you might send him a PM and ask him directly.

Thanks for the reply. Yes i’ve read the post of Rauce it’s interesting. I was wondering if anyone closer to me has done it though.

And yes I understand that i will not get 0.015” of difference on the diameter. The tool will move for about 0.015 from the center cutting axis and make a difference on the diameter which will depend on the parts diameter. The smaller the worst.

 

[jstem4]

View attachment 60691
@jstem4 - above is a simple scetch of the utilathe. You can adjust the gibs to tighten up your clearance. I stoned my ways to remove any burs and then adjusted the (3) gib plate to take out most of the play. It takes some time but well worth it.

Thanks for your reply. Yes I saw your post on this and it help me a lot. But on my lathe if a mesure with a depth mic the difference between my apron and the underside of the bed a get values from .617 to .599. If i move my apron the values change… so if i adjust the gibs plate to the worst value (.617) i will still have a lot of play… i’ll take pictures and post them.

Julien

 

[Hruul]

Welcome from Regina, SK.

 

[Mcgyver]

I haven't taken anything apart on the lathe yet to regrind it but from what i can see i think i can have the bed re-grinded all the way even underneath the headstock, yes everything is going to be lower but am I right to assume the this is going to be the easiest way to have the headstock and tailstock line up again?

Just remember, when reground, the geometry does not come out exactly the same as the original so the HS will not be a perfect fit on the new ways. It will also be high compared to the worn TS. The carriage and TS won't fit either, but they'll be worn and have to be scraped in any event. You have to scrap the HS, TS and saddle into the freshly ground surfaces. Inevitably, when there is lots of wear, you have to fix the TS (bore lapped, quill hard chromed and ground to fit), then scrape the bottom of the TS
(to mate and for alignment) as it will be lower than the HS Then you scrape the HS to fit both the the ways and into alignment with the ways and TS.

In a paragraph, that is most of what's involved in reconditioning a lathe. It's a lot of work, but there's no point in having it ground if you don't follow through with the above.

 

[jorogi]

Just remember, when reground, the geometry does not come out exactly the same as the original so the HS will not be a perfect fit on the new ways. It will also be high compared to the worn TS. The carriage and TS won't fit either, but they'll be worn and have to be scraped in any event. You have to scrap the HS, TS and saddle into the freshly ground surfaces. Inevitably, when there is lots of wear, you have to fix the TS (bore lapped, quill hard chromed and ground to fit), then scrape the bottom of the TS
(to mate and for alignment) as it will be lower than the HS Then you scrape the HS to fit both the the ways and into alignment with the ways and TS.

In a paragraph, that is most of what's involved in reconditioning a lathe. It's a lot of work, but there's no point in having it ground if you don't follow through with the above.

All good points to consider but applying/installing/incorporating turcite is a viable and effective option too.

 

[Mcgyver]

Agreed, but turcite still has to be scraped in (Moglice otoh doesn't). Personally I'm not a fan of these as a home shop approach. They make make sense as a less expensive method to get more life out of a machine in a commercial setting, but what happens is crap gets embedded in it instead of being flushed away with oil and that wears the ways more rapidly. For me, when you put that kind of effort in you want your dream machine to last forever not wear more rapidly. I'm sure there are some who disagree with that (or at least wish it weren't so lol) but its as best I can reason it's what happens. It would be very hard to quantify in real life conditions but it seems logical.

 

[jorogi]

Agreed, but turcite still has to be scraped in (Moglice otoh doesn't). Personally I'm not a fan of these as a home shop approach. They make make sense as a less expensive method to get more life out of a machine in a commercial setting, but what happens is crap gets embedded in it instead of being flushed away with oil and that wears the ways more rapidly. For me, when you put that kind of effort in you want your dream machine to last forever not wear more rapidly. I'm sure there are some who disagree with that (or at least wish it weren't so lol) but its as best I can reason it's what happens. It would be very hard to quantify in real life conditions but it seems logical.

When I first saw the idea I rolled my eyes. From what I understand though, there are manufacturers that use it in new builds. If your way wipers are effective it might not be an issue. I can see it being an advantage to peel worn turcite off and replacing when needed and not having to do any grinding. Probably not an advantage to too many of us though.

 

[Mcgyver]

From what I understand though, there are manufacturers that use it in new builds. If your way wipers are effective it might not be an issue. I can see it being an advantage to peel worn turcite off and replacing when needed and not having to do any grinding.

I believe they do. While they might bill it as low friction (who cares what the friction is, its fairly low already with cast iron and oil?) I think they use it because it's low cost and it is more likely to lead to more rapid wear of the ways because of embedding - like sometimes you think the soft bronze bearing will be worn, but instead its the hardened steel shaft (because of embedding).

There were some machines with replaceable ways, but imo, the best way to go is cast iron on cast iron and lots of oil.

 

[Lucky7]

I know what the SM 9” and 10” Utilathe anatomy looks like and a regrind and scrape of these two lathes would not require turcite under saddle ways. Not sure about a 12” Utilathe. Also not sure if your lathe has a hardened bed? Depth of hardening? Could the OP please post a pic of his lathe showing feedscrew and thread cutting screw fixing to bed at both gearbox and tailstock ends.

There’s regrinders and then there’s regrinders. Be careful who you use.

