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I've been searching for an alternative to the linear scales for quite some time. I have a sherline lathe and mill and have proved very difficult to mount in addition to be in the way as well as unsightly. I saw some info about using magnetic tape and read head a la a cassette but I was concerned that the tape might stretch over time.

So I wanted to share with the community. I haven't had a chance to formerly type this up in detail so I've attached pictures and the CAD drawings can be found here: http://bit.ly/2mpksdo

I used the the AMT-102 from CUI (http://www.cui.com/product/components/en...mt10-v-kit) which you can pick up for about $20. They are quadrature encoders, thin and durable.

My first approach was to mount them colinear with the lead screw (http://bit.ly/2mppsPb) as is done when purchasing a DRO solution from the manufacturer (http://bit.ly/2mpBms8).

It uses a timing belt (often found in 3D printers due to it's flexibility but little stretch): http://r.ebay.com/fljXk9 -- 2 pulleys and the belt will run you about $8. The design above uses bearings but with very little rotation, you could probably get away with bushings or nothing at all.

While the AMT-102 has been a pleasure to work with; simple and has worked out of the box without any problem. They are also impressive giving amazing resolution even at high speed (up to 10,000 RPM so it could be used as a tachometer). But I've been searching for lower cost encoders as well.

I found these on ebay for $10: http://r.ebay.com/2LlV3f for $10 and have had great initial success. 

My goal is to get the per axis cost to about $10. So I've ordered a few different mechanical quadrature encoders from arrow (https://www.arrow.com/en/products/ec09e1...s-electric) and will keep the community updated of my progress.
(02-23-2017, 06:11 PM)andrewj Wrote: [ -> ]I've been searching for an alternative to the linear scales for quite some time. I have a sherline lathe and mill and have proved very difficult to mount in addition to be in the way as well as unsightly. I saw some info about using magnetic tape and read head a la a cassette but I was concerned that the tape might stretch over time.

So I wanted to share with the community. I haven't had a chance to formerly type this up in detail so I've attached pictures and the CAD drawings can be found here: http://bit.ly/2mpksdo

I used the the AMT-102 from CUI (http://www.cui.com/product/components/en...mt10-v-kit) which you can pick up for about $20. They are quadrature encoders, thin and durable.

My first approach was to mount them colinear with the lead screw (http://bit.ly/2mppsPb) as is done when purchasing a DRO solution from the manufacturer (http://bit.ly/2mpBms8).

It uses a timing belt (often found in 3D printers due to it's flexibility but little stretch): http://r.ebay.com/fljXk9 -- 2 pulleys and the belt will run you about $8. The design above uses bearings but with very little rotation, you could probably get away with bushings or nothing at all.

While the AMT-102 has been a pleasure to work with; simple and has worked out of the box without any problem. They are also impressive giving amazing resolution even at high speed (up to 10,000 RPM so it could be used as a tachometer). But I've been searching for lower cost encoders as well.

I found these on ebay for $10: http://r.ebay.com/2LlV3f for $10 and have had great initial success. 

My goal is to get the per axis cost to about $10. So I've ordered a few different mechanical quadrature encoders from arrow (https://www.arrow.com/en/products/ec09e1...s-electric) and will keep the community updated of my progress.

Hi andrewj.

Please let us know your progress on this.

up007
did this project ever get going any furthur ?
animal
There isn't that much to this. As long as you can reduce the backlash/stretch in the belt, the encoders will work just fine. Frankly, unless you have a very specific reason to use this setup, I'd just get the cheapest glass scales you can find on eBay or AliExpress, though. When it's all said and done, they won't cost that much more but will save you a lot of head ache.
Regards
Yuriy