Forum

Welcome Guest 

Show/Hide Header

Welcome Guest, posting in this forum requires registration.





Pages: [1]
Author Topic: Motors dont function in SD standalone and freezing screen
brobes05
Newbie
Posts: 20
Permalink
Post Motors dont function in SD standalone and freezing screen
on: December 22, 2016, 22:32
Quote

Happy holidays,
I am primarily experiencing motor issues and some software issues.

First, I cannot activate the motors from USB mode although the serial port is recognized and I have both uploaded the machine size and set the home point. Pressing Ctrl-C yields the message, 'regenerating preview queue'. This occurs while the commands are not read and

As a result, I have abandoned the USB approach and have switched to using the standalone SD card (which is the approach I want to use).

Anyway, I have followed Sandy's vimeo on how to do this by uploading the machine specs, setting the home positions, generating the g-code and then exporting the queue as a .txt file. I then upload this to the PolargraphSD shield and touch to turn on the motors. Here is where things get interesting. The left motor locks and the right motor does not fully lock, while they both (or make warbly, vibrating sounds.
Next, I load the SD file and initiate the process. At this point everything is frozen and nothing happens.

I have a feeling that there could be two problems here: A) power supply issues or B) motor issues. I am inclined to think that the first is the culprit.

I have read on Sandy's post about powering the SD standalone here: http://www.polargraph.co.uk/2014/01/external-power-input-on-polarshield/

As a result, I have tried these options: A) plugged a 9v 1amp power supply into the polargraphSD with no power to the arduino. B) 12V 2amp into the polargraphSD (I know this is too high). C) USB power to the Arduino and 9v 1amp into the PolargraphSD.

I suppose at this point, I am asking advice on what to do to troubleshoot this process. I will test each motor on my adafruit shield since I cannot test them on the polargraph shield, but as for the freezing I am at a loss.

Thank you so much for your comments.

sandy
Administrator
Posts: 1408
Permalink
sandy
Post Re: Motors dont function in SD standalone and freezing screen
on: December 23, 2016, 18:05
Quote

Hi Brobes, there's a couple of things there isn't there.

The motor locking (or not locking) sounds like a physical issue to me, the fact that one motor locks, and the other doesn't can't be a software thing, and its not like a power problem that I've seen before.

When the cabling is faulty, then it often exhibits movement, but it's actually not controlled. It's usually that the two pairs of wires that lead to the two coils in the motor are mixed up, or switched around. This can be totally secure wiring that is just the wrong way around or it can be loose or intermittent connections. The loose connection is a little more dangerous, because it can lead to the motor drivers getting damaged.

The problem of nothing happening when you run a script file is another story. I'd get the USB comms fixed first, because that'll give you the error messages that you need to diagnose the rest. You can connect ok? (Green, and a READY... showing up in the console?)

sn

brobes05
Newbie
Posts: 20
Permalink
Post Re: Motors dont function in SD standalone and freezing screen
on: December 28, 2016, 03:58
Quote

Sandy, thanks for your reply

You are right it is a hardware issue. I connected the steppers to an Adafruit Shield v2 and they work fine. They actually work perfectly and I've been producing some nice drawings.

Anyway, I am perplexed as to why the polarshields are not working. (I have two which I purchased in the last year). I think it must be a problem with the 'easydriver' shields and/or the plastic terminal connections. I might try connecting without the terminal heads. Nevertheless, I am glad it is working. Thank you for in advance for your reply.

//---------------------------------------EDIT--------------------------------------------

I forgot to mention that the PSU is potentially the culprit. It is strange when I run 12V 2amps into the Adafruit board, the motors run cool; however, when through the polarshield they are quite hot. I know you recommend 2.66 amp, but those are hard to find. Maybe the adafruit board has a larger acceptance range?

Pages: [1]
Mingle Forum by cartpauj
Version: 1.0.34 ; Page loaded in: 0.024 seconds.