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Lathe bed welding casting
- Thread starter spenca
- Start date
- Joined
- Jan 1, 2018
- Messages
- 1,154
Is your plan to build your own metal lathe?
I have no experience with what you are purposing. I will offer a suggestion though. Most old worn out metal lathes have considerable wear in the first foot of bed next to the head. Buy a worn out old lathe for cheap and cut off the first foot - foot and a half of bed then use the rest for your project. Many of the old lathe beds I have seen are pretty virgin one you get past that first foot or so of worn bed. It also seems like the longer the bed on the old worn out lathe the cheaper they are as most hobbyists don't want to dedicate the shop space to a long bed lathe.
Just a thought to hopefully spur some creative thinking.
Welding usually means building up stresses in the metal so if you do go this route you will want to peen your welds well to reduce the built up stresses which cause warping.
Maybe you could describe your project in a bit more detail?
I have no experience with what you are purposing. I will offer a suggestion though. Most old worn out metal lathes have considerable wear in the first foot of bed next to the head. Buy a worn out old lathe for cheap and cut off the first foot - foot and a half of bed then use the rest for your project. Many of the old lathe beds I have seen are pretty virgin one you get past that first foot or so of worn bed. It also seems like the longer the bed on the old worn out lathe the cheaper they are as most hobbyists don't want to dedicate the shop space to a long bed lathe.
Just a thought to hopefully spur some creative thinking.
Welding usually means building up stresses in the metal so if you do go this route you will want to peen your welds well to reduce the built up stresses which cause warping.
Maybe you could describe your project in a bit more detail?
Last edited:
- Joined
- Jan 25, 2015
- Messages
- 2,558
Welding is going to warp it and you'll be back to scraping it flat again.
Look up "gingerly lathe" for some ideas on making your own.
Personally, I wouldn't diy it if you intended to have any great degree of accuracy. . But everyone has a different comfort and skill level. There's also availability. Guam is pretty close to Taiwan and China, so I would expect there are at least some options in your area.
Edit: whoops, thought it said Guam as a country, missed that it is actually Slovenia....you're probably looking t some old USSR equipment where you are. Some of the stuff they made is really good, you just have to hunt it down...
Look up "gingerly lathe" for some ideas on making your own.
Personally, I wouldn't diy it if you intended to have any great degree of accuracy. . But everyone has a different comfort and skill level. There's also availability. Guam is pretty close to Taiwan and China, so I would expect there are at least some options in your area.
Edit: whoops, thought it said Guam as a country, missed that it is actually Slovenia....you're probably looking t some old USSR equipment where you are. Some of the stuff they made is really good, you just have to hunt it down...
I have been using a home built wood lathe for about 15 years. It is built of welded steel (no concrete). It works great as a wood lathe but would not meet my needs as a metal lathe. I used thick steel and careful welding to minimize warping of the bed, the headstock (and tailstock) was machined after welding. Your concept is possible BUT will require good planning, material selection, meticulous craftsmanship and control of expectations.
- Joined
- Jan 2, 2019
- Messages
- 6,526
These guys build tool grinders on a polymer concrete base.
www.starcutter.com
I've built a milling machine from fabricated steel. I can testify that if you're looking for high precision you will need to do a bunch of work to make something like this accurate.
I also suspect that materials will be more than buying a used machine and refurbishing it.
If your goal is to go into production with a CNC lathe you will be dollars ahead buying a suitable machine. Another approach is leasing the machine which companies use to preserve capital.
If your use is hobby only, and you have time, retrofitting or building from scratch is an option.
Of course what's available in your country will limit you, but being an EU country should afford you options from either Germany or Italy which both have robust CNC manufacturing economies.
Cheers,
John
NXT Tool & Cutter Grinder - Star Cutter Company
The NXT is a small footprint machine, with a large grind zone, an ability to run small and large diameter wheels.
www.starcutter.com
I've built a milling machine from fabricated steel. I can testify that if you're looking for high precision you will need to do a bunch of work to make something like this accurate.
I also suspect that materials will be more than buying a used machine and refurbishing it.
If your goal is to go into production with a CNC lathe you will be dollars ahead buying a suitable machine. Another approach is leasing the machine which companies use to preserve capital.
If your use is hobby only, and you have time, retrofitting or building from scratch is an option.
