Lang-Elektronik motorized stage

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mintakax
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Lang-Elektronik motorized stage

#1 Post by mintakax » Thu Jan 23, 2020 1:03 am

I've just acquired a Lang-Elektronik MS 317 motorized x-y stage. I'm wondering if anyone has any experience with this ? I located the German company that made it ine the 90s , but they have since purged any info.
I have the joystick working now, but I had to fix an electronic issue and take the entire thing apart and lube it. I had no idea that the rack and piñon gearing was supported by many tiny cylindrical bearings which dribbled out unexpectedly. It took me 8 hours to re-seat them all.

Hobbyst46
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Re: Lang-Elektronik motorized stage

#2 Post by Hobbyst46 » Thu Jan 23, 2020 1:05 pm

From experience with other stages: likely the stage has two photo-cell sensor microswitches that mark the ranges of motion, X direction and Y direction respectively. It is important to install them in the exact original positions.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

mintakax
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Re: Lang-Elektronik motorized stage

#3 Post by mintakax » Thu Jan 23, 2020 6:53 pm

Hobbyst46 wrote:
Thu Jan 23, 2020 1:05 pm
From experience with other stages: likely the stage has two photo-cell sensor microswitches that mark the ranges of motion, X direction and Y direction respectively. It is important to install them in the exact original positions.
Thank you ! There are several switches like the one in the photo 1.
photo 1
photo 1
IMG_3457.jpg (154.78 KiB) Viewed 2671 times
I have no idea what they do, but I cant see anything that looks like a photo detector. I did not disassemble or move them. Photo 2 shows the controller.
photo 2
photo 2
IMG_3455.jpg (179.43 KiB) Viewed 2671 times
The stage moves when either the joystick is activated or when the start button is pressed. The start button causes continuous motion only in the x axis in the direction of the lighted button switch for that axis. I can not figure out how to get motion in the y axis using the start switch. Each of the two motors (x and y) can be mechanically isolated, but isolating the x motor only means the x motor runs but doesn't move the stage. I don't know if there is some procedure to get the y axis to function with the start button or if the y-axis part of the circuitry is broken. When I received the unit, the "downward" y axis of the joystick did not function because the switch was stuck. I fixed that and now the y axis functions fine with the joystick. The speed knob does what I assume it should, but I have no idea what the "interval" knob is supposed to do. It seems to have no effect when either the joystick or the start button is activated.

Hobbyst46
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Re: Lang-Elektronik motorized stage

#4 Post by Hobbyst46 » Thu Jan 23, 2020 7:30 pm

I am trying to guess.
The stage motion must be controlled by reference to a pre-defined "zero" starting point. A "reset" position. Possibly, pressing the start button sends it to this reference position.
If that is correct, then pressing "start " after the stage has been moved with the joystick to any arbitrary x>0 AND y>0 position should bring the stage back to the same reference position, namely to x=0, y=0.

The actual (physical) x and y coordinates of the reference point are stored within the controller. In stages that are interfaced to a computer, the reference can be re-defined.

If the several switches, as I guessed, are electronic, they send an infrared rather than a visible beam. Perhaps the receivers (sensors) are hidden within the mechanical parts.

Alternatively, perhaps these are simple contact micro-switches, that open/close a circle and thereby, create 0/1 logic that the controller detects. I would expect four switches then.

The interval: likely, the joystick moves the stage in steps, "intervals". A single rapid press of the joystick perhaps "nudges" the stage. The size of the interval per each setting of the interval knob (1..10) might be determined by installing the stage on a microscope, with a stage micrometer on top, and viewing by how much the scale marks are shifted upon operation of the joystick.

Hope these ideas/hand-waving/conjectures will help.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

MicroBob
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Re: Lang-Elektronik motorized stage

#5 Post by MicroBob » Thu Jan 23, 2020 7:39 pm

I can't help you with the repair but this is an interesting item for sure. It would be interesting to use it to shoot a batch of images that then can be stitched together.
If these are stepper motors it might be possible to exchange the complete contro box against a control board of a 3D printer.

