Which kit???

[John11668]

Hi folks
Having built my own CNC mill (if you can call it that) I have had a spate of recent problems which have led me to suspect the kit i chose for the project. I did not know whether I could make a success of it so was maybe a bit frugal when buying the gear.
I am beginning to wonder if I might have been better advised to spend more in order to get better quality.

But which equipment should I buy ?
Which drivers ? Where should I go for stepper motors ? Do I go for an all singing/ dancing breakout board or one which is little bore than a joint box,
Is it better to have discreet electronics such as a spindle board or is it ok to have that function incorporated in the BOB.

Take for example stepper drivers .
For a middle of the road price of just under £40 but carriage and Vat takes it to pushing £60 I can have one of these . https://www.cnc4you.co.uk/Microstepping-Driver/Stepper-Motor-Driver-4.5A,-50V-CNC-Microstepping-CW5045

Or I can get four of these carriage paid for the same outlay .https://www.ebay.co.uk/itm/Universal-DM542-Stepper-Motor-Driver-Fit-For-57-86-Series-2-Phase-Digital-Z1P2/333613460893

And how on earth do I know if there is any difference .

If you were putting together a kit to build a CNC mill then which kit would you select.and which suppliers would you use ??

[JAZZCNC]

To be honest John it's not that simple because without knowing more about the machine you intend to fit these too no one can advise you reliably.

Many factors like voltage and motor inductance etc come into play and not just motor size.

Give me some idea of the machine and I'll gladly point you to suitable gear. Best advice at moment is to Stay away from Ebay Kits.

[dazp1976]

What about stepper online?
Some of their steppers / drives are available in uk.
I would get some of these myself:
https://www.omc-stepperonline.com/digital-stepper-driver-24-72a-18-80vac-or-36-110vdc-for-nema-34-motor-dm860t.html
This will cover you for both nema 23 & 34 size steppers.
My 860 drives are running my nema23 566oz motors sweet at 4A, 60V.
You could use a simple AC toroidal power unit on those ones too.
I put 3 in basket and came out at £142 for 3.

With motors you want a balance of the torque you require and the lowest induction possible.
Mine are 3mh inductance, the absolute highest I'd want. Hence why I put them on 60V. (3sqr rt * 32 = 55V)

I did start off with an ebay kit but dumped the motors pretty quickly so saved nothing going that route.
CNC4YOU shipping prices make you suck your teeth in.

[John11668]

To be honest John it's not that simple because without knowing more about the machine you intend to fit these too no one can advise you reliably.

Many factors like voltage and motor inductance etc come into play and not just motor size.

Give me some idea of the machine and I'll gladly point you to suitable gear. Best advice at moment is to Stay away from Ebay Kits.

Lots of detail about my machine here Jazz. No laughing allowed or even aloud

http://www.mycncuk.com/threads/13746-Compound-table-conversion-of-an-old-Deckel-mill

I am not doing anything professional, Just a toy so that I can hopefully get a handle on the CNC process . I am currently running with the switches set for 2.84amps at half current which I presume means I am sending about 1.5 amps to my motors and this seems to handle the loads I am putting on so far . I have not been flogging it

[John11668]

Will have a look Daz

I did use CNC4you for breakout boards and for a single replacement driver
As you say it looks like they use shipping to jack up the prices .

Useful help line initially but getting a bit abrupt now

[Doddy]

As a fellow northerner I'm also sometimes a bit reluctant to part with the readies. My concern with your approach is that you're proposing to replace what you have with new gear, without looking at what's wrong with what you have already. Perhaps stretching a point, but a bit like taking your car to the garage and asking them to replace everything to fix a problem - it might work... it might not, but it'll cost you to find out.

My suggestion - for OP to ignore or accept (equally at his peril) - use this thread to solicit advice on new kit, as titled, which I'll back out of, and a separate thread to investigate the specific problems that you're having. I was following your earlier thread and was wondering power-supplies, grounding strategies etc. But, these are two separate topics and deserve their own threads.

Of course, you're totally entitled to replace all your control system...

[JAZZCNC]

Lots of detail about my machine here Jazz. No laughing allowed or even aloud

http://www.mycncuk.com/threads/13746-Compound-table-conversion-of-an-old-Deckel-mill

I am not doing anything professional, Just a toy so that I can hopefully get a handle on the CNC process . I am currently running with the switches set for 2.84amps at half current which I presume means I am sending about 1.5 amps to my motors and this seems to handle the loads I am putting on so far . I have not been flogging it

John I wouldn't laugh at anyone who is willing to have a go at CNC only applaud them for trying. I will go take a look at your thread.

