Help with a usb BOB Spindle problems

[Lahdiel]

first off sorry if this is the wrong place to post it i'm new to posting here

i have one of these cheap usb controllers for mach 3 i'm using in a 190vmc conversion and all of the axis' work perfectly however i can't seem to get the spindle to work for me at all, i've looked all over trying to find how to use the 10v analog output for the speed, whatever settings i change i always get a 0v reading from the terminal, somewhere showed them using one of the output pins being used as a pwm signal, couldn't get that to work but that would be a 24v pwm signal so would need a voltage divider and RC circuit to smooth anyway.

and yes i do have the power hooked up to 24v

i've gone through a paraport bob and now this trying to get things to work right and am starting to think i should have just spent the money on a smoothstepper, would that make life a bit easier?

[JAZZCNC]

Doesn't matter which controller you are using if you don't wire it correctly or set it up correctly then it won't work.
However that said I wouldn't use USB on any CNC machine it's just not stable enough for me but that's another story.!

Which terminals are you using.?

[Lahdiel]

I have it wired up right i've checked it, like i said the axis all work and the outputs switch fine but i cant get anything from the 10v output, no terminals give any reading in relation to the 10v terminal so i'd think its floating in relation to everything else, if thats the case would you say the boards busted or i just need to play with more settings

[JAZZCNC]

So which terminal are you calling the 10v terminal.? I know you say you have it wired up correctly but it's not working so maybe you don't.? It's easily done.!

I can't say if it's busted or not but I can tell you that if just 1 setting is wrong or you are on the wrong terminals it won't work and it's more likely to be something like this than being busted.!

[Lahdiel]

The terminal in the corner of the board that's labelled 10v, i'm aware the wires for the spindle aren't hooked up in the picture i sent as i didnt want the spindle to spin up then shut off every time it got an enable signal while i was trying to get a signal from the terminal

[JAZZCNC]

The terminal in the corner of the board that's labelled 10v, i'm aware the wires for the spindle aren't hooked up in the picture i sent as i didnt want the spindle to spin up then shut off every time it got an enable signal while i was trying to get a signal from the terminal

Right well, I don't know this board but I've seen plenty like it. I'd take a guess that the 10V is the reference voltage that you would need if you used a potentiometer for analog inputs, etc, the actual terminals you'll need for 0-10V will be ACM and AVI.
DCM and any of the outputs you would use to control Forward or Reverse.

If you show me the VFD I'll tell you which terminals to use but they are often marked with Similair labels ACM = (0V) analog common, AVI = Analog voltage (0-10v)

DCM = Digital common and usually FOR or REV.

[Doddy]

I'm inclined to agree with Jazz on this one...

From this image...,

29289

The "10V" terminal looks to be the (input) supply to a charge-pump (simple RC) circuit, with the cap discharged through the switching of the local opto-isolator. There's a trace through a transistor that drives the AVI signal. My bet - this speed control is electrically isolated from the rest of the main board, and the ACM (gnd) AVI (0-10V output) - connect to the Spindle controller AVI (input) and 10V (*** INPUT TO THE BOARD ***) which needs to be connected to the 10V reference on the spindle controller.

[Lahdiel]

Ah okay, i've never seen a lot of those acronyms before, i'm not using a VFD as its for a 190vmc conversion the controller is a lenze534 and i've already sorted the reverse relays for that
I just got the spindle working controlled from an external power supply too so i think im sorted with those connections

I'll try these suggestions and see if i can get anywhere with it

[Doddy]

Ah okay, i've never seen a lot of those acronyms before, i'm not using a VFD as its for a 190vmc conversion the controller is a lenze534 and i've already sorted the reverse relays for that
I just got the spindle working controlled from an external power supply too so i think im sorted with those connections

