Hi I had a problem the other day in which I thought I was losing steps in a canned drilling cycle and this was the first time I had run a canned drilling cycle. I came on here and asked for advice in that in the canned cycle I could not use CV mode only Exact Stop and I thought this was the reason I was losing position. Graham Waterworth helped me out with some example code for a subroutine, I wrote the code “Very Similar In The Amount of Moves In The Canned Cycle” and lo and behold I got the same sort of error.
I then just tried to test the axis and not scrap any more metal.
I then changed my code to move Z up then down by 60mm in a subroutine 60 times I ran the code and got an error of +0.1359mm
I then thought that my motor settings were incorrect “My Motors Are Running At Only Half Speed” I slowed it down some more and reran the code same result.
I then changed the acceleration value from 300mm per min to 150mm per min and ran the code again I got an error of +0.1283mm
I then changed the acceleration value to 75mm per min and again ran the code this time I got an error of +0.1308mm
I the came to the conclusion that there was something wrong with the mechanics of the Z axis so I was about to start redesigning the Z axis when I thought I would try the Y axis
It should be noted that I use 795 steps per rev on this axis and 400 on the Y axis
I changed the code to suit the Y axis and ran the code starting from Zero to -60mm
This time I got an error of -0.2585mm
Then I changed the code to run from Zero to +60mm I got an error of -0.2575mm
I then changed the code to run from +30mm to –30mm I got an error of -0.2550mm
My conclusion now was that there is nothing mechanically wrong with my machine and that I was not losing steps as the results were pretty much the same except one axis was losing and one was gaining I then checked the motor direction, one is reversed compared to the other and that the fact that one axis error is double the other axis is down to the steps per rev being double in these two axis and it just can’t be a coincidence.
My motors are configured as
Dir Low Active X
Step Low Active X
The Drivers are from Motion Control Products, which are very popular and highly thought of in the UK model MDS980
So is this a bug, I am using version Mach3 2.60 by the way
Here is the last version I ran on the Y axis
Starting with my dial indicator nearest to me at Zero on the dial the Y DRO reading +30 I then run the code “Thanks Graham for the help”
F100
G90
G1 Y28
Z15 F1000
M98 P123 L50
Y28
Z0
M30
O123
Y-30
Y30
M99
If someone also using 2.60 could run that code using a driver other than the one i am using say a Gecko and check the results.
Or maybe someone can tell me another reason i am getting this error, i am all ears.
Phil_H
Guest
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