hello,
One thing I learned when building a delta was that the belt must be parallel with the linear movement or you get x y error on the part. I had to change were the ends of the belts connected and make the top pulley measure the same size as my drive pulley.

 

Changes in angularity translate into less movement in the travel of the truck along the extrusion. So in the middle of travel error is very small, but at the ends of travel the error is larger the closer you get to the end. When a delta printer is printing a large part all three trucks are getting very close to the bottom of the axis at various positions on the part so the effect on accuracy is all over the place.

 

SeeMeCNC forum was my initial source for figuring out why my machine was printing parts with artifacts.

 

I noticed that the V slot actuators have the same problem and I am going to print a standoff for the belt to interface the plate so that the belt is parallel over the entire length of rail. If i use a drive pulley that is larger than the idler pulley supplied then I will print an idler to match it's diameter.