Design Discussion: High Performance CNC Spindle

Measuring tool offsets offline with BT30 is tricky too.
Haven't tried it yet, but I'm not so sure about that. I think I'll turn a chunk of steel to have a BT30 ID taper and face both ends. This goes on the surface plate with the socket taper facing up.

Stick a tool holder in the spindle and get the difference between the spindle face and the holder tip. Then put the holder in the socket on the surface plate. The difference in the length betwen your socket face and the tip is the other value.

The difference between values is the offset you apply when you measure all other tools. Zero on the socket face, measure the length of the tool, and add/subtract the offset.

Or you could face the socket incrementally until it measures exactly the same as your spindle. Now you don't have to worry if your socket/fixture taper is perfect - just as long as a tool/holder resting in it on the plate is the same length as when its installed in the spindle.

At this point I am still leaning toward BT30 because I think the performance will be better and I like the wide range of tooling available. Being able to share tooling with future machines is also a plus in my mind.

This, plus no pull-out. Even with as few paying jobs as I get, I can buy a lot of tool holders if I scrap a part from pull-out. I don't want to have to baby-sit the machine and feed-hold the instant I hear chatter.

TTS works great and is cheap. I've pushed it pretty hard with no issues - but the minute there is some squealing or chatter I get some pull-out even with my drawbar torqued well above the Tormach recommendations (plus clean taper, fresh Bellevilles, and light lube on the sliding surfaces).
 
Franken motor experiment successful!

That's seriously awesome! Great work. Really opens a lot of doors. As a motion control guy, I've watched how all the companies take really drastic efforts to make their motor to drive interface proprietary - even on "open" networks. This circumvents that.
 
It appears that the next hurdle in the 'Ralph Hijacks This Thread" saga is that the Frankenservo has a strange 18mm stepped shaft.

A QD bushing to fit 18mm doesn't exist on this planet. Mount 14mm QD bush lightly snug in pulley, pulley in the 4-jaw, indicate the taper and have a go?
 
We've sort of continued the conversation on the other thread. Due to a number of delays, I'm just getting back to sorting out my spindle motor... nothing set in stone quite yet.
 
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