Print fails after two hours

Problems with your print or projects? talk here

Print fails after two hours

Postby Waynester » 2012-Oct-Thu-16-Oct

Hey Guys,
This is very strange. I recently tried to print a part that I have printed successfully several times.
Now for some reason, when the layer height reaches about 3/4" it loses track of where it is and
the print head runs a inch or so off the path and continues thinking it's doing a great job.
This print job is a 3hour plus so I started a second try and the exact same thing happened.
I've checked all the belts and belt locks they seem fine. The first part of the print looks really good.
Until all hell breaks loose.
Any help would be great.
Thanks again.
W.
  • 0

Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Print fails after two hours

Sponsor

Sponsor
 

Re: Print fails after two hours

Postby SolidVis » 2012-Oct-Thu-16-Oct

Waynester wrote:Hey Guys,
This is very strange. I recently tried to print a part that I have printed successfully several times.
Now for some reason, when the layer height reaches about 3/4" it loses track of where it is and
the print head runs a inch or so off the path and continues thinking it's doing a great job.
This print job is a 3hour plus so I started a second try and the exact same thing happened.
I've checked all the belts and belt locks they seem fine. The first part of the print looks really good.
Until all hell breaks loose.
Any help would be great.
Thanks again.
W.


It happened to me too. Heating the motors from that long run plus a current that is not strong enough can make the motor to skip steps (usually with a harsh noise). Did you played with the position of the potentiometers?
  • 0

SolidVis
I'm an end stop.
 
Posts: 69
Joined: 2012-Jun-Sun-18-Jun
Location: QC, CANADA
Reputation: 0

Re: Print fails after two hours

Postby Trentent » 2012-Oct-Fri-14-Oct

I experienced a similar issue with the Y motor getting too hot and causing it to go wonky. The solution is to put cardboard or an insulator under the printbed so the heat from the printbed isn't going straight down onto the Y motor.

At least, that worked for me.

Trentent
  • 0

Trentent
Loading filament...
 
Posts: 11
Joined: 2012-Jul-Sun-13-Jul
Reputation: 0

Re: Print fails after two hours

Postby holmes4 » 2012-Oct-Fri-14-Oct

I have my hotbed up on springs so there is an air gap, and I put metal foil tape down on the wooden bed to reflect heat up. Seems to work well.
  • 0

Steve
PB+ Backer 1402
User avatar
holmes4
Bowden extruder
 
Posts: 875
Joined: 2011-Dec-Sun-12-Dec
Location: New Hampshire, USA
Reputation: 14

Re: Print fails after two hours

Postby Waynester » 2012-Oct-Fri-15-Oct

Hello Again,
I've attached a photo of the print job.
This is the fourth attempt and it always seems to fail in the last 10 % or so.
Not exactly the same place but very close.
I've resaved the file, tried a different version of the file.
Tightened all belts and pullies, Added insulation to the bottom of printbed.
Tried to print a solid cube that goes higher in the z plane just to see if that made a difference.
Printed the solid 30mm cube perfectly. The bad print has a z height of around 20 mm.
It's got to be the Y plane (printbed) somehow is slipping or changing position/location...
I just don't get it.
Any other ideas.
Thanks
w
  • 0

Attachments
bad Print.JPG
Bad Print
Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: Print fails after two hours

Postby mdfast1 » 2012-Oct-Fri-16-Oct

Have you followed SolidVis's advice? It might not be a height issue, but more a motor heat issue. When it reaches that amount of run time the motor gets too warm and skips a step. I'd hate to have you waste plastic on another run, but keep your Y motor cooler (fan, heatsink, ice cubes-jk) or mess with your trim pots on the printrboard for the Y motor they should be about at the four o'clock position.
  • 0

Printrbot LC+ - Build in Progress

Printrbot Original- Donated
GT2 - 20 Tooth Pulleys
GT2 Belts
Brass Threaded Rods
Spur Gears from drawcut
.35mm nozzle
User avatar
mdfast1
Calibration mode.
 
