Retrofitting a 1986 Maho MH400E

I had this idea yesterday after reading your post Mark that I could cross-referrence the Philips machine constants I have with the relevant manual from the Heidenhain website. They bought the Philips CNC branch and still have the documentation available online. But unfortunately, I'm having trouble accessing the file list today, their website posts an error of service unavailable.

There are manuals there with instructions for installing the controller in a machine, and finding various values to be entered in the MC list when you're starting from scratch. Checking them would help a lot I assume, but the control logic of the Philips was probably different and we'd have to search for any paramters that could be relevant to a Linux installation.

Bob, I wish my MAHO was that fast. All the FP Deckels from the 1980s I've seen for sale had rapid traverse speeds around 6m/min. I always assumed that the difference was down to spindle design. Deckels also had faster spindles. I'm sure Maho also made mills with various designs, but both Mark and I ended up with high torque models, probably designed for cutting hard steels with medium sized tools. They're somewhere between a 50 taper machine and a more standard toolroom mill with direct spindle speed control.

It's actually a blessing to get these nowadays I think, because it's super easy and rather cheap to attach a HF spindle for fast light cuts, while retaining the torque for fast material removal with larger tools. And Linux allows you to configure them beautifully, which wouldn't be a cheap option on a new industrial controller.

BTW, when I had my LCD monitor on the electric cabinet next to my VFD, the display would go completely haywire when the VFD was on. I had initially made some tentative plans to install the unit in the cabinet, but seeing the electrical noise it generates and having very little faith in the shielding of my wiring and components in the cabinet, I've decided against it. The VFD will stay outside, and I'll just make some holes, or use the existing holes to get the cables inside to connect the thing to LinuxCNC. I might make some kind of stand for it, so that it doesn't sit on its cables anymore and is protected from stray chips and oil.

Thanks for posting your acceleration values. They are nearly twice as high as mine, so I'll take another shot at tuning and see if I can get close.

the control logic of the Philips was probably different

Regardless what the internal motion control algorithms of the Phillips 432 looked like, the external control loop was the +/-10V velocity command to the Indramat, and position feedback from the LS403 scales. Whatever performance the Phillips could command, LinuxCNC must be able to as well.
Mark

If anybody can check from their computer whether their website is available, it's heidenhain.com. Then you have to click on documentation, then mauals and finally O.M.A. controls. I don't know why it won't work for me, it used to in the past.

I'm attaching a picture of my old machine constants printout which has the software version of the controller listed at the start. Checking these against the manual is my best idea for getting a glimpse into what the engineers that made these machines thought about tuning servo drives.

A tapmatic 70X came up locally for only €99, so I took a chance on it sight unseen





When it arrived I was pleasantly surprised that it had a J441 collet in it.



This is a Swiss made one, with a B18 taper in it. I'll need to buy or make a BT40 - B18 shank, and the wedges for pulling the #3 morse shank currently fitted. It seems to work in that it drives forward with axial load on the output, and then reverses to a higher RPM when you pull on it. I have nothing with a MT3 taper to test it, as the Boleys tailstock is MT#2.
Mark

It comes up "This service is unavailable" for me as well.

That kind of BT40 to B18 shank sounds like a job for This Old Tony.

It's a shame the service is currently down, let's hope it becomes available again soon. I downloaded documentation from there some months ago but I didn't get the right controller version and the constants are completely different between versions.

There's also Anders' smoregrava file with a different version of the controller than mine. But I think Heidenhain has them all, or at least they have a lot.

I'm also having a CNC service tech come over to look at the alignments on my machine next week (if he actually makes the time, that's not a given over here). He was interested to hear about my retrofit on the phone and he's experienced with industrial controllers so I can ask him what he thinks about my servo setup. Experts like to be critical and educational at the same time when they see the work of a noob, also I might pay him to do a better job and post the results here. I'm sure someone who's serviced dozens of machines would have a very good idea of how a tool room mill should be expected to work.