I’d have no hesitation taking on a lathe rescrape, but it would have to be the right lathe. There’s a lot of reasonable condition excellent design lathes still for sale. Maybe not as many or as cheap as twenty years ago, but still worth searching out. Just consider that small Monarch from Ottawa that just sold on GC auction? No offence, but don’t think an older SM would be a contender. A Schaublin or Habbegger? Heck yeah. A Monarch if I needed another mid sized lathe? Yup. (No, this 57 year old is not taking on a NN) But wouldn’t try rescraping a lathe without another working lathe in the shop and plenty of experience with scraping both for alignment and bearing.

On edit- added a paragraph

 

[Mcgyver]

I’d have no hesitation taking on a lathe rescrape, but it would have to be the right lathe.

wouldn’t try rescraping a lathe without another working lathe in the shop

Excellent points, 100% agree

and plenty of experience with scraping both for alignment and bearing.

A lathe is a big project ... imo you have at some point decide to go for it, or not, but its hard to ease into/work up to. There's not really the minors for machine tool reconditioning .

 

[Christer_Wallin]

Welcome from Stockholm, Sweden

 

[philipFROM-PNW]

Welcome, from South of the Border!

That is a huge project! I have read the comments given, and one thing I have not read is "have you laid a Known good straight edge onto your bed?"

I would put a Straight Edge on the bed, AND in as many different areas as possible, including diagonal Left Front to Right Rear, and reverse of that.

Further Straight Edge work on SUB ASSEMBLIES!

In other words, 0.015 inches is understood, BUT exactly where is the Worst?

I am not familiar with TURCITE, nor its application, etc. but before Using any BUILD UP PROCESS, perhaps **mapping out** the Negative areas [ & ] Positive areas may give a better understanding of what is needed.

I had a SMALL Mill/Lathe combination that **seemed** to be out of plumb, and I went over it with a 12 inch Straight Edge, and my best machinist squares before I attempted any ONE idea to fix it.

In the end, THAT process showed me the ERROR ZONES, which were rotary brushed (Dremel) then, For me JB WELD, and scraping AFTER allowing a few days for Complete Cure.

I could barely see a light between scraped areas and real metal when my straight edge was rechecked.

(BUT, Caution I have had no WAKE UP COFFEE, Yet, I may have left out thoughts)

Regardless, Good Luck on your project!

philip, from the Great Pacific NorthWET, Oregon Division, USA

 

[jstem4]

I know what the SM 9” and 10” Utilathe anatomy looks like and a regrind and scrape of these two lathes would not require turcite under saddle ways. Not sure about a 12” Utilathe. Also not sure if your lathe has a hardened bed? Depth of hardening? Could the OP please post a pic of his lathe showing feedscrew and thread cutting screw fixing to bed at both gearbox and tailstock ends.

There’s regrinders and then there’s regrinders. Be careful who you use.

I’d have no hesitation taking on a lathe rescrape, but it would have to be the right lathe. There’s a lot of reasonable condition excellent design lathes still for sale. Maybe not as many or as cheap as twenty years ago, but still worth searching out. Just consider that small Monarch from Ottawa that just sold on GC auction? No offence, but don’t think an older SM would be a contender. A Schaublin or Habbegger? Heck yeah. A Monarch if I needed another mid sized lathe? Yup. (No, this 57 year old is not taking on a NN) But wouldn’t try rescraping a lathe without another working lathe in the shop and plenty of experience with scraping both for alignment and bearing.

On edit- added a paragraph

Hi lucky, thanks for your reply. I'm with you for a shaublin or monarch, they just don't come up for sale very often in my area. We have a bunch monarchs 10ee at work, maybe one day I'll be able to buy one. Here are some pictures of my utilathe 12.:

 

[jstem4]

I did some more investigating yesterday and even if I have 0.015'' or wear in the ways about 8 to 10 inches from the headstock it's not significant enough IMO. I calculated the error if the tool is off center by 0.015'' and it's not that bad.... i can live with that and by using the lathe i'll get to know it. Here are the differences on the radius for different sizes...It's not that bad after all.

I did a test cut on a 2inch steel stock yesterday and I was off by 0.004''' on 5 inches with a light cut. I think my problem is more with the headstock alignment with the bed. I will try to shim it like Brent H and see how much I can improve it.

If someone has a Standard modern lathe , could you measure the deflection from the top of the apron to the underside of the bed all the way from the headstock to the tailstock. Right where the gibs plate make contact? I attached a picture where i positioned my dial indicator.

I have about 0.015'' there, I would like to know how much you guys have. Should I just adjust the gibs plate to the closest I can or should I look into something spring loaded to remove any play. I can't really adjust the gibs plate to remove this much play IMO.


If I can get the lathe to get inside 0.001 for a couple of inches I would be extremely happy, and I think I wouldn't hassle to regrind it... I have too many projects already in the making.

Thanks

Julien

 

[Susquatch]

If I can get the lathe to get inside 0.001 for a couple of inches I would be extremely happy, and I think I wouldn't hassle to regrind it... I have too many projects already in the making.

If you use the cut measure adjust, cut measure adjust method, you shouldn't have any trouble hitting a thou. You pretty much have to do that if you use carbide inserts anyway.