Retrofitting a 1986 Maho MH400E

This matrix keyboard didn't come out last time.

Thanks a lot Mark, that clears things up for me! Yes, I'm using your schematics so that all the same wires are connected to the same terminals. Have you posted your entire hal config in this thread somewhere? It's a very good idea to copy the relay portion.

Regarding the EXE, mine also had separate circuits for each axis. I'd never spot a fault in the schematics!

Originally, the Philips control displayed all the letters on the screen and you'd choose the one you wanted for your code. Then, the control progressively limited your input based on previous choices (e.g. if you started a pocket cycle, the control would require you to enter all the relevant parameters and the other letters would disappear; I thought it was an elegant, if somewhat cumbersome solution to not having a fully-featured keyboard). One of the best things about this retrofit is that once it gets going, I can shamelessly copy programs directly from my workshop PC with Fusion 360, so there'd be very little manual programming (for a few months at least, probably). I guess it's also possible to use a keyboard in addition to the panel, or are they mutuall exclusive? If so, I have to set up Linux to automatically log in and start LinuxCNC, which I haven't done yet.

The plates from the Philips case limit the footprint of the new parts in comparison to DIN rail mounting due to the vertical orientation, but they're not really all that stable. Without the support of the entire frame of the case, the individual plates are kind of wobbly.

I didn't wnt to send the whole HAL and confuse you, but you have made great progress in the last week. I'll copy the HAL from the MAHO and post it.

Yu are right that the phillips keyboard and a normal keyboard are not mutually exclusive. I use on of the little logitech blue tooth keyboards with a build in mousepad when I need more than just the onscreen touch keyboard. Works very well. WHen setting up matrix-kb, you have to be careful to copy the "_" verse "-" in the HAL. There is one place where it has to be an underscore, but then that turns into dashes in the pins (or was it vice versa).

Yesterday I took a shot at machining out the internal space of the pendant housing. Was too aggressive with both the Ap and Ae, and the mill took the ferry over the Jordan. 14mm HSS 2 flute. 61m/min, 0.054mm/tooth, and Ae =10 mm deep.


The next attempt is with a 16mm two flute, and since I need to go 51mm deep, I have dialed way back to 3mm per level.

Mark

Mark, try an Ap of 1/2D, with Vc=75 and fz=0,04. These would be middling parameters for a 16mm HSS-Co endmill (no coating) in my Precitool calatog, which is IMO safer than minimums for the tool (they increase wear). This all assumes you're cutting aluminum.

So on the MAHO I'd use S=1500 and F=120 with an 8mm depth of cut (Ap) for your 16mm two flute. Keep using flood coolant to get the chips out and prevent the aluminum from clogging up your endmill. Your previous endmill broke I think because you used an excessive depth of cut with an fz that was too high. Without knowing the endmill manufacturer's recommendations it's risky to assume an Ap>1/2D.

Thanks for looking at that. Yes, it is 7075-T6 aluminium. A block I bought at Boeing surplus about two decades ago.

I did one layer yesterday at Ap=3mm, Vc=1150 RPM and Fz= 170mm/min, and had a fair bit of chatter. I was already planning to search for better recommended feeds and speeds , so I just recalculated the tool path with the Ap=8, Vc=1500 and Fz=120 you recommended. I'll report back once I test it this afternoon. At the same time I'll download the HAL/INI and post it.
Mark

You could also consider plunge milling which eliminates all side forces and there should be no chatter at all. Then just do finishing pass as normal. Works great with deep pockets/slots and smaller machines.

Here is example code:

G91 G81 X0 Y0 Z-11. R5. F100
X4. L20 (Good value for side step is about 20-25% of cutters D)
G80
G90

Good example from NycCnc: