Y axis zeroing off the bed

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Y axis zeroing off the bed

Postby mattvl » 2017-Nov-Wed-23-Nov

So I just installed a new stepper motor for my extruder and my Y axis is now zeroing half on half off the bed. When it goes to the other side during bed levelling, in the pre print run through, it goes too far out across the X axis so that the probe goes off of the bed and the hot end tip dives into the board. I tried adjusting the M210/M211/M212 settings in Cura, to no avail. Any ideas?
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mattvl
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Y axis zeroing off the bed

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Re: Y axis zeroing off the bed

Postby RetireeJay » 2017-Nov-Thu-10-Nov

Is the stepper motor the only thing you changed since the last time the printer was working? From some of your other posts, I wonder if you have a new Printrboard or you may have flashed new firmware onto your board. The Extruder stepper motor change by itself would not cause the Y axis to go bonkers. You need to start with examining the contents of EEPROM using M503.
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Printrbot Plus operational January 2013
Brass threaded rods (5/16" X 18) & nuts for Z axis
GT2 belts & pulleys
Cable chain to reduce probability of fatigue failure in wires
E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
PB fan mount + 40mm fan -- using printed mount adapter, not the E3D supplied fan
Injection molded extruder gears
Optical Z "endstop" (custom designed and built)
Have used many pounds of T-Glase filament. Now also doing some work with Ninjaflex SemiFlex
Print on glass with Scotch Craft Stick or other glue stick
"My next printer is..." Prusa i3 MK3, upgraded to MK3S
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Re: Y axis zeroing off the bed

Postby mattvl » 2017-Nov-Thu-18-Nov

You're right, I had changed the printrboard as well awhile back, but never got the extruder going again since. I thought I had checked the homing, but it's been long enough that I can't be sure. I tried using the M501 command to adjust the min/max positions and the home offsets, but it didn't change anything. Here are my M503 results:

< echo:Steps per unit:
< echo: M92 X80.00 Y80.00 Z2020.00 E96.00
< echo:Maximum feedrates (mm/s):
< echo: M203 X125.00 Y125.00 Z5.00 E14.00
< echo:Maximum Acceleration (mm/s2):
< echo: M201 X2000 Y2000 Z30 E10000
< echo:Acceleration: S=acceleration, T=retract acceleration
< echo: M204 S3000.00 T3000.00
< echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum XY jerk (mm/s), Z=maximum Z jerk (mm/s), E=maximum E jerk (mm/s)
< echo: M205 S0.00 T0.00 B20000 X20.00 Z0.40 E5.00
< echo:Home offset (mm):
< echo: M206 X0.00 Y0.00 Z0.00
< echo:PID settings:
< echo: M301 P22.20 I1.08 D114.00
< echo:Min position (mm):
< echo: M210 X0.00 Y0.00 Z0.00
< echo:Max position (mm):
< echo: M211 X250.00 Y250.00 Z254.00
< echo:Bed probe offset (mm):
< echo: M212 X0.00 Y0.00 Z0.60

Any ideas?
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mattvl
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Re: Y axis zeroing off the bed

Postby RetireeJay » 2017-Nov-Thu-19-Nov

I don't see any smoking guns there. The steps/mm on all axes look reasonable, the minimums are all zero and the maxima are 250 or 254mm, which corresponds to the build size of the Metal Plus at 10" on every axis.
What happens when you tell the printer to go to Y home? Does it successfully find the "end stop" switch?
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Printrbot Plus operational January 2013
Brass threaded rods (5/16" X 18) & nuts for Z axis
GT2 belts & pulleys
Cable chain to reduce probability of fatigue failure in wires
E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
PB fan mount + 40mm fan -- using printed mount adapter, not the E3D supplied fan
Injection molded extruder gears
Optical Z "endstop" (custom designed and built)
Have used many pounds of T-Glase filament. Now also doing some work with Ninjaflex SemiFlex
Print on glass with Scotch Craft Stick or other glue stick
"My next printer is..." Prusa i3 MK3, upgraded to MK3S
User avatar
RetireeJay
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Re: Y axis zeroing off the bed

Postby mattvl » 2017-Nov-Thu-19-Nov

It looks like it finds the end stop switch without a problem as there isn't any grinding. It just bumps the switch and then backs up, as per usual. However, it doesn't back all the way onto the bed. It ends up sitting half on and half off.

