Yet Another Project - Techno 9x20 Cnc Lathe

AR1911

AR1911

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I've stalled on my Emco 5 CNC project, and haven't touched the Lab-Volt unit in months. So of course I need another CNC retrofit project. This one has been in the local CL for months. The seller finally got ready to sell, and was wobbly on price, so I went by there today, and it followed me home.

IMG_6609.JPG
So now I'm trying to figure out what I have. It appears to be based on an Asian 9x20 bed, tailstock and cross-slide, but that's about all the parts comonality.
It has ball-screws powered by servos. I can't seem to find out anything about those, but here's what's on their label: IMG_6614.JPG
It has a nice 3/4HP Baldor 3-phase spindle motor, driven by a 110V VFD

As nice as the OE controls looks, I don't think I will be able to use it. All the electronics are on one board, so I can't isolate the drivers, or the spindle control like on some other units. At the PC it uses a proprietary PCI board. The cable looks like SCSI-2.
IMG_6603.JPG
So, I expect i'll be looking for an interface to Mach 3, if Mach 3 supports servos.
Plenty of room in that cabinet!

Oddly enough, most of the information I have found was on the Techo site.
Can't seem to find out much on the servos.

Suggestions welcome.
 
what do you mean if mach supports servos? I run Allen Bradley servos and Allen Bradley Ultra3000 drives with 2000 line encoders, it runs perfectly in mach3, they are on my Acer 9x42 mill, 100ipm rapids with a 3:1 reduction, that's 3hp and about 12lb-ft of torque at the screws....
sure is a cute little machine tho, I like it
 
KD4DIJ - I did check CNCzone. There was a little info, but not nearly as much as I expected.
I also downloaded that manual, but it's just a few pages on initial setup on arrival. It references the G-code manual, which is much larger, but I never was able to find a working link to download it. Many of the download links on Techno's site did not work for me, including the email link for the resident expert.
 
Chevydyl - The reason I asked about servos in Mach3 is because all the conversions I saw seemed to use steppers. The only detailed Techno conversion I found used steppers in place of the original servos.

These servos are rated at 50 oz-in of torque, which seems pretty weak. But the one video I found showing them moving seemed to indicate plenty of authority. Are servos rated differently, or is the design such that a lower torque rating is equivalent to a higher rating on a stepper?
At any rate, I'd like to use the existing servos if possible.
 
It's the drives you need to worry about, finding the right drives to work with the motors and encoders. Not sure if you have read the mach3 manual but you should 3-4 times over like I have, seems I miss something everytime lol.
Steppers and drives are cheap, that's why more use is seen. But they suck, lost steps and heat, my servos have never even changed from room temp, I've left em set on for hours holding torque/position while I screwed around fixing a cam issue, then run the part for the next 2hrs at moderate speeds, again never changed temp I was amazed because there is a sticker that says hot surface on it. I had steppers for something else and they were hot at all times it seemed. I think your motors may be low rpm DC, mine are high rpm 5k AC brushless, I think you should try your and see if they are enough, if not then upgrade. I personally would want Rapid feed at least of 100ipm, minimum, but 150 would be better or more, I have the ability to increase mine to 250ipm but 100 has shown to be OK for my mill. Your also sitting on iron ways so I would think it would work well for you too.

I think this project is cool, I have some parts stacking up to make a small cnc lathe, linear ball ways, with 19" Z travel and 14" of X, with the parts I have now, the screws I have already sorta limit the z travel, but it's a good mix
 
That's sort of my thinking on the servos. I just can't find any info on the existing units beyond what is on their labels (and listed on the lathe specs). I do have pinouts on the board connections, so I think I can reverse-engineer the wiring.
My next question is who sells a decent servo driver compatible with these at a decent price?

I have that mach3 manual, I'll do some reading
 
Www.a-m-c.com may be able to help, they were recommended to me on another forum. Not sure of price but you Probably Need to call em and figure out what you need. On the other hand you may be able to source used servos/drives on ebay for alot less, just be careful and make sure what you get is currently supported by the manufacturer. I went with Allen Bradley because of that, little more expensive but great products, I think the motors and drives retail for around 2 grand item
 
I too have used Allen Bradley drives on two of my conversions and can't imagine using anything else. My drives are slightly older than the ones chevydyl used but they are still readily available and cheaper. The Allen Bradley servo setup program is free and many times better than other manufactures setups I have seen. Keep an eye on eBay for some really good deals. I have bought Allen Bradley Servo drives from $100 to $400 each over the years and 1hp+ servo motors from $125 to $250 each. These are all used but I never got a bad one yet just know what you want and watch what you buy.
Ray
 
No way I'd spend for than about $500 on this. What I would like to find first is a driver board that will support these drives, then a breakbout board to connect them to a PC running mach3 (or mach4).

If that doesn't work I'll go the stepper route. Or if, a servo driver board exceeds the cost of steppers + drivers.
 
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