My advise is don't buy anything yet and like Doddy says maybe look to what you have and why it's not giving you what you expect or want.!
Often your better taking a step back to go forwards and concentrate on getting a better and fuller understanding of what's needed or the parts you have already.

For instance the Half current actually refers to switching the drive to half current when it's NOT moving to reduce motor heating, when spinning it gets the full 2.84A. But don't worry things like this are often misunderstood which is why it's worth taking a step back from the building to do a little research or ask questions about things you don't understand, no matter how daft you may think they sound.

[John11668]

Thanks for the replies guys
Will come back shortly and give you a potted history about what leads me to wonder about the quality of the kit

[John11668]

Right , so todays news
I switch on and I open Mach 3 (mill)
Reset the onscreen button and try to jog to a start position. Y(negative ) does not respond but Y positive does .
I can jog Z+ and Z- and then Y - will work
I can then carry on and run a job from start to finish.

If when I switch on and find Y- not working I wonder if it is my keyboard so hit tab for the onscreen pendant and find it does not work on Y- either .
I cant understand this at all.
I am wondering about downloading a clean copy of Mach 3 and starting afresh but worried what will happen to my licence in the process.

I have downloaded and bought licence for UCCNC and copied into the directory , but it is still showing on my screen as demo mode . Maybe I should persevere with UCCNC as I do find Mach 3 often does things I am not expecting.

Any ideas ??

[John11668]

Further to above I resolved the licence issue with UCCNC managed to get running in that.
It shows the same issues , sometimes a motion will move , sometimes it wont .
Sometimes this one , then that, then the other .

If it happens on both platforms that suggests to me it is not the software which is the issue ,
I have changed both leads so they should not be the problem. Breakout is CNC4you, KK01 with 5 volt supply via usb.
I dont think it is the microstepper driver wiring cos the problem occurs on different motions, rather than any particular one.

So where do I go from here?????????? :dispirited:

[Doddy]

This would be better in a separate thread, however, I appreciate your frustration here.

If you can confirm my assumptions:-



So, in summary, 3-axis machine - a DIY conversion of a mill. 3 motors, driven by three stepper-drivers, driven by a KK01 BoB, which in turn is driven by, what we understand to be a legitimate UC100. Software : Mach3 and UCCNC with the same observed behaviour.

I don't recall what stepper drivers you are using, or your main stepper PSU.

Observered behaviour: Missing steps (to the point where an axis will halt completely) in a given direction. This impacts typically at any time one axis, but that axis can differ on different tests?


Can you confirm: When an axis freezes - can you jog another axis whilst frozen? (so, if holding cursor-up freezes on Y+/Y-... does pressing cursor-left/right allow X to move)? (my reasoning... under the failure condition, does this only affect one axis or are other axis not currently active/observed also affected)

How often does this problem present itself. Is this once-in a blue moon, or every time you go to the machine. Or somewhere in between?

Is there any other relationship you can describe - for example does the problem only occur if the spindle is running, or otherwise (this is feeding a question into system noise and shielding and grounding strategies).

Visually, according to CNC4YOU website - it looks as though (though not documented) there is a power LED top-right of the board - is that illuminated constantly in use (both in good and bad operation)?

That you are losing motion across different axis *tends* to agree with your analysis that its unlikely to be the individual stepper drivers, or even steppers. So if you're looking for a common-mode failure you'd be looking at the PC/Software, UC100, KK01 or Stepper PSU. Personally I'd rule out the software because you've tried both Mach3 and UCCNC with the same behaviour. I'm not 100% convinced, but close enough that I'd not investigate the PC at this time (although it's an easy test if you have a spare PC/laptop).

Now, under normal conditions your specific description of losing steps in one direction, but not the other, is really very interesting - because it should never happen. Forgive me if you understand this already, but the conventional step/direction interface which clearly does work (at least part of the time) requires that the "direction" signal is a binary "left" or "right", or whatever you chose to refer to. The "step" signal is a pulse that commands the move. So, whether you're traversing "left" or "right" - you're generating a pulse train on the step pin - if you lose the "direction" signal you simply risk moving in the wrong direction.

So, if I believe your observation, my initial thoughts are that your direction signal is interfering with your step signal. At this stage I'd be eyeballing the wiring around the KK01, making sure there are no strands bridging between terminals or debris on the board. If the UC100 was dismantle-able I'd be doing the same with that. That's the first check.