Posts: 626
Joined: 2012-Feb-Thu-12-Feb
Reputation: 11

Re: Print fails after two hours

Postby Waynester » 2012-Nov-Fri-20-Nov

Hi,
Yes, I've litterally done everything that was reccommended by all the posts and a few other tricks.
I've ordered a new stepper motor just to see what happens.
I'll keep you all posted and thanks again for your input.
W.
  • 0

Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: Print fails after two hours

Postby Mooselake » 2012-Nov-Sat-01-Nov

Have you checked the motor when it screws up? IR gun, thermometer, or just a finger "ouch" test to see if it's really an overheat issue?

Kirk
  • 0

Last edited by Mooselake on 2012-Nov-Sat-13-Nov, edited 1 time in total.
User avatar
Mooselake
Print complete...
 
Posts: 1494
Joined: 2011-Dec-Tue-23-Dec
Location: Upper Michigan, USA
Reputation: 79

Re: Print fails after two hours

Postby eddiema » 2012-Nov-Sat-07-Nov

Mooselake wrote:Have you checked the motor when it screws up? IR gun, thermometer, or just a finger "ouch" test to see if it's really an overheat issue?

Kik

And mark the shaft. The heat may cause pulley slip.
Motors loosing torque when the magnets get hot seem quite feasible.
Some rare earth magnets loose strength at 80C or so.
  • 0

User avatar
eddiema
Aluminum coupler brain
 
Posts: 756
Joined: 2011-Dec-Mon-17-Dec
Location: Ipswich, Queensland Australia
Reputation: 1

Re: Print fails after two hours

Postby Waynester » 2012-Nov-Mon-10-Nov

This is getting crazy, I checked the potentiometers they're at 4:00, I put a fan on the Y motor, it wasn't that hot anyway, ....replaced the entire motor and belt (this new motor is a little more heavy duty and has a flatted surface on the shaft...very nice. I reloaded my software, I'm baffled....
Now as you can see from the little circlular print, each layer is out of alignment ..Any suggestions ???
HElp... The cylinder to the right printed fine until about 3/4 through print and then out of alignment ....These photos show the problem going off to the left but it's just the way I placed them for the camera ...the alignment problem actually goes to the rear of the machine...on the Y axis..
It's been over two weeks and I can't print anything anymore.
W.
  • 0

Attachments
Bad Print.JPG
Bad Print
Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: Print fails after two hours

Postby plexus » 2012-Nov-Mon-10-Nov

Are you printing from USB or SD card? try the opposite method from what you are doing (eg if USB then try printing from SD). that will rule out a data communication error especially if you are printing from USB. check everything around the belts and travel - ensure there are no obstructions or jams anywhere. check carefully because you've already done the obvious stuff so its something that you are not seeing. don't assume. look for the least obvious things.

Looks like you have funky stuff going on under your printbed with added screws and things: can you post some clear pics of the underside of the Y platform showing the rails and belt etc?

It would be great to get pics of the belt and Y gear too but that means disassembly.

I agree, strange. my first call would be a heat issue, but exactly where... unsure. also you can try printing slower and see if that helps/changes anything. make note of your original speeds and your new slower speeds.
  • 0

User avatar
plexus
Site Admin
 
Posts: 1960
Joined: 2011-Dec-Mon-16-Dec
Location: Toronto, Canada
Reputation: 78

Re: Print fails after two hours

Postby Mooselake » 2012-Nov-Tue-00-Nov

This is a little far out, but it looks like you have those springy aluminum couplers. Any chance you're getting some bounce and causing the extruder to drag? Since you've found a quicker test print maybe you could stick some pieces of business card in the slots to stiffen them and see if it makes a difference.

Is the heat bed or x axis wiring hitting anything when it gets higher? Any strange noises when it starts happening? Can you edit the code to the offending layers and run it without filament to see if something's hanging up?

Kirk
  • 0

User avatar
Mooselake
Print complete...
 
Posts: 1494
Joined: 2011-Dec-Tue-23-Dec
Location: Upper Michigan, USA
Reputation: 79

Re: Print fails after two hours

Postby plexus » 2012-Nov-Tue-00-Nov

Mooselake wrote:This is a little far out, but it looks like you have those springy aluminum couplers. Any chance you're getting some bounce and causing the extruder to drag? Since you've found a quicker test print maybe you could stick some pieces of business card in the slots to stiffen them and see if it makes a difference.

