Southbend 8K (SB1001) Lathe for CNC

Hi All:

This forum is huge. I wasn't sure the best place to post this. Hopefully I can get the answers I need here.

I am looking at buying a Southbend SB1001 8K lathe because - based on all my reading here- this is a higher quality lathe for the small Chinese made lathes. My intentions are to Convert it to CNC. I have run into a few issues though.
1). I hear the 8K might be discontinued and parts may be hard to get. Can anyone confirm that?
2). I don't see anyone that has converted this lathe to CNC
3). I can't seem to fin any 8X conversion kits around. Does anyone do this....anywhere.?

If the SB1001 8K is not a good candidate, than does anyone have advice for one that is? I am limited on space, so the 8K is about as large as I can fit.

Thanks.

Mike Norman
G-Force Racing Development
www.mngforce.com

Here is a picture and a link of my CNC South Bend 8K SB1001 along with the parts needed to CNC it.South Bend 8K CNC

I used the same Nema23 570 oz/in motors as on my G0704 mill. Hoss Machine has a pretty good description of the G0704 electronics/motors and any of these will work on the SB1001.G0704 Electronics Three things I will say is that the 570 oz/in motors work fine when using direct drive on the South Bend lathe, The C35 breakout board makes hookup pretty easy CNC4PC and a spindle encoder with a single pulse index reading will give you nice threading capability.
Attachment 278288

South Bend 8K CNC

Attachment 278290Attachment 278290Regarding the SB1001 CNC lathe:
It is a 280 lb lathe. Adding CNC to it doesn't make it a 5,000 lb lathe.

Mine cuts a lot of aluminum and plastic. When I need a steel part I take light cuts in low-gear and it cuts fine.

Threading using the C3 index pulse card from CNC4pc works well. With shipping it runs around $40 for a ready to hook-up package, but you could rig up any kind of $10 optical or magnetic proximity sensor to do the same thing. My lathe is limited to a single pulse index as I am using an Ethernet Smoothstepper. I originally wanted several index pulses, but one is all you need for good threads.

Of final note, I'm happy with my SB1001 CNC Lathe. It is small, is capable of doing everything I need right now. A heavier lathe with a bigger spindle thru-hole bore would be nice, but it is light enough for me to move it on my own. When I do get a bigger shop with bigger machines this little South Bend lathe will still be nice enough to bring along.

South Bend 8K CNC

Thanks for the detailed information and feedback. I will be gathering up my photos, drawings and progress as I work through my CNC conversion.

*I have ordered the Z-axis ballscrew 16mm x 5mm lead x 800mm overall length, and the X-Axis ballscrew 10mm x 2.5mm lead x 240mm overall length (This one will be tricky to make work).
*I am looking to work with cuttingchips for his mounts, etc.
*I am trying to determine what size NEMA motors I really need. I have 425oz-in NEMA 23 motors on my G0704 conversion. Maybe they are proper? Maybe they are too big? Maybe the X-Axis could use a smaller motor? I would like to keep the motor length/size as short as possible.
*Once I have selected the motor size, I need to figure out the best electronics package to drive it all. That is far harder to figure out than the mechanical parts.

Any feedback would be great!

Cheers!


More soon.

Your 425 oz/in motors should work fine on your SB1001. Assuming the 570 oz/in motors have a higher Amp rating than the 425 motors, you could get the larger motor for the Z-axis and run it using your current control settings. If you wanted more power in the future you wouldn't need to upgrade the motor.

I picked the 570 oz/in motors for my lathe as that was what was on my G0704 mill and it allows me to use the same control. Initially I thought it would be overkill, but after a year of running it a few hours a week there haven't been any problems. On the Z-axis of my mill I have a Nema34 1200 oz/in motor... which replaced the first 650(ish) oz/in motor I tried. My control has a 48v 6.7amp power supply for the 570 oz/in motors and a seperate 60v power supply for the Nema34 on my mill's Z (another later date upgrade).

Hoss Machine's page on the G0704 electronics gives the best writeup I have found on the electronics end. In retrospect the 3-axis digital driver would probably be a great choice for my mill and lathe. My mill's Z-axis runs on a digital driver and it runs much quieter than the Keling analog drivers. I've also dumped any desire to run my machines through the parallel port of an old Dell computer. Getting an Ethernet SmoothStepper or UC100 lets you use a modern laptop computer and you won't have to upgrade later. The best way to save money is to buy the right thing the first time!!

I'll post some pictures of my control sometime next week.

Anyway, short answer is that your 425 oz/in motors should be fine for both the lathe and mill. With these bechtop machines a lot of getting good results is figuring out how much slower you have to go than on a full sized machine.

South Bend SB1001 8K Lathe CNC

Any luck with more pics of your control? Also, do you by chance have CAD models of any of the parts you made? I would like to add those to the models I am creating for my design.

Thanks so much.

Mngforce

Quote:

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Originally Posted by cuttingchips

Your 425 oz/in motors should work fine on your SB1001. Assuming the 570 oz/in motors have a higher Amp rating than the 425 motors, you could get the larger motor for the Z-axis and run it using your current control settings. If you wanted more power in the future you wouldn't need to upgrade the motor.

I picked the 570 oz/in motors for my lathe as that was what was on my G0704 mill and it allows me to use the same control. Initially I thought it would be overkill, but after a year of running it a few hours a week there haven't been any problems. On the Z-axis of my mill I have a Nema34 1200 oz/in motor... which replaced the first 650(ish) oz/in motor I tried. My control has a 48v 6.7amp power supply for the 570 oz/in motors and a seperate 60v power supply for the Nema34 on my mill's Z (another later date upgrade).

Hoss Machine's page on the G0704 electronics gives the best writeup I have found on the electronics end. In retrospect the 3-axis digital driver would probably be a great choice for my mill and lathe. My mill's Z-axis runs on a digital driver and it runs much quieter than the Keling analog drivers. I've also dumped any desire to run my machines through the parallel port of an old Dell computer. Getting an Ethernet SmoothStepper or UC100 lets you use a modern laptop computer and you won't have to upgrade later. The best way to save money is to buy the right thing the first time!!

I'll post some pictures of my control sometime next week.

Anyway, short answer is that your 425 oz/in motors should be fine for both the lathe and mill. With these bechtop machines a lot of getting good results is figuring out how much slower you have to go than on a full sized machine.

South Bend SB1001 8K Lathe CNC

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