That conveniently ignored the observed behaviour that this can affect different axis. That's more challenging and less logical. At that stage I'd be really questioning whether the behaviour of the KK01 was what I expected, and - short of deducing it was U/S - I'd be examining if the power to the board is correct (trust me - there's no such thing as a digital world - everything is a balance of probability) - and it's possible that the board is semi-operating without power by scavenging through the signal lines. I've seen it happen, in fact there was an investigation on here that was sourced from a a similar-ish issue (the solution for that isn't relevant here!). So, as much as you say your KK01 is fed from USB - please check and re-check that you've configured the KK01 correctly for USB power - pins 1&2 on the header next tot the USB socket.

How confident are you at tinkering with electronics, and in particular Arduino etc - the is a great use for them to either inject a pulse-direction signal into the KK01 (isolating the UC100), or to monitor the pulse train from the UC100. 30 minutes of coding could get you significantly better understanding of the problem.

Sorry, more questions than answers at this time. Be methodical and we can get to an end-state here.

[Doddy]

... AND ANOTHER THING.....

Is it possible to decouple the motors from the axis screws?, just too completely isolate this to an electrical, rather than mechanical problem?

[dazp1976]

Further to above I resolved the licence issue with UCCNC managed to get running in that.
It shows the same issues , sometimes a motion will move , sometimes it wont .
Sometimes this one , then that, then the other .

If it happens on both platforms that suggests to me it is not the software which is the issue ,
I have changed both leads so they should not be the problem. Breakout is CNC4you, KK01 with 5 volt supply via usb.
I dont think it is the microstepper driver wiring cos the problem occurs on different motions, rather than any particular one.

So where do I go from here?????????? :dispirited:

I would pull all the wiring and check the lot.
Then if it's broke fix it and reinstall. Should eliminate any possible wiring defect.

You could try another board too if you really wanted to. You can get one similar to the KK for less than £10.
Same as the one I have ran for 3 years (£5 at the time).
https://www.ebay.co.uk/itm/5-axis-CNC-Breakout-Board-with-optical-coupler-for-Stepper-Motor-Driver-MACH3/282673162800?hash=item41d0a22a30:g:rFcAAOSwbP1aZvG a

[Doddy]

You could try another board too if you really wanted to. You can get one similar to the KK for less than £10.
Same as the one I have ran for 3 years (£5 at the time).
https://www.ebay.co.uk/itm/5-axis-CNC-Breakout-Board-with-optical-coupler-for-Stepper-Motor-Driver-MACH3/282673162800?hash=item41d0a22a30:g:rFcAAOSwbP1aZvG a

Cautionary note to OP; linked BoB - if you're looking to replace the BoB, above linked item (which I also use, as do many of us) requires a separate 12-24VDC power supply - it supplies the Opto-isolators used for limit switches and e-stops. Also, for the 0-10V spindle supply, if required. This, independent from the 5V supply from the USB lead.

Just want to make sure that any decision you make is fully understood.

[dazp1976]

Cautionary note to OP; linked BoB - if you're looking to replace the BoB, above linked item (which I also use, as do many of us) requires a separate 12-24VDC power supply - it supplies the Opto-isolators used for limit switches and e-stops. Also, for the 0-10V spindle supply, if required. This, independent from the 5V supply from the USB lead.

Just want to make sure that any decision you make is fully understood.

If you disable all the limits, stop etc though in mach etc, it's a cheap way of just testing the axis movements without needing to have a 24v supply. Just to test the KK board axis movements themselves aren't a problem.
Just don't move them to their ends.

I've never been a fan of the KK board anyway tbf.
Having everything on the same 5 volts always seemed a bit iffy to me. Especially when it came to e stop, limits, relay etc.
Everything else I see has 5v and 24v to isolate the inputs and outputs from each other.

Now I've mentioned that, that is worth ruling out. I mean the board I linked uses the 5v for the outputs and a seperate 12-24v for the inputs. Thus isolating inputs and outputs from each other

I have no VFD type spindle drive but I also have no cable sheilding and I'm using 3 axis with proximity sensors on the limits and seen no problems thus far.

[John11668]

Consensus here seems to be wiring I think. I will check the USB/PSU Jumper,
I replaced KK with CP1-10 provide spindle control , but the latter packed in so went back to KK (may have overlooked the jumper at that stage.)

I think it is maybe worth a rewire anyway. I used 0.5 throughout and while I guess it is probably OK for the signal wiring I did wonder whether to beef it for the motor wiring ( PSU seems to be giving steady +42 V as far as you can tell on a digital Multimeter)
I dont think the couplings are the problem It seems to happen randomly on all axes

Looking at the table arrangement what settings would you guys choose for the driver currents?


28648?


I will go back over wiring and grounding of shielding, I will also put a seperate 5v to the board and then Come back .
If it is with good news then fine , If it is not good then maybe I should start a new thread as I think Doddy suggested .

