Error in calibration of triangular kinamatics

Troubleshooting
1

Hey everyone
I have built my Maslow CNC using the roller chain of 10 mm pitch and triangular linkage of 345mm.
After performing the triangular calibration test
It shows no error in X-axis but Y-axis is very off

For test of 100X100mm
X reaches 100 but Y axis only reach to 90mm only, I’ve tried it to many times but results are same.
After putting values from triangular cutting test
The machine opt chain correction value of 444.738 and linkage radius to 251mm

Please help

Regards
Vikram Singh Rana
IIT KANPUR INDIA. (Manchester of east )

1 Like
2

Can you post the contents from your groundcontrol.ini file?

3

Do you feel good that the linkage kit is working correctly? If you rotate the sled in place does the router bit move at all?

4

Router bit is absolutely on center.
Linkages are built of aluminum by water jet cutting.
After calibration cutting test my linkage radius change somehow

5

That seems normal, the calibration process uses the measurements you enter to adjust the linkage radius. How accurate do you think the measurement between the motors is?

6

1~2mm difference

7

The value between motors shows 3001 after pull chain measurements

8

A change from 345 mm rotation radius to 251 mm suggests something is misconfigured. You said the chain has a pitch of 10mm… did you adjust the chain pitch in settings? Also, is it a 10-tooth sprocket or something else that you are using? Anything else different (motors, gear ratios, etc.)?

9

I am using the original Maslow motors.
Currently I am using 10 teeth sprocket with 10mm pitch

10

what is the “machine opt chain correction value” of 444.738? If this is the chain sag correction value, something is way off.

1 Like
11

groundcontrol.ini (1.4 KB)

12

This is my GroundControl.ini file
please have a look

13

After calibration cut, These are my values

Screenshot%20(13)
Screenshot (13).png1366×768 70.7 KB

14

A chainsagcorrection factor for 316.18 (this from the groundcontrol.ini file)… suggest your sled weighs a ton or something went wrong during calibration. Do you recall the measurements you entered for the cuts?

15

i don’t know whats going wrong

16

I suspect we’ll find its a simple answer.

17

From cut 1 to 2 = 1874
from 3 to 4 = 1834
from work space to cut 5= 328

18

my current correction factor is 305

19

When you did the calibraiton, what was your motor spacing and what did you enter as estimates for rotational radius and height of motors?

Also, have you run the calibration only once? You can go Actions->Advanced->Run Triangular Test Cut Pattern to refine your measurements.

20

The motoroffsety = 270.9 is very high. Can you confirm that that is hand measured the top of the sheet to motor height?