Why dose it do that ?


No matter what i do my home built machine do like the image you can see on this link http://www.geocities.com/kyllop/cnc.html

When I want to draw a square the x axis drive fine, the y axis drive fine BUT
when it comes to the last drive on the y axis it stop before the end.
I use mach3
I have try to change the y steppermotor but it's still the same.
i have a gear 3/1 on the x and dirrect drive on y (belt).
and have config mach3 to 600 step on x and 200 on y.

Any one know what's wrong ?

Cartesian coordinates are normally X horizontal and Y vertical.

Are you changing the Y axis settings thinking it's the X?

Either that or you have a big backlash problem.

Thanks for your reply!


Yes i am suer about x and y settings... so it must be a backslash...

I seems like it is when the Y is going to the left (away from home)....

If it is a backslash problem ...is it then normaly that it is only a problem in one direction ?

Hello Oliver,

I am having problems too and they are related to missing steps, and it is more noticeable in one dirextion than the other. It can be usually proved by slowing the stepping down greatly and see if that fixes it. If it does then may be the steppers are too small.

This may help.

Hi brian

Thanks for reply :-)

I'am afraid your are right about the missing steps... and even if i slow down the stepping, it still loosing steps ... my stepper is too small.. I have to find another.

I was having similar issues.
Turn OFF the backlash setting in Mach3 first and run it again. See if it improves. If it does, then refigure the backlash.

I also had to play with the Acceleration "ramp". I could not just hit the motor at full speed all of the sudden, the acceleration starts it out slow and accelerates it at a gradual ramp until full speed is reached. It also will slow the motors down at the same rate.

goog luck.

Hi all

I just wanna tell that my machinery is driving werry well now.

The reason it was lusing steps was my mess :frown: . As i write in the first tread I use belt, and i found out that the toothed wheel on the stepper motor did not macth the tooth on the belt.
When it draw the y axis against the motor it did well, but... when it push it away it loosing up the belt and then the motor could make some step with out drive the belt... It's a littel hard to explain hope you understand whar i mean.

I will just post it so that other with a similar problem can check out if they have make the same mistake as i did.

And thank you to all of you who had use there time to help me. I did learn a lot about backslash ... :o

Oliver