Search For Encoders

Wow.... This is as tough as anything...
(I found a replacement for the broken servo), but now I am working on picking out replacement encoders. Its not an easy search. They either cost
over $1K each or there is no information, or they don't work...
I am kinda looking at this one: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item 0522123169&fromMakeTrack=true
The 8-30 power means I would have to provide a separate power supply for them since most standard control setups like to just provide 5V. That's no big deal for me. I have a number of small 12V regulated power supplies on the shelf for other applications. 512 res is greater I think than the original encoders on this machine. I think they were only 200. 512 gives a theoretical precision of about .00039. The machine manual only claims .001 with .0005 repeatability anyway so that seems ok. DL means 5V out so that's good for most controllers.
I should go measure the pitch of the ball screws just to make sure, or see if its in my manuals somewhere. I just assumed 5tpi.
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On Sun, 2 Jan 2011 10:14:42 -0700, "Bob La Londe"

Iff they carry what you need, Automation Direct has the best prices I'm aware of for housed encoders. http://www.automationdirect.com/adc/Shopping/Catalog/Sensors_-z-_Encoders/Encoders
If you can't find what you want there or on ebay you may have to go to a mfr like Encoder Products -- they'll build whatever you specify. The prices seem to have come down in the last few years. The small hollow shaft models start around $200. http://www.encoder.com/quickreference.html
--
Ned Simmons

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wrote:

http://www.automationdirect.com/adc/Shopping/Catalog/Sensors_-z-_Encoders/Encoders
That's a decent research reference. The actually list prices instead of "call for pricing." (I hate that.)
Thanks Ned.
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On Sun, 2 Jan 2011 11:10:56 -0700, "Bob La Londe"

The prices on Encoder Products' site are real world prices. I recently bought a heavy housed encoder thru one of my regular suppliers and the online price and what I paid were very close, if not identical.
--
Ned Simmons

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I suppose I could make a mounting setup for them, but it would be awkward and I would have to leave the motor covers off. A hollow shaft encoder is really a better solution.
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I haven't looked at them yet, but the link won't open for me.
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I think that their website is down or something.
i
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...

I've used USdigital on six macines now. I had trouble with the single ended missing pulses on one machine (drove me friggin' nuts with position drifting due to losing pulses only during tool change cycle). So, be sure and get differential units. I've also only bought their encoder kits where they mount on to an existing shaft.
If you need the entire encoder in a housing with bearings, eBay is your friend, get allan bradley.
Karl
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The back of the servos have .500 shafts. That is where the old servos were mounted except on the Z axis where it is mounted on the screw. I have been looking for options in .500 hollow shaft encoders.
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