Of course what's available in your country will limit you, but being an EU country should afford you options from either Germany or Italy which both have robust CNC manufacturing economies.
Cheers,
John
Hy guys.
Thank you for answering.
Will i talk about some stuf i am moving around for 20 years.
When i saw lathe cnc lathe i was stuned. And i wont to own one.
But here is a snag.
if i buy old manual one, it is all worn, ways are worn, gears have spacing betwen them, oil leks everywere and so on. There is no spere parts. This is a real problem. I like manual lathe it is a charm and magic in them. But you will not earn living with it. and be fair. This wil hurt realy hurt. Old machinery had realy good grey cast iron. I am disapointed that we live in now, and we cant make beter cast iron as 50 years ago. Rigidity of machine is les cast iron is **** and so on. I know of one lathe on witch you can remove and put on new ways. It is lathe Potisje from Prvomajska and it has difrent types as 30B, 22 and so on. Ways are tempered put on lathe and whole lathe is then put on big macine where they grind it scrape it and this is it.
As buying seling is concerned. Peopel buy lathe work on it and seel forward, when you see that you need to reper it and repair cost more as you can make from it. It is the same in cnc world. If i buy weiler for exsample i need to pay 50% of price then loading and shiping costs. This is usaly al together 2.5X price of lathe on seling inetrnet store auction stuf. IF you buy center lathe, usaly it is robed of everthing, colets, chuck, axsesories. You got what cant be removed from lathe. I am loking now two nice lathes, but on them is so meny things mising it is horable. Then you ened to repair it this is one year job at earliest. Cost is betwen 3K euro to 48.000 euro schaublin 150 rebuild for exsample. If you buy cnc for i dont know 20.000 you have old destroyed cnc lathe and you need to scrap al electrical systems, paint and so on. You need to repaint it, put ney linear gudes and so on it and ney cnc system. But it is doable. I am not afraid of this. It is exspencive but you will have nice lathe. Center lathe are modified cut in some places you canot weld cast iron, i have one exsample of this at home.
So what to do?
If i buy manual lathe it need to be without gears, if you wona put on servo motor you canot go this with 6000 rpm on gears. Then problem is with ways, you need to repair them. But soon or later you need to rebuild ways witchis costly, linear guide ways you yust change and this is it.
It woud be nice to make one lathe plans for a lot of people and this is it.
So if i took sheet metal and weld it, yes it wil warp, but,... weldment can be thrown in fire and strees relived, yes?
But here is a snag. Steel vibrates, as i read. So this is the reason for gray cast iron. But Polimere concrete is much better option, as vibration is concerned.
If you build metal weldment. I think gray cast iron cant be welded, yes? And then put gray cast iron bed from old lathe witch wass milled on miling machine so you cut of the ways, so you can put on linear rails, wudnt this be an option? Question is "will miled bed warp becose you miled ways away?". THis we shoud ask some guy who know. Or put on it polimer concrete bed.
Then you buy linear rails and ballscrews, put in on.
There i sproblem with the spindle, you need spindle build from schrach.
If i look at repering old center lathe, this is a disaster. Okisidised nuts, and bolts, dirty oil stains like glue, previus modification reapairs on komponents, ways repair, worn gears and pinions, removing paint, repaint it. I was there do this,... .
I realy dont know what is beter option. Build from schratch or repair old center lathe. And when you are done. What you have. On center lathe you have 8 to 12 rpm values with determined feeds in two directions. As cuting feeds and speeds is concern is a litle triky. Ok you need to use hss toling witch is cheper. But, if you build one cnc from schrach you ahve veristiltiy of speed and feed, positioning on psindle and option to use hss or carbide. And you can run more identical parts easily, for exsample.
And remember, new lathes, have bad gray cast iron, you dont repair this kind of lathe machine, you buy another one. Potisje and prvomajska didnt have good cast iron. But wiser, schaublin, willer and other german lathes for exsample had dem. Even french, british and so on had beter cast iron. If you buy china, you buy good exspencive lathe it will last, if you buy you know what it will not last. I talked to owner who had one he said that lathe bed is twisted becose of torsion forces, and all lathe is squiling when he try to cut 1mm of ordinary steel.
