Morning, My workbee CNC Duet controller on screw drives is cutting 60mm square perfectly but when cutting a line of 300mm on the X axis it measures 305mm not 300mm but when cutting a 300line on the Y it is bang on. Ive checked all nuts and bolts and play in any wheels and all those are right. is it possible to edit the screw rotation measurement in the config?
not just possible but REQUIRED as a step in the normal setup of a machine (-: That is why there is a calibration wizard in OpenBuildSCONTROL software. It defaults to 100mm, but don't use that, use the longest distance you can measure on your machine.
The link below explains the theory of calibration. Openbuilds Control won't unfortunately work with your Duet controller. Do you know what version of Ooznest's firmware you are using (so I can tell you which config file to change) or which version of the Workbee you have? You can't calibrate accurately with a cut - that brings other variables into play such as backlash and tool deflection. Calibrating your cnc Alex.
Hi all, thank you for your reply. OoZnest has got back to me with these steps. I think we are all fixed after following these. Hi, For the calibration, have you followed steps similar to this: Step 1: Make sure the Y-Axis is aligned on both sides as per Step 10: 2. Testing Your WorkBee Step 2: To Test the machine's movement. Tell the machine to move a specified distance (Expected Travel), and then measure what the machine actually moved (Actual Travel). If the two numbers are different, we can adjust the steps/mm of the machine to correct it. To get the numbers for the X/Y-Axis, we recommend watching this video from 5:15 to 10:35 - To get the numbers for the Z-Axis we recommend watching this video from 17:28 to 18:33 - You should have two sets of numbers (Expected Travel & Actual Travel) for each axis. Step 3 : On WorkBee Control go to this page: WorkBee Control Overview Look at the panel 'Machine Steps/mm Calibration' Note down the Current Steps/mm in X-Axis, Y-(Left)-Axis, Y-(Right)-Axis and Z-Axis. Step 4: To calculate the New Steps/mm do the following calculation: (Current Steps/mm) * (Expected Travel) / (Actual Travel) = New Steps/mm Do this for X-Axis, Y-(Left)-Axis, Y-(Right)-Axis and Z-Axis. (You will use the same Expected Travel & Actual Travel numbers for both Y-Axis) Step 5: Enter the New Steps/mm into the input fields in the 'Machine Steps/mm Calibration' panel. Step 6: Repeat Step 2 to check the machine is now cutting accurately.
@PRW-92, that's the same advice David and I gave you EXCEPT you really can't calibrate accurately over a distance of 100 mm (you might have to use a short distance for Z). As you have a Duet controller neither Openbuilds Control nor UGS wizards will work for you, but the sums aren't difficult. PS, assuming that you are using the latest firmware from Ooznest (based on Rep-Rap Firmware V3.3) it is possible to calibrate each side of the Y axis separately, but Ooznest have unfortunately included steps/mm settings in two separate config files and the second one to run on start up overwrites the settings in the first one. Contact me by private message if you want to know how to do that. Alex.
