Howdy folks,
I've been working the last few months on converting my G0704 to cnc. I've got most of the design complete, ordered a majority of the parts, and now starting to machine everything. My first goal is to get the machine working and them make additional improvements to it. My list of major parts for the build includes Acorn controller, 60VDC power supply, DMM servo drives, and roton ballscrews (should of looked harder).
I took the time to model the machine in CAD and boy there is hardly anything that is square or symmetric on this thing. I had to get creative to measure some of the parts that were longer than my calipers.
I made the mistake of trying to measure and model the dovetails. Did i mention there isn't anything square on this thing
Below is the final design. I initially wanted to use Clearpaths but moved away from them due my limited budget and found a great deal on some used double stack NEMA 23 Servo motors. I haven't model the head yet as its going to be a future project.
I will mention that all the motor mounts and ball screw mounts are being made out of steel as I'm going to try to have both ends of the ball screws fixed. The choice to use metal is try to match the CTE to the cast iron as i'm hoping for very little lateral movement in the ball screws and prevent it from binding up during the large temperature swings ( that's what I have in my head at least). From what I have read, this will have the most stiffness vs a floating end or unsupported end. T
The biggest issue I have at the moment is how all the mounts are attached to the saddle. I think the two screws jamming the nut against the saddle is a very poor design choice but a very go choice to assembly it easily. I don't think I have seen this before but I'm going to bolt the ball nut mounts to the saddle. This will take additional machining of the saddle, but it is well worth it in my opinion not having the jam screws loosen up or cause the ball nut mount to deform. Below is the design for the X Axis mount
Below is the Y axis mount. Again this requires more machining on the saddle and base.
I'll share more pictures of the build as it progresses. I also need to give a shout out to my new friend Lucas for the machining he has done and is doing for me!! With out his help, this project would be much more difficult to do