I recently purchased a series II BP with Boss 4 CNC.
I plan to upgrade to Gecko drives and Mach 3, I am going to try to use the factory steppers. I have a couple questions.

What should I check on this machine beofore I start, Is there an article on how to check backlash, ways and how to adjust the gibs someone could direct me to?

What is a good break out board that works well with mach 3?

What signal does the break out boards use for speed control to the VFD, 4-20 mA?

Pretty hard to check the backlash without having a control as there is not really any way to know how much it actually is. If your control works then you can use a dial gauge to check it.
Dont know of any breakout that has the speed control onboard but I did see a new one from CNC4PC and seem to remember it had quite a few extras on it, possibly speed control was one. You can get several different seperate speed control boards, Homann designs and CNC4PC both do them, usually they are 0 to 10v operation but they may work with your VFD.
I use a PMDX122 breakout and it works well and is reasonably priced.
Hood

I have not bought a VFD yet, I think most of them can be configured to use different types of inputs, I was just curious what people are using. Do you just set the speed before you start the CNC cut? I downloaded a demo of mach 3 and it has a speed sp.

Is there a way you can disengage the stepper motor and check the ball screws that way?
Thanks for the info.

I have a VFD but so far dont have it controlled from the PC. I just have a speed sensor (optical switch) so that I know what the spindle speed is and can then just turn the potentiometer, which is connected to the VFD, to get my desired speed. When funds allow I will get a speed control board and work it through the PC but every time I have been about to get one something else comes up and swallows the funds :(

The difficulty in just disconecting the stepper to measure the backlash is you dont know how much you have turned the screw. You could make up some sort of a dial I suppose, like on a manual bridgeport but might be a bit of hassle to do that.

Hood

Bob Cambell makes a break-out board that has relays to control activation of the spindle, coolant, e.t.c. Take a look here: http://www.campbelldesigns.com/Combo-board.php

As for a VFD, I have been using one of the Automationdirect GS2 models. Yes, it is China-made.......but has been working good for me so far (2-years and counting).

Check here: http://web6.automationdirect.com/adc/Shopping/Catalog/AC_Drives_-z-_Motors/GS2_(115_-z-_230_-z-_460_VAC_V-z-Hz_Control)

Looks like a nice board from Bob Campbell, seems to do most things required. The CNC4PC board I mentioned above does indeed control the spindle, you will see it here http://www.cnc4pc.com/Multifunction_CNC_Board.htm
I have no experience of either of these boards so cant comment on what they are like.
Hood

The combo board does look nice and it has the analog output, I think I will try one. I have also been looking at the drive mentioned. I just didn't want to buy all the electronics till I was 100% sure my mill is in good condition.
Thanks for all the help.

I have the 1st generation of the Campbell board. Never had any problems and works like it was advertised.

I have a breakout board and scheme that allows use of the original Bridgeport stepper drives along with the motors. I still recomend the original drives for driving the original motors because of their current rating, complete documentation and their repairable nature.

This is basically a brain transplant from the BOSS computer and software to a PC running Mach3.

Darek

Hillbilly,
Can you give me a schematic on how you wired one of the original drives?
Did you use the original power supply too?
I think the Z axis drive on my machine is smoked, but maybee it could be repaired.
Thanks

Email me at ashburn@icx.net and I will send you some info.

Darek

Hillbilly,
Can you give me a schematic on how you wired one of the original drives?
Did you use the original power supply too?
I think the Z axis drive on my machine is smoked, but maybee it could be repaired.
Thanks

If you give me the Z-Axis drive part number, I will compare it to what I just removed from my Boss 6; which I have been slowly selling the OEM control stuff cheap.

FWIW - The boards from Campbell are good.

-jd

JD,HOOD,
If you like Campbell's Breakout Board you'll love the Mini-I/O from
http://www.CandCNC.com

they are the same guys that did the B/O for Campbell.
I'm using one on my BP 2J.....a lot of Breakout for $57.
They also have a nice MPG Pendant combo.
W. Smith

You are right! That does look interesting. Thanks for the link.

For the servo users lest we forget www.rogersmachine.net. Jim Cullens did a board for him that allows a much finer error trip than the 128 steps you get with the G320s. On my list-o-stuff to get next. I'm calling it near closed loop. It's all I need. Not sure I have the brain cells for the GRex route or the $$$ at present.

Between jobs at present. :-( So gotta get that resolved first...... should be soon, I can feel it! :-)

Thanks for the link, it costs about the same as the PMDX when you add the extras which the PMDX has but still a nice wee board. One thing I do like about the PMDX is you can power it from the USB port.
Hood

snakebit,
On second thought I have decided to go with all new controlls.
It would just be a matter of time before I would have to change another board.
Judging by the pile SCRs that have been desoldered and tossed in the bottom of the panel it must have required alot of maintenance.
Thanks.

I think that is a good decision!! Let me know if there is anything I can do to help.

Wayne

snakebit,
On second thought I have decided to go with all new controlls.
It would just be a matter of time before I would have to change another board.
Judging by the pile SCRs that have been desoldered and tossed in the bottom of the panel it must have required alot of maintenance.
Thanks.