Is the heat bed or x axis wiring hitting anything when it gets higher? Any strange noises when it starts happening? Can you edit the code to the offending layers and run it without filament to see if something's hanging up?

Kirk


oh my god yes, you have to get rid of those things (springy couplers)! i didn't even notice those. the PB was not designed to use those. think about it. well... i was going to tell you but i will let you think about it first. ;)
  • 0

User avatar
plexus
Site Admin
 
Posts: 1960
Joined: 2011-Dec-Mon-16-Dec
Location: Toronto, Canada
Reputation: 78

Re: Print fails after two hours

Postby brookdrumm » 2012-Nov-Tue-03-Nov

Good troubleshooting here. I agree on the couplers, BTW. To minimize guessing, I would try other long prints to see if the failure happens at about the same time - if so, it may point to heat or motor fatigue. I do recommend flatting the shafts on X and Y motors to ensure it is not slippage on the pulley. We are moving to all D-shafts to help prevent the set screw from loosing grip - I have seen this a few times on the bot farm, myself. Printing from the microSD card is also a good practice to eliminate the possibility of a computer issue - I have seen hard drives and screens go to sleep at various times and screw things up. If you can pinpoint the problem to faulty equipment, I'll replace it. Hang in there!
cheers,
Brook
  • 0

brookdrumm
PBHQ Official
 
Posts: 56
Joined: 2012-Apr-Mon-01-Apr
Reputation: 31

Re: Print fails after two hours

Postby Mooselake » 2012-Nov-Tue-03-Nov

The faster printing cylinder failing probably rules out motor fatigue.

Kirk
  • 0

User avatar
Mooselake
Print complete...
 
Posts: 1494
Joined: 2011-Dec-Tue-23-Dec
Location: Upper Michigan, USA
Reputation: 79

Re: Print fails after two hours

Postby Waynester » 2012-Nov-Wed-22-Nov

Hello Again,
I tried to post a video showing the problem but it wouldn't upload.
I just want to say thank you for all your posts and I have littlerly tried all suggestions except.....SD card, because I don't have one yet...and didn't need it before....

So I'll try to give more details. I have made many mods to my bot. I replaced the Z rods with finer threads with new chrome couplers and replaced heaver duty Z motors with flatted shafts. Modified G-code to acccommodate .... worked great Prints improved nicely. I then changed out belts and pullys for G2. Much more accurate and smoother. I then put heavy duty springs under my bed screws for leveling etc. This worked well when I had to change out my hotend nozzle and the new one didn't end up exactly on threaded hotend so I adjusted the bed in seconds and bingo...great prints. Small and large...some lasting over 2.5 hours. Mechanics worked great my only complaint is with extruder and filament, temp .But that's another post for another time. I replaced printbed with a composite material found in a kitchen store used as a cutting board, my wooden bed had a slight warp in it. This new improvement is same size and weight but perfectly flat and smooth. Works great. This next mod is a bit more radical. I moved the Y motor over about 20 cm so belt could be in exact center of printbed. Of course I had to use a hole saw and cut the base which meant moving circuit board over as well. This really helped with some of the jerky side to side vibration and improved print percission as well. In fact, I think PrintrBot should consider this one.
One of my favorite add ons is the clip on bracket I printed to hold a small laser pointer with tape over lens and pinhole in tape for tiny pin spot dot on printbed. Great for calibrating X/Y movement. Just mark the pin spot (which is about the size of the tip of a pen) move the print head 40 mm or whatever, mark pinspot with small dot...sharpie marker and measure with calipers. Fun stuff.
So needless to say I have taken this machine apart and put it together a few times. That's what's baffling me with this problem.
So, to troubleshoot my software problem ...I loaded different files to slicer, Reinstalled slicer/Pronterface software.
HELP...
w.
  • 0

Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: Print fails after two hours

Postby Waynester » 2012-Nov-Wed-22-Nov

Hi,
Oh, I forgot to mention....latest print tests are getting worse. Print fails about third layer everyime and by fifth layer it's about 5cm...Y plane only.
This was kind of curious. First the misprint was moving away from center to rear and then radical change and moved front of center by several cm's
and just makes one big mess.
No weird sounds no scraping or rubbing...check out calibration with laser...right on the money...
w
  • 0

Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: Print fails after two hours

Postby Mooselake » 2012-Nov-Thu-02-Nov

You've probably checked this one, but GT2's are (supposedly; I don't have them) slip more easily than the XL belts. Would it be hard to put a dab of white paint/whiteout/something on the belt, and mark both it and the pulley where you could easily see them (maybe with the bed at Y zero, easy to find again), then check to see if it's slipping on the pulley. Or perhaps mark it with something that will show up on both the belt and pulley? It would be nice to eliminate (or point to) slipping belts vs. missed steps. Everything moves OK with the power off? Can you make the belt slip with quick power off moves?

