Bought a CNC lathe

[ibuildstuff4u]

I just bought a CNC lathe.  It's a prolight 3000 and is loaded with all the goodies.  There is a automatic tool changer, a pneumatic chuck that can be opened and closed via the computer as well as the door for the machine.  It also came with a standard three jaw chuck.  As a bonus the chuck can be removed and a 5c collet will fit inside of the spindle! The tool changer holds four 1/2" tool holders which came with and four 1/2" round tools for drilling and boring.

The bad part is it's missing the control box, so I will have to build my own but for $500.00 I can't complain.  Now I need a CNC mill to go along with it.

Any one here have a similar machine?

[Ross]

Never knew CNC lathes as small as this existed! Very cool

[ibuildstuff4u]

There are a few companies that make one even smaller, but for me they are too small.  This one has a 4" chuck,  6" swing and 10" in the Z axis.  The only option it doesn't have is a tail stock, but I only intend to turn small items so that shouldn't be a problem.

Here is a picture of a smaller machine made by D&M.  The seller has this one for sale too and it has been converted to flash drive.  It's a bit smaller than mine, but larger than a sherline lathe.  If any one is interested let me know and I can get more info for you.  It's located near Kenosha Wi.

[Jonny]

Got a Boxford TCL125 thats about the same size.

[DICKEYBIRD]

Wow, that's going to be a nice machine when you get it running!  I envy you with the toolchanger but don't envy you having to learn how to program it.

What control components does it still have?  Is the spindle motor AC w/VFD or DC?  I assume you're going to go with Mach3 or EMC?

I'm fixing up a Denford ORAC and am getting pretty close.  It came with no electrics at all and I built it up from some stuff I had already, a lot of misc eBay purchases and some used parts that nice folks gave me.  It has a 3/4 hp Baldor DC motor with a KBIC-120 speed controller that is controlled by Mach via CNC4PC C11 multifunction B.O.B with a CNC4PC C3 spindle index card/sensor for threading (hopefully.)

I'm in the process now of fitting a twin QCTP plate that bolts to the carriage and will have to learn Mach3 tool offsets.

[ibuildstuff4u]

The lathe is missing the control box which had the stepper drives, power supply, breakout board, etc.  However it came with the stepper motors, spindle motor, spindle motor drive, optical pickup for the spindle and limit switches so there is a good starting point.  The spindle is a DC motor and I think it has the same board as your machine. 

I'm planning to buy three KL6050 stepper drives and a Bob Campbell breakout board and run it with Mach 3.  I had a D&M mill in the past and did a retrofit to it so I'm familiar with putting the control box together, but am worried about a few things such as how to intergate the spindle pick up to the breakout board and how the tool changer is going to be programed to index as I have never played around with Mach 3 for the lathe, only for the milling machine that I had.

I used the Bob Campbell breakout board in the past and really liked it because it had three power supplies built into it so you just have to hook it up to 110vAC and it will provide two isolated 5 volt sources for the board and an additional 12 volt supply for relays or proximity limit switches.

I see your using a CNC4pc C3 card for the spindle sensor and I will have to look into that to see if I need one for my machine.

Looking at your pictures I see a KB signal isolator, what does that do?  Also where did you get the stepper drive from?  Was that original to the machine? 

Looks like a neat project you will have to keep me posted on your progress.

Dale P.

[Brass_Machine]

I just caught this thread. That is a cool lathe... Looking forward to seeing this restored.

The KL6050's are pretty good... but what is a Bob Campbell breakout board? I haven't heard of that one.

Eric

[ibuildstuff4u]

Here is a link for the breakout board.
http://campbelldesigns.net/breakout-board.php

Also some pictures of my D&M mill before and after I retrofitted the machine to work with Mach 3 as the old control system only worked with D&M custom software.  The mill was OK, but too small for my needs so I sold it a few years ago but am now looking for a larger CNC mill to replace it.

[DICKEYBIRD]

Looking at your pictures I see a KB signal isolator, what does that do?  Also where did you get the stepper drive from?  Was that original to the machine?

