I got some more work done on the CNC, realizing I needed even more holes to be able to easily clamping pieces down. I have tapped over 600 holes of M10, sigh...
Some basic info. 3x100W servo motors, 2.2kW Spindle, 18000rpm, 600hz "high torque" model. About 950mm*950mm*200mm of XYZ travel. Designed and built by me
Initial design/model rendered
The router chassis have been milled and faced so the aluminum sheet that lays on it will lay as flat as possible
Both sides milled in the same mill without letting the setting gobetween the passes.
Motor mounting point
Faced distances for the aluminium table
Holes for the ball screw. We ended up changing this. Going for two ball screws with a drive line between them.
Milling the sides
Milling slots for linear guides on the X-axis
Linear guides mounted.
X-axis servo motor seat
Most of the frame done! We ended up changing the arms for 40mm steel thickness because of issues with vibration. Turns out that was not the issue but the machine did get more sturdy because of it.
Faceing the Z-axis plates
Faced and milled Z gantry. These are also grinded in this picture so they are very even in thickness.
Testing the servos and controller system. Testing everything in Mach3
Testmounted spindle and servos. An 2.2kW, 18000 rpm 600hz "high torque" spindle.
Realized that this was a bit messy so I ended up getting a box.
First time together with the protective housings on. You can also see the bigger arms here. 40mm thick steel.
Testing for the first time! Not a very good run. Z-axis lost steps like crazy. After several days I finally found the problem. The VFD was giving noise to the Z-stepper motor. I had to get shielded cables and finally ended up putting the VFD on the X-axis to reduce the amount of meters the cables had to go along each other.
Made a desk for the computer
New shielded cables (orange) and some very much needed paint! Time to assemble everything again...
The box I built to house all the different cables. The VFD on the right is not there now (moved to the X-axis). Also fuses and added safety measurements was added.
I knew I had to take everything apart so I did not spend that much time fixing this right here.
Everything back together after paint, new cables etc!
Making a slot for cooling fluid to escape
Had to let go of the table and use clamps from underneath the table to hold it down since I did not have the range to do the top slot otherwise...
Super pleased at this moment. ap:3mm ae:10 feed:1000mm/m and about 7000 rpm if I remember correctly. Further than this would probably be pushing it.
Really need to design a dust shoe to take some of these chips from the beginning.
Hole for the fluid to escape. Will be making a sieve that fits here.
Very much pleased with the quality of the cut
I was going to start with my projects here. But I realized that I needed to make more holes for clamping and also some kind of sacrificial board in a material that can handle the cutting fluid.
Lots and lots of chips, and they are going everywhere in a 2m radius...
Chamfers for tapping. Will be faceing this whole surface 0.5mm so don't mind that the chamfer tool was too small
Run out of battery for the second time here. Doing all these M10 by "hand" was quite taxing, both for me and the power drill! A much needed break
I don't have to do all the holes but almost all of them. 18*18 rows of holes (324 holes!!!). But some was done earlier.
All done... Thank god...
Cleaned the table and was very pleased with the results!
Clamping down the sacrificial board. A 10mm sheet of aluminium that will be faced and 12mm holes will be drilled over all the M10 holes. The plan is to be able to fit 12mm solid shafts to use as guides and also as holes for M10 screws for clamping.
Spoil board all cut out! I Countersunk 12 M6 MF6S so I can face of about 6mm from the 10mm board before hitting the M6 screws. This should last me a very long time.
Really liking the finish after the cutter. I should have adjusted the feedrate of the chamfer cut a bit.
Time to get the spoil board of and face the table.
Faceing the orignal table on the router to get the surface flat. This takes out height differences on the aluminium sheet and build errors.
Faceing the 20mm Alu board. About 1200mm/min and 0.5mm ap (depth of cut)
All done! Although a bit dirty from the cutting fluid.
Cleaned with some alcohol!
All done! I also got some weird artifacts from the phone camera (the teal stuff)
Found out it was about 0.1mm per meter. This need to be fixed. This was at 0 deg
Even worse here, over 0.2mm (this error for over a 250mm diameter). This was at 180 deg. I adjusted the 90 and 270 deg position with a angle and moved it quite a bit and that got very close after just doing that. But it was bad before that.
Time to put some shims in. Very, very sensitive. Had to try a lot of different sizes. 2x0.08mm shims turned out to give very nice results. I am now keeping the error within 0.01mm over a circle of 250mm in diameter. Very happy with this. Took about 2 hours to fix in total. But I hope it pays of in the long run.
All four positions below 0, 90, 180 and 270 degrees.
All set, waiting for a fresh 12mm end mill and then we are go!