External Drivers TB6600 low current output

Eeb171
Posts: 6
Joined: Wed Sep 21, 2016 8:08 am

External Drivers TB6600 low current output

Post by Eeb171 » Sat May 27, 2017 1:15 pm

I purchased the : TB6600 Upgraded Version 32 Segments 4A 40V 57/86 Stepper Motor Drive from:
https://www.banggood.com/TB6600-Upgrade ... 81997.html.
Want to use them to drive nema 23 on OX cnc.
Now I had the cnc working fine with DRV8825, but decided to go for 2.8amps = the rating on the motors = TB6600.

After hooking them up, again the cnc was working but realised I could easily move the gantry when motors are locked or even stop it from moving.
Measuring the total current on my 24V supply, with all 4 motors running hardly draw more than 3.5 amps total. (Should be close to 10amp?)
Not sure if I can accurately measure the current on a coil of one of the motors, but I tried and the highest I measured was 1.3amp.

In theory the 2 tandem HP server PSU can deliver 75amps at 24V. http://www.rchelination.com/setting-hp- ... er-supply/

I tried adjusting current with dip switches makes almost no difference, even tried changing the micro stepping.
The wiring is done like this: https://youtu.be/IJQLfMOM5_0?t=54.

Any suggestions out there as to what I am doing wrong, or is this external driver not compatible with your Raspberry Pi CNC Hat V2.58 with External Driver conversion board.

Bertus Kruger
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Re: External Drivers TB6600 low current output

Post by Bertus Kruger » Sun May 28, 2017 7:13 pm

Input and output current are not the same thing.

The 2.8A you are looking for should be on the coil side and you need to keep in mind that both coils are powered.

Do you have the decay time set to ZERO? if not it stepper drivers switch off after a few seconds and are free move.

Eeb171
Posts: 6
Joined: Wed Sep 21, 2016 8:08 am

Re: External Drivers TB6600 low current output

Post by Eeb171 » Mon May 29, 2017 2:25 am

Bertus, thanks for the reply.

Input and output current not the same:
I though as much, but not sure how else to measure.

On the coil side I will measure 1.3 amp max (one of the coils), that's on idle. When stepper running I measure no current at all, Fluke to slow?
So, in other words, if jumpers are set for 2.8, that will be 2.8 total, 2coils added together. The 1.3 I measure may be 2.6 amp then?

When you say "Decay Time set to ZERO", not sure what you mean.
In grbl, I adjust the $1 - Step idle delay, milliseconds. But this will only work with DRV8825, I think external drivers ignore this?
Or are you revering to M910 X3 Y5 Z2 E3 command, will this work with grbl?

The long and the sort is it takes little effort with my hand to stop gantry movement with these external drivers.

Steppers I am using: http://www.makerstore.com.au/product/ne ... 5mm-shaft/
Someone posted this video on the driver: https://www.youtube.com/watch?v=cQ2jUzK2eh4
Datasheet of chip in driver: https://toshiba.semicon-storage.com/inf ... 67S109AFTG

Whittler
Posts: 52
Joined: Mon Sep 26, 2016 2:26 pm

Re: External Drivers TB6600 low current output

Post by Whittler » Tue May 30, 2017 8:54 pm

I believe that the external stepper drivers are controlled the same as the internal stepper drivers.

He is a link about weak motors and the settings.
viewtopic.php?f=17&t=342
Research is the only place in a company where you can continually have failures and still keep your job.
I knew immediately that was where I belonged.

Eeb171
Posts: 6
Joined: Wed Sep 21, 2016 8:08 am

Re: External Drivers TB6600 low current output

Post by Eeb171 » Wed May 31, 2017 9:19 am

Hi Whittler, thanks. Yes I do have $1 = "step idle delay" to 255, which then should lock the motors.
However the motors are weak and can move gantry easily..

Some more ideas I can try?

Whittler
Posts: 52
Joined: Mon Sep 26, 2016 2:26 pm

Re: External Drivers TB6600 low current output

Post by Whittler » Wed May 31, 2017 1:55 pm

Are you sure the switches of S4, S5, and S6 on the TB6600 are set to Off, Off, On ?
Research is the only place in a company where you can continually have failures and still keep your job.
I knew immediately that was where I belonged.

Eeb171
Posts: 6
Joined: Wed Sep 21, 2016 8:08 am

Re: External Drivers TB6600 low current output

Post by Eeb171 » Wed Jun 07, 2017 7:13 am

Yes, checked again. Will make short video to show the problem....

Edit: Have a look at this video: https://youtu.be/QMJNHS0fHI4

Might shed some light on my issue!

$0=3
$1=255
$2=0
$3=1
$4=0
$5=0
$6=0
$10=3
$11=0.010
$12=0.002
$13=0
$20=0
$21=1
$22=1
$23=3
$24=100.000
$25=2500.000
$26=25
$27=3.000
$30=12000
$31=100
$32=0
$100=26.667
$101=26.667
$102=200.000
$110=7500.000
$111=7500.000
$112=1000.000
$120=250.000
$121=250.000
$122=200.000
$130=800.000
$131=1200.000
$132=200.000

Thanks

Bertus Kruger
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Location: Wellington , New Zealand
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Re: External Drivers TB6600 low current output

Post by Bertus Kruger » Wed Jun 21, 2017 7:27 pm

Nice setup!!!

To isolate the CNC Hat from this. Take an axis and manually enable it with Enable pin(to 5V I think) on the stepper driver.
Try to move it again. If it still moves like that, it indicates that the stepper driver/steppers setup is to weak.

With the current setup you are only driving 2A to the steppers. What are the steppers rated at?

Have you tried to increase the micro stepping?

Eeb171
Posts: 6
Joined: Wed Sep 21, 2016 8:08 am

Re: External Drivers TB6600 low current output

Post by Eeb171 » Sun Jun 25, 2017 4:45 am

Bertus

Thanks, pitty its not working yet....

Made another short video: https://youtu.be/UwUzF9WUnBI

To test weak current/torque issue, I swap the signal to the PU- and DR- and apply +5V to PU+, DR+ and EN+. I confirmed that +En has 5V. Made an adjustment to the GRBL config file and $2 and $3 in particular to accommodate change in wiring. Microstepping is still enabled on all, however I did try changing it to 1 as a test. Makes terrible noise and it did not solve the problem changed it back. Also changed the dip switches to max current, made no difference.

I plan to order one of thesehttp://www.makerstore.com.au/product/st ... -12-30vdc/ to test.

Do any have suggestion to other external drivers that you know works well with Raspberry Pi CNC Hat V2.58?

Thanks

gmoney484
Posts: 135
Joined: Wed Nov 09, 2016 8:52 pm

Re: External Drivers TB6600 low current output

Post by gmoney484 » Sun Jun 25, 2017 7:04 am

I'm using TB6560's running at 2.6A (out of max 3.0A) @ 24V - I will try them at 12V this week (Im trying to get a full 12V system) - looks like I have the same NEMA 23's as you too.

Bought cheap ones of Ebay and they work much better that the Pololu 8825 drivers I was using.

I've read that the 6600's go into manual mode when Enable goes LOW. Yours kind of sounds like its sort of in manual mode when you move it. Maybe there is noise in the Enable line? or some grounding issue?
Gavin Milne
HoD Science
Dilworth School

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