Knocking Motor
August 24, 2012 03:51AM
Figure I best start a new thread on this...

So I just got home, did some stuff, plugged in Tantillus and my (problematic) X motor is like a small, but determined man at my door - knocking, knocking, knocking. Pronterface isn't even connected yet - but this is actually the state that I left it at, as I recall.

OK - gonna spend more time massaging this little phillips screw head that I don't quite understand...
Re: Knocking Motor
August 24, 2012 04:15AM
This sounds like the current is a little high and it is going from its normal state to thermal protection mode and back and fourth. Just turn down the pot 1 degree and it should stop.


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Re: Knocking Motor
August 24, 2012 04:25AM
Thanks for the late-night response. I'm starting to feel like it's just me and this little f^*#k^ng phillips head. Turning degree by degree, time after time..

Funny thing is that I can just keep turning and turning, and it doesn't seem to change too much. I"m sure I've done a few laps by now - but I'll put on my lab coat (code for beer) and have another go.

It certainly gives me a greater appreciation of what people have brought and put into the reprap project.

I'll be sure to (try) to put my interpretive dance of success into words when it happens...
Re: Knocking Motor
August 24, 2012 04:35AM
If it keeps giving you issues I will just replace it. It should not be that hard. Could it be that something is too tight and it requires to much power to move the axis?


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Tantillus.org Mini Printable Lathe How NOT to install a Pololu driver
Re: Knocking Motor
August 24, 2012 04:46AM
I dunno, it feels pretty even with my Y. I spent some good effort in finding the sweet spot in the gearing for this axis. The only thing I've not done is lubricate the rods, as I don't have any Vaseline. I considered coconut buttering them, but it doesn't feel like it's worth the risk (Tantillus being allergic to coconuts or som'n).

I don't want to be a pain in the ass or wallet, but I'd be super-stoked to swap out my X and extruder controller units for some that are dialed. I'd prefer to bring a working machine to the build day next week than one that's not had it's first plastic 'movement'smiling smiley

I think I read that you were in the big smoke on Sunday. If it's not the case, ignore. If it is, I'd be happy to track you down and swap some chips (Bond-style), so I can at least stop whining here on the boards..
Re: Knocking Motor
August 24, 2012 04:51AM
ernchesto Wrote:
-------------------------------------------------------
> I dunno, it feels pretty even with my Y. I spent
> some good effort in finding the sweet spot in the
> gearing for this axis. The only thing I've not
> done is lubricate the rods, as I don't have any
> Vaseline. I considered coconut buttering them, but
> it doesn't feel like it's worth the risk
> (Tantillus being allergic to coconuts or som'n).
>
> I don't want to be a pain in the ass or wallet,
> but I'd be super-stoked to swap out my X and
> extruder controller units for some that are
> dialed. I'd prefer to bring a working machine to
> the build day next week than one that's not had
> it's first plastic 'movement'smiling smiley
>
> I think I read that you were in the big smoke on
> Sunday. If it's not the case, ignore. If it is,
> I'd be happy to track you down and swap some chips
> (Bond-style), so I can at least stop whining here
> on the boards..

Uh - I just had a quick look and see no sign of you coming to the city on Sunday.
I'm guessing it's that little screw's fault...
Re: Knocking Motor
August 24, 2012 04:56AM
Re: Knocking Motor
August 24, 2012 06:05AM
smileys with beerSuperlative customer servicesmileys with beer
Re: Knocking Motor
August 24, 2012 04:33PM
ernchesto Wrote:
-------------------------------------------------------
> smileys with beerSuperlative customer servicesmileys with beer


Seriously superplative. I had all new electronics show up at my doorstep less than 2 days after having problems and without even asking for them. Unbelievable thumbs up
Re: Knocking Motor
August 24, 2012 04:45PM
Awesome.

Hey Eric - did you mess with your extruder gear jam? I just dismounted mine to test by hand, and it doesn't seem too rough to turn - but I'm at least getting some death-screech-knock out of it. I'm curious if yours has started working through your tweaks. Any news?
Re: Knocking Motor
August 24, 2012 04:53PM
The high pitch noise is a result of the stepper drivers being current chopping drivers which means they turn the current on and off at a high frequency to keep the current exactly where you have it set. Unfortunately that frequency is in the audible range. This is why you want to adjust the current until the axis or gears turn and then tweak it just slightly until the noise changes to something acceptable.

Also the extruder will not move unless the hotend is heated up.


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Tantillus.org Mini Printable Lathe How NOT to install a Pololu driver
Re: Knocking Motor
August 24, 2012 05:02PM
OK - I actually was doing adjustments with the hot end heated. I seem to go round and round in teensy increments and am not getting the motion in the extruder (or the X). I'm going to pick up some Vaseline today to try and help with X. I took a break from pots adjusting the extruder, as I was thinking that perhaps my gears were jammed, as Eric had mentioned about his. So I shut it all down to dismount the extruder, but they seem OK.I guess I need to get my increments even teensier..

