CNC Build - TEP milling machine conversion

[craynerd]

First job was to strip the electronics completely from it. I will be using a TB6560 3 axis driver. I`ve heard nothing but BAD things about these, but I have one anyway and it`ll certainly get me going if I can avoid blowing it up.
I wanted to flip the X axis and although replacing the entire side piece would have been ideal, I couldn`t afford it and had some pieces suitable in stock. I raised the sides and used a plate to join them. It may need some supports bridging the sides later on.
After flipping the X, I could then mount a Z axis. I made the Z axis from a small leadscrew someone kindly gave me and the slides are olite 8mm ID bushes on 8mm silver steel rod slides. The rest is just plate bolted together. There is a problem in that I`ve used a flexible coupling but I haven`t "trapped" the leadscrew. This means that the Z axis compresses on the flexible coupling and moves the relative position of the axis - not good!! This is easy to correct but I haven`t done it yet.
Once i had the X flipped and raised and the Z built, I couldn`t help try it out... it is running of only 12v at the time and the noise from these small motors is horrific, I think the TB6560 is also to blame but since then I`ve jumped upto 24v and the noise is quieter.



At this point, the mill went back to its owner while we negotiated price. Other than electronics that we both agreed wouldn`t be needed, it was all replaced to original, thankfully, if he had seen the work I`d put into it I expect the price would have gone up!
Further updates to come: Now running on 24v from two ATX supplies in series, spindle connected, first door sign engraving done...all good fun! Issues: still not sorted the z axis flexible coupling issue. Is the Z axis height too big. Flex is the spindle.

[craynerd]

The spindle is taken from Blackburn Marks advice on a brushless DC motor. Using a ER16 chuck with a 8mm shaft and direct replacement adding a bearing house:

camera phone shot.


Up and running, intial tests:

[craynerd]

During the last week I`ve stripped the machine to do some mods and in the last few days got it back together. However, I just can`t get my head around the fact that the movement is well out of sync! Just a simple example, say I draw two ovals concentric to one another, they will end up overlapping and even with little flats on them instead of nice curves!

The wierd thing is, I get the same results on both Mach3 and EMC2... so either I`ve got a setting wrong in the software on both or something is wrong with the TB6560 driver?

I`m sure it was working OK just last week and so after nearly a full day trying to correct it today, any thoughts or suggestions would be helpful...I`m totally out of ideas!

Chris