Electronics for New Machine + Chinese Spindle + VFD

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Originally Posted by mturneruk

lol. Cheers Chaps. I assume you have never done it then...

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Many many times. My old machine used long timing belt which were uncovered this grabbed my shirt and half ripped it from my back before de-railing it's self. Even the Oh Shite button wasn't saving me that day because I couldn't reach it.!! . . . Now all my machines have several Oh shite buttons dotted around.!!

DONT Under estimate the power of steppers when connected to ballscrews. They will happily crush or rip your hand off just has easy they cut thru metal.!!

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Originally Posted by JAZZCNC

Fingers.!!!. . .Then under wear.. .:hopelessness:

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Two fingers and knickers to you !:toot:

Yeah been thinking about that would love to have my moving parts and ball screws covered really, but my design does not lend itself to that easily.
Been looking at brush bars to see if that would help. Still working on it.

That have not much to do with Ballscrews, the same can happen with acme screws.

The Spindle have a diametre of 12mm and your motor a torque of 2,5Nm. If something was wrapped around the spindle, so it pulls with 2500Nmm/6mm~400N or 40Kg. Thats impossible to hold, especially if it happened surprisingly.

Duplicate. Please remove.

It only bloody works. Managed to get the 24v psu powered up today along with the relay to prove your latching circuit Jazz. It worked and nothing blew up!
Top shout thank you!

I was able to power up the 48v PSU via the relay and then when pressing the Estop the relay would switch and the 48v PSU would power down. After releasing the Estop, pressing the momentary would then fire the 48V PSU back up again.

Great idea!

Here are some pics of my wiring. I used a 2 Amp fuse for the 24v / 5v PSU's and a 10Amp fuse for the 48V PSU. Hope that's right. Does everything look ok to you ?

Attachment 16775Attachment 16774Attachment 16778Attachment 16779Attachment 16777


Here is the shelf that will carry the UC300 / KK01.

Attachment 16776

Right onto the 48v Stuff now. Leaving the VFD out of the equation for now.

Thanks again.
Martin

Martin A mute point but I might have used Brown and Blue for the 230V cables and red and black for the DC stuff. Its very easy to get mixed up later. Or now it has been done use a different colour for the DC stuff

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Originally Posted by JAZZCNC

Attachment 16643

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I was just looking at this diagram in post #52. I have always done latching circuits using the +ve as the latch loop and it took me a second to realise why Jazz does it this way, as between the Estop switch and the relay you have a point to signal Estop back to the motion controller. Thanks Jazz for this fresh insight. I suppose that this is more towards the way a PNOZ safety relay works.

I have a latching circuit that pulls in a 100A contactor to switch workshop power. It means I can have Stop buttons where I want them and a Go/Stop box at the workshop door. When I leave at night I can shut off everything in one go.

Rob

Clive. Agreed that would of been better. Next time.

Decided that shelf was no good. Didn't like having the 5v stuff so near the mains stuff.
3d printing a better solution right now for the control boards.

Can I just say again how grateful I am for all the time you guys have afforded me.
Want to buy you a pint or six, but hard to over the tinternet.

Couple of final questions if you would be so kind.

1. Just setting the dip switches on my drivers.
I was told that 3.8Amps / 10 Microsteps would be a good place to start. With SW4 (half current mode) set to to off.
Does that make sense?

2. Also are these two wiring diagrams effectively the same thing ?
I am having a mental block. My wiring diagram shows A below, but I want to do B. Only worried about blue line e.g. ground / 0V.


Attachment 16805

3. Any problem with using the outside metal part of these as a way of passing the shield ground from stepper wiring into the box and on to the star ground?
My plugs only have 4 pins.
Attachment 16806
4. Jazz would those 5A time delay stepper fuses in your diagram in theory protect the machine / me at all if it should stall or crash ?

Cheers Chaps.
Martin

Q2 - wiring. Those two circuit diagrams are effectively the same. Not sure why you would want to do B. Diagram A shows a short wire connecting two terminals on the BOB; in B you need two longer wires running to the switches. However, as I say, electrically they are equivalent.

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Originally Posted by mturneruk

I was told that 3.8Amps / 10 Microsteps would be a good place to start. With SW4 (half current mode) set to to off.
Does that make sense?

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The Amps should match or be close to the Motors rating as possible. Good drives will let you set exactly to match motors but If no exact match then set to next lowest. You'll just have lower than rated Torque but better than going higher and having more motor heating.

Wouldn't go above 10x Ms because you'll gain very little just stress the system more. Often the machine will dictate to some degree the best MS setting based on the resonance and how it affects the motors at different speeds. Again better drives will handle this better allowing optimum Ms without sacrificing anything in terms of motor smoothness/speed.

