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Is 40 the size in megabytes or something else?

Sure, "they don't make 'em like they used to."

However, the benefit of modern China stuff is that it's cheap, readily available, and more-or-less standardized. If I replace the steppers and drives, I'll have the same steppers and drives that countless others run. That will make potential issues easier to troubleshoot. Also, if something fails, it's cheap and easy to swap in a new component.

The DM860 is exactly what I'm considering. It seems to be well-regarded. However, from what I've read, it will not work properly with my existing steppers. I would need to go with a DM1182, instead.

Most stepper motors (except variable reluctance steppers) have permanent magnets. Modern steppers use rare earth magnets - making them smaller, more efficient, and more powerful. Brushless motors also have permanent magnets. Their magnets are located on the rotor, rather than in the stator (the reverse of brushed motors).

I understand that a transformer-type power supply will produce less noise (harmonics?) than a switching power supply. However, does it make that much of a difference in this application? Has anyone had trouble with a LinuxCNC system working correctly on a hobby-grade machine, due to the use of switching power supplies on the stepper drives? I can certainly investigate re-using one of the power supplies this machine came with - apparently, several others have done this. The appeal of the switching power supplies to me is that they are readily available and modular. However, I'm not "stuck" on using them!

I have absolutely no idea.

This machine has a huge cabinet for a power supply. That cabinet is full of transformers and such. I do not know if the power supply is "regulated" or "linear." When I look up those terms, they appear to refer to the same thing - a power supply that uses a transformer to regulate voltage, before rectifying and smoothing. What is the distinction I should look for? I'm positive that there are no modern switched power supplies in this machine.

I believe that this machine has several different voltages in the control cabinet. According to "Boss5" over at CNC Zone:
"You'd be spending your money in the wrong place. The original motors put out plenty if you feed them at the proper DC bus voltage and amperage. You should see 140 IPM with a 6 amp driver backed by a 160VDC bus. The matchbook sized hobby stuff is designed to run double stack size 34 motors, operates at relatively low voltage, and can generate about 200 watts under optimal conditions. Running torque starts at about 70% of holding torque values, and drops of rapidly with speed unless you have plenty of driver voltage to kick the motor in the rear and push out the constant torque zone (knee of the curve) to 1000 full steps per second and beyond, before it starts dropping. It takes serious voltage to overcome the winding inductance. If you are looking for 200 IPM, then spend money on new size 42 motors in conjunction with a proper driver.
You don't need a power supply, the stepper drivers of this style simply use 120 AC input. You can search ebay for used name brand American drives, like Pacific Scientific, Superior Slo Syn, Compumotor, or buy new China made product... goggle Leadshine. These are sold on ebay under various names, Keling appears to be a distributer that rebrands them. I'd go direct to the manufacturer's site, as it is very complete and they carry all the latest, not just old outdated models / stock. You can order online through their American distributor. Look for DM1182 or DM2282, these are digital drives sized for NEMA 42 steppers and you can buy the communications cable and download the programming software to tune for max performance, if needed. Runs around $200. A Gecko sets you back about ~$150, and then you need to build a power supply and provide a heatsink. If you want to save money, scout ebay and you should be able to find similar drives in the $75-150 range used from the previously mentioned American manufacturers, but they won't be digital programable, however robust for sure. Like I said, ditch the hobby stuff, get serious. Remember to wire the motor windings in series, they will accept 6 amps RMS (8.2 amps peak) without overheating, but make sure to use the current reduction when idle. FYI, the Bridgeport factory settings were 8.2 amps per winding unipolar, driven by 56 volts DC per winding. Wired in series, the heat load is identical to the factory setting if you use 6 amps RMS with a modern bipolar drive, and the windings will each see approximately 80 volts, thus the reliable top speed will increase to about 140 IPM, rather than 100 IPM. Make sure the machine ways are well lubed, it makes a difference."

I have no idea if any part of this machine works. I have not attempted to apply power to it, nor do I have access to 460V 3-phase power in my shop. It looks like the mice living in the bottom of the control cabinet might have been nibbling on some wires. Most of these sat in the corner of a shop for decades. They spoke a proprietary language, and the way you provided them programming was by a reel-to-reel tape drive that read holes on a punched paper tape. These machines were basically obsolete when they were new.