And a dumb question, you said you flatted the Z motors but i don't see where you mention the Y or X motors. Any chance the pulley setscrews loosened? Hard to see lines on the Y shaft/pulleys without pulling the bed.

Good Luck! 3D printing was invented to test your patience and expand your vocabulary of obscene expressions :)

Kirk
  • 0

User avatar
Mooselake
Print complete...
 
Posts: 1494
Joined: 2011-Dec-Tue-23-Dec
Location: Upper Michigan, USA
Reputation: 79

Re: Print fails after two hours

Postby Waynester » 2012-Nov-Thu-10-Nov

Hey Kirk,
Thanks again for your input. I've been using the GT2 belts for a couple of months, I personally think their a little more accurate then the originals. Anyway, if they were slipping wouldn't it show up on my callibration tests as well as live print ? And yes, I have replaced the "y" motor with a flatted shaft. I will try your suggestion with a white mark and see what happens.
W.
  • 0

Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: Print fails after two hours

Postby Mooselake » 2012-Nov-Thu-13-Nov

Waynester wrote:Hey Kirk,
Anyway, if they were slipping wouldn't it show up on my callibration tests as well as live print ?

It would most likely be slipping under load and at higher speeds (more speed is more force on the machine), and calibration is usually at low speeds. (Calibration's an interesting subject - I just read the common practice of measuring printed objects really isn't all that great because of variations in extrusion width - but that's a whole other subject.)

The mark is to let you know if you should look at (or ignore) the belt slipping. If the motor, missed steps, slipping shaft, etc. is at fault the relationship between the pulley and belt shouldn't change.

Kirk
  • 0

User avatar
Mooselake
Print complete...
 
Posts: 1494
Joined: 2011-Dec-Tue-23-Dec
Location: Upper Michigan, USA
Reputation: 79

Re: Print fails after two hours

Postby Waynester » 2012-Nov-Thu-22-Nov

Hey,
Good idea. I found some "liquid Paper" in my desk.
Marked out a spot on belt and pulley. ran several movements back and forth etc.
Mark is right on the money......but I discovered somethings...1. Either I made a mistake in callibrating
or now 5 x 10 mm clicks on Pronterface (using my nifty little laser beam) now equals 70 mm's.
I thought I was on to something but the X axis measured exactly the same as Y... 20 mm's off.
Checked z just for fun it's exactly 50 mm'. as it should be..
2. and this is the big one....................when advancing the printbed back and forth over and over...
every now and then ...right near ground zero it slips or skips....very suttle and not every time..
But now having the little white mark not moving means the belt is not slipping on the pulley.
I also checked the set screw and that is totally tight. Still cant' tell what's happening exactly.
But I'm encouraged.
W;
  • 0

Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: Print fails after two hours

Postby Mooselake » 2012-Nov-Thu-23-Nov

Glad you're making progress!

Do you put your calibration numbers in your gcode (via slic3r configuration) or do you do an M500 and write them to EEPROM? If they're in your gcode did you print anything after you last power cycled it - if not, they're the saved eeprom numbers. Been bitten by that a couple times before I saved them in the printrboard. M503 will tell you what they are.

I had my calibration numbers get whacked once, don't know how, but cycling power fixed them and it's never happened again. Blame it on the universally despised scapegoat, "power surge".

Have you tried a test print and checking after it skipped?

Sometime back I wrote some simple basic programs to crank out gcode to exercise all 3 axes to break them in. It's on a different computer, but if you'd like I'll dig it out and generate something to hammer on your Y axis.

Kirk
  • 0

User avatar
Mooselake
Print complete...
 