You want half current Mode On because it lowers motor heating when stood still.

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Originally Posted by mturneruk

4. Jazz would those 5A time delay stepper fuses in your diagram in theory protect the machine / me at all if it should stall or crash ?

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No won't protect you or the drives from stalling or crashing or will it need to because the drives should be able to handle that them selfs and you should have E-stop fitted to protect YOU.!!. . . But will in the event of short circuit in say motor etc.

Well got most of the wiring run today, and i thought I would give it a quick test with just the X-Axis hooked up to see if i could get basic communication and motor control.

Having installed the drivers and connected the UC300 to the computer successfully i thought i was home free, however i got absolutely no response in Mach from either the Estop button or the XAxis motor when jogging.

As per the BOB KK01 diagram from CNC 4 You, I have the Estop wired to pin 15 / ground.

There is 5V wired to the UC300 and the BOB, and both have power lights on.
The LPT cable is attached from UC300 to the BOB. Tried both standard ports.
Under Ports and Pins, Mach 3 knows to look for Estop on Pin15 and xaxis motor on Pins 2 / 3 (Port 1).

Have i missed something or is it possible i have a faulty BOB / uc300?

Anyone got any suggestions on how to troubleshoot this ?

Thanks guys
Martin

Sorted it. Was messing about in Mach 3 and i discovered that the port should of been 2 and not 1. Pure guess, but now everything works as expected. That was lucky.

Hey guys.

Have first movements video from yesterday.

https://www.youtube.com/watch?v=6g0k9oSLejQ


Looking good. Really pleased. My long axis seems (which i call y / a) seems to make much more noise than my short axis (which i call x).
Obviously there is two steppers running, but the noise seems a lot more. I think is could be down to the movement resonating through the table.
The noise is far more at higher speeds. So far i have only dared to go to 2000mm per minute with acceleration of 250.

What do you think those stepper motors could handle if I wasn't worried about the noise?

The anti backlash Nuts were tightened to the gantry near the end of the ball screw travel to ensure they were correctly aligned.
As you can see i have used some plastic combined with aluminium angle to make a rudimentary guard around the screws.

Onto the sensors now, which i am trying to work out how to mount.
The electronics seem to be sweet so far.

Cheers
Martin

Depends on ballscrew pitch and Volts your running steppers at. But given it's relatively light weight construction ie not heavy gantry and using External motion controller then some thing like below.

If 10mm pitch and say 60-70V then you should easily velocity at 10mtr/min and would proababy max out around 14-15mtr/min. Maybe slightly less on the Y axis. With Accel of roughly 800-1000. Just remember can't have both high Vel and high Accel.

If 5mm pitch and 60-70v then roughly half the above velocity figures. With slightly less Accel.

If less volts then slightly less speed but with around 40-50V I'd only expect about 15-20% less.

How you tune the motors will depend on several factors like type of work you'll be doing etc. Good all round setup for such a small machine would be Max velocity of 8000mm/min with Accel around 1200-1500.
This is based on 10mm pitch/60-70v. It will give you good balance of speed and accel along with reliabilty.

Nice job by the way and you'll make some nice stuff with that. Well done. .:applause:

Jazz
Thanks...

I am running 1605 ball screws at 48v.

I tried last night on 4000mm per minute, and that seems just about ok actually. I tried higher, but it was screaming at me, so I tuned it down.
As far as the acceleration goes, i have increased it to 600 and that seems ok with hardly a noticeable ramp up in acceleration.

At the end of the day, i guess i will just have to play with it to find the best settings for my machine.
I don't really need it to be able to run stupid fast, but I am hoping to be able to make much deeper cuts which will be the main time saving.

I think I am going to need a way to lift my machine up off it's castors when it's in use.
I seem to be getting an amount of table movement when the machine is moving around.

Cheers
Martin

Martin, its looking good...you'll love making bits with that. Will be interested to see what you plan for machine build number 2 ;)

Are you putting any sort of dust/chip extraction in? One thing I've found is that dust and chips goes everywhere and I mean everywhere!

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I think I am going to need a way to lift my machine up off it's castors when it's in use.
I seem to be getting an amount of table movement when the machine is moving around

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Martin My machine is on castors two fixed straight one's at the back and two swivel one's at the front.
What I do is lift the front end with a lever (bit of 3x2) and then put two blocks under the frame and I find that is OK for me.
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I think your machine is much too clean and needs to be making a mess now:joker:

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Originally Posted by mturneruk

I am running 1605 ball screws at 48v.

