1987 Bridgeport Production Center Interact 412 to Mach3 Conversion

[JHChoppers]

The DC Servo Motor was successful in that it could turn the large spindle when connected to a simple DC Power Source.  However, as servo system it was very difficult to tune and had problems controlling the large load at low RPMs.

Since the application needs high torque at low speeds, we tried a large stepper motor.  This method seems to work well.  I used some relays to disconnect the motor outputs from the stepper driver when the spindle is running and only connect them when we want to orientate the spindle for a tool change.  This might not be the best solution, but it is working for now. 

We have ran the test over a 1000 times with success.  The deceleration of the motor from the home sensor was an issue at first, in the video you can see that make sure the motor is at full speed before looking for the home switch.

<a href="http://www.youtube.com/v/Xo_WdSXmuWg&amp;hl=en&amp;fs=1&amp;rel=0&amp;color1=0x006699&amp;color2=0x54abd6&amp;border=1" target="_blank">http://www.youtube.com/v/Xo_WdSXmuWg&amp;hl=en&amp;fs=1&amp;rel=0&amp;color1=0x006699&amp;color2=0x54abd6&amp;border=1</a>

[poppabear]

Hey JH,

   unless you are already happy with what you have, I can offer to you some good solutions for tool rotation indexing that I have used on retrofits.
there are several methods that work well, and range in price (for your parts), depending on how you want to do it.

if you have control over the Spindle motor speed and can drop it down to a slow turn rate, i.e. like 50rpm and stuff, there are some simple and very accurate "other" options you can do with native mach3, to get accurate indexing.

give me a hollar if you want to.........   BTW: put some louder "slip-ons" on the Pig and did the breather thing, and tuning thing. Now the beast is MUCH loader, has more power, and backfires alot (on decelerating), which pisses off the dogs, and scares old ladies.........  both are very cool to me........  hehehhee.

scott

[capsteve]

What controller was originally on your 412???
mine doesnt have the spindle encoder but rather has a magnetic pickup for one pulse per rev and indexing..
but there is a small vbelt groove on the spindle currently unused, where i can add a small belt driven encoder..

thanks for posting the pics, you got me thinking now....

steve

[JHChoppers]

What controller was originally on your 412???

Heidenhain TNC 155

[JHChoppers]

After selling off all the stock controls and hardware a while back, the cabinet is nice and empty.  Starting with the LCD Screen first, my plan is to cut the opening a little and mount the screen inside.  I have a keyboard with trackball on some of the other machines and like that so I plan to do the same on this project.  Not a big fan of touch screens, I like buttons and lights.  The MPG will be fixed to the cabinet similar to the stock control.  This should leave a large section for button and lights and with self on the bottom for small tools and stuff.

For the I/O hardware, I am using a PoKeys USB device.  I haven’t messed around with it more than a couple of hours, but so far it’s working great.  

External Button Feature wise, I plan to have the flowing:

eStop/Reset with Red LED

Cycle Start with Green LED, Feed Hold, Stop,

Coolant with Blue LED,

MPG, Axis selection, Axis resolution

Feed override, RPM override

Open for ideas here….  What would you add if you could do it over?

[JHChoppers]

The XY and Z Axis are functional with the new AC Servos, Spindle Orientation is functional with the Stepper Motor, the ATC Carousel and Tool Management Software is working, the Spindle is functional under MOD Buss Control, the Draw Bar is operational….   Time to integrate these systems and test.

<a href="http://www.youtube.com/v/3W-LRS9eSFg&amp;hl=en&amp;fs=1&amp;rel=0&amp;color1=0x006699&amp;color2=0x54abd6&amp;border=1" target="_blank">http://www.youtube.com/v/3W-LRS9eSFg&amp;hl=en&amp;fs=1&amp;rel=0&amp;color1=0x006699&amp;color2=0x54abd6&amp;border=1</a>

[Matospeter]

Damn man that thing is really starting to run like a VMC!!! Nice work... I am insanely jealous of that thing and I am gonna get something like it come hell or high water.  Looks like you are getting things figured out nicely.  I would like to hear what poppabear has to say about alternative means of indexing spindles.  I have a sensorless vector drive on my rf4r5 and I am considering changing the spindle for something else that would require indexing.  Anyways, really nice work and that is gonna be some machine when you are running. Any idea how long until you can make a test run cutting metal... Peace

Pete

[JHChoppers]

Spent some time on the control panel this weekend, got the screen is mounted in the old control box, made a frame for the screen and a blank panel that will be used for all the buttons and switches.  Also added a keyboard mount to the bottom.  A little sanding with DA and some paint, turn out nice.

[cnc-it]

The XY and Z Axis are functional with the new AC Servos, Spindle Orientation is functional with the Stepper Motor, the ATC Carousel and Tool Management Software is working, the Spindle is functional under MOD Buss Control, the Draw Bar is operational….   Time to integrate these systems and test.

<a href="http://www.youtube.com/v/3W-LRS9eSFg&amp;hl=en&amp;fs=1&amp;rel=0&amp;color1=0x006699&amp;color2=0x54abd6&amp;border=1" target="_blank">http://www.youtube.com/v/3W-LRS9eSFg&amp;hl=en&amp;fs=1&amp;rel=0&amp;color1=0x006699&amp;color2=0x54abd6&amp;border=1</a>

Looks great. Just wondering what the max axis rapid speeds will be on this set up and what are the limiting factors ie. hardware or software.

[JHChoppers]

Looks great. Just wondering what the max axis rapid speeds will be on this set up and what are the limiting factors ie. hardware or software.

Thanks!  In the video, its running X and Y at 250IPM and the Z at 200IPM.  I have not tried to MAX it out yet, just getting the system together and tested with ATC.  The stock machine only ran at 300IPM, I think this is achievable with the new AC Servos. 

As far as limitations, the only thing left to implement is taping.  I plan to cross this bridge when I get there.

Thanks,
JH
(get it working first, then optimize)