Re: [Emc-users] Linear / glass Scales (Disc position)

Maybe these have changed a bunch since I looked at them, but the way they *used to* work was there was a lead screw that did coarse positioning, then a mirror and lens under audio frequency servo feedback loops looking at the reflection pattern to see how close to the center of the pattern it is.

Re: [Emc-users] Linear / glass Scales (Disc position)

On Thu, 18 Feb 2016 20:47:28 -0800 Chris Albertson wrote: > On Thu, Feb 18, 2016 at 11:23 AM, Nicklas Karlsson > wrote: > > > I guess it would be possible to position an ordinary disc read head quite > > accurate. Either one for DVD/CD

Re: [Emc-users] Linear / glass Scales

On Thu, Feb 18, 2016 at 11:23 AM, Nicklas Karlsson wrote: > I guess it would be possible to position an ordinary disc read head quite > accurate. Either one for DVD/CD or magnetic. How many bits are stored per > turn? > Those devices use the data that is recorded

Re: [Emc-users] Linear / glass Scales

On Thu, Feb 18, 2016 at 4:32 AM, Dave Cole wrote: > > > > Never thought about the Enco catalog, good idea. > > The digital calipers; I think they have their own serial protocol?I > could live with a 250 ms update time on the position so something like > that could

Re: [Emc-users] Linear / glass Scales

On 02/18/2016 01:23 PM, Nicklas Karlsson wrote: > Do you know accuracy of the linear resolvers? > > I guess it would be possible to position an ordinary disc read head quite > accurate. Either one for DVD/CD or magnetic. How many bits are stored per > turn? > > > GE pin scales are fairly low

Re: [Emc-users] Linear / glass Scales

There are some very similar units on Ebay as well, but at higher prices. Good to know that these work well.. Thanks, Dave On 2/18/2016 5:36 PM, Marshland Engineering wrote: > Try here > > Great products with covers and mounting hardware. > >

Re: [Emc-users] Linear / glass Scales

Hello Nicklas On 02/19/2016 03:23 AM, Nicklas Karlsson wrote: > Do you know accuracy of the linear resolvers? http://www.ruhle.com/linear_transducers.htm states +/-1um, I was surprised it was not better > I guess it would be possible to position an ordinary disc read head quite > accurate.

[Emc-users] Linear / glass Scales (Jon Elson)

When I needed to install a DRO on my mill, I found that toolmann had good quality stuff, not too expensive and he will sell pieces. The scales appear to be quadrature. try sa...@toolmann.net. - Original Message - From: emc-users-requ...@lists.sourceforge.net To:

Re: [Emc-users] Linear / glass Scales

Try here Great products with covers and mounting hardware. http://www.aliexpress.com/item/New-Design-5um-aluminium-alloy-DC10-optical-linear-scale-encoder-ruler-measuring-from-50-300mm/1697688495.html Cheers Wallace.

Re: [Emc-users] Mesa 5i25 firmware - is there a mistake?

On Thu, 18 Feb 2016, Viesturs L?cis wrote: > Date: Thu, 18 Feb 2016 23:01:37 +0200 > From: "[UTF-8] Viesturs L?cis" > Reply-To: "Enhanced Machine Controller (EMC)" > > To: "Enhanced Machine Controller (EMC)"

[Emc-users] Mesa 5i25 firmware - is there a mistake?

Hello! I am trying to set up a cnc machine with 5 steppers that is supposed to run with 5i25 card and simple breakout board. I downloaded 5i25.zip file from mesanet.com webpage and found that 5i25_g540x2.bit might be the most appropriate firmware to use. The problem is that in .pin file I see

Re: [Emc-users] Linear / glass Scales

Do you know accuracy of the linear resolvers? I guess it would be possible to position an ordinary disc read head quite accurate. Either one for DVD/CD or magnetic. How many bits are stored per turn? On Fri, 19 Feb 2016 01:51:05 +0800 TJoseph Powderly wrote: > somebody with

Re: [Emc-users] Linear / glass Scales

All good info guys. Those magnetic sensors are really appealing. I want to try those. Siko Global gave me a quote for some magnetic heads and 10" of tape and that setup is just under $700 for one sensor, tape and cable which is actually more than the Balluff sensors we were looking at. That

Re: [Emc-users] Linear / glass Scales

somebody with more time than me (tm) could try the linear resolvers like skunkworks had it looked as if they could be made as pcb's http://www.google.com/patents/US4705971 http://www.analog.com/media/en/technical-documentation/application-notes/394309286AN263.pdf google for inductosyn iirc Jon

Re: [Emc-users] Linear / glass Scales

On 02/18/2016 06:32 AM, Dave Cole wrote: > > > Are the Chinese glass scales on Ebay ok from what you have heard? > There is at least one 8" device for $200 or less listed.I like > saving $$ but if the device is unreliable it will cause a lot of issues. Well, I don't know. Most likely, for a

[Emc-users] Linear / glass Scales

Dave, I had toyed w/ replacing my glass scales and found the following on Ebay: Here's a renishaw copy (new) of a linear magnetic read head: http://www.ebay.com/itm/231172803441 The same guy was selling these: http://www.ebay.com/itm/231135218237 But, looks like he's all out of them.

Re: [Emc-users] Linear / glass Scales

On 02/18/2016 04:32 AM, Dave Cole wrote: > > > On 2/17/2016 9:17 PM, Jon Elson wrote: >> On 02/17/2016 03:52 PM, Dave Cole wrote: >>> I'm shopping for some linear/glass scales for a custom industrial machine. >>> >>> I only need to read 8" of travel. >>> >>> Does anyone know of an economical

Re: [Emc-users] Linear / glass Scales

On 2/17/2016 9:17 PM, Jon Elson wrote: > On 02/17/2016 03:52 PM, Dave Cole wrote: >> I'm shopping for some linear/glass scales for a custom industrial machine. >> >> I only need to read 8" of travel. >> >> Does anyone know of an economical solution.I'd like full quad >> outputs - ttl would

Re: [Emc-users] Linear / glass Scales

Thanks Philipp, This is for an industrial machine and the competition is a Baluff sensor which measures over an 8" stroke. The quote for the Baluff device came back at almost $1200. So it shouldn't be too difficult to beat that price, I hope! :-) I sent Siko an inquiry. Dave On 2/17/2016