There are two problems. How to build lathe bed and spindle this is it. I loked on intenret and i didnt foudn nobady to sell this both things., You can get old lathe sfor cheap. Old releve gray cast iron bed. I woud love to know if we mill that bed it will perform
. Probbaly you will tel me i am stupid to even think about it. . That it is sin to cut gray cast iron lathe bed. Idotn kare, i have one laying around, and it is realy good gray cast iron, but you know what. Al other parts are sh.t. I throw it in the scrapyard and get 40 euros for it or i mill it.
Thank you for your opinions, aprovals, disaprovals, hard core teroretical and practical opinions and fact. I relay love to talk and brainstorm this topic.
Some pricing:
tnp 160 lathe 3000 to 7000 euro (14 000 euro totaly rebuild one)
tnp 245 lathe 2000 to 5000 euro
wiler comodore lathe 3000 to 10 000 euro
potisje lathe 4500 to 8000 euro (18 000 totaly rebuild one)
emco v 10 1000 to 2800 euro
wagner lathe new best quality as otehr 8000 firly big lathe will not bend bed torzionaly with hard use even after 5 years (they tested it)
schaublin dont tuch it from 15 000 to 20 000 euro (totaly rebuild 35 000 to 48 000 euro)
schaublin 125 cnc 12 000 euro around here somere
Have a nice day.
Thank you for answering.
Will i talk about some stuf i am moving around for 20 years.
When i saw lathe cnc lathe i was stuned. And i wont to own one.
But here is a snag.
if i buy old manual one, it is all worn, ways are worn, gears have spacing betwen them, oil leks everywere and so on. There is no spere parts. This is a real problem. I like manual lathe it is a charm and magic in them. But you will not earn living with it. and be fair. This wil hurt realy hurt. Old machinery had realy good grey cast iron. I am disapointed that we live in now, and we cant make beter cast iron as 50 years ago. Rigidity of machine is les cast iron is **** and so on. I know of one lathe on witch you can remove and put on new ways. It is lathe Potisje from Prvomajska and it has difrent types as 30B, 22 and so on. Ways are tempered put on lathe and whole lathe is then put on big macine where they grind it scrape it and this is it.
As buying seling is concerned. Peopel buy lathe work on it and seel forward, when you see that you need to reper it and repair cost more as you can make from it. It is the same in cnc world. If i buy weiler for exsample i need to pay 50% of price then loading and shiping costs. This is usaly al together 2.5X price of lathe on seling inetrnet store auction stuf. IF you buy center lathe, usaly it is robed of everthing, colets, chuck, axsesories. You got what cant be removed from lathe. I am loking now two nice lathes, but on them is so meny things mising it is horable. Then you ened to repair it this is one year job at earliest. Cost is betwen 3K euro to 48.000 euro schaublin 150 rebuild for exsample. If you buy cnc for i dont know 20.000 you have old destroyed cnc lathe and you need to scrap al electrical systems, paint and so on. You need to repaint it, put ney linear gudes and so on it and ney cnc system. But it is doable. I am not afraid of this. It is exspencive but you will have nice lathe. Center lathe are modified cut in some places you canot weld cast iron, i have one exsample of this at home.
So what to do?
If i buy manual lathe it need to be without gears, if you wona put on servo motor you canot go this with 6000 rpm on gears. Then problem is with ways, you need to repair them. But soon or later you need to rebuild ways witchis costly, linear guide ways you yust change and this is it.
It woud be nice to make one lathe plans for a lot of people and this is it.
So if i took sheet metal and weld it, yes it wil warp, but,... weldment can be thrown in fire and strees relived, yes?
But here is a snag. Steel vibrates, as i read. So this is the reason for gray cast iron. But Polimere concrete is much better option, as vibration is concerned.
If you build metal weldment. I think gray cast iron cant be welded, yes? And then put gray cast iron bed from old lathe witch wass milled on miling machine so you cut of the ways, so you can put on linear rails, wudnt this be an option? Question is "will miled bed warp becose you miled ways away?". THis we shoud ask some guy who know. Or put on it polimer concrete bed.
Then you buy linear rails and ballscrews, put in on.
There i sproblem with the spindle, you need spindle build from schrach.
