Retrofitting a 1986 Maho MH400E

Bob, that looks like an excellent score. That K&O looks very similar to my friends TOS BN-102 , which replaced the Clarkson he sold to me. T&C grinders are an excellent time waster. You can produce extremely accurate swarf with them, so small it looks like dust.

Unfortunately the slotting head and overarm have no tooling. I haven't got them home yet, as a relative of my wife lives two blocks from the seller in Tirol, and picked it up for me. His daughter studies in Vienna, so he will deliver it to me when he next comes this way. Saves me eight hours of driving.

I have a little taiwanese made 6" rotary table, and have visions of a CNC rotary table for the MAHO, but so far my six pack of self medication have kept the visions under control. I like the way you through out that little tidbit about a magical Müllernick rotary table for me to now obsessively comb the internet for

I say Andy Pugh's Holbrook blog thread (excellent work) and the video of the cycloidal rotary table design, but didn't know it had been made.
Mark

I was also thinking that you only really need the A axis on a CNC mill. I like the use of a harmonic drive by Brainright:


But you have taken that to a new level. With D1-4 interface...respect! How did you guage the nose taper? The ISO 702-2 standard for that taper results in a +/- tolerance of under a 0.01mm.

Did you finish that project? The Blog ends with you contemplating the motor and LinuxCNC integration.
Mark

Yesterday I finished wiring up the buttons. Ended up with a bit of a ratsnest in the middle, and still need to test that all the circuits are correct.



Next step is installing and wiring the two PEC-15 encoders on the user module, which will be Feedoverride, and maybe spindle speed override, or rapid override. I am pretty sceptical of implementing speed override, as having the machine pause, and change gear in the middle of a cut sounds like a recipe for scrap to me.
Mark

I would love to see some current videos of your lathe in use Andy. You made an incredible job of it, but like mostretrofit's, once it is up in running, the audiance doesn't lose interest.

Is spindle speed override used to compensate for too conservative assumptions in the CAM tool path generation, or more used to alter frequencies to prevent chatterdue to harmonics?

Mark

Considering I designed it, this control panel is going together quite well.


Normally by now I would have discovered that assembly requires a cyclotron to provide the strong magnetic field to levitate the critical screw while six, highly dextrous, infant hands similtaneously assembled everything else around it. Hope I am not dooming myself with premature optimism.
Mark

Mark Thank you for more Maho progress reports. The control panel seems to be in the final build stage .
The You-Tube video I was thinking about ( Generative gear cutting with a very simple tool (on a CNC with EMC2) ) started with a Walter T&C to grind a gear cutting tool and also showed Mr. Mueller using his reworked rotary axis. As I remember it , his rotary axis rework involved changing the bearings plus adding a encoder ( Heidenhain ROD 270 ? ) and a servo motor. The ROD 270 encoder was used by Maho on their manual and cnc rotary tables and they claimed the B axis resolution to be .001 Deg. I have seen MH400x machines having a cnc B axis rotary table vers a straight fixed table and thought you might keep a eye out for a rotary table.
Did read about Andy Pugh building his rotary axis and also his like for resolvers vers digital encoders. My thought is, if making a rotary axis now then what Andy has done could be less time and money for at least equal results . Can a resolver do .001Deg resolution ?
Mr Mueller had a second gear video ( no Walter T&C ) showing him making spiral gears ( Generative gear cutting with a less simple tool ). Mr Mueller may be back on You-Tube again! Yeah !

All right --break time is over - get back to the Retrofitting an more progress reports:
Bob