I had a terrible time getting the analog 0-10VDC output circuit in the C11 B.O.B. to control the KB DC speed control.  The instructions were not specific &  clear enough (to me) as to the "isolation" factor and I killed one KB and vaporized a track on the C11 over the period of time I tried to get it to work.

I finally read the KB manual (free .pdf available online) more thoroughly and it clearly shows that to implement the voltage following feature, you either have to know exactly what you're doing re: the isolation thing (I don't) or use their KBSI-240D Signal Isolator which magically & totally isolates the source control voltage from the mains voltage in the KB speed control.  All I know is that before I picked up one on eBay and hooked it up per the instructions, all I could get were dazzling flashes, fuses popping or the motor running at berserk speeds, totally out of control!  It works great now and gives me exact Mach control of spindle speed to within 5 or 10 rpm.

The 1996 SmartStep/3 stepper drive board is an extra one I bought (used) from the Denford folks in the U.K. as a backup.  Last year I had a long-running job using my little modified Denford MicroMill (w/lathe mod) and was afraid the original board might die on me before I finished the 1100 part run.  The rectifier bridge in the original board died early on in the project and although I was able to replace it cheap and keep the board running, I was afraid something else might fail so I bought a spare.  The ORAC came along earlier this year and I decided to use the SmartStep on it to keep the budget low.  It's only rated at 2A/40V but seems to work well with the Xylotex 2.8A stepper motors.  They're underdriven but in early test runs seem to work fine for my needs.  I'm old & not in a big rush when I make things.;) 

Hopefully I can make enough money with it to pay for the stuff I've had to buy for it so far and move up to some more powerful drivers & steppers later.  The toolholder plate and twin QCTP's are heavy and will need more power to shove around if I start yearning for more speed.

Keep the pics coming as you move forward with your Prolight.  I'll bet your toolchanger is common with those used on other small lathes.... like an Emco C5 or 6 or possibly even the Denford ORAC like was an option on mine.  If so, the Mach thing has been done with them and there should be threads on how to hook up and program them over on the Mach support forum.  Some of those guys are scary smart!

[ibuildstuff4u]

The build is going to go slow as I have to find the budget to buy all the parts that I need.  I will make sure to take lots of pictures and post them as I go. 

I keep looking at different drives and power supply combinations to save money but I worry if I go too cheap I will regret it and end up with a slow machine that is easy to miss steps with.  My D&M mill was easy to stall and could only take light cuts and I don't want to end up with something like that again.  I should have replaced the stepper drives while I was at it when I did the retrofit.

Dale P.

[DICKEYBIRD]

The build is going to go slow as I have to find the budget to buy all the parts that I need.  I will make sure to take lots of pictures and post them as I go. 

I keep looking at different drives and power supply combinations to save money but I worry if I go too cheap I will regret it and end up with a slow machine that is easy to miss steps with.  My D&M mill was easy to stall and could only take light cuts and I don't want to end up with something like that again.  I should have replaced the stepper drives while I was at it when I did the retrofit.

10-4 on the budget situation...I feel your pain brother!:(

I bumped into an online Prolight 3000 spec sheet yesterday (can't seem to find it today) and it mentioned the stepper motor spec. at 150 oz/in.  Not sure if that's what they all came with but it seems a little on the puny side.  Mine's not much higher than that (190 I think) and so far so good but it won't do any hogging of steel that's for sure.

On the bright side though it did say your spindle motor is 1 hp DC so that ought'a be great.

[ibuildstuff4u]

Yes, I saw that spec sheet too.  I'm hoping that 150oz will be good enough for a lathe as the cutting forces are much less than a mill, but if I have any trouble with them I will up grade them in the future.  I'm going to buy a larger power supply and stepper drivers than the old motors need and just tune them down so if I do replace the motors I won't have to worry about the drives or power supply being large enough.  I should be able to just replace the Z and X axis and leave the third motor for the tool changer alone so the up grade will be around $100.

Thankfully 99% of the stuff I cut is aluminum so there shouldn't be a problem

Dale P.