I tried last night on 4000mm per minute, and that seems just about ok actually. I tried higher, but it was screaming at me, so I tuned it down.
As far as the acceleration goes, i have increased it to 600 and that seems ok with hardly a noticeable ramp up in acceleration.

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Ok well that's a nice safe setup thou I'd be inclined to up the Accel a little. Having higher accleration can actually reduce cycle times more than velocity on some jobs, mostly those with short moves and direction changes like engraving etc.

If I was running that setup I'd be tuning it at 4500-5000mtr/min with 800-1000s/s.

Speed you cut at is mostly determined by the material, cutter and machine ridgidty etc. It shouldn't really be based on what you feel comfortable with in terms of being afraid or scared to push machine. Your far more likely to break cutters and ruin work by under cutting than you are ever likely to break the machine.! . . . . The machine it's self will soon let you know when it's not happy.!

NOW get them switches on and make some Bloody chips. . .:yahoo:

Chaps...
Having problems wiring my 3 wire (blue) prox sensors as per this diagram.
Problem is it dosen't work. There seems to be a light on the Prox sensor, but this does not come on and Mach3 stop is not triggered.
Everything is setup correctly in Mach3...

I am feeding +24 into the brown wire from my 24v PSU.
The blue wire goes to GND on my KK01 BOB.
The black wire goes to pin13 on my KK01 BOB (signal).

I'm guessing that either the blue GND wire need to go to the negative side of the 24 PSU instead of the GND on the BOB ?
Or...
I need to connect the GND on bob to the negative side of the 24v PSU ?

Any help much appreciated.

Cheers Chaps.



Attachment 16893

I guessed and won.
The ground on the BOB needed to be wired to the 24v negative side. I might actually be learning something here.

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Originally Posted by mturneruk

I guessed and won.
The ground on the BOB needed to be wired to the 24v negative side. I might actually be learning something here.

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Classic mistake a lot make. So you are defiantly learning.:applause:

Hey guys....

Somehow mach3 managed to stop driving my A axis in sync with my Y axis.
Luckily i realised before any damage was done I think. i maybe moved the y axis 15mm while the A was stationary.

Here is the sequence of events that led to this.

1. Pressed Home to home the machine.
2. Pressed stop after the Z had homed, during the Y axis homing.
3. Manually Jogged the Y Axis. (A did not move).

Anyone else ever experienced anything like this ?

Seems like a fairly dangerous bug to me...

Cheers
Martin

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Originally Posted by mturneruk

Hey guys....

Somehow mach3 managed to stop driving my A axis in sync with my Y axis.
Luckily i realised before any damage was done I think. i maybe moved the y axis 15mm while the A was stationary.

Here is the sequence of events that led to this.

1. Pressed Home to home the machine.
2. Pressed stop after the Z had homed, during the Y axis homing.
3. Manually Jogged the Y Axis. (A did not move).

Anyone else ever experienced anything like this ?

Seems like a fairly dangerous bug to me...

Cheers
Martin

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Well you haven't said how you have got it all wired!! Also you said you pressed stop before the homing was finished and then tried to jog. After the stop or estop you need to rehome the machine. I wonder where the dangerous bug is.:whistle:

It's not so much a bug rather less than perfect way mach homes with slaved motors and your actions while homing.
When homing mach de-couples slaved axis meaning they work as separate axis again. When you interuppted the homing sequence mach is still in de-couple mode so when you jog it only moves that axis, in your case Y.

If you had pushed E-stop and reset mach then this probably wouldn't have happened because the home script would have been cancelled.

However there is a possible work around if you want to prevent it happening.? I haven't tested this but sure it will work.
You can change the homing script and turn off Jogging while homing. To do this use this command at the start and end of the homing script.
DoOEMButton(103)

To do this go to Operator menu and select Edit button script. This will start the Ref-all-home button flashing. Click on it and script editor will open.
Insert DoOEMButton(103) at the beginning and end of the script then save it.

Now it should toggle Jog off while homing and toggle back on when finished. Obvisouly you won't be able to jog if you press stop or cancel homing. Also you may have to turn Jog back on manualy because it won't get toggled back on because the home script didn't finish.

Try it there's nothing to lose.

That's good to know Jazz.
I would describe it as a bug as there should be no way you can end up mashing up the machine regardless of what you do in Mach3.
Obviously i won't do it again.

Cheers
Martin

Hey chaps...

Here is a video build log of the machine and first cuts which were made yesterday.
Thanks for all your help.

https://www.youtube.com/watch?v=vjjTnn1KmRg

Cheers
Martin

Very Nice Martin its a credit to you.

[emoji106] good start to the year! Well done Martin!

