Home made encoder questions
05 Sep 2019 17:48 #144255
by Scot
Replied by Scot on topic Home made encoder questions
Is there any chance I can get a higher res photo of this so I can compare the rings of the slits?
Thanks in advance. This really helps me understand my issues.
Scot
Thanks in advance. This really helps me understand my issues.
Scot
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05 Sep 2019 18:34 - 05 Sep 2019 18:39 #144260
by Dinuka_Shehan
Replied by Dinuka_Shehan on topic Home made encoder questions
It can give you Phase Z
I cannot say it clearly.slight change in the second optocoupler will give you phase Z.halscope can use to tune it.
I am currently using alien english.I have the idea but cannot translate it english.you may not understand it.so
Moderators will helo you in this case.
I cannot say it clearly.slight change in the second optocoupler will give you phase Z.halscope can use to tune it.
I am currently using alien english.I have the idea but cannot translate it english.you may not understand it.so
Moderators will helo you in this case.
Last edit: 05 Sep 2019 18:39 by Dinuka_Shehan.
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05 Sep 2019 18:37 #144261
by pl7i92
Replied by pl7i92 on topic Home made encoder questions
its a grayscale disk so just google for image
but you may want something that fits your spindle / RPM / BOB / electronics
but you may want something that fits your spindle / RPM / BOB / electronics
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05 Sep 2019 18:40 #144263
by Dinuka_Shehan
Replied by Dinuka_Shehan on topic Home made encoder questions
Correction there.i'm mentioned phase z there not phase b.sorry
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05 Sep 2019 23:30 #144288
by andypugh
Replied by andypugh on topic Home made encoder questions
I think this is all being over-complicated.
Just use plain slots in the disc. Then make one of them longer, for the index detector.
Then all you need is three fork-type detectors, possibly one a little deeper than the others for the index.
Arrange the A and B so that when A is exactly in the middle of a slot B is exactly on an edge. (not, as I once did, with B exactly between slots. 180 degree quadrature does not work at all)
And it is probably easier to get the disc laser cut. If you want a very fine slor spacing then the chaps who make solder stencils for PCB manufacturing can do very fine work:
photos.app.goo.gl/9eGSUs1yxW9AWuWF7
Those are about 50mm bore.
Just use plain slots in the disc. Then make one of them longer, for the index detector.
Then all you need is three fork-type detectors, possibly one a little deeper than the others for the index.
Arrange the A and B so that when A is exactly in the middle of a slot B is exactly on an edge. (not, as I once did, with B exactly between slots. 180 degree quadrature does not work at all)
And it is probably easier to get the disc laser cut. If you want a very fine slor spacing then the chaps who make solder stencils for PCB manufacturing can do very fine work:
photos.app.goo.gl/9eGSUs1yxW9AWuWF7
Those are about 50mm bore.
The following user(s) said Thank You: Dinuka_Shehan
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06 Sep 2019 07:03 #144330
by Scot
Replied by Scot on topic Home made encoder questions
"Just use plain slots in the disc. Then make one of them longer, for the index detector."
That seems pretty simple. Evenly spaced slots with one longer toward the center is what I'm imagining. Is that what you meant?
"Then all you need is three fork-type detectors, possibly one a little deeper than the others for the index."
These are off the shelf parts? If the parts are available, I'm sure I can secure everything and wire it in.
Arrange the A and B so that when A is exactly in the middle of a slot B is exactly on an edge.
Now this is where I'm confused. When you're saying arrange A and B, are you talking about placing the detectors? I've never worked with these parts, so I'm unsure of exactly what you mean. Do they have aligning marks on them?
Thanks though. It's very helpful and it's painting a much more clear picture in my head.
As for the pictures you shared. Those are some you've made? They don't seem to match the description I'm imagining, though.
That seems pretty simple. Evenly spaced slots with one longer toward the center is what I'm imagining. Is that what you meant?
"Then all you need is three fork-type detectors, possibly one a little deeper than the others for the index."
These are off the shelf parts? If the parts are available, I'm sure I can secure everything and wire it in.
Arrange the A and B so that when A is exactly in the middle of a slot B is exactly on an edge.
Now this is where I'm confused. When you're saying arrange A and B, are you talking about placing the detectors? I've never worked with these parts, so I'm unsure of exactly what you mean. Do they have aligning marks on them?
Thanks though. It's very helpful and it's painting a much more clear picture in my head.
As for the pictures you shared. Those are some you've made? They don't seem to match the description I'm imagining, though.
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06 Sep 2019 07:19 - 06 Sep 2019 07:22 #144331
by Dinuka_Shehan
Last edit: 06 Sep 2019 07:22 by Dinuka_Shehan.
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06 Sep 2019 07:23 #144332
by Dinuka_Shehan
Replied by Dinuka_Shehan on topic Home made encoder questions
This will give you some idea
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06 Sep 2019 09:29 #144352
by andypugh
Replied by andypugh on topic Home made encoder questions
Yes.That seems pretty simple. Evenly spaced slots with one longer toward the center is what I'm imagining. Is that what you meant?
www.mouser.co.uk/Optoelectronics/Optical-Switches/_/N-abuscThese are off the shelf parts? If the parts are available, I'm sure I can secure everything and wire it in.
Yes. If you buy ones with slotted screw mounting holes then you can adjust the phase using halscope to monitor it.Now this is where I'm confused. When you're saying arrange A and B, are you talking about placing the detectors?
Those were for a miniature reflective sensor ( uk.rs-online.com/web/p/photodetector-amplifiers/1783221/ ) , and were not a great success. I would not suggest using reflective sensors for that reason.As for the pictures you shared. Those are some you've made? They don't seem to match the description I'm imagining, though.
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10 Feb 2020 01:52 #156926
by MarkD2
Replied by MarkD2 on topic Home made encoder questions
You can make a simple quadrature encoder with 3 detectors A and B offset half the distance between the slots and the index offset inwards to pickup a single longer slot. I have made similar using optical end stops for detectors.
I used drilled holes but slots are more forgiving.
MarkD
I used drilled holes but slots are more forgiving.
MarkD
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