I'll try these suggestions and see if i can get anywhere with it

Okay, if I was trying to sort this out this is what I'd be doing:-

1) On the Lenze, establish the +V, Gnd and sense lines. On the Lenze 531, these are pins 9, 7, 8 respectively. The user manual should confirm that, and it sounds as though you know these already with the speed control that you have. From herein I'll use those acronyms ("+V", "Gnd" and "Sense") in relation to the Lenze controller. At least one Lenze manual refers to these as "E", "A", and "S".
2) Confirm Lenze.+V is 10 Volts, or thereabouts wrt the Lenze.Gnd terminal. Don't proceed it this is wildly off. Note, Lenze.Gnd may be (will be) floating above equipment earth - so take care with measurement and avoid shock hazard.
3) On the USB-BoB, confirm with DMM on resistance range, Open-line (OL) - very high resistance (>10MR) between terminal [BOB.ACM] and [BOB.GND]. Do not proceed if not.
4) Repeat for [BOB.10V], to [BOB.GND]. Expected: Open-line (OL) - Do not proceed if not.
5) Repeat for [BOB.AVI] to [BOB.GND]. Do not proceed if not.

At this stage you can expect the BOB variable output to be electrically isolated from the main BoB circuitry, Power everything off.

6) Connect [BOB.ACM] to [Lenze.Gnd]
7) Connect [BOB.10V] to [Lenze.+V]
8) Connect [BOB.AVI] to [Lenze.Sense]

Test. I would not connect the PC to the USB board until I've observed the absence of magic smoke from the BoB.

But that's just me.

[depronman]

I’ve just finished a boxford vmc190 conversion to linuxcnc
I can confirm that what doddy says about the lenze controller 10v and ground terminals floating at a rather high voltage
My lenze grd floated at 110 volts and the terminal which needs to be at 10volts to get full speed floats at 120 volts all measured against the machine ground
There is an isolation board which should be bolted to the end of the lenze controller
The lenze connects to the isolation board using terminals 7,8 & 9 from memory. The isolation board then connects to the BOB and it isolated the floating voltage of the lenze controller

On my vmc190 the isolation board had failed so I had to work around the floating voltage issue. I used a diycnc board which uses step and direction from the BOB and creates an isolated 0volts to 10volts that is feed into the lenze. There is also a relay on the diycnc board which is used to switch the lenze controller on and off. It all works perfectly
My vmc190 is now installed in the workshop and not that easy to open up the electronics bay but I did take some photos of the wiring so ask away and I will help where I can

Cheers. Paul


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[Lahdiel]

She's alive once again! Thanks guys i would never have figured out that 10v was an input on my own doh
I still had the isolation board on mine so it only floated about 3v different to earth ground
Thanks again

[Lahdiel]

may have been a bit quick to celebrate then
was working for about an hour until it tripped the RCD and now the spindle tries to spin up and trips the breaker in the back of the cabinet whenever its turned on, the relay that i thought was supposed to control the spindle enable doesn't seem to change much whether its there or not so i was probably wrong about that
this is what i get for working on things when tired i suppose

[Doddy]

Tripping the RCD - highly probable it's something in the spindle motor. If you can still find them - replace the spindle with a 240V 60W lamp and check that doesn't blow the RCD. If you was closer I could loan you a 180VDC spindle motor instead, but Nottingham is a bit far for that.

Daft question - when did you last "properly" run the spindle?

[Lahdiel]

haven't properly run the spindle since playing around with the manual controls before taking out the old controller board so about 2 months ago
i'll try find a lamp and try that

[Lahdiel]

if you think its the motor do you think it would be worth taking out to take a look at and clean out? thinking about it it might have been my fault it started doing it as it only happened after taking off and putting the motor cover back on to see if there was anything that needed oiling like the ways do but i see there isn't

[Doddy]

It's the next logical step. Or the first one, depending how cold your workshop is!

Clear out the spiders and clean up the commutator, de-grease and get rid of any carbon on the inner casement.

What better way of spending the new year!


The idea of testing with a bulb (or any other load) is to isolate the fault to the motor.

[Lahdiel]

Will still try that when i can find a proper load for it but for now the motor seems fine, ran smooth without any problem on my bench supply. Still can't really figure out whats causing the motor controller to try move the spindle as soon as it gets power, i'm assuming thats what's tripping the breaker in the cabinet

[Doddy]

Will still try that when i can find a proper load for it but for now the motor seems fine, ran smooth without any problem on my bench supply. Still can't really figure out whats causing the motor controller to try move the spindle as soon as it gets power, i'm assuming thats what's tripping the breaker in the cabinet

How's the Lenze "Controller Enable" input wired?

