Andy's approach is what I had in mind. Additionally I also made sure that I turned the outside to be concentric with the inside.
It's a very tight fit on the 14mm motor shaft. And a firm fit on the encoder shaft. And still it wobbles. So out comes the dial indicator with the encoder clamped in the mill vise. At the top of the shaft the encoder shaft wobbles by 0.0125" while just pushing on the shaft moves the indicator by 0.0005" Pushing my new coupler onto this measuring at the same shaft point but on the coupler shows 0.00125" wobble. Move and inch up into the area of the 14mm hole and that wobble is exaggerated to 0.025" Now I know why I was given that $800 encoder over 10 years ago. Obviously taken out of service because it had been damaged. So time to rethink if I want to install a flex coupling instead. This is after all just for testing. What I'm finding is the RPM indication on the servo drive will read 101RPM but the display on Axis is oscillating between 93 and 107RPM. I don't know how much of that is electrical noise from the AC Servo and how much is due to the wobble or if the motor really is bouncing around like that. Might be better to initially use the Servo Drive Encoder outputs. But then I have to wire up a 3 pair differential receiver. This will never end I think... John > -----Original Message----- > From: andy pugh [mailto:[email protected]] > Sent: June-18-21 9:50 AM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] Machining question > > On Fri, 18 Jun 2021 at 16:52, John Dammeyer <[email protected]> wrote: > > > I'm thinking the better approach would be to drill all the way through > > undersize 3/8" and then drill half way with 13mm. Then only > use the boring tool to bring the back half up to 3/8" and the front up to > 14mm. > > I would drill 8.5mm then bore all the way through to 3/8 for the fit I > wanted on the encoder shaft. > Then bore half way through to the 14mm testing the motor fit. > The point is that you can machine the 3/8 first on the accessible side > of the work, then machine half of it away. > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > � George Fitch, Atlanta Constitution Newspaper, 1912 > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