Sublime - I've been using Pause in Pronterface to stop the madness while testing the motors. Then I Disconnect and unplug Tantillus to start again (after I've cooled down the hot end). Is there a simpler way to abort a print?
Re: Knocking Motor
August 24, 2012 05:28PM
ernchesto Wrote:
-------------------------------------------------------
> Sublime - I've been using Pause in Pronterface to
> stop the madness while testing the motors. Then I
> Disconnect and unplug Tantillus to start again
> (after I've cooled down the hot end). Is there a
> simpler way to abort a print?

Unfortunately not. Marlin has an 8kb buffer and it will keep printing until it the buffer is empty. The only thing you can try is pressing the reset button on the Ramps board and it will clear the last move. You may need to press it 8 times to clear all of it, but disconnecting the power and USB clears the entire thing.


FFF Settings Calculator Gcode post processors Geometric Object Deposition Tool Blog
Tantillus.org Mini Printable Lathe How NOT to install a Pololu driver
Re: Knocking Motor
August 24, 2012 07:49PM
OK - nice to know I'm not being a twit.

Liking the RAMPS reset.
Re: Knocking Motor
August 24, 2012 08:37PM
ernchesto Wrote:
-------------------------------------------------------
> Awesome.
>
> Hey Eric - did you mess with your extruder gear
> jam? I just dismounted mine to test by hand, and
> it doesn't seem too rough to turn - but I'm at
> least getting some death-screech-knock out of it.
> I'm curious if yours has started working through
> your tweaks. Any news?


Sounds like you did the same thing I did - dismount the extruder and test the gears by hand. Mine were hitting a really difficult point in the rotation where I had to apply a lot of force to get them to turn, so I took out the large gear and cleaned it up with an exacto blade and a small file. One side of the teeth (the bottom side when the part was printed) had some deformed plastic and that's all I had to remove. After cleaning it up the everything worked fine. Any way you can record the death-screech-knock sound and upload to youtube or something? My gears only made a knocking sound when they were stuck, no screeching.

I'd guess Sublime is right about the POT's. All four of the POT's on my drivers are oriented at the same approximate angle FYI. I'm guessing you've tried orienting your Extruder and X-axis POT's at the same angle as the POT's for your working Y and Z axis?
Re: Knocking Motor
August 24, 2012 08:50PM
Eric Young Wrote:
-------------------------------------------------------
> ernchesto Wrote:
> --------------------------------------------------
> -----
> > Awesome.
> >
> > Hey Eric - did you mess with your extruder gear
> > jam? I just dismounted mine to test by hand,
> and
> > it doesn't seem too rough to turn - but I'm at
> > least getting some death-screech-knock out of
> it.
> > I'm curious if yours has started working
> through
> > your tweaks. Any news?
>
>
> Sounds like you did the same thing I did -
> dismount the extruder and test the gears by hand.
> Mine were hitting a really difficult point in the
> rotation where I had to apply a lot of force to
> get them to turn, so I took out the large gear and
> cleaned it up with an exacto blade and a small
> file. One side of the teeth (the bottom side when
> the part was printed) had some deformed plastic
> and that's all I had to remove. After cleaning it
> up the everything worked fine. Any way you can
> record the death-screech-knock sound and upload to
> youtube or something? My gears only made a
> knocking sound when they were stuck, no
> screeching.
>
> I'd guess Sublime is right about the POT's. All
> four of the POT's on my drivers are oriented at
> the same approximate angle FYI. I'm guessing
> you've tried orienting your Extruder and X-axis
> POT's at the same angle as the POT's for your
> working Y and Z axis?

I actually hadn't thought of that - I'll check and do some more testing tonight when I get back.

I did lube up my X + Y rods and it feels quite a bit smoother. Hopefully I'll be able to get those pots working, so I don't have to harass Sublime for a swap.
Re: Knocking Motor
August 24, 2012 08:53PM
Crossing my fingers for you smiling smiley It worked right away for my X-axis when it was having trouble.
Re: Knocking Motor
August 24, 2012 10:06PM
Sublime Wrote:
-------------------------------------------------------
> Unfortunately not. Marlin has an 8kb buffer and it
> will keep printing until it the buffer is empty.
> The only thing you can try is pressing the reset
> button on the Ramps board and it will clear the
> last move. You may need to press it 8 times to
> clear all of it, but disconnecting the power and
> USB clears the entire thing.

I use Marlin on RAMPS, and when I hit the reset button it completely resets, as in it clears the buffer, turns off the heaters and motors, etc. and reports to the host that it has been reset.