MichaelG.
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Re: Lang-Elektronik motorized stage

#6 Post by MichaelG. » Thu Jan 23, 2020 8:18 pm

mintakax wrote:
Thu Jan 23, 2020 6:53 pm
There are several switches like the one in the photo 1. IMG_3457.jpg I have no idea what they do, but I cant see anything that looks like a photo detector.
That looks like a simple mechanical ‘microswitch’

MichaelG.
.

Edit: it may possibly be that this is the successor firm to lang-elektronik
https://www.lang.de/en/product-overview ... n-systems/
Too many 'projects'

mintakax
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Re: Lang-Elektronik motorized stage

#7 Post by mintakax » Fri Jan 24, 2020 1:20 am

Thank you Hobbyst46-- I'll experiment with your suggestions. First I have to get the y axis to respond.

mintakax
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Re: Lang-Elektronik motorized stage

#8 Post by mintakax » Fri Jan 24, 2020 1:24 am

MicroBob wrote:
Thu Jan 23, 2020 7:39 pm
I can't help you with the repair but this is an interesting item for sure. It would be interesting to use it to shoot a batch of images that then can be stitched together.
If these are stepper motors it might be possible to exchange the complete contro box against a control board of a 3D printer.
Possibly true if it can ever be restored. Right now there are sometimes large inconsistencies in the speed of travel. The motors turn the gears by friction against some worn rubber pads. I think this is where the inconsistencies originate. If so, it should be possible to replace the pads with something the same thickness, texture and compressibility. How can I tell if these are stepper motors ?

mintakax
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Re: Lang-Elektronik motorized stage

#9 Post by mintakax » Fri Jan 24, 2020 1:26 am

MichaelG. wrote:
Thu Jan 23, 2020 8:18 pm
mintakax wrote:
Thu Jan 23, 2020 6:53 pm
There are several switches like the one in the photo 1. IMG_3457.jpg I have no idea what they do, but I cant see anything that looks like a photo detector.
That looks like a simple mechanical ‘microswitch’

MichaelG.
.

Edit: it may possibly be that this is the successor firm to lang-elektronik
https://www.lang.de/en/product-overview ... n-systems/
Thanks Michael-- Yes, that is indeed the company. They were nice enough to quickly reply to my inquiry, but as I said in the OP, they have no info.

mintakax
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Re: Lang-Elektronik motorized stage

#10 Post by mintakax » Fri Jan 24, 2020 1:28 am

I should say that for my uses, the joystick works just fine. I do a lot of scanning and this makes it so much easier than reaching back and turning those knobs. I'm happy to have this and hope it can last a bit longer.

MicroBob
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Re: Lang-Elektronik motorized stage

#11 Post by MicroBob » Fri Jan 24, 2020 8:19 am

mintakax wrote:
Fri Jan 24, 2020 1:24 am
How can I tell if these are stepper motors ?
Stepper motors have 4 or more wires leading in and you can feel the poles precisely when you turn them over. While a normal motor just gets voltage and current, the stepper gets impulses to move one step further, e.g. 1,8°. So the controller is completely different. I would first rectify the mechanical issues an then see what is left to do.

Bob

MicroBob
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Re: Lang-Elektronik motorized stage

#12 Post by MicroBob » Fri Jan 24, 2020 12:58 pm

I can imagine that this stage has been sold over a microscope manufacturer. Maybe you can find information after you have found out for which microscope it was made?

mintakax
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Re: Lang-Elektronik motorized stage

#13 Post by mintakax » Fri Jan 24, 2020 5:25 pm

MicroBob wrote:
Fri Jan 24, 2020 12:58 pm
I can imagine that this stage has been sold over a microscope manufacturer. Maybe you can find information after you have found out for which microscope it was made?
Good idea, but I feel like I have exhausted all information avenues. I'm not sure where to go next. It does fit my Nikon TMD, but I don't know how specific (or universal) microscope stages are. When I say "fits", I mean the piece (yoke ? ) attached to the base of the stage is an exact match for the dovetails right below the condenser rack on the TMD frame. The whole motorized part is a separate unit that attaches to the base.
Last edited by mintakax on Fri Jan 24, 2020 5:31 pm, edited 1 time in total.

