I have just purchased a boxford 240 cnc lathe but it does not have the computer for it. Can anyone help with information where to get the computer or would it be easier to retrofit it.

Hello,

I have a TCL 240 that I have been refitting to run with Turbo CNC.

Mine ran from a BBC Master computer, not PC compatable. The control was via the BBC's 1MHz Tube Bus I think. The Control card in the Lathe had a Z80 processor and some other logic. I think the Host computer issued movement and control functions to this card and the card cordinated the movements.

I have made a interface board to link between 2x PC Printer ports for control. There are a couple of tasks I have not finished yet, Spindle control and Spindle index.

The Spindle Speed I was planing to do with a PIC or Atmel microprocessor. The Spindle index just needs testing at the moment.

I have friends that are using Mach3, and may end up modifing the system to run on Mach3 with a revised control pannel, insted of the Boxford design.

Currently I am using the original motor drivers. The only tricky part is the Tool index control if you have that option. It had relays on the bottom of the driver card that switched it to run from either the X or Z step & Direction signals. I bypassed this so the signals were driven direct from the interface card as another axis. There is VB code on the Mach3 web site that can manage the tool change as Y axis.

Regards Peter

Peter,and all,

I have just bought a 240, my machine has no computer also, did you get anywhere with yours?

Do you have a manual? drawings or schematics?

My machine has all the stuff under the Bonnet (hood), but no driver!!

Picked it up 12/09/09, so ii think there might be a few sleepless nights ahead!

The machines seem quite sturdy, I'm slightly impressedd so far, just wish i knew what all the wires were far.

Best regards

Christian

Hello Christian,

There are two types of internals i have seen in the 240 model.
A photo of the inside will tell me what type it is. I can help work out the wiring and may be provide a replacement interface board if it turns out to be the best way to getting your machine running.

The documentation I have is the opperating manual for the BBC controled version. I can create circuit diagrams from the one I have. If yours is the later design I can help identify the wiring, but I am not sure I could get it running with the existing control board that is in it.

I have been distracted from working on mine, as I have been cleaning up around home after getting a milling machine into the shed its a BridgePort clone. It needs new electronics and axis motors, as they were removed before I purchased it. There is also some minor mechaninal damage I wan't to repair before I get it going again.

How were you thinking of controlloing it? By PC or BBC ?
If PC then MACH3, Turbo CNC, EMC2?

I think it is better to get it running under control of a PC because the available software is much better these days.

Regards Peter Wintulich

Richard,

Thank you for your reply.

I am planning on running the machine with a pc, i was thinking of using emc2, or something that runs in dos. I have slowly been trying to build a cnc router over the years and had a lot of trouble getting high stepper motor control with anything running with windows.

I'm a sponge though, any advise is welcome.

I have attached some photos of the guts of the boxford lathe for you perusal.

Just another question while Ive got you. The spindle motor on my lathe is a Lenze dc jobby. When I put the machine in manual, I can get the z and x axises to dance about. When I press forward spindle the contactor comes in, when I press reverse the other contactor of the reversing contactor pair comes in. The spindle dosnt run though??on the dc drive board the power led is on. Is this problem because there is no 'cnc' controller? and there is no speed reference, I would have thought that manual would mean you had control of everything.

thanks for yor reply.

I look forward to hearing from you.

Best regards

Christian Gill

Hello Christian,

From your photos I see that the machine is the same as the one I have but without the automatic tool turret.

I dont think there will be any problem with the DC Spindle control. Try holding down one of the spindle direction buttons for a few seconds. What happens is first the button enables the drive, then as it is held it increces the drive voltage to the motor control circuit. Also there may be saefty interlocks with the Hood and the drive belt door.
I also found the motor controler had a very slow acceleration setting (think it's a potentiometer setting on the motor controler).

I will dig through my notes. I had worked out the important wiring. This will save you some time.


The simplest way to get your machine going will be if I can make you up a board the same as I have put in my lathe. It basicly has 2 headers that match with parrallel printer interface of PC's. There are buffer chips between the parallel port signals and machine but no optical isolation. The board goes in place of the green Z80 control board.

The current way I had set things up needed a second printer port to get most of the buttons on the front pannel opperating. There is probably a better way than this though.

I had been customizing Turbo CNC for the front pannel and the tool changer. I was going to control the spindle speed with a small microcontroller and a serial link. I will look a bit more at EMC and MACH3 as I think both these have spindle control already.

What is your electronics experiance?

Regards Peter

Peter,

Thanks for getting back to me.

How much would the board be including delivery to England, I could pay with pay pal.

I have quite a bit of electrical/electronic experience, I am a mechanical design engineer by trade, designing machinery for the printing coating and laminating industry. We get to commission our own machines, so your never too far away from a 'Spark' electrician, little bits rub off here and there.

I could build to circuit myself if you sent me instructions and the drawing, obviously I would pay for these.

I have had limitied experience with turbocnc, I'm pretty sure from memory that you can start and stop the spindle, coolant pumps etc.

Looking forward to hearing from you.

Best regards

Christian