Retrofitting a 1986 Maho MH400E

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

I had another look at the MuellerNick video, and see what you mean. Did you notoice that Nick posted a video last week? He has been absent from the internet for a few years, but the video is a teaser of what looks like a new workshop.

I think Andy's solution with the harmonic drive has got to be the better approach. However, as tempting as it would be to get started on a fourth axis, I am going to be strong and continue to work on my two axis MAHO, hopefully on day fixing the vertical encoder to make it a three axis machine.

Although I was counting on Bob for quality assurance, it turns out he was napping on the job, day dreaming about rotary axis, and failed to notice that I only wired one side of a switch...

So I had to fix that.

Then started mounting the two PEC-16 rotary encoders.




These ones have the push button function which will be set up to reset the feed and jog overrides back to 100% and a set standard respectively. Luckily there were two spare nodes on the 5X5 matrix_keyboard, so I can wire those buttons in there.


I'll wire the encoder signals to the 7i77 with a separate CAT5 cable.

Need to go to Conrad and get some connectors, and knobs.
Mark

J Green wrote: Can a resolver do .001Deg resolution ?

Not directly.
www.tamagawa-seiki.com/products/resolver...olver-fa-solver.html
Shows an error of between 7 and 15 minutes of arc, that is 0.25 degrees.
But if mounted to a 100:1 harmonic drive that is 0.0025 degrees.

It is much easier to make an incremental encoder accurate and linear, and quite hard to make a resolver linear. (which is why they are expensive). Typically a resolver (being analogue) will have worse linearity/accuracy but better resolution than an encoder.

My Harmonic drive 4th axis actually has an encoder.

Yesterday I wired up the Encoders. I'll recycle the exisiting 21x 0.14mm² cable which connected the Phillips keyboard, and put two connectors on this end. Bad planning on my mark, as I could have done it with a single dSub 25.



Mark

I'm on vacation, but a friend who is a programmer is helping with the gearbox control COMP, and needs an explanation if the direction reverse pin of the MAHO's gearbox control so I'll upload it here and link it to the GITHUB for his COMP.



We are trying to understand Dominik's gearbox comp, and create one which is well commented and easier to support. For this Jin has created a GIT .

Mark