Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: wes709 on November 09, 2016, 06:18:25 AM
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HEY! Having a problem tuning my new diy woodworking cnc. I am making a clock just to test out the machine i have made the clock my previous machine so i know what it should look like.
When the machine goes around the outside of the clock to cut it out and make other circular shapes the x motors do a large clunk when the drop down to 0 rpm and then turn the other direction.
I am using:
Mach 3
chinese tb6560
nema 23 steppers
board set at 1/8 chip setting
sorry i am still learning all of the cnc stuff
Here i have a link to describe the problem also my mach settings are at the end of the video.
https://www.youtube.com/watch?v=0OyRO91hfTk
Thanks for any help/advice!
wes
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Not surfier its the problem or just a symptom but it sounds like the acceleration is set really really low - it takes a very long time to slow and speed up.
Could be resonance in the motor maybe?
Sure someone will be along to help out.
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I agree with Dave, I think you could go on to YouTube and look at how to setup Mach3
Here is a place to start, you should "do" all of them, about 4 I think
regards Ford
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I have watched the setup videos to no avail. i have spent hours trying to get the motors to work as smoothly as possible do you think the voltage could be a problem? i am running 4 motors off of only 12v ... the board i have says its good for 12-36, i have no other ideas,,, this is not my first build so i have been through the process before and have had a very smooth running cnc the only diffrence in my new one is its bigger and is 4 axis running 4 motors instead of my old 3 axis running 3.
Thanks for that advice i will continue to investigate
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I would certainly look at stepping up to 24v, 12 is way too low i think.
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will stepping up to 24 v change any characteristic of the motors ? such as speed? temperature? steps per inch ?
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It should increase the capacity to change speed better, they can reach speed faster if settings allow it, they will get a little warmer only if current is changed as well - this needs to be set at motor limit not over, steps per will NOT change - this is a hardware setting.
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I used a 40 volt transformer and cranked it down to 36, the more volts you use the more watts and the more watts will give more HP.
I also asked the supplied of my card which microstep settings to use so I used that setting.
I think they are all different on different cards so please check that as you say "board set at 1/8 chip setting" sounds to me worth checking as I dont know what that means.
regards Ford
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Word of caution on using the 36v supply on a 36v driver - it will have no or little headroom for over voltage caused by back emf when slowing down.
:)
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How did you 'crank down' a 40 volt transformer to 36 volts ??
Tweakie.
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Back in the day i would just unwind a few turns. :)
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It would appear I was using 24v and my power supply only goes up to 27.4 should I go up or down ?
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I went up if anything it helps the slightest but still not happy ,, might be time to go for 4 motor drivers and a bob instead of this all in 1
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I've not heard anything good about these all-in-1 boards really, they seem to either work, work for a while or do not work at all and very hard to debug.
Before going for drivers, what settings do you have in mach for velocity, acceleration, steps per.
What feed rate is the code in the video calling for, post a snippet?
The voltage would help a little but not if a setting is out or driver is duff.
Do you the board set for max motor current?
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Here is another video showing you the acceleration it seems the faster i set the motors the less it wants to clunk . https://www.youtube.com/watch?v=yi7arF9Qers
i will also add the g code. 400 steps per mm yes the board is set to max current.
http://www.ebay.ca/itm/141267600275?_trksid=p2060353.m2749.l2648&ssPageName=STRK%3AMEBIDX%3AIT
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gcode
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if i did go for drivers would these be good enough to power my nema 23 steppers? http://www.banggood.com/TB6600-Upgraded-Version-32-Segments-4A-42V-5786-Stepper-Motor-Driver-p-981997.html?rmmds=cart
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Hmm, I'm running out of knowledge now ;)
The speeds look ok - between 760 and 2540mm/min although the first video seemed much lower?
i Gather the 400 steps per yields the correct size parts, if so then it is correct and does not need looking at further.
What is the drive method - trapezoidal screw, ball-screw, threaded rod ??
I have only used the leadshine style drives similar to the ones you linked and very well known.
As i said, i'm running out of tips really, I've only been doing this a few years myself so still learning ;)
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Thats alright i think i am going to go with the driver style any ways , this is just too much of a headache and like you said to hard to debug since if one thing goes wrong the whole thing is pooched. so is the driver i linked going to be good for my application ? is one 24v powersupply enough to power all of these drivers or should i order another ? is there anything else other than a bob and the drivers that i need to get going ?
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Those drives *should* be ok but as i said i have not used them before.
Yes just the drives and a break-out board should do it, get a decent opto-isolated BOB.
How big was your PSU?, I would use at least a 600W 36v one myself, but 24v would probably be ok as speeds are not blistering fast. 36v should be fine on those drives but no higher.