Cameron

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Re: Knocking Motor
August 24, 2012 10:48PM
NewPerfection Wrote:
-------------------------------------------------------
> Sublime Wrote:
> --------------------------------------------------
> -----
> > Unfortunately not. Marlin has an 8kb buffer and
> it
> > will keep printing until it the buffer is
> empty.
> > The only thing you can try is pressing the
> reset
> > button on the Ramps board and it will clear the
> > last move. You may need to press it 8 times to
> > clear all of it, but disconnecting the power
> and
> > USB clears the entire thing.
>
> I use Marlin on RAMPS, and when I hit the reset
> button it completely resets, as in it clears the
> buffer, turns off the heaters and motors, etc. and
> reports to the host that it has been reset.

Maybe this is new. I will have to look into the newer Marlin as my branch was branched a few months ago.


FFF Settings Calculator Gcode post processors Geometric Object Deposition Tool Blog
Tantillus.org Mini Printable Lathe How NOT to install a Pololu driver
Re: Knocking Motor
August 27, 2012 04:35PM
Just an update and a Q:

Sublime was kind enough to exchange my problematic servo controllers with new ones. Upon installation, my extruder works (no filament in it yet).

The X has also come to life, but it's still giving me some grief. I've re-lubricated the rods, tested the motor de-coupled from the drive gear, and have found the a pretty sweet spot in gear meshing.

So now that the motor has tested to be responsive when not meshed with the drive gear, I'm able to nudge the X around thru pronterface. The issue is that it seems to either get hung up from time to time - which I'm suspecting will be overcome if I increase the pots - is this a correct assumption? I should add that the X 10 nudge will often work when X 1 and 0.1 won't work, so it suggests that they're getting the wattage required - that makes me not want to mess with the pots adjustment.

A more confusing issue is that sometimes the nudge for X disregards the direction command (- or +). It simply moves in the direction that it wants to at the time. I'm thinking that this might be that it's going to whatever direction that it feels less friction in.

Any advice or thoughts are welcome!

Cheers.
Re: Knocking Motor
August 27, 2012 04:47PM
If it goes in a random direction it makes me think the motor is not connected properly and only one phase is working. But as this is unlikely I would think it may just be the current is not high enough. Try turning up the pot just a little and see if it helps. Turning it up should not hurt anything, it will go into thermal protection before it can damage the driver. Short of that try connecting the X motor to the Y driver and see if it is the driver or the motor/friction on the rods.


FFF Settings Calculator Gcode post processors Geometric Object Deposition Tool Blog
Tantillus.org Mini Printable Lathe How NOT to install a Pololu driver
Re: Knocking Motor
August 27, 2012 04:57PM
ernchesto Wrote:
-------------------------------------------------------
> So now that the motor has tested to be responsive
> when not meshed with the drive gear, I'm able to
> nudge the X around thru pronterface. The issue is
> that it seems to either get hung up from time to
> time - which I'm suspecting will be overcome if I
> increase the pots - is this a correct assumption?
> I should add that the X 10 nudge will often work
> when X 1 and 0.1 won't work, so it suggests that
> they're getting the wattage required - that makes
> me not want to mess with the pots adjustment.


Stepper motors are moved by sequencing power to the coils. The direction is determined entirely by the order the sequence is generated, and in our case it's the Pololu stepper drivers that does this.

If you're using Sublime's config then I doubt it could be due to endstop configuration, which can sometimes cause this sort of behavior.

The DIR signal could be screwed up somewhere between the Arduino and the stepper driver. This signal simply tells the driver which way to step the motor, and if it's not able to change state then the driver will always move the motor in the same direction. Does it travel the expected distance when you click the Pronterface button?
Re: Knocking Motor
August 27, 2012 06:18PM
Thanks for your answers folks.

I've got news! Not good news, however. I was testing while upping the pots adjustment. Before I knew it I went into firefighter modehot smiley

Does this help point to the direction of the issue?
Attachments:
open | download - fire_EM.jpg (57.8 KB)
open | download - fire2_EM.jpg (34.3 KB)
Re: Knocking Motor
August 27, 2012 08:40PM
Well, that should not be possible but it obviously happened. Can you wait until Thursday when I see you and I will replace the driver again and see if maybe it is an issue with your motor or RAMPS board.


FFF Settings Calculator Gcode post processors Geometric Object Deposition Tool Blog
Tantillus.org Mini Printable Lathe How NOT to install a Pololu driver
Re: Knocking Motor
August 27, 2012 10:25PM
Sublime Wrote:
-------------------------------------------------------
> Well, that should not be possible but it obviously
> happened. Can you wait until Thursday when I see
> you and I will replace the driver again and see if
> maybe it is an issue with your motor or RAMPS
> board.

For sure. Thanks. I look forward to it.
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