[John11668]

PS for the price of that BoB it is worth having as a spare . I have just ordered one.
I do have a more basic one somewhere if I could find it :numbness:

[cropwell]

John,

When I lost my licence file, Artsoft were incredibly helpful and quickly sent me a copy. If you have a fully legal licence and have registered with Artsoft, you should be good.

Rob

[dazp1976]

PS for the price of that BoB it is worth having as a spare . I have just ordered one.
I do have a more basic one somewhere if I could find it :numbness:

I think I've got 3 stashed :rolleyes: :smile:

[John11668]

Right so BoB wont go amiss. Sounds like you are pessimistic about them Daz:untroubled:

So am reporting back with some better news . While I was jogging back and forth looking for a pattern I just happened to spot that when a jog failed , the red power light on he KK01 went out so on a failing jog the board power seemed to be dropping out.

I rigged a seperate power supply from a 5v PSU and moved the Jumper , and Hey presto , the problem seems to have gone away.
Deep sighs of relief followed .

I will still go though the wiring and upgrade the motor cables , also see that the screening is well grounded .

Maybe get some work done now :cool:

Thanks to all of you . This has been bugging me for days . I cant tell you how relieved I am

[Doddy]

Right so BoB wont go amiss. Sounds like you are pessimistic about them Daz:untroubled:

So am reporting back with some better news While I was jogging back and forth looking for a pattern I just happened to spot that when a jog failed , the red power light on he KK01 went out so on a failing jog the board power seemed to be dropping out.

I rigged a power supply from a 5v PSU and moved the Jumper , and Hey presto , the problem seems to have gone away.
Deep sighs of relief followed .

I will still go though the wiring and upgrade the motor cables , also see that the screening is well grounded .

Maybe get some work done now:cool:

Thanks to all of you .

Sounds promising. Can I suggest one thing - take a breath and consolidate your understanding of the problem and that is truly is fixed (I'm about 90% confident from your description), before making too many changes.

[John11668]

Need to understand a few other things too in UCCNC before I will be confident with it , but really only been using it over the weekend . I think I will prefer it to mach3.

One thing is when I change from Mach to UC (and Vice Versa) it "reinstalls the firmware for UC100 ?????

I set the pin numbers for the homing switches on each axis and now it will home , but I never really understand why I can jog through these switch positions . If I hit them in a program it will stop .

There is one helluva manual and It will take me some time to get to know the software . I will play for a day or two before I rehash the wiring.

Is there a reconfigure function in UCCNC I havent found it if there is .

[Doddy]

Is there a reconfigure function in UCCNC I havent found it if there is .

I really don't understand this question - if you mean is there a profile system (so you can load different configurations) then absolutely - create/save profiles and load them from a modified icon which provides the machines name. Details in the manual - and I use this to run two different mills perfectly well (even with a cheeky M9998 to provide relay switching between the motor drives on the two mills).

If you mean can you configure pins/ports etc, I'm sure you're there already if you've got it working - hence my confusion. The only annoying thing for me is the constant Apply/Save mantra to not lose settings - but from memory Mach was a bit like that - at least on the motor tuning pages.

[ngwagwa]

I set the pin numbers for the homing switches on each axis and now it will home , but I never really understand why I can jog through these switch positions . If I hit them in a program it will stop .
.

Have you got "Enable Soft Limits" turned of (Configuration - General Settings) if so that may be why you can jog through the home positions?

You will also need to define the Soft Limits in the Axis Setup menu.

[John11668]

I really don't understand this question - if you mean is there a profile system (so you can load different configurations) then absolutely - create/save profiles and load them from a modified icon which provides the machines name. Details in the manual - and I use this to run two different mills perfectly well (even with a cheeky M9998 to provide relay switching between the motor drives on the two mills).

If you mean can you configure pins/ports etc, I'm sure you're there already if you've got it working - hence my confusion. The only annoying thing for me is the constant Apply/Save mantra to not lose settings - but from memory Mach was a bit like that - at least on the motor tuning pages.

Sorry Doddy
Brain in neutral (It was late 0)
I should have said "regenerate "

[John11668]

Have you got "Enable Soft Limits" turned of (Configuration - General Settings) if so that may be why you can jog through the home positions?

You will also need to define the Soft Limits in the Axis Setup menu.

Just to report that changing the BoB to a PSU supply seems to have restored proper function so moving on:-
I have enabled soft limits and set what I thought were sensible ones but things dont seem quite intuitive particularly on Y axis but I think a new thread is callled for

[John11668]

Sorry Doddy
Brain in neutral (It was late 0)
I should have said "regenerate "

So is there no Regenerate function in UCCNC