Fehlemann Picomax 100 Retrofit

No progress in the last weeks.
Still struggling withe the glas scales and the spindle.
For the Spindle I might have found a solution in form of a 7.5 KW 8000rpm servo with driver from china. This would also solve my encoder problem for rigid tapping. And I can use the analog input from mesa for spindle load. But it's an unplanned investment.
The question is how much do I get for the old spindle motor and drive to ease the pain a bit.

anfänger wrote:

I tried to tackle the encoders today and found something odd, even with the corrected color code i can't get a signal.
then I tires to mesure with a multimeter. and all the signal were high even with no wiring present. is this normal?
thanks Patrick
 

It is not clear what you are measureing with the multimeter. You really need an oscilloscope to look at the square wave signal which should be coming out of an encoder. I made one of those €20 toy kitself osci from DSO-Shell,  and it is really handy for this stuff.

I should have an usb oscilloscope somewhere. But I last used it three relocations ago, so I have no clue where to search.
But the DSO-Shell things look quite handy.

found it totally forgot that it was also an 8 channel logic analyzer

It ha nos software which runs on ma current laptop. But maybe the linux software still runs

Still didn't take a look at the scales, but ordered a new Spindle Motor and drive. I hope I get some money for the old one. But changing that solves so much issues. But I guess it will take two months till its here.
Also found an extra set of glas scales for the column and got some good input from Andy how to use them for Z offset.
And the most important part it's getting warmer, so its more fun to spend some time in the shop

Saturday is shop day...
So I went to the shop to tackle the glas scales. But they're not working.
Checked another encoder and it works.
Oscilloscope doesn't help I get no signal. I found a data sheet for the glas scales, cable colors are correct BUT the lamps only draw 20-30 mA which is to low it should be 120 mA.
It would be odd if all three encoders would be defective. But having three wrong wired encoders would be too. Except it was on purpose.
So what now? Do encoders survive try and error by trying to find out how they are wired up?

What type of glass scales are this?

What model number of exe do you have?

If they have been in service the last 10/15 years, the bulbs might be have been exchanged to led. Then 20-30 mA would be ok.

I have no real history of this machine. It was kind of an impulse to buy it.
All ar Heidenhains
X axis LS 403 ML 1020 mm ID Nr 226 520 1K S.Nr 898292 A E5
Y axis LS 403 ML 470 mm ID Nr 226 520 OP S.Nr 1405525 B F6
Z axis ROD 456 5000 02S09-04 ID Nr 295 459 D.Nr. 14 165 553 A D5

To replace them would be a pain and the it might be cheaper to change the old DC servos to modern ones and don't use scales.

i did a short overread of the whole thread.

I can't find anything about exe boards in this thread... Could it be that you trying to connect the scales diretly to the mesa board?

This are analog scales with 11uA Output, to get a ttl signal for mesa, you need interpolation electronics like heidenhains exe boards...

This would explain a lot Yea I was trying to connect them directly.
I was assuming they were normal ttl or htl scales. cause one came with the machine, but doesn't fit (it was for the scooter table length) and it is htl.

Thanks!

Watt started as, this should be an easy retrofit, is causing way more trouble than I expected. First check at these board look like they don't come cheap. So there are three options:

Keeping the scales and using an EXE board
+ Don' need to reroute the cables - old technology still don't know if one of the scales might be faulty and still old servos

Changing the scales to ttl or htl ones
+ they will work with linuxcnc -still old servos and initially a bit more expensive

changing the servos
+ new servos with encoders glas scales still are an option - most costly and the Z-axis might get funny

since I moved the machine I am considering option 2 at the moment. And maybe sea I can get some money by selling parts of the old control. I also still have the servos and drives from the Gildemeister but have no Idea what I would get for those parts.