Posts: 1494
Joined: 2011-Dec-Tue-23-Dec
Location: Upper Michigan, USA
Reputation: 79

Re: Print fails after two hours

Postby Waynester » 2012-Nov-Fri-12-Nov

Kirk,
That would be totally whacked out but I've got to explore it, worse case I'll learn a few things along the way.
Bottom line is everything works great except Y axis changing on every layer....Oh that's interesting..
If it makes a perfect 30 mm circle on my test print first layer...that means that callibration must be okay.
The second layer is off only on the Y plane and continues to shift as each new layer is spewed forth.
By the forth or fifth layer it really gets crazy and shifts to the front a spews forth into space.



I made my calibration changes only in Slicer settings Start/End Gcode
Take into account that I have printed dozens of very good prints with all these settings
Wow...just realized it's been almost a month since I had a good print.
So when you load a file into slicer/ponterface these G-code settings overwrite the
EPROM settings on board ???? at least for that one print that is loaded.???

G28 ; home all axes
M92 X44.444
M92 Y44.444
M92 Z2018.845
M92 E700

Okay. I have no idea how to Write to EPROM but I did M503 on command line and this is a copy of code
So the M503 displays the EPROM code ...


echo:Steps per unit:
echo: M92 X63.36 Y63.36 Z2272.72 E590.00
echo:Maximum feedrates (mm/s):
echo: M203 X60.00 Y60.00 Z2.00 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)
echo: M205 S0.00 T0.00 B20000 X20.00 Z0.40 E5.00
echo:PID settings:
echo: M301 P22.20 I1.08 D114.00
  • 0

Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: Print fails after two hours

Postby Mooselake » 2012-Nov-Fri-13-Nov

The values in your slic3r code only take effect after they are executed when you print a file containing them. If you turn the power off they're gone. So, the 50% difference wasn't a problem.

The EEPROM values are copied to the printer's working memory ("RAM") when you turn it on, then changed when M92 commands are processed ("executed", they're part of a programming language) either from Pronterface's command line or by running a code file. Think of RAM as a scratchpad that's thrown away every time the power goes off and starts blank each time.

Your eeprom values look like the shipped defaults. The default acceleration is a bit high, try lowering it from the command line as a test with

M201 X1000 Y1000

And see if the cylinder will print. Probably not, but worth a try. Also try this: Use the home all button to zero everything, then enter these lines (without the comments starting with the semicolons)

G1 X100 Z10 F5000 ; center extruder and move up a bit
G1 Y100 F9999 ; fast Y move
G1 Y0 F9999 ; back to zero

See if that makes it slip, check the marks on the Y belt, and your laser could help see if it goes back to zero. F sets the feed rate in mm per minute, which is currently limited by your settings to 60mm/s or 3600 mm/minute. 9999 is easier to type.

So far it looks like the belts and pulley screws are OK, the motors don't run hot, current's OK. Most likely the table doesn't hit anything. The belts aren't rubbing anywhere? Heated bed wires aren't hanging up? That leaves something binding in your Y axis, maybe a bearing? Quick wipe down with some light machine oil (3-in-one, sewing machine oil, something similar), just a little bit on a rag, of the Y rods? I can feel the vibration in my flaky bearing by touching it while the table moves, maybe you can find one that's off.

Kirk
  • 0

User avatar
Mooselake
Print complete...
 
Posts: 1494
Joined: 2011-Dec-Tue-23-Dec
Location: Upper Michigan, USA
Reputation: 79

Re: Print fails after two hours

Postby Mooselake » 2012-Nov-Fri-16-Nov

Here's a little gcode file that will set your config values, home all axes, move the extruder to 100,0,10 (center it in the X axis and move it up a bit so it won't hit anything), then move the table back and forth at 100, 150, and 200 mm/sec. It will start at 100/sec move from 5 to 15mm, then 5 to 25mm, continuing to 195 (I'm assuming a PB+), bump up the speed, and do it again. It also boosts the max speed, and sets the acceleration to 1000mm/s/s. You should cycle power to get your old values back, although they shouldn't hurt anything, and you can edit the gcode (file, edit in Pronterface IIRC) to change the acceleration if you want to experiment - if it runs without slipping you should try boosting acceleration back to the original 2000 and see if it fails. It takes under 3 minutes to run on my PB+. Try your laser to see if it comes back to it's start point - it should end up at Y5.0

For grins you can set the acceleration to something very low, like 100. It's fun to watch it speed up and slow down, but not very useful.

