Inconsistent layers with hot bed on. Perfect with hot bed off !?!? June 25, 2015 11:27AM |
Registered: 9 years ago Posts: 70 |
Re: Inconsistent layers, tried many things to no avail (pictures inside) June 25, 2015 07:57PM |
Registered: 9 years ago Posts: 70 |
Re: Inconsistent layers, tried many things to no avail (pictures inside) June 25, 2015 08:37PM |
Registered: 9 years ago Posts: 344 |
Re: Inconsistent layers, tried many things to no avail (pictures inside) June 25, 2015 08:42PM |
Registered: 9 years ago Posts: 70 |
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cristian
Ooze is quite normal at the end of the print (at least for me), and the only problem you may have when you tighten the nozzle too much, is that you break something. If you did not already, then it is fine.
Re: Inconsistent layers, tried many things to no avail (pictures inside) June 25, 2015 10:47PM |
Registered: 9 years ago Posts: 70 |
Re: Inconsistent layers, tried many things to no avail (pictures inside) June 26, 2015 07:08AM |
Registered: 9 years ago Posts: 344 |
Re: Inconsistent layers, tried many things to no avail (pictures inside) June 26, 2015 07:14AM |
Registered: 9 years ago Posts: 70 |
Re: Inconsistent layers with hot bed on. Perfect with hot bed off !?!? June 26, 2015 07:19AM |
Registered: 9 years ago Posts: 344 |
Re: Inconsistent layers with hot bed on. Perfect with hot bed off !?!? June 26, 2015 07:56AM |
Registered: 9 years ago Posts: 70 |
Quote
cristian
It looks like all the motors were skipping steps, not only the extruder one: the edges of the object become shorter and shorter. Maybe your power supply is not powerful enough, or your board.
Re: Inconsistent layers with hot bed on. Perfect with hot bed off !?!? June 26, 2015 08:42AM |
Registered: 9 years ago Posts: 1,873 |
Re: Inconsistent layers with hot bed on. Perfect with hot bed off !?!? June 26, 2015 11:22AM |
Registered: 9 years ago Posts: 70 |
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JamesK
Fantastic! Well done for spotting the problem. You can check the power supply easily by keeping the meter attached to the supply outputs. If the voltage drops when the heat bed comes on (best to check with the hotend running too) then you will know that you need a bigger PSU.
How is the heat bed configured in the firmware, bang-bang (what a name) or PID? If you're using bang-bang changing to PID might smooth things out a bit. If you are using Marlin you could also try reducing MAX_BED_POWER to limit the bed power consumption, although this will increase your warmp-up times:
// This sets the max power delivered to the bed, and replaces the HEATER_BED_DUTY_CYCLE_DIVIDER option.
// all forms of bed control obey this (PID, bang-bang, bang-bang with hysteresis)
// setting this to anything other than 255 enables a form of PWM to the bed just like HEATER_BED_DUTY_CYCLE_DIVIDER did,
// so you shouldn't use it unless you are OK with PWM on your bed. (see the comment on enabling PIDTEMPBED)
#define MAX_BED_POWER 255 // limits duty cycle to bed; 255=full current
/* Reprap firmware based on Sprinter Optimized for Sanguinololu 1.2 and above / RAMPS This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see [www.gnu.org]. */ /* This firmware is a mashup between Sprinter, grbl and parts from marlin. (https://github.com/kliment/Sprinter) Changes by Doppler Michael (midopple) Planner is from Simen Svale Skogsrud [github.com] Parts of Marlin Firmware from ErikZalm [github.com] Sprinter Changelog - Look forward function --> calculate 16 Steps forward, get from Firmaware Marlin and Grbl - Stepper control with Timer 1 (Interrupt) - Extruder heating with PID use a Softpwm (Timer 2) with 500 hz to free Timer1 for Steppercontrol - command M220 Sxxx --> tune Printing speed online (+/- 50 %) - G2 / G3 command --> circle function - Baudrate set to 250 kbaud - Testet on Sanguinololu Board - M30 Command can delete files on SD Card - move string to flash to free RAM vor forward planner - M203 Temperature monitor for Repetier Version 1.3.04T - Implement Plannercode from Marlin V1 big thanks to Erik - Stepper interrupt with Step loops - Stepperfrequency 30 Khz - New Command * M202 - Set maximum feedrate that your machine can sustain (M203 X200 Y200 Z300 E10000) in mm/sec * M204 - Set default acceleration: S normal moves T filament only moves (M204 S3000 T7000) im mm/sec^2 * M205 - advanced settings: minimum travel speed S=while printing T=travel only, X= maximum xy jerk, Z=maximum Z jerk, E = max E jerk - Remove unused Variables - Check Uart Puffer while circle processing (CMD: G2 / G3) - Fast Xfer Function --> move Text to Flash - Option to deactivate ARC (G2/G3) function (save flash) - Removed modulo (%) operator, which uses an expensive divide
Re: Inconsistent layers with hot bed on. Perfect with hot bed off !?!? June 26, 2015 01:55PM |
Registered: 10 years ago Posts: 14,672 |
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geemoto
Should I switch firmwares to something better?
Re: Inconsistent layers with hot bed on. Perfect with hot bed off !?!? June 27, 2015 01:12AM |
Registered: 9 years ago Posts: 70 |
Re: Inconsistent layers with hot bed on. Perfect with hot bed off !?!? June 27, 2015 10:15AM |
Registered: 9 years ago Posts: 1,873 |
Re: Inconsistent layers with hot bed on. Perfect with hot bed off !?!? June 27, 2015 06:44PM |
Registered: 9 years ago Posts: 70 |
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JamesK
Some voltage drop through the RAMPS is inevitable for the mosfet forward voltage, so I think that's ok. I'm kind of surprised that we didn't see the power supply dropping. Did you also have the stepper motors powered up when you measured it? They don't have to be moving, just drawing current - perhaps that's enough to push the psu over it's limit. If you keep the meter connected to the psu during a print, you could check the value as the problem happens and see if there is any change in output. Still thinking the psu is the most likely problem at the moment.
12V vs 12.7V - do you have an LCD connected to the ramps? 12.7 is fine for everything except the 5v voltage regulator on the mega2560 which runs a bit near it's limit at the best of times when there is an lcd connected. Raising the 12v voltage makes that regulator work harder and can make them fail. On the other hand increasing the 12v supply helps with bed warm-up time.
How much does the bed temperature vary by during the print? Some print beds flex quite a bit as they heat-up which shift the center up and down if the temperature isn't well controlled. If you bring the bed up to temperature and then put the nozzle at z=0 (or .1) and then watch the gap through a couple of on/off cycles you should be able to see if there is much Z movement going on in the bed.
I can't see any problem with connecting the constantly on fans to the place you indicated. It's in the 5A fuse circuit, but typical cooling fans don't draw a lot of currrent.
Re: Inconsistent layers with hot bed on. Perfect with hot bed off !?!? June 27, 2015 07:14PM |
Registered: 9 years ago Posts: 1,873 |
Re: Inconsistent layers with hot bed on. Perfect with hot bed off !?!? June 27, 2015 08:21PM |
Registered: 9 years ago Posts: 70 |
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JamesK
Sounds like a reasonable thing to try, especially as you say they aren't too expensive. I just can't quite imagine how the ramps would cause the interaction between heat bed and any of the motion axes. But then, none of my ideas have been correct yet, so I'm obviously missing something! I'll look forward to hearing how it goes - you've got to be close to the answer at this point
Re: Inconsistent layers with hot bed on. Perfect with hot bed off !?!? July 17, 2015 10:44AM |
Registered: 9 years ago Posts: 70 |