DRO on the cheap ?

[cyclestart]

I'm buying a large mill and it will be manual for the foreseeable future. DRO's with scales large enough to cover the full travel are beyond my budget. Otoh, counting screw rotations is a pita.

Would it be practical to hook these encoders to the screws ?
http://preview.tinyurl.com/yds9qt4
And then use a pc as the counter ?.

I think I can handle the software end of things. The wiring bit is not in my comfort zone.

It should be at least as accurate as reading the graduations on the collars ? (hoping)

[Al_The_Man]

Will this s/w work for you?
http://www.lindsayengraving.com/othe...rests/dro.html
Updated s/w here http://bellsouthpwp.net/A/r/Arts_home_page/DRO/
I have hooked the encoders directly to the port without the buffer transistors and worked OK.
Al.

[WayneHill]

http://www.cadcamcadcam.com/usb-dro-sys.aspx

[cyclestart]

Thanks for the replies.

The first option has a price that can't be beat.

The second option has some bells and whistles and likely some level of support from the manufacturer. The extras aren't something I will be needing anytime soon but good support has value. I'll give the free one a try before spending.

Neither of the options recommends a specific model of encoder. The one I linked to okay ? I'm picturing spinning the shaft with a belt..

[Al_The_Man]

I found the differential line driver type I could input without buffers.
Al.

[cyclestart]

Originally Posted by Al_The_Man I found the differential line driver type I could input without buffers. Al.

uh, can you offer a translation ? I'm don't have much electronic (or even electrical) knowledge. This project is going to mean learning some new things.

[Al_The_Man]

The differential encoder has two each of the channels as output, you will see them labelled as A /A B /B etc you would just use the A & B of each output.
By buffers I meant you can do away with the intermediate transistors that are shown in the link diagram.
Al.

[MyCattMaxx]

The one from Lindsay will use this http://www.usdigital.com/products/en...otary/kit/e8p/

[tusavision]

Another option is to make a small bracket to affix a harbour freight pair of 12" digital calipers to your table, and screw the other end to a small push button mag base like off of littlemachineshop.

[MyCattMaxx]

Originally Posted by tusavision Another option is to make a small bracket to affix a harbour freight pair of 12" digital calipers to your table, and screw the other end to a small push button mag base like off of littlemachineshop.

12'' isn't a large mill. He stated a large mill.

[tusavision]

Originally Posted by MyCattMaxx 12'' isn't a large mill. He stated a large mill.

Beats the old system of a counting revelutions or a dial indicator & 321 blocks.

The mag base means it's adequate for parts smaller than 12" which for many users is good enough.

Didn't say it was ideal. Compared to a cheap encoder system: it may not even be economically competitive. Particularly if there's a potential for scrapped parts.

All the same: it's another option that the op/others may not have been aware of.

[cyclestart]

Originally Posted by tusavision All the same: it's another option that the op/others may not have been aware of.

Your input is welcome and appreciated.

Large is relative. The travel is 12"x30". Tiny for those use to bridge mills. A monster compared to my current mini-mill. Most of my parts are small but the plan for this mill is to take in some paying jobs. I plan use a sliding DRO on the quill and read it directly..