After suffering from the inadequates in our supplied HM45 mill head for too long we have had enough.
No more 70C gearboxes, enough of so much backlash in the gear chain that you get chatter in the finished product. No more to spindles where one of the bearing surfaces is the casting of the head.
(hit here for images of the guts of a spindle on one of these things)
So we took the plunge and ordered a "cheap" chinese spindle off ebay
The hope is to mainly work aluminium and any steel we want to look at ceramic cutters so as not to overload the bearings (too quickly anyway).
2.2Kw water cooled from linearmotionbearings2008
its bigger than it looks in this picture, feels like a serious bit of kit.
Then the question became how to mount it, we could hang it off the side of the existing head, but the problem there is the existing head weighs 100kg and is giving us trouble with the Z axis, putting what looks like backlash but I think is stick and slip into it.
So we figured this was a great time to try out the phenolic basalt we were looking at, its like epoxy granite but should be cheaper. Inital testing on a 50x50x800 bar indicates it has roughly the same stiffness as a solid steel bar of the same dimensions.
So the plan is to make this.
The side plates are 8mm steel, with threaded bar running through it clamping onto an aluminium adapter from the round spindle into the PB. Part of the reason for doing it this way is so we can tram the front to back angle of the finished product. We are keeping the existing slide and mounting onto it with the ring of 6 pipes with bars through them you can see at the top, this should be an improvement on the 3 bolt system (of which only 2 did anything) of the old head mount.
Keeping this also means we can still tilt or at least tram the head.
Personally I'm liking the look of the cads at least, it looks like a proper bit of kit with all the nuts and bar sticking out everywhere.
Russell is hoping to get working on the molding soon and hopefully cast one up over the xmas break. We are interested to hear any thoughts you guys have on it too so don't be afraid to chime in.
Many brains make for fewer bugs