Installed an Enco x axis table feed on the B'port

[frostheave]

Hi Bob

I installed a 3 Axis DRO on my small mill. It was a Easson ES12 with glass scales from Hong Kong. The scales they supplied were SinPo and Sino.
Two things to watch with glass scales.

They are much larger than the Electronica Magnetic scales supplied by DroPros and would be much harder to fit to the quill. I recommend you investigate Magnetic scales. Magnetic scales are also coolant proof.

Also some of my scales were supplied with an integrated Backing Plate and Cover. Much easier to fit the Backing Plate first and true up then the actual scale goes drops on. Piece of cake.
This is particularly useful when fitting to uneven surfaces such as the Y and Z axis. Not so important fitting to the X ( back of the table) which is machined.
Hope this helps
Ron

Thanks Ron. Yeah, I actually have both types of scales from DRO Pros. I have the glass scales on my small mill and the magnetic on my lathe. You are right, the magnetic scales are much smaller and I can see how they would be an easier fit on the quill. I haven't investigated the quadrature signals on the magnetic scales yet, but I think they may use RS-422 signals rather than simple A and B signals.

Do you have any pictures of the "integrated Backing Plate and Cover." I'd really like to see that. It sounds like a great idea!

Bob

 

[ronboult]

Bob
If you go to the M-DRO website, they show the Backing Plate & Protective covers (http://www.machine-dro.co.uk/digita...tive-cover-suitable-for-gs300-620-scales.html) They are available from a number of manufacturers. The ones that I have were supplied with Sino Scales from China.

Also the Tech specs for glass scales (http://www.agl-distribution.co.uk/docs/mdro/m-dro-gs300-encoders_technical.pdf) and Magnetic scales (http://www.agl-distribution.co.uk/docs/mdro/dro-el-s1_techincal.pdf) are shown. From my limited knowledge the electrical outputs for Glass & Magnetic Scales are identical 5 volt TTL Quadrature, but the connections in the DB9 plugs on each are different.

In fact M-DRO actually sell an adapter to enable Electronica Magnetic scales on a Easson Display (Normally glass scales). See http://www.agl-distribution.co.uk/docs/mdro/console-encoder-compatibility_techincal.pdf. I am just about to order an Electronica 1uM magnetic scale and adapter from M-DRO to use on my Lathe cross slide with an Easson ES12 Display. I am awaiting them to get back to me with a price. The Z axis will remain a 5uM glass scale

Ron

 

[frostheave]

Bob
If you go to the M-DRO website, they show the Backing Plate & Protective covers (http://www.machine-dro.co.uk/digita...tive-cover-suitable-for-gs300-620-scales.html) They are available from a number of manufacturers. The ones that I have were supplied with Sino Scales from China.

Also the Tech specs for glass scales (http://www.agl-distribution.co.uk/docs/mdro/m-dro-gs300-encoders_technical.pdf) and Magnetic scales (http://www.agl-distribution.co.uk/docs/mdro/dro-el-s1_techincal.pdf) are shown. From my limited knowledge the electrical outputs for Glass & Magnetic Scales are identical 5 volt TTL Quadrature, but the connections in the DB9 plugs on each are different.

In fact M-DRO actually sell an adapter to enable Electronica Magnetic scales on a Easson Display (Normally glass scales). See http://www.agl-distribution.