Just had my first oh shit emergency stop.

For some reason during a multipass cut of 18mm Birch plywood, the machine lost about 10mm in the Y direction during pass number 4.
I was cutting 4mm passes at about 1500 mm / per min.

As i was towards the end of the cut the cutter was already 16mm into the wood, so when the Y lost 10mm the cutter started to plow into the full depth plywood.

After slamming the Estop. I jogged the machine back to what should of been the Zero start point but the Y was 10mm behind where i started. The gantry still seemed square.

It buggered up my very nice piece of ply, but Jazzes Estop circuit worked perfectly! Anyone got any ideas what might of happened?.
I thought i set a fairly conservative feed rate / multipass depth to be honest.

Thanks
Martin

I just ran it again at a slower feedrate and it completed ok. Not happy though. Would love to understand what happened.

Also I noticed that when I was surfacing my table the other day (using Jog), every now and again the jog would stop while I still had my hand on the key.
However no reason was given as to why by Mach3. No limit switches tripped etc. I had to reset the machine before i could continue. This must of happened 10 times during my table surfacing.

Do you think this could be down to Noise ?
Anyone got any suggestions ?

Thanks Martin

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Originally Posted by mturneruk

Do you think this could be down to Noise ?
Anyone got any suggestions

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Nope it's dodgy keyboard happens often. Change keyboard at try it again think you'll find it's ok.

The losing position could be number of things.? Most common is slipping coupler or pulley. Mark them and keep an eye to see if move.

Could be you have over tuned the motors and it's losing steps on rapid moves between positional moves.? What Velocity and Accel do you have set for each Axis.?

I was thinking slipping couplings. My ball screws don't have any flats on them so they are effectively only held by the tightness of 2 M4 screws in the coupling, where as the steppers do i think.

I would of thought if it had slipped, it would of been one side or the other rather than both Y and A.

As you say - I will mark and see what happens.. Do you think my 1500mm per min feedrate / 4mm depth cut was fairly conservative with a 6mm cutter ?
My cutter is only a straight two flute and it was screaming a little. Might be time to invest in some better cutters.

I read compression bit for plywood and cut the whole 18mm at once! Sounds like that might cause me a problem.

Cheers
Martin

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Originally Posted by mturneruk

I would of thought if it had slipped, it would of been one side or the other rather than both Y and A.

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But are you sure it both screws lost position together.! Did you check.? After you homed the gantry would square back up so unless you checked then won't know without marks.

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Originally Posted by mturneruk

Do you think my 1500mm per min feedrate / 4mm depth cut was fairly conservative with a 6mm cutter ?
My cutter is only a straight two flute and it was screaming a little. Might be time to invest in some better cutters.

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Unless cutter was Knackerd it should easily handle that feed rate and DOC. What RPM.?

Thanks Jazz. Hmmm. I hadn't homed the machine today. Also my Y / A currently only has prox sensor on one side e.g. Y. Are you saying I should have sensors on both sides e.g Y and A?
Makes sense when i think about it. Now i think i understand why Y and A decouple during homing.

I dont know if both screws lost position or not. Will measure tomorrow. I suspect there is some slippage going on on one side or the other. Would a small drop of loctite be sensible on the coupling bolts ?

RPM was around 14,000. I tried faster and slower and that sounded most comfortable.

My machine started losing position, it was a loose pulley on the stepper...I hadn't put enough loctite on it!

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Originally Posted by mturneruk

Would a small drop of loctite be sensible on the coupling bolts ?

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Not sensible more Essential. I'd also file a flat on the Ballscrews.

Regards Homing to separate switches then Yes you want them so can reset gantry square if start losing steps. If not then over time if you lose steps on the unswitched side it will never get reset so error builds over time and eventually racks the gantry and stalls one of the motors while other keeps going. Often this happens at high speeds when torque is lowest and you can imagine the results.!!

OK. It did it twice more this morning, and i am certain that the couplings are not at fault. I marked them and they haven't moved.
I homed the machine this morning before i started.

The first time the Y was 250mm off where it should of been when it started cutting along the x direction, and the second time I have no idea what it was doing, but basically it appeared to slow right down and then start cutting in the wrong direction. I was profile cutting 18mm lightply.
In all instances the feedrate has dropped from what i set (1500) to very slow when the problems have occurred, although Mach3 did not show this on the screen.

I have tried going back to the default Mach Screen layout as i was previously using 2010 screenset, and it still did it.

I am trying now a mid air cut, to see if i can reproduce it, and to film what actually happens without any danger.

You have got the steps per setting right haven't you.? Have you checked it's moving the correct distance.?