Magnetic Linear Encoder http://www.contraptor.org/forum/t-203008/magnetic-linear-encoder Posts in the discussion thread "Magnetic Linear Encoder" - Single Sided Magnetic Linear Encoder Board Mon, 06 Feb 2012 04:31:34 +0000 http://www.contraptor.org/forum/t-203008#post-660633 Re: Magnetic Linear Encoder http://www.contraptor.org/forum/t-203008/magnetic-linear-encoder#post-660633 Tue, 22 Dec 2009 23:06:19 +0000 Sam Maghsoodloo 417059 good point. optical wouldn't be as robust

]]> http://www.contraptor.org/forum/t-203008#post-660597 Re: Magnetic Linear Encoder http://www.contraptor.org/forum/t-203008/magnetic-linear-encoder#post-660597 Tue, 22 Dec 2009 21:29:59 +0000 ril3y 390237 So yes we could do this however you should think about what we are trying to do and on what application. If we are trying to ensure that steppers are stepping accurately by relying on the linear optical encoders we run the risk of one major flaw in this design. We are cutting material with a dremmel, router, etc throwing bits, dust and god knows what else all over the place. Including right into the linear optical sensor :)

If we rely on magnetic fields for accuracy then we dont care about dust and debris.
However I have ordered a few linear optical encoders to mess with. For non-cnc applications.. perhaps on additive fabbing. IE makerbot style.

Ril3y

]]> http://www.contraptor.org/forum/t-203008#post-660592 Re: Magnetic Linear Encoder http://www.contraptor.org/forum/t-203008/magnetic-linear-encoder#post-660592 Tue, 22 Dec 2009 21:17:22 +0000 Sam Maghsoodloo 417059 The engine would have to work on aluminum though. You'd probably have to put a strip of tape or something on a strategic position for each axis. Probably would work.

]]> http://www.contraptor.org/forum/t-203008#post-660590 Re: Magnetic Linear Encoder http://www.contraptor.org/forum/t-203008/magnetic-linear-encoder#post-660590 Tue, 22 Dec 2009 21:15:05 +0000 Sam Maghsoodloo 417059 Let me bounce an idea off of you.
Could you gut an optical (or laser) mouse for its optical engine, and use that for tracking on the linear motion components? I'm sure it wouldn't be too hard to interface the mouse component with an arduino.
I vaguely remember something I read a few years ago about using optical mouse engines on a roomba or some robot to track its own movement.

]]> http://www.contraptor.org/forum/t-203008#post-660577 Re: Magnetic Linear Encoder http://www.contraptor.org/forum/t-203008/magnetic-linear-encoder#post-660577 Tue, 22 Dec 2009 20:52:34 +0000 ril3y 390237 I have another magnetic encoder I ordered to do some stuff with rotation. But this one uses magnetic strips (multipole). Here is an attempt at me creating my own multipole strip very cheaply with really strong mini magents.
4204933521_cd0ea9c5c0.jpg
Writeup Here

However I have not tested to see how high res of pulses this provides as it was late when I finished. You can see the manufacturer's high res magnetic strip i got from there on this link:
http://blog.synthetos.com/initial-linear-encoder-results/

I will post more when I get some initial results.

Ril3y

]]> http://www.contraptor.org/forum/t-203008#post-660566 Re: Magnetic Linear Encoder http://www.contraptor.org/forum/t-203008/magnetic-linear-encoder#post-660566 Tue, 22 Dec 2009 20:27:07 +0000 Albanetc 381022 Basically magnetic strip along the axes

]]> http://www.contraptor.org/forum/t-203008#post-660563 Re: Magnetic Linear Encoder http://www.contraptor.org/forum/t-203008/magnetic-linear-encoder#post-660563 Tue, 22 Dec 2009 20:23:47 +0000 Sam Maghsoodloo 417059 Or would this be attached to the motor and monitor the internal rotation?

]]> http://www.contraptor.org/forum/t-203008#post-657016 Re: Magnetic Linear Encoder http://www.contraptor.org/forum/t-203008/magnetic-linear-encoder#post-657016 Thu, 17 Dec 2009 00:12:15 +0000 Sam Maghsoodloo 417059 Sweet. So would you need to make a strip of magnets along the axes and setup the sensor on the linear motion parts?

]]> http://www.contraptor.org/forum/t-203008#post-656886 Re: Magnetic Linear Encoder http://www.contraptor.org/forum/t-203008/magnetic-linear-encoder#post-656886 Wed, 16 Dec 2009 21:33:15 +0000 ril3y 390237 So if you watch this super cool video it would explain :)
http://www.flickr.com/photos/31697990@N00/4170462649/in/set-72157622690487871/
But there are 4 wires. Ground, VCC, and then your 2 digital read signals. I will post some more info when I create it. For now it was more to see if it could be done. I have been a bit side tracked on some real life "work".

So until then I think the video will explain it. If not let me know.

Riley

]]> http://www.contraptor.org/forum/t-203008#post-656873 Re: Magnetic Linear Encoder http://www.contraptor.org/forum/t-203008/magnetic-linear-encoder#post-656873 Wed, 16 Dec 2009 21:20:09 +0000 Sam Maghsoodloo 417059 So where would this device take the reading?

]]> http://www.contraptor.org/forum/t-203008#post-651968 Magnetic Linear Encoder http://www.contraptor.org/forum/t-203008/magnetic-linear-encoder#post-651968 Wed, 09 Dec 2009 14:26:17 +0000 ril3y 390237

http://blog.synthetos.com/magnetic-linear-encoder-and-it-works/ - Blog Link
http://www.thingiverse.com/thing:1409 - Thingiverse Entry + Files

Here is a board I designed (derivative work from Zach Hokken) that uses the AS5306 austriamicro systems chip. Its still in the beta stages here. But hopefully we will be able to close the loop on the mini cnc (or any other contraptions in the future). Meaning instead of saying take 5 clockwise steps then moving on. You can actually say take 5 steps…. Did you take 5 steps? Yup.. Then move on.

Few challenges:

  1. Understand the multipole linear magent design needed
  2. Test with a Oscope/logic analyzer
  3. Code some more hello world programs to test with arduino
  4. Finalize connectors. Zach's board uses CDROM audio cables. Perhaps we stay with this.
  5. Change the BLUE LEDS!!! Wayy to bright.

Ril3y

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