mintakax
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Re: Lang-Elektronik motorized stage

#14 Post by mintakax » Fri Jan 24, 2020 5:30 pm

Hobbyst46 wrote:
Thu Jan 23, 2020 7:30 pm
I am trying to guess.
The stage motion must be controlled by reference to a pre-defined "zero" starting point. A "reset" position. Possibly, pressing the start button sends it to this reference position.
If that is correct, then pressing "start " after the stage has been moved with the joystick to any arbitrary x>0 AND y>0 position should bring the stage back to the same reference position, namely to x=0, y=0.

The actual (physical) x and y coordinates of the reference point are stored within the controller. In stages that are interfaced to a computer, the reference can be re-defined.

If the several switches, as I guessed, are electronic, they send an infrared rather than a visible beam. Perhaps the receivers (sensors) are hidden within the mechanical parts.

Alternatively, perhaps these are simple contact micro-switches, that open/close a circle and thereby, create 0/1 logic that the controller detects. I would expect four switches then.

The interval: likely, the joystick moves the stage in steps, "intervals". A single rapid press of the joystick perhaps "nudges" the stage. The size of the interval per each setting of the interval knob (1..10) might be determined by installing the stage on a microscope, with a stage micrometer on top, and viewing by how much the scale marks are shifted upon operation of the joystick.

Hope these ideas/hand-waving/conjectures will help.
I'm not sure if the micro switches are functional or not, but for the x axis, pressing "start" just moves the stage in the direction of the lighted x axis button. It will move until it hits the end of the rack with motors still spinning or until the "stop" button is pressed. I have done several experiments with positions when starting, and no matter what, the mechanism does not stop until "stop" is pressed.

MichaelG.
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Re: Lang-Elektronik motorized stage

#15 Post by MichaelG. » Fri Jan 24, 2020 6:32 pm

mintakax wrote:
Fri Jan 24, 2020 5:30 pm
I'm not sure if the micro switches are functional or not, but for the x axis, pressing "start" just moves the stage in the direction of the lighted x axis button. It will move until it hits the end of the rack with motors still spinning or until the "stop" button is pressed. I have done several experiments with positions when starting, and no matter what, the mechanism does not stop until "stop" is pressed.
At this great distance, I can only guess ... but
it is very easy to check microswitches, IF you can isolate them.

It does seem likely that at least one of the microswitches is faulty.

How accessible are the terminals ?
and
Can you see any product identification on any of the switches ?

MichaelG.
Too many 'projects'

mintakax
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Re: Lang-Elektronik motorized stage

#16 Post by mintakax » Fri Jan 24, 2020 7:15 pm

MichaelG. wrote:
Fri Jan 24, 2020 6:32 pm
mintakax wrote:
Fri Jan 24, 2020 5:30 pm
I'm not sure if the micro switches are functional or not, but for the x axis, pressing "start" just moves the stage in the direction of the lighted x axis button. It will move until it hits the end of the rack with motors still spinning or until the "stop" button is pressed. I have done several experiments with positions when starting, and no matter what, the mechanism does not stop until "stop" is pressed.
At this great distance, I can only guess ... but
it is very easy to check microswitches, IF you can isolate them.

It does seem likely that at least one of the microswitches is faulty.

How accessible are the terminals ?
and
Can you see any product identification on any of the switches ?

MichaelG.
As always, thank you Michael ! I think at this point I'm going to leave well enough alone for a while. I bought the unit to use the joystick and that does work. When I took the stage apart to lubricate, I honestly did not think I could get it back together again. If I start pulling switches... well enough said :shock:
Maybe if I get bored down the road I'll consider tinkering some more !

Thanks everyone for your comments !

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