Messages

1

General Mach Discussion / Re: Bridgeport 2J Vari-Speed Head, Sensorless Vector Drive, Mach3, cheap tachometers

« on: December 07, 2015, 07:36:40 PM »

Yikes, I will keep that in mind. OK so if it's safe to run 120 Hz continuously, then I will set to 2500 RPM @ 60Hz.

2

General Mach Discussion / Re: Bridgeport 2J Vari-Speed Head, Sensorless Vector Drive, Mach3, cheap tachometers

« on: December 07, 2015, 03:08:48 PM »

So if I set the variable head at the 1000 speed mark and going to 300Hz to get 5000 RPM, it's not gonna put extra load on the spindle or on the VFD? Just making sure stuff doesn't fail prematurely, thanks!

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General Mach Discussion / Bridgeport 2J Vari-Speed Head, Sensorless Vector Drive, Mach3, cheap tachometers

« on: December 07, 2015, 01:04:02 PM »

Hi I have a Hitachi WJ200 VFD hooked up via Modbus through RS485 to take advantage of SLV drive. I have a cheap $15 tachometer (AGPtek DT-2234C) that came with some reflective tape on the spindle. My vari speed crank is labeled up to 4000 RPM but stops doing anything past the 3600 RPM label, which turns out to be around ~3200 RPM @ 60hz, according to the cheap tachometer.

If I synchronize the head to the Mach3 at 1500 RPMs, then when I set Mach3 to 3000 RPMs the tach shows 2960 RPMs, and Mach3 @ 4000 RPMS -> 3950 reading. Is this considered acceptable? I tried going to Spindle Calibration page but couldn't find any documentation on it. It seems to be only for closed loop spindles.

A few other questions:

How accurate are these cheap digital tachs? They seem to be quite precise and consistent when I barely crank the variable head to adjust the RPMs manually.

Is there a difference between setting the Variable speed head lower and upping the frequency on the VFD to achieve the same RPMs versus setting the variable head at max? I don't think I would want to run it past 5000 RPMs anyway.


Thanks for your help!

4

General Mach Discussion / Re: Intermittent problem connecting Mach3 to board

« on: December 03, 2015, 05:02:54 AM »

Great success! RC-304 pci card works great and supplies proper 5V. CW8060 driver (and 60V power supply) more than doubles speed from 70 to 200 ipm. Mach3 seems to be interfacing consistently. I would recommend dedicated 5V power supply to BoB rather than hooking up USB to computer for power.

Diagram for this board in case anyone needs it:

https://i.ytimg.com/vi/Mv8mCXMVKUo/maxresdefault.jpg

Thanks guys!

5

General Mach Discussion / Re: Intermittent problem connecting Mach3 to board

« on: November 30, 2015, 03:49:50 AM »

Found Rosewill RC-304, which I believe will supply 5V output. There is a $10 breakout board on eBay that apparently only requires 5V power from USB cable to computer. Not sure if that will work or not.

6

General Mach Discussion / Re: Intermittent problem connecting Mach3 to board

« on: November 30, 2015, 02:17:23 AM »

Thanks for your reply! That's what I figured. Do you know of a list somewhere of cards that have the 5V TTL output? When I shop around no one lists the voltage output spec that I can find.

The board/driver combo seems to be only able to output 3.5A to the motors anyway, so they seem a bit underpowered. I have a couple CW8060s originally meant for another project, which can put out 6A and 24-70V. Do you have a recommendation for good breakout board suitable for these motors? If I'm gonna upgrade I don't want to get something that wastes the motors' potential.

7

General Mach Discussion / Intermittent problem connecting Mach3 to board

« on: November 29, 2015, 01:56:03 PM »

Hi folks. I've recently acquired a Bridgeport Series 1 w/ variable speed head converted to CNC. There wasn't much documentation on anything, but it appears I have 1200 oz-in Nema 34 motors (4-wire, part # 86HS114DF05D) connected to a 4-axis blue TB6560 board. I'm running latest Mach3 v3 through a PCI card for parallel. I metered some of the pins and they seem to be putting out 3.3V. With a lot of guesswork and googling, I finally figured out that the motor output pins are :

axis step dir
x 3 2
y 5 4
z 7 6

When I start the computer the motors always lock up. When I open up Mach3 sometimes it connects and motors stay locked up and I can jog, and sometimes it doesn't and motors unlock. When it doesn't, I change Z dir pin to 1, and then only Z- works jog and none of the others work. Then I change it back to 6 and then all of a sudden all of the other motors work again.

I've been playing with the output signals to try to figure out if I need to enable anything. I believe I had it at:

enable1 port 1 pin 14
enable2 port 1 pin 2
enable3 port 1 pin 6
output1 port 1 pin 9

But I don't think this can be right because pin 2 appears to be x dir.