What in the world is going on?

[Sallen1215]

Ok so after i carved a successful one in MDF 58767i then turned my sights onto cast acrylic.. as the project was proceeding i didn't watch it as close as i guess i should have because the first part carved fine however as you can see the rear of the first carve somehow got out of line but yet never moved because the project was in a carrier sled with double sided tape and press fit into the sled pocket. After i noticed what happened i stopped the project and this is what i ended up with58766 so this one i figured something odd could have happened but who knows so i stopped peeled the tack paper off the clear acrylic and started over... this time i carved the project again on a new piece of acrylic and in the same exact place it put the rear carve out of position like the next photo shows
58765is there something i am missing? here is the MPC i am using which is not altered in any way from the original 5876458764

[mtylerfl]

Hi Stephen,

It looks like you lost steps in the X-axis...sled not making soild contact 100% of the time on the Brass Tracking Roller? Turn the sled upside down and see if you can view the "teeth marks" from the brass roller...if you have a gap (smooth section) then that's where the sled is losing contact.

What's your shop temperature? Cold shop will tend to cause tracking problems, as well.