I use one of these to set up my CNC router (this one is randomly picked off ebay). If you want to run it off 12V it'll either need about a 470R resistor in series or a 3V power source (think lithium battery). I built a little adjustable LM317 constant current supply, but that's overkill...

Kirk
  • 0

Attachments
Y-exer.zip
(333 Bytes) Downloaded 34 times
User avatar
Mooselake
Print complete...
 
Posts: 1494
Joined: 2011-Dec-Tue-23-Dec
Location: Upper Michigan, USA
Reputation: 79

Re: Y Axis to skew or not to skew ???

Postby Waynester » 2012-Nov-Mon-18-Nov

Hello,
Kirk, I followed your advice and ran the Gcode (from the ZIP file ) twice through the printer. Quite entertaining. It went through all the moves just fine.
I then removed code and loaded a small sample print file with the original G code settings....and guess what.
My first good print in over a month. ..... Now before I break out the champagne I'll going to run a few more
jobs through, but it's just good to see some potential success. Also, I just want to say, you and all the other help have been just great.
Thanks again..
I'll Keep you posted.
Waynester.
P.s. You mentioned CNC machine, is this a hobby or a business for you. The reason I ask, I have a product that I'm developing and need to get a sample cut from Delrin for the mouthpiece. If you visit www.xharp.com you can see the project in more detail.
Let me know if you're interested.
Thanks again.
w.
  • 0

Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: Y Axis to skew or not to skew ???

Postby Mooselake » 2012-Nov-Mon-21-Nov

Waynester wrote:You mentioned CNC machine, is this a hobby or a business for you.

Glad you got something to print! Hope it continues. Perhaps one of your linear bearings is hanging up - I just got these to replace my bad Y bearing. They came today, but won't be installed until after the Thanksgiving (US holiday this Thursday) trip to my mother-in-laws.

I call my CNC interests a hobby, my wife has been known to call them something else :) I mostly make wooden gear gadgets, lithophanes, and just dink around, or I would if all my hobby time wasn't going into the Printrbot. I've done one job that I sort-of got paid for, some engraved welding gas tags for a local shop. I say sort-of because it was for a small store credit, but it did convince my wife I hadn't bought all those engraving tag samples for nothing.

Kirk
  • 0

User avatar
Mooselake
Print complete...
 
Posts: 1494
Joined: 2011-Dec-Tue-23-Dec
Location: Upper Michigan, USA
Reputation: 79

Re: One problem for another

Postby Waynester » 2012-Nov-Mon-22-Nov

Hey Kirk,
Man you were right about these machines were designed to test our patience and beyond.
After all this time I finally started my extended time print aprox 3 hours and it was going quite well
until I noticed that the extruder motor was turning but had loosened itself on the shaft and no filament was extruded for the the entire fifth or
six layer. So I decided it was the time to install the upgraded motor with the flatted shaft. But now the extruder motor just grinds away like the two gears are jammed.
But only on extrude forward not reverse extrude. Loosen motor mounts, test by hand extrudes beautifully, retighten mounts ....same thing. Smoothe as silk in reverse but shakes the whole Printrbot in forward extrude. Try a test print....works but not laying down filament very evenly and working way to hard....
Any thoughts on this one.
w.
  • 0

Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: Print fails after two hours

Postby Mooselake » 2012-Nov-Tue-02-Nov

Can you remove the filament, turn off the power, and see how the extruder turns by hand. Those look like the herringbone gears in your pictures. My cast gears had a number of tight spots that I had to file to make them run smoothly. I used some magic marker, which rubbed off where it was tight, then filed on the rubbed off spots. It took a lot of trial and error.

However, it was working before, so maybe you just have the gears too close together - they need a tiny bit of clearance, especially since these aren't precision gears and are not perfectly round. Find the tightest spot and then retighten the motor with just a little pressure on it - make it tighter or looser if needed. You can get two of the screws, then the one covered by the gear later. I'm assuming by motor mounts you mean the ones that connect the extruder stepper to the body. Also make sure the small gear lines up with the big one (this might be tricky since the big gear might not be straight to the shaft, either) and isn't rubbing on the motor.