[Lahdiel]

i tried changing that too, normally the two pins are just jumpered with a small wire, i tried putting them between a relay but still popped the stop circuit as soon as the machine was turned on, starting to suspect i killed the isolator board and its just stuck somewhere its trying to spool up as soon as its powered

[Doddy]

Isolate the isolator board. Connect the +Ref on the Spindle board to the sense line to force full speed. Test. If pops then either spindle or Lenze. Proceed as earlier with incandescent lamp to verify if spindle, or not.

[Lahdiel]

been using the mill fine using my external bench supply for the spindle, tempted to just ditch the lenze and buy a cheap pwm 60v controller and be done with it since my psu can only do 32v
is that a terrible idea

[Doddy]

Not the best.

I'm surprised that the motor is only rated at 60V... whoops... a quick google confirms someone else with a VMC190 with a 60V spindle... so let's go with that.

Using a standalone PSU you've only isolated the supply to the spindle - in other words isolated the spindle from the RCD. You[ve not fixed anything, just avoiding the protection normally offered. Did you get around to cleaning the spindle motor?, or testing the Lenze?

(full disclosure: I did pretty much what you're suggesting - replacing a spindle motor and controller card when it was cheaper than replacing the OEM controller card - so call me a hypocrite)

[Lahdiel]

i don't know if i mentioned it properly but it stopped popping the RCD and instead now just trips the breaker actually in the machine, i did take the motor out but its pretty much spotless and everything about it looks next to brand new
still not tested the lenze with a different load yet
just for reference if i did decide to do the same what motor did you end up replacing it with?

[Doddy]

i don't know if i mentioned it properly but it stopped popping the RCD and instead now just trips the breaker actually in the machine.

I think you probably did, but I've forgotten that bit. I can understand your thought process here.


just for reference if i did decide to do the same what motor did you end up replacing it with?

Hah, no, that's a special case. I needed to replace a NEMA34 sized BLDC motor with something that would fit the same space envelope, and give me an easy spindle-speed control (the original Sieg SX BLDC had a very fragile controller card [blown it up twice] that only supported a "speed up" / "speed down" control). In the end I plumped for a Chinese AC servo which gives me a stupidly easy speed control (simple step/dir with electronic gearing).

That's not necessarily a solution for all, but it got me the power/control I wanted into the cast-iron spindle-head enclosure on my SX2.7. Not particularly cheap (£261.11 all-in)... compared to a replacement BLDC controller card (£247.48... fragile as F.. and no easy speed control).

[Lahdiel]

gotcha, think i'll just look for another dc controller since whatever i try and do with the lenze the second it gets power it spins up the spindle and pops the breaker
might try get it working some day but the headache it seems to cause isn't worth the time right now

[depronman]

Have a look at tread mills I bought one for £20 a few months ago fully working and local
It’s got a DC controller and dc motor. Meant to be 2hp but that will be Chinese 2hp if you get my drift

Paul


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[Lahdiel]

i'll keep that in mind for when i inevitably want a more powerful spindle
that said my little motor has been cutting steel fairly well most of the day

[depronman]

I don’t find my vmc190 to be underpowered
It’s a small machine and as such you can’t expect it to take massive cuts
I’ve added flood cool to mine over Xmas and that makes a big difference

Cheers. Paul


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[Lahdiel]

i think i got a decent deal with mine, came with the factory mist system, though i probably will upgrade to a flood at some point if heat becomes an issue

[depronman]

I didn’t fancy breathing in the coolant fumes
Not a fan of mist coolant systems to be honest

Paul


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[Lahdiel]

i guess you're right but since its pretty much an enclosed space it should be fairly easy to setup a trap or extractor for that i'd assume

[depronman]

i guess you're right but since its pretty much an enclosed space it should be fairly easy to setup a trap or extractor for that i'd assume

Yes possibly but is it worth the trouble


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