I need some help.

[tankdoc]

Hey there.
I opened this issue to get some help from the program developer.
To make a large SCARA 3d printer, I used your firmware.
this firmware is good to run, however, I have 2 problems.
As first, the calibration doesn't work.
when I excute the calibration, the wrong arm length or 'NAN' appears.
this first problem looks solved when elder student in my lab put different length.
Next, second problem is : printing.
When we print some model, second layer prints so slowly.
Me and everybody in my lab are working on, however, the problem cannot figured out.
If you still there, please give me some hand.
Thanks.

[wangsamas]

Hi,

I don't know what is NAN, maybe you enter a wrong parameter.
About the slow motion, i have not solve that one too. Maybe because the calculation from cartesian to scara coordinate is too heavy for the microcontroller.

I am thinking only 2 solutions for this problem. One is remove some unnecessary codes, second is use better microcontroller

[tankdoc]

Ok, i will try change arduino mega to due and try again.
And if you possible, can you show how to do calibration?
I'm sure about my calibration method is wrong.
Or, if you have video, share the link please.
Thanks.

[wangsamas]

You can find calibration guide txt in this github repo.
I'm using finding radius of a circle using 3 points method. Rotate the angles and mark the points on a paper on the printbed.

But this method is also hard to get precise result. The best way is to measure them manually, trial & error.

Please inform me the arduino due result.

[tankdoc]

Thanks for quick replying!
Me and my elder master student are trying to re-calibrate the coordinate.
and the arduino due change was......
well..........
I think it cannot be done in few days.
I get some information from the reprap forum, however, that modification was for marlin.
I assume that wangsamas firmware is based on repetier firmware, right?
so.......
that will take some time for me.
Also, i share the link to everyone can try it.
The link is :
https://reprap.org/forum/read.php?219,479626