I haven't tried this, but maybe if you loosen the set screw on the small pulley and turn the big gear by hand it might line itself up - if it moves in and out with the big gear try the center position. This is just a guess, but it sounds good - I might even try it on my bot the next time I get to it, although I should really print spur gears.

Kirk
  • 0

User avatar
Mooselake
Print complete...
 
Posts: 1494
Joined: 2011-Dec-Tue-23-Dec
Location: Upper Michigan, USA
Reputation: 79

Re: Print fails after two hours

Postby Waynester » 2012-Nov-Tue-10-Nov

Mornin',
Thank for the advice.
I have replaced my herringbone gears with srur gears a couple of months ago this set is very well made and work well together (until now)
I tried all your suggestions but can't find a "tight spot" on gears, and it only grinds and spews small amounts of filament when filament is secured in place. If I loosen small gear and disconnect from large gear with extruder still hot it hand turns perfectly smooth and very easily. If I reverse extrude the gears run smoothly together, If I reverse extrude and remove filament from assembly completley it turns perfectly smooth again. Refeed filament and back to same problem grinds so hard that the big gear just barley moves on a five mm extrude test. So the bottom line is for some reason the gears only jam under a load. I've tried ajusting the spring clip on extruder both ways. Well I have to admit, I'm really getting to know my little bot....And I'm not sure if we're still best friends...
w.

ALL I WANT TO DO IS PRINT SOME STUFF
  • 0

Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: Print fails after two hours

Postby Mooselake » 2012-Nov-Tue-13-Nov

I didn't see where you put a flat on your original extruder motor. If not, file, dremel, or use your other favorite method to put a flat on the old extruder motor shaft, then put it back. There's directions elsewhere on the forum, make sure you do something to keep the filings out of the motor. Since you've eliminated the gears that leaves a defective/otherwise inadequate new motor.

I violate this rule too often, but it's a good idea to only change one thing at a time when troubleshooting.

Kirk
  • 0

User avatar
Mooselake
Print complete...
 
Posts: 1494
Joined: 2011-Dec-Tue-23-Dec
Location: Upper Michigan, USA
Reputation: 79

Re: E Motor Jamming

Postby Waynester » 2012-Nov-Wed-18-Nov

Wow, I wouldn't have thought a brand new motor could act so wierd. After much hesitation, I took your advice and replaced with old motor. No more Grinding
In fact, I'm actually printing something. Let me just say that after all the down time I've had over the past month that I'm looking very seriously at the new MakerBot Replicator 2.
About 2500 with all the bells and whistles. But I am hooked on 3d printing and now that I've gone RepRap not sure if I want to constantly be tweeking this or that .....
Let's see how this three hour print job goes...about a half hour in and looks fantastic.
By the way Kirk, after I was up and running again I tried a test print. it started the skew routine again, so I ran your code again and it seems to be working out.
What do you make of that ?
W.
  • 0

Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: Three Hour Print Complete

Postby Waynester » 2012-Nov-Wed-21-Nov

Let's just say that I had my doubts after all the crazy mishaps of the past few weeks that I would ever get this bot back on track. But I'm about to remove the bottom half of the Xharp (my new invention electronic harmonica) body from printbed ...which looks very good. The top half will be printing shortly.
So, let's reflect on problems so others may benefit. I wish I could say exactly what was going on but still don't really know. Here's a brief rundown. My problem started when for no obvious reason the Y axis would just become skewed. Posted photos and got lots of suggestions. Like a belt slipping, or motor overheating , but couldn't and never really did pinpoint the problem. Replace motor, added fan, replaced belt. Kirk suggested running a string of code he or someone had written to test the bot, speed, accuracy, overall test drive. After running the code through pronterface my prints were now back on track. Maybe someone knows why but I'm still baffled on that one. So after two successful short runs I decided to install the new Extruder motor with the flatted shaft. Because the new motor had a different connector on the end I just cut, soldered and heat shrinked, is that a word.... and installed the new motor in place. After two days of pulling the rest of my hair out, because the new motor would just grind away under a load. It worked smooth as silk with filament removed or in reverse but the second you tried to extrude it would just grind away and do nothing. So reluctantly, I replaced it with the old original motor. And was up and running immediately. Just now finishing my second two hour plus print. Which looks good so far.
Thank you all for your suggestions and helpful tips.
Great forum.
W.
  • 0

Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: E Motor Jamming

Postby Mooselake » 2012-Nov-Sun-22-Nov

Waynester wrote:By the way Kirk, after I was up and running again I tried a test print. it started the skew routine again, so I ran your code again and it seems to be working out.
What do you make of that ?W.

