New cnc Lathe build.

[blighty]

hi all,

time to build a cnc lathe

to start with im having a bit of a problem with the motor i'm going to use.... not to good with this electronic stuff and i'm not getting any luck on the zone.

theirs been a lot of talk about using a treadmill motors to drive the spindle on mills and lathes, so i thought i would give it a go. problem is, there doesn't seem to be any on UK ebay but shed loads on the U.S one. so i ended up buying a second hand treadmill. took it to bits and found this little lot.

 

[blighty]

this is all well and good, but what the fluff and chuff do i do now??

i know you can get a 10k pot and put it on the board to control the speed of the motor, but any ides where it would go.

also i would like to reverse the motor, but i don't think the controller board will do that. so i dont think i will be going with the treadmill controller board.

been looking up a C6 board from cnc4pc. so that would be the mach to motor interface sorted, but i have know ider what to use for the controller.


:wall::wall::wall::wall::wall:

 

[blighty]

3 posts in one day....... must be a record for me.

everything bar the motor is sorted. been collecting bits and bob's.

got the Z rails already, picked out all the driver's, bob, stepper, power supply. just need to get the credit card out.

chuck wise..... a mate has found two 6inch chucks at the back of his work shop that will do the job.

then build the ruddy thing.

 

[mu38&Bg#]

Try to find a name on the motor control. You can probably find a spec/tech sheet online. I think I see a markingon the board "POT16 SPEED". That three conductor red/white/black lead is a likely candidate. That motor has plenty of power.

 

[blighty]

hi dieselpilot,

that red/white/black lead ether went to a encoder for the lift motor or it was the pick up for the main motor.

think your right about the power of the motor. i just hope if the chuck stalls the lathe don't flip over.

 

[mu38&Bg#]

Did you find a part number on the drive?

 

[blighty]

Couldn't look it up last night as it was 4am and I was at work

Just had a look, it's made by Pulse Power Systems p/n 1400 or it could be p/n qq-2066

 

[bb218]

If you are going to build a CNC Lathe I would think you would need a stepper type motor so the Computer control would know the speed and rotation positions for cutting threads and also be able to track the RPM very closely for feed per rev I think the motor on the tread mill is a DC motor with variable speed, good for variable speed on a manual machine but no encoders to track positon.
I have ran a lot of CNC equipment but never did much work on the machine itself so the above comment may not be completely correct. Mike

 

[canadianhorsepower]

Couldn't look it up last night as it was 4am and I was at wor

Just had a look, it's made by Pulse Power Systems p/n 1400 or it could be p/n qq-2066

if you have the complete threadmill there was a potentiometer on the control board to set your speed, take it with the wiring and you should be fine

 

[blighty]

If you are going to build a CNC Lathe I would think you would need a stepper type motor so the Computer control would know the speed and rotation positions for cutting threads and also be able to track the RPM very closely for feed per rev I think the motor on the tread mill is a DC motor with variable speed, good for variable speed on a manual machine but no encoders to track positon.
I have ran a lot of CNC equipment but never did much work on the machine itself so the above comment may not be completely correct. Mike

stepper not needed, as on the back of the spindle there is a disk with a hole in it. a senser then sends a pulse back to mach so mach knows the rpm of the spindle.

i think you can put an encoder on the back of the tread mill motor and then controll it with a gecko G320 and have step and direct....... seen this done with Nordic DC motors, but as norm they don't go into it. they tend to show what they got and it working....tend to leave out the bit in the middle

 

[blighty]

if you have the complete threadmill there was a potentiometer on the control board to set your speed, take it with the wiring and you should be fine

the potentiometer on the treadmills control is digital. you just pushed + - i've had a look at the wiring from the buttons and the go into a IC then of to the motor controller board with a ribbon cable.

 

[canadianhorsepower]

the potentiometer on the treadmills control is digital. you just pushed + - i've had a look at the wiring from the buttons and the go into a IC then of to the motor controller board with a ribbon cable.

what's the part number of the chip is probably a shift register
I could tell you with wire to use

 

[blighty]

what's the part number of the chip is probably a shift register
I could tell you with wire to use

thought a few pics would be better.

the last pics shows where the track goes to the ic, but i think it could be the earth as it goes to both speed buttons.

 

[aarggh]

The beige chip highlighted in the last photo is a resistor pack. More than likely a pull-up/down for the I/O pins of the I.C. with the label. If you want to follow the earth traces, the black TO-226 package riveted to the PCB in the bottom right of the last photo looks like an LM7812/7805, or an LM317, if it's one of those, the middle pin will be ground.

cheers, Ian

 

[canadianhorsepower]

Can you send me a close up picture of the flex pcb " picture with arrow"

 

[DICKEYBIRD]

Having been through various treadmill motor control options myself, I'd advise you to get a KB brand SCR or PWM speed control. They are plentiful on ebay both new & used. The used ones work great and are very cheap if you shop around. The manuals are free .pdf downloads with all hookup & adjustment data included. Being industrial units, they are near bullet proof.

For your motor may I suggest a KBIC-240 (older but avail. used cheap) or if you want to reversing with dynamic braking, built in, a KBCC-225R. These are both SCR controllers and work very well with Mach control via CNC4PC or Homann speed control boards. KB has PWM controllers as well but they fetch more money.

I have a KBCC-125R (110V USA mains power) and am tickled pink with it. I can input an M3S1800 command and the spindle smoothly runs up to 1800 RPM. I then can type in M4S1800 (without an M5 (stop) command) and the spindle brakes smoothly down to "0", the control relay clacks and the spindle runs right back up to 1800 in the other direction, no muss, no fuss.

It also has provisions for a DC tach generator input to regulate the speed to 1% of set speed. I am presently getting close to finished with my tach-gen installation. I want to get that working and adjusted before trying threading with Mach.

Good luck with yours & keep posting as you progress.

 

[mu38&Bg#]

You need to figure out what sort of signal is being sent down the RJ45(?) telephone connector looking leads. The control board for the treadmill should be completely independent of the motor drive. The signal will tell the drive how fast to run the motor, that is all. If you're lucky it's 0-5V and you don't need anything. Look for a mfg or model number on the drive itself.

I agree though, a KBIC-240 is ~70USD on Ebay. I used one on a treadmill motor when I had the old Craftsman lathe.

 

[blighty]

canadianhorsepower....

i can't do your a pic at the mo as i'm at work i'll upload one tomorrow.
would be good just to get the motor turning when its out of the treadmill.

i could hook it all back up and use "Fitness program 3" and see if it cuts an 8mm thread.


DICKEYBIRD...

that in the long run is what i'm looking for. just looked up a KBCC-225R. and your right, theirs loads of them, just like a Nordic dc motor. also like the Nordic there all in America:wall::wall:

like the idea of not using m5 before a M3/4 comand. the amount of time i have popped a relay...... ok, you just push the button back in, but its moving the 700lb of lathe to get to the button that gets on my tits.

take it your on about the C6 board?

i'll see what i can find on UK ebay.

 

[blighty]

would this be what im looking for

http://www.ebay.co.uk/itm/Used-KB-E...600?pt=LH_DefaultDomain_0&hash=item19d6948f28

so if i do end up getting one of these. i can plug 240vac 50Hz strait into it and have mach tell a C6 board what i need it to do..... forwards/backwards etc.?

 

[blighty]

just found this......... http://www.axiscontrols.co.uk/shop/kbcc-range/9924

not to sure with this bit......
it says it's 240vac in, thats bits fine and the motor is 11 amps DC and again OK. however the DC output is 180v. the motor i have is rated at 220vdc would this make the motor run slower/less power. or is this another electronics thing that don't work like that.?