Hi all, First time posting here, I hope I haven't overseen anything. I will cut to the chase. I own a 1000x1000 Workbee, screw driven and with a Duet as a controller board and the latest firmware (as of December 2019). Yesterday I was working on a small box I designed in Fusion 360 (for which I have the corresponding post processor). I wanted to create a couple for inserts for a very small brass hinges and when it was done with it, I realized that the measurements were a way off, compared to the values on Fusion. I am well aware that the measurements never translate one-to-one on these hobbyist machines, but I am talking of an error of 0,70mm over a value of 20.00mm. Taking into account that the reported accuracy of the machine is from 0,05 to 0,1mm, I think 0,70 is way off... I proceeded to check the steps/mm of the motors and to my surprise I notice that the motors were not moving the same depending on the direction. For example on the X axis, with the same requested distance, the actual distance was not the same if moving to the right or moving to the left. That led me to think that I had either a problem with the motor couplers or with the backlash nuts, or with both. So today I spent some time to adjust everything a little bit: the tension of the wheels (which I left to the "default"), the couplers (which I left with the motor shaft in contact with the drive screw), I loosen the backlash nuts and tightened them again and I put some grease on the screws. After that I squared the Y axis, I rechecked the movement and, to my enjoyment, the distance was equal no matter the direction. At this point I calibrated the steps/mm and started the box from scratch again. When I finished on of the parts, I measured it and contrasted the values with the expected ones. The result are as follows (see attached picture for clarification): d1: act.= 72,70; exp. 72.00 d2: act.= 40,65; exp. 40.00 d3: act.= 60,08; exp.= 60,00 d4: act.= 24,94; exp.= 25,00 So, what I can see is that compared with the first box, the measure of interior dimensions (d3 and d4) are way more accurate and well within what I expected. The exterior dimensions, however are consistently aprox 0,70 larger than the ones in fusion. The box will be perfectly usable, but I do wonder about why some dimensions are pretty accurate and the other are consistently larger. More info: external dimensions are a contour operation in Fusion whereas internal dimensions are from a 3d adapting clearing operation (without "stock to leave" and/or contour operation as finishing). The dimensions of the endmill are accurate. Any insight in understanding this will be much appreciated. Thanks in advance!