Bummer, DOA motor. You could try to return it for credit or replacement.

One or more of your Y axis bearings are hanging up and need either a clean and relube, or replacement - I'd guess there's a piece of grit in one of them. I used some "plastic safe" electrical contact cleaner that was laying around to clean my Z bearings (probably any light solvent-type cleaner that you'd be willing to get on your hands would work, or even something like paint thinner or Simple Green), then relubed them with a good light silicone grease. You could use light machine (sewing machine, gun, etc.) oil instead of the grease. Be careful you don't dislodge any balls when reinstalling them. There's a discussion about cleaning linear bearings somewhere in the forum.

I wrote a several small programs in M$ Small Basic to crank out gcode to break-in the axes on my PB+ when I first received it, the file I posted was a shortened and slightly edited output from that. The source is posted somewhere on the forum.

Glad to hear it's working. If you're in the states hope you had a good turkey day; we did at the inlaws (in an Internet free zone) for the holidays. Good luck with your X harp.

Kirk
  • 0

User avatar
Mooselake
Print complete...
 
Posts: 1494
Joined: 2011-Dec-Tue-23-Dec
Location: Upper Michigan, USA
Reputation: 79

Re: Print fails after two hours

Postby Waynester » 2013-Jan-Sun-01-Jan

Hey Kirk,
Well the ghost appeared again out of the blue. Third layer usually started to go off skew in the Y plane as before. I Replaced motor, belts, Gears...went back to my old original belf and pulley that came with bot. Same thing ...For over a week I could not get a decent print after first 3 or 4 layers. Then a miracle happened I was looking at some old posts on RepRap "BlogSpot" and someone was talking about intentionally making prints fail. This guy would turn down the voltage on the X and Y motors randomly while printing and his failures looked just like mine......then the lights went on..........What was happening on the third layer of this small part the print speed on the infill would cause both X and Y to really jog back and forth with short strokes so what was happening is the Y motor would skip but you couldn't hear it because it was lack of power for a split second and that's all it took. I flipped my bot over, turned up the voltage regulator and just completed the part I've had fail three dozen times over the past week. Everyone talked about overheating etc......but I never heard the other potential failure ....UNDER powered.
Another nightmare put to rest.
Thanks again for all your help and suggestions. I thought I'd post just in case someone else runs into this.
Good Night.
W.
  • 0

Waynester
Levelling print bed...
 
Posts: 28
Joined: 2012-Aug-Wed-09-Aug
Reputation: 0

Re: Print fails after two hours

Postby SolidVis » 2013-Jan-Sun-08-Jan

Waynester wrote:... Everyone talked about overheating etc......but I never heard the other potential failure ....UNDER powered. ...

I was saying "...plus a current that is not strong enough..." means under powered. Glad you get it.
  • 0

SolidVis
I'm an end stop.
 
Posts: 69
Joined: 2012-Jun-Sun-18-Jun
Location: QC, CANADA
Reputation: 0

Re: Print fails after two hours

Postby Rob311 » 2013-Jan-Sun-10-Jan

It sounds like you solved your issue, but I'll share my experience anyway. I was getting 1/2" up on a calibration block, and everything was fine, but it all of a sudden it looses itself on the y axis. After printing out many styles of belt tensioners, i realized that the set screw on my pully was loose. It wouldn't turn all the way around, but it would wobble on the flat of the shaft, making it look like i was skipping steps.
  • 0

Rob311
Loading filament...
 
Posts: 21
Joined: 2013-Jan-Sun-09-Jan
Reputation: 0


Return to Project troubleshooting

Who is online

Users browsing this forum: No registered users and 7 guests

cron