As an added note, I believe I also changed the extruder carriage since it was last going. Printrbot released a new one that reduces cable bending...I don't really see how that could affect the homing as the measurements appear to be the same, but it's a little hard to compare as the new one is connected to the actual printer right now.
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mattvl
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Re: Y axis zeroing off the bed

Postby RetireeJay » 2017-Nov-Thu-21-Nov

I think I'd look at the physical location of the Y zeroing switch and also the part which touches the switch to activate it. On the old machines, Printrbot used an adjustable screw to determine exactly where motion along each axis would acutate its respective switch.
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Printrbot Plus operational January 2013
Brass threaded rods (5/16" X 18) & nuts for Z axis
GT2 belts & pulleys
Cable chain to reduce probability of fatigue failure in wires
E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
PB fan mount + 40mm fan -- using printed mount adapter, not the E3D supplied fan
Injection molded extruder gears
Optical Z "endstop" (custom designed and built)
Have used many pounds of T-Glase filament. Now also doing some work with Ninjaflex SemiFlex
Print on glass with Scotch Craft Stick or other glue stick
"My next printer is..." Prusa i3 MK3, upgraded to MK3S
User avatar
RetireeJay
My next printer is...
 
Posts: 4992
Joined: 2013-Jan-Wed-13-Jan
Location: Greenville, SC
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Re: Y axis zeroing off the bed

Postby mattvl » 2017-Dec-Sat-07-Dec

So upon closer inspection the lever arm actuator was bent perfectly in half allowing it to work, but a couple mm later than usual. It looks like I'm going to have to buy a new one of those as well. Are there any specs on the switch? I'd like to purchase one locally, if at all possible.
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mattvl
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Re: Y axis zeroing off the bed

Postby RetireeJay » 2017-Dec-Sat-14-Dec

Needle nose pliers to bend it back to nominal shape? Adjust the screw (if there is one) that fine-tunes the actuation point?
Look on the switch for a part number and Google it?
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Printrbot Plus operational January 2013
Brass threaded rods (5/16" X 18) & nuts for Z axis
GT2 belts & pulleys
Cable chain to reduce probability of fatigue failure in wires
E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
PB fan mount + 40mm fan -- using printed mount adapter, not the E3D supplied fan
Injection molded extruder gears
Optical Z "endstop" (custom designed and built)
Have used many pounds of T-Glase filament. Now also doing some work with Ninjaflex SemiFlex
Print on glass with Scotch Craft Stick or other glue stick
"My next printer is..." Prusa i3 MK3, upgraded to MK3S
User avatar
RetireeJay
My next printer is...
 
Posts: 4992
Joined: 2013-Jan-Wed-13-Jan
Location: Greenville, SC
Reputation: 498

Re: Y axis zeroing off the bed

Postby mattvl » 2017-Dec-Sat-15-Dec

I'd already tried bending it back but it just fell right off. It doesn't have any adjustment screw and the only thing legible on the side is "SS" which I googled before and just got the companies list of switches but nothing specific to the model number. I'll probably just bring it in to a local shop and see if they can give me an equivalent one.
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mattvl
Levelling print bed...
 
Posts: 28
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Re: Y axis zeroing off the bed

Postby RetireeJay » 2017-Dec-Sat-20-Dec

Generically, these are called "microswitches" because they actuate with a pretty small motion of the nub that the lever pushes on.

The key parameters for you to look for are:
(1) physical size - it has to fit
(2) It should be either a "Normally Closed" SPST (Single Pole, Single Throw) or, preferably, a SPDT (Single Pole Double Throw). The latter gives you options just in case the logic of the endstop switch on the Printrboard has been changed for some reason.

The voltage rating and current rating are pretty much irrelevant, because any switch you find in this physical size will be able to handle 12V at a few milliamps.

I'm sure you'll find a huge selection at DigiKey.com, which is where Printrbot gets most of their electronic parts.
  • 0

Printrbot Plus operational January 2013
Brass threaded rods (5/16" X 18) & nuts for Z axis
GT2 belts & pulleys
Cable chain to reduce probability of fatigue failure in wires
E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
PB fan mount + 40mm fan -- using printed mount adapter, not the E3D supplied fan
Injection molded extruder gears
Optical Z "endstop" (custom designed and built)
Have used many pounds of T-Glase filament. Now also doing some work with Ninjaflex SemiFlex
Print on glass with Scotch Craft Stick or other glue stick
"My next printer is..." Prusa i3 MK3, upgraded to MK3S
User avatar
RetireeJay
My next printer is...
 
Posts: 4992
Joined: 2013-Jan-Wed-13-Jan
Location: Greenville, SC
Reputation: 498

Re: Y axis zeroing off the bed

Postby mattvl » 2017-Dec-Thu-12-Dec

So I picked up a couple here in Canada with the same specs, but also one from Printrbot just in case. The former were super cheap, so I figured it would be good to have a couple extra kicking around. Anyway, I installed the new limit switch and it's still doing the exact same thing. Is it possible to change the Y homing coordinates to make the auto-levelling probe on top of the bed rather than just off the side of it?

EDIT: Wellllllll after reading through an assembly guide, I've discovered that the arm on the limit switch is supposed to bent at 90 degrees to be activated earlier (see attached). So...problem solved! Thanks for your help!

https://drive.google.com/file/d/0B9oj0J ... JEQkE/view
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mattvl
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