[DICKEYBIRD]

I should be able to just replace the Z and X axis and leave the third motor for the tool changer alone so the up grade will be around $100.

Sounds like a good plan Dale.  Do the steppers hook up direct or is there a timing belt reduction pulley setup between the motors & ballscrews?  If so, 150 oz/in can do quite a bit of work on a small lathe.

Man, you need to share your source of power supply & drivers for $100; that sounds great!

[ibuildstuff4u]

Ha I wish, the $100 is just for two new stepper motors if needed.  The new control system is going to cost hundreds.

Three KL 6050 stepper drives $50.00 each = $170 shipped
Breakout board  $110.00 shipped
50 volt 400w transformer with capacitors $150 shipped
box to house all electronics $100.00 shipped
Two nema 23 stepper motors (if needed) $100.00

Total = $530.00 to $630.00 and that doesn't include wire, fans, switches, etc.  Could be as high as $800 in the end but I really hope not.

[DICKEYBIRD]

Dale those KL6050's look to be a good deal: $50 for 5A/60V.  That's a lotta power for the money.  Have they been reliable and consistent for you?  I may get one later if I have to add power to the Z-axis.

Milton D.

[ibuildstuff4u]

I haven't tried them yet.  I only read some reviews on CNC zone and it seems like they work pretty well.  The KL 5056 is my second choice.  It has a bit less power but more micro steps and other features.

Dale P.

[ibuildstuff4u]

I bought the lathe, but haven't been able to pick it up yet.  It's still sitting at the sellers house    It's a three plus hour drive to get there and I just haven't had the time to pick it up.  I just found out that I have off Friday and it works out with the seller so it looks like I'm going to have my machine by the weekend! 

I can't wait to get it and take a better look at the inside to see how the retrofit will work.

Dale P.

[DICKEYBIRD]

I just found out that I have off Friday and it works out with the seller so it looks like I'm going to have my machine by the weekend! 

I can't wait to get it and take a better look at the inside to see how the retrofit will work.

Man, are we not a strange bunch?  We get all excited about getting expensive machines that don't even work and then can't wait to get our hands on them so we can spend hours & hours working on them not to mention the piles of cash thrown at 'em.

My wife has that roll-ey eyes look permanently tattooed on her mug these days....looks just like an internet forum rolleyes smiley.  She's had it for almost 25 yrs now.

[ibuildstuff4u]

Well I got the machine home Friday and have spent some time taking it apart to see how it ticks. I have a pretty good idea on how I'm going to retrofit it to work with Mach 3, but figuring out the spindle speed control has been a challenge so far.

The spindle motor board has a manual input for a pot switch and also a 0 to 10 volt control for the computer.  The pot switch on the lathe has an On and Off switch connected to the back of the pot switch and will select the from computer control to manual control.  I'm pretty sure I can simply reuse this and hook it up to a breakout board with a output for a 0 to 10 volt VFD.  There is a LCD screen that displays the spindle RPM and the back of the board hooks up to the computer.  I think it needs the original software to make it work so I'm just going to remove it and throw it out.  RPM will be displayed on the monitor any way.

The trouble that I'm having with the speed control is that it's hooked up to a large resistor and relay and I'm not sure what they are there for.  I think it's to provide a slow start for the motor to prevent blowing fuses and damage to the speed control but I'm not positive.  If so I will simply reuse the circuit, the only trouble is the relays coil needs 28 volts to operate and my control box will not have a power supply that will work.  I could add a 24 volt supply, but then my breakout board would have to switch a 12 volt relay to turn on the 24 volt relay which seems kinda silly.  I could replace the relay, but I worry about finding one that will work as it has a ton of contacts that are all being used.  *Does anyone know if Mach 3 offers a spindle slow start when using the computer to control the spindle speed?  If so I could remove the slow start circuit and let Mach 3 do it.

Here are some pictures of the lathe.  Please let me know if you have any ideas on how I should hook up my spindle speed control to the breakout board.

Thanks Dale P.