Your 55 holes should be fine, in quadrature that would give 220 counts/rev.
This is a little blurb I wrote about putting a spindle encoder on a Bridgeport head, using the bull gear as the encoder "disc". Pretty much similar to what you are suggesting.
Jon

Linuxcnc 2.10
mesact 2.17
mesaflash  3.5.11
Mesa board 7i95T
Ubuntu 24.04

I downloaded and compiled linuxcnc 2.10. It's working great. I installed mesact from github and can successfully run it to create a working config.  i also used gdebi to  install mesact 2.1.7 and that works good to. The problem is that QTplasmac is not an option in the GUI,  I hate being stupid but how can I get mesact to support it and create the necessary files (.ini etc).  PNCCONF does have QTPlasmaC as an option but it doesn't support 7i95T either in drop down or discovery. Last resort would be to take pieces from pncconf and mesact to manually build the files but I was hoping for a shorter path.

Thanks,

Mike

Much of what I know about the factory steppers came from postings made by "Boss5" over on the CNCZone forum:
www.cnczone.com/forums/bridgeport-hardin...ills/210116-cnc.html

Thanks for the advice about SteppersOnline. Where do people typically buy their China-brand steppers and drives? Is there a better source I should investigate?

I've certainly looked into Gecko for the drives. However, to my knowledge, they don't build drives that are a proper match for my steppers.

Thanks for the response!

The original drives are Bridgeport cards plugged into a backplane and mounted to a three foot heatsink. These apparently take "quadrature" inputs - not "step and direction?"

I'm not sure who made the original motors. I've been unable to find any markings/tags on them (maybe I need to unscrew the back plate, and look inside?). From what I've read, Bridgeport used a couple of different brands of steppers on these - either "Sigma" or "Superior." Apparently, they are "high voltage" steppers, and require a "high voltage" drive to run.

Thanks for your response!

This machine has an auto oiler on it - so that will be one of the first things I mess with to ensure it's working correctly. I've seen some people state that the oiler nozzles on these machines can become clogged with gunk from sitting for so long.

Yep, the first order of business will be to remove the two big control cabinets from it, and vacuum all of the "man glitter" off if it, and give it a bath and a lube!

I'm looking at replacing the steppers for several reasons. Based upon the information I've found about these machines on various forums:
* The steppers are an old design. They apparently ran at a higher voltage than most modern steppers. This requires special drives (like a DM1182). For less than the cost of a suitable "high voltage" drive, I can buy modern steppers with matching drives and power supplies:
www.omc-stepperonline.com/ys-series-3-ax...ower-supply-3-clys90
* Given the age of the steppers, many people are stating that they are likely weak - due to the age of their magnets and the type of magnets they used.
* From what I understand, these steppers are not closed-loop.
* Again, according to others, these steppers are "notchy" and "jumpy". They aren't as smooth as modern steppers, and don't have the accuracy/resolution (though, they are probably plenty accurate for my needs).

I'm sure that some "Double-E" out there could figure out how to connect a RPi's GPIO to the existing stepper drives. However, that's well beyond my level of expertise. The existing drives are cards that are plugged into a sort of backplane. They have Bridgeport's name on the boards, so I assume that they are proprietary. There's a document floating around, which explains how to reuse the existing stepper drives and steppers with Mach 3:
manuals.chudov.com/Bridgeport/Series-I/H...Boss_6_to_Mach_3.pdf

This looks like something I could absolutely do (substituting LinuxCNC for Mach 3). I could pick up one of Byte 2 Bot's parallel port hats, and run a BoB to drive the original Bridgeport electronics. However, it also seems like a lot of work to go through - just to rely on ancient, obsolete drives, steppers, and power supplies. In the end, I have an "oddball" system that is difficult to support. These original drives were also known to run pretty hot.

(AXIS,hide) / (AXIS,show) works fine

I didn't tried [#<_task> EQ 1], but will test soon and report

thanks a lot guys

I am terribly sorry about saying the inhibit being pullea high, I opened the manual and you are correct, its low.
Like you said lcnc will not have a feedback for the enable signal itself from those drives, it just assumes they enable when commanded.
Go with the e-stop approach or use one output to turn on/off the existing relay.

ContinenteCNC wrote:

Hi Craig!

Those are insane machines! Great job!

Are them all controlled by LinuxCNC?

 
We created our own real-time system under Windows.
The axis interface was a PCI board with 12 DACs (16bit) and 24 quadrature encoder interfaces (we do dual-loop feedback) so this was PC-Based.

I have thousands of CNC tube-bender controls, worldwide.

Had enough of the PC and so now we switched to microcontrollers but with an Android-based HMI.

This year, I intend to introduce a TRUE open-source CNC metal forming control that utilizes ubiquitous hardware that anyone can obtain for pennies

All axes controlled by the RPi Pico. Any number of axes.
HMI can be any Android device such as phone, tablet, or panel-pc.

It's time that this stuff was simplified 

Thanks a lot, I'll try asap

What drives/motors does it use?

I ordered two more of those PCI-E Sunix boards, so more testing ...

forum.linuxcnc.org/10-advanced-configura...to-example-mesa-7i77