Hi Roland,
I haven’t finished the build yet. Ive had some other problems to content with lately and was also waiting for some parts to arrive. Ive made the arms from 25 x 5 stainless as I had it lying around. They are quite heavy, so I may replace with 25 x6 ali. I’ve drilled the holes on my mill with digital readouts so they are within 0.01mm. I ordered some 6mm ball thrust bearings, that took forever and only just arrived on Friday. Choice for ball bearings over needle roller was the balls have a groove in the washers to run in, so I figured they would stay truer . Ive installed them in all the pivot points and it has come up very ridgid. I will have to add one more bearing to the top of each of the 2 centre fix points under the nuts as the movement is undoing them. They are sitting on standoffs about 75mm long hopefully to keep the balance point right.
The main frame of the sled is steel so all very ridgid still have to add the lower weights which will probably be steel also. There will also be short pivot links to attach the chains to so all the arm holes stayed in the same line.
Unfortunately the supplied z axis motor mount brackets are not ridgid enough, so I have new stronger ones of those to finish making. As soon as I can finish the build, which unfortunately will probably be a couple of weeks away, I will post results.
