Prague build calibration problems

[Praguemorgan]

Hi everyone,

me and my friend are building a morgan in Prague, Czech Republic. We’re finished with the assembling phase and we’ve been trying to calibrate it on and off for about a month. This is our first reprap build. We’d finished calibrating about a week ago, but our steps per unit were way too low (18.64) and the printing movements were not very precise so we started from scratch but with our calculated steps (215 – 0.9 deg, 16 uStepping A4988, 12 toothed pulley, T 2.5) it makes horrible squealing noises and does’t move the whole time. We don’t know how to fix it. 🙁 It may be something obvious, that we missed because we never built a different printer… We tried looking for a solution elsewhere but couldn’t find it. Please help

Home with 215 steps: https://www.youtube.com/watch?v=pVThxr-VDgM

M360 with 215 steps: http://youtu.be/hjjn9h9uhK0

Home and M360 with 18.64 steps: http://youtu.be/GZ0pi1J0QPk

This is our M503 log:

echo:Steps per unit:
echo: M92 X215 Y215 Z100.00 E450.00
echo:Scaling factors:
echo: M365 X1.00 Y1.00 Z1.00
echo:Maximum feedrates (mm/s):
echo: M203 X300.00 Y300.00 Z300.00 E45.00 (it does the same thing if we lower the feedrate to 50)
echo:Maximum Acceleration (mm/s2):
echo: M201 X400 Y400 Z400 E8000
echo:Acceleration: S=acceleration, T=retract acceleration
echo: M204 S9000.00 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 X10.00 Z10.00 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

[Jaco Annandale]

Hope you dont mind me chipping in…

I had similar problems. My problem was heating on the A4988. The current was set to the right value.

It worked at the beginning and later on started squealing.

Added a small fan to the top of the stepper drives and it worked.

So check current and check heating.. Hope it helps !!

Jaco

[Quentin Harley]

215 steps are much too much… The motors are running over the max speed and just going into harmonic slip.

Check the steps per unit again. Remember that it is not actual steps per mm, but rather steps per angle. the M360 M361 calibration routine will work out the correct steps per degree for your setup.

The slipping during 18steps M360 is a concern, and you will have to find the mechanical solution to that before continuing with the calibration.

We are going to do a set of Morgan videos this weekend at a local Hackathon. It will be a guide to help kids to calibrate and use a Morgan – Adult kids included!

[Praguemorgan]

Thank you for your tips Quentin and Jaco, we will try again and hope it works.

Looking forward to seeing the videos Quentin, I think they will be very helpfull 🙂

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