 

[ibuildstuff4u]

Here are some more pictures of the lathe.  As I suspected the tool changer has a micro switch so it knows when the tool is in position.  Hopefully this will be easy to interface with Mach 3.  The machine also has limit switches on all of the axises which will be nice to have. 

The machine has a nice Baldor 1 hp motor for the spindle and an optical pickup on the spindle as well as an encoder.  I think it needed one to let the computer know the spindle speed and the second one was for the LCD screen on the front panel.  I'm not going to keep the LCD screen as I don't think it will work with out the original software so I can use ether pickup for the computer, I'm just not sure how to hook up the encoder to the breakout board so I probably will just use the optical pickup.

The lathe also has a pneumatic chuck and a 110vac solenoid so it can be opened and closed with the computer.  The plexiglass door also has a pneumatic cylinder and solenoid so the computer can open and close it too!  This will be easy to wire up to a breakout board and I will be able to operate them with a simple G code command.

The seller gave me a second chuck for the lathe that works with a standard key instead of the pneumatic chuck and to my surprise it was a Bison brand chuck!

[DICKEYBIRD]

Cripes, that puppy looks brand-new!  You lucky feller you.
 
I'm confused as to your ref to a vfd; isn't that a Baldor DC motor?  The board in the upper center of the electronics unit sure looks like a DC motor speed control.  If so it should have trim pots for accel, min/max speed, etc.  Seems strange they'd put that big honking resistor in the circuit.  Does it have a brand name on it?  Sure would be nice to get your hands on a manual and schematic for the machine.  It'd help a lot.

You're gonna have a great machine when you get it running!

[ibuildstuff4u]

Sorry I wrote that wrong, your right it's not a VFD, it's a DC motor and drive. It's a Minarik pcm21000a .  I found some good info on the web about the drive, but nothing showing the use of the resistor as it's hooked up.  Like I said, I'm pretty sure it's to provide a soft start for the motor but I have to take a better look at the circuit before I can be sure.  The old control box hooked up to the relay and must have used it to turn the spindle on and off, but it's a 28 volt relay so hooking it up will be hard unless I find a new 12 volt relay to take it's place.

[DMIOM]

.....The trouble that I'm having with the speed control is that it's hooked up to a large resistor and relay and I'm not sure what they are there for.   I think it's to provide a slow start for the motor to prevent blowing fuses and damage to the speed control but I'm not positive.  ......

Dale,

I wonder if that's actually a braking resistor?  Just cutting the power to a motor it will (a) freewheel to a halt, and (b) generate its own voltage. You can brake a motor by applying a dead short, but it can give a current surge - so maybe the resistor is across the motor when its stopped, and to give safer/expedited braking when you hit e-stop.  You really need to try & trace the circuit around that relay etc. to find out what the designer felt it needed.

Dave

[jiihoo]

Hi,

Cute lathe!

The old control box hooked up to the relay and must have used it to turn the spindle on and off, but it's a 28 volt relay so hooking it up will be hard unless I find a new 12 volt relay to take it's place.

If you have a hard time finding a suitable 12 volt relay that would be identical to your current 28 volt one, you can replace it with two. Just connect the coils of the two 12 volt relays in parallel and use it as one relay (after carefully tracing the original connections and making sure that the new ones are identical...) This way you can replace a hard-to-find relay with two easy-to-find ones if needed.

Cheers,

Jari

[ibuildstuff4u]

I bet your right about the braking resistor!  I will have to take some time this week and draw out the circuit and see how it works. 

Looking at the instructions for the Minarik speed control I see it also offers some braking but I'm guessing it's not as good as using the large resistor.  So far it looks like they hooked up the E-stop to the braking feature on the Minarik board so there would be even more braking when pressed.

As for the original relay I'm going to start looking for a replacement since I can't think of an easy way to hook it up.  Most breakout boards offer a 12 volt source to power up relays and this one needs 24 to 28 volts to work.  Using two relays is a good thought too if I can't find the correct replacement.

Thanks for the ideas guys! 

Dale P.