If i look at repering old center lathe, this is a disaster. Okisidised nuts, and bolts, dirty oil stains like glue, previus modification reapairs on komponents, ways repair, worn gears and pinions, removing paint, repaint it. I was there do this,... .
I realy dont know what is beter option. Build from schratch or repair old center lathe. And when you are done. What you have. On center lathe you have 8 to 12 rpm values with determined feeds in two directions. As cuting feeds and speeds is concern is a litle triky. Ok you need to use hss toling witch is cheper. But, if you build one cnc from schrach you ahve veristiltiy of speed and feed, positioning on psindle and option to use hss or carbide. And you can run more identical parts easily, for exsample.
And remember, new lathes, have bad gray cast iron, you dont repair this kind of lathe machine, you buy another one. Potisje and prvomajska didnt have good cast iron. But wiser, schaublin, willer and other german lathes for exsample had dem. Even french, british and so on had beter cast iron. If you buy china, you buy good exspencive lathe it will last, if you buy you know what it will not last. I talked to owner who had one he said that lathe bed is twisted becose of torsion forces, and all lathe is squiling when he try to cut 1mm of ordinary steel.
There are two problems. How to build lathe bed and spindle this is it. I loked on intenret and i didnt foudn nobady to sell this both things., You can get old lathe sfor cheap. Old releve gray cast iron bed. I woud love to know if we mill that bed it will perform
. Probbaly you will tel me i am stupid to even think about it. . That it is sin to cut gray cast iron lathe bed. Idotn kare, i have one laying around, and it is realy good gray cast iron, but you know what. Al other parts are sh.t. I throw it in the scrapyard and get 40 euros for it or i mill it. Thank you for your opinions, aprovals, disaprovals, hard core teroretical and practical opinions and fact. I relay love to talk and brainstorm this topic.
Some pricing:
tnp 160 lathe 3000 to 7000 euro (14 000 euro totaly rebuild one)
tnp 245 lathe 2000 to 5000 euro
wiler comodore lathe 3000 to 10 000 euro
potisje lathe 4500 to 8000 euro (18 000 totaly rebuild one)
emco v 10 1000 to 2800 euro
wagner lathe new best quality as otehr 8000 firly big lathe will not bend bed torzionaly with hard use even after 5 years (they tested it)
schaublin dont tuch it from 15 000 to 20 000 euro (totaly rebuild 35 000 to 48 000 euro)
schaublin 125 cnc 12 000 euro around here somere
Have a nice day.
- Joined
- Jan 25, 2015
- Messages
- 2,558
You can weld cast iron, but its not easy. It tends to harden and get very brittle at the weld, often cracking right at that spot.
I’ve welded cast before, but it must be preheated, then I use tig (ie: easy to control arc, filler and precision) and nickle filler rods (nickle so it doesn’t draw too much carbon into the weld area from the cast and make it brittle) and it must be slowly cooled post welding (ie: buried in warm sand, etc).
It still won’t be very strong and will be prone to cracking at and around the weld area.
Personally, I’d avoid welding cast iron if you can.
I’ve welded cast before, but it must be preheated, then I use tig (ie: easy to control arc, filler and precision) and nickle filler rods (nickle so it doesn’t draw too much carbon into the weld area from the cast and make it brittle) and it must be slowly cooled post welding (ie: buried in warm sand, etc).
It still won’t be very strong and will be prone to cracking at and around the weld area.
Personally, I’d avoid welding cast iron if you can.
Thank you sir. So option to buy cst iron blocks from diller and weld together stuf is off. Only option exsist now to buy big chunk of cast iron block like 400x300x1500mm and put it on mill and mill it. It woud be nice to dril some big holes in so weight is reduced.
Thank you sir again for your advice.
Thank you sir again for your advice.
- Joined
- Jan 2, 2019
- Messages
- 6,526
If this is your first lathe I suggest buying a manual machine and learning how to run it before diving into building a CNC.
If you want to make money you can do repairs for local people that wouldn’t be possible on a CNC.
As you learn and gain experience you will find out you can make a living.
IMHO, if you can’t afford to buy a good used machine you will not be able to build anything useful for less.
John
If you want to make money you can do repairs for local people that wouldn’t be possible on a CNC.
As you learn and gain experience you will find out you can make a living.
IMHO, if you can’t afford to buy a good used machine you will not be able to build anything useful for less.
John