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wes709,
I would suggest you do some reading before you buy any piece of Chinese junk
problematic unsupported drive. Others may have a different opinion on them!
Go to the Gecko site and read the support info:
http://www.geckodrive.com/support.html/
Maybe consider this drive:
http://www.geckodrive.com/geckodrive-step-motor-drives/g540.html
Till then,
RICH
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+1 on Gecko.
It hurts to have to buy something twice. Think how bad it will sting if you have to buy this stuff again for the third time!!!!
If you can afford it, buy name brand stuff that is going to work for the next 20 years and still have resale value when you sell the machine.
I had a mill that came with a 4 drives on one board. It ran the mill but upgrading to Geckos really woke up the machine. I went from 10ipm rapids to 150ipm in testing and I turned it down to 50 ipm IIRC in actual use just to not wear out the machine ways.
Mike
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I have looked at the g540 and I do like it but I think I will stick to the drivers and Bob because I would eventually like to add a 5th motor possibly for a extruder :) I realize Chinese stuff is junk but the all in 1 board that I'm replacing was 45 dollars and the bob and 5 single axis drivers was 85 so I'm 130 deep still not half of what the g540 is worth and if this fails looks like I'll be buying a gecko and then it will sting , keep in mind I am very young and don't have alot of money for this stuff
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I understand not having the money to do it right. What I am trying to do is tell you what I have learned from my experience. If you could have spent the money on good stuff up front, all the time you have spent fiddling with drivers could have been spent running the machine.
That being said sometimes you need to experience certain things for yourself.
Welcome to the life long addiction, I mean hobby of CNC.
Mike
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Those TB6600 drives you linked to are OK. The good thing about separate drives, is you can replace/upgrade relatively easily in future.
I've got a couple of those TB6600 drives on the desk for when I get around to retrofitting an engraving machine, and from the research I done, they're a major improvement over the older all in one TB6560 boards. The main thing is make sure you're not pushing them too near their limits.
The big killer of the older chips was people running them pretty much on their voltage limit, along with often poor board design, meant a slight voltage spike took them overvoltage frying them, or they simply overheated.
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I am very young and don't have a lot of money for this stuff
We have all been there and understand. So enjoy what you are doing with what you have. :)
A user, such as mc, may have an "identical" driver and can help you out.
Good Luck,
RICH
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Hey a little off topic but you all seem smart I'm trying to check this motor for shorts am I doing it right ? (Building a RC tank)
https://youtu.be/-rYI7W-YqxE
https://youtu.be/OWcKul4gC_s
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wes709,
Didn't look at the links.
Just check the resistance ( inductance if you can) of each phase wiring of the stepper. The values should be close for each.
Test if there is conductivity of the phase also to ground ( unlikely since if there was you would probably blow the drive).
Also check that the is "no" conductivity between phases.
RICH
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Hey a little off topic but you all seem smart I'm trying to check this motor for shorts am I doing it right ? (Building a RC tank)
https://youtu.be/-rYI7W-YqxE
https://youtu.be/OWcKul4gC_s
That looks like a wiper motor from a car? There should be a connection for the motor - this will have resistance, and also a connection for a 'park' switch - this will be open or closed depending where the motor stopped.
They are useful motors.
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Hey There my B.O.B and drivers have finally arrived! However hooking them up is proving to be harder than i expected... any advice? i have this video as always to show you where i am at.
https://www.youtube.com/watch?v=NpSZJ-2uITs
Thanks !
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Your wiring should be something like this, with the addition of 5Volts supply to the BoB (not sure about using a BEC as I have never tried that).
Tweakie.
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I think it will work the BEC is rated for over 25v , does the 5v for the b.o.b go into the p14 ?Where does the ground go from the BEC ?
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THANKS TWEAK ! I finnaly got my motor to turn ,however I can only jog it one way , here is a video of my machine settings https://youtu.be/9v5qi3_ZDaU
Thanks again
Wes
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You are making progress.
Try selecting Step Low Active for your X axis (Motor Outputs) and see if that makes a difference.
Also measure the voltage on your Parallel Port X axis Direction pin (between pin 3 and pin 25) it should change between approx. 0 volts when jogging in one direction and 5 volts when jogging in the other direction. If it only changes between approx. 0 volts and 3.3 volts then that may be the issue.
Tweakie.
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Hey there I have managed to get my motor to turn the other way but it was just me fiddling around with the jog keys that did it :s please see video
https://youtu.be/zcZY1yiYlrY
Thanks tweak for your help so far !
Wes
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That's more progress. ;)
I think you need to sort out that keyboard problem before you proceed.
Could be your keyboard, other connected USB devices or your PC.
Tweakie.