im looking to replace the c beam x axis on my machine and am looking for some advice on length or depth of the gantry plate. are there any pro's or con's to having the gantry plate, and so z axis, extend lower than the bottom edge of the gantry? image below shows plate same depth as the x axis profile. im trying to get away from the torsional twist im seeing in my c beam and hence the new profile and plates but dont want to introduce flex by dropping the gantry plate and have the spindle lower? any advice or comments welcome. cheers
I have done something similar to what you are doing. I added a second X axis beam and made mine higher by purchasing the High Z Mod for Lead 1010 CNC. I then made custom plates for the front, sides, and the back--similar to yours. On mine, the Z axis C beam goes up and down and has a 3/8 inch aluminum plate fastened to it that the router is attached to. The total weight of the gantry with router is 37 pounds. I find that I can me much more aggressive with my cuts now, and I cut some aluminum parts for the son of a friend of mine that is in a robotics club. They needed blades for their battle bot. I was able to be a bit more aggressive with the aluminum as well. I had to use a 1/8 inch endmill due to tight radius, and it seemed to cut cleaner with less chatter than my previous version of ,my CNC (based on the OpenBuilds OX CNC Machine).
giarc thanks for the response. its interesting that you mentioned the weight. ive just put the rails into the profile and even without the the ball screw and spindle it weighs a tonne. may have to put it together and see how the steppers hold up. cheers
I am using the Openbuilds High torque Nema 23 steppers and they have no issue moving it at over 5000mm/min. That is what I set its peak at. I set my acceleration up quite a bit to speed up 3D carves. By doing that I had to lower the top speed so it would not stall. Prior to increasing acceleration, I was had the max speed at 6500mm/min.
