Fried g-shield

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FaVo
Posts: 13
Joined: Thu Oct 02, 2014 9:01 am

Fried g-shield

Post by FaVo » Sat Apr 25, 2015 10:40 pm

Hi there,

I think my gShield's x-Channel is fried...

Last time I used my Shapeoko2 all works fine... than there was about a week where it stands around not connected, not used... and today I tried to mill s.th. the X-Axis doesn't move. The stepper only makes a strange noise. To check wether it's a stepper failure I switched x and y Axis Steppers and then the X-Axis moves fine but the Y-Axis makes the noise... so I guess the driver for the X-Axis is gone?!

Since the gShield is very expensive, seems to not last very long and is mostly not available at the stores I wonder what to use instead of the gShield v5. Or is there any chance to repair the shield?
What kind of other stepper controller is compatible with arduino and grbl? Is there some cheap china controller available or s.th.?

I use Nema 23 stepper which can use some more Amps than the gShield can offer. So a controller with more Power would be nice...

Any suggestions?

Thanks!

FaVo
Posts: 13
Joined: Thu Oct 02, 2014 9:01 am

Re: Fried g-shield

Post by FaVo » Sun Apr 26, 2015 8:27 am

Art These tb6560 based Controller boards useable with the arduino and Grbl? They look much more robust than the tiny grbl shield and can provide more Power to the steppers.

E.G.
Http://www.ebay.de/itm/SainSmart-CNC-4- ... =undefined

WillAdams
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Re: Fried g-shield

Post by WillAdams » Sun Apr 26, 2015 12:46 pm

Wish I could help. Still trying to wrap my mind around the electronics so as to improve: http://www.shapeoko.com/wiki/index.php/ ... lectronics

I’d be grateful if you’d share your research, no matter how basic so that we can have a page which is a good comparison of the options and a treatise on their merits.
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

cvoinescu
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Re: Fried g-shield

Post by cvoinescu » Sun Apr 26, 2015 12:47 pm

Almost all of them work with GRBL on Arduino, if you wire them correctly. That looks like one of the better ones.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

FaVo
Posts: 13
Joined: Thu Oct 02, 2014 9:01 am

Re: Fried g-shield

Post by FaVo » Mon Apr 27, 2015 2:26 pm

So, I ordered one of these TB6560 based 4 Channel boards...

Hope it will arrive within the next days. I think it should work when it's correctly wired to the Arduino. I will post feedback if I got the board and time to test it out.

This is a 4 Channel controller, so I hope I can copy the y-Axis by connecting the y-Axis signals from the Arduino to two of the 4 channels. Then I have 1 separate channel for each of the both Y-Axis stepper. That would be better than the connection I have with the 3 channel gShield where both steppers shared one channel.
And with up to 3.5 Amps per Channel the new Board has plenty of Power...
My NEMA 23 can take up to 2,5 A each and have 254 oz-in. With the gshield I could only drive the two Y-Axis steppers together on one channel with about 2 A. So it will have much more power in the future ;) even a lot more power to break things :lol:

FaVo
Posts: 13
Joined: Thu Oct 02, 2014 9:01 am

Re: Fried g-shield

Post by FaVo » Thu Apr 30, 2015 9:12 am

Small Update:

I connected the controller board to my Arduino and did the necessary config on the controller (set dip switches for microsteps and output power).
To get two channels (y and a) to work for my two y-axis stepper motors I just connected the Y-Axis "step" and "direction" pins from the Arduino to both channels on the controller (just split the signals). That works fine.

In general the controller works and is a huge upgrade from the gshield. But there is a downside... I have problems with the z-axis... there is a very strange behavior.

When I manually controll the 3-Axis with the universal gcode sender all seems to work smooth. But when I run some g-code the z axis seems to loose steps and sometimes moves down a little bit during milling when it should not move down.

Example: I milled a test square pocket 50x50mm and 5mm deep. The X and Y movement looks normally and is working fine. But the Z-Axis does not. It was not deep enough in the first step (should have been 3mm but was only about 1mm). And at the beginning of every new round while milling the pocket, the Z-Axis moves a little bit (0.5mm or less). It's totally strange...

Then I changed the x and z axis to check wheter it's the port of the controller board or something else. Looks quiet fine in the first moment. Z-Axis movement was ok, X-Axis, too. But when milling bigger things it looks like the x-axis misses some steps now...

I'm not sure if the controller board has a broken z-axis port or if there are some interference...

I will try another test tonight. I will ignore the z-axis port and use only x,y and a channels (y-axis steppers both parallel to the y-channel). If that runs completely fine the z-axis channel on the board is broken.

Edit:
The test using only x,y and a Axis of the controller board works fine. So it seems that the z-Axis Port ist broken or badly designed. However, the machine is running fine for the moment with ignoring the z-Axis port of the controller board.

:idea: Note for the Future:
I would go for single Axis controllers next time. Each stepper with a single controller (maybe TB6560 based because they are cheap and work good for the shapeoko2) connected to the Arduino running with grbl. That seems to be the best combination and if there are any problems with one channel the broken controller can be changed and there is no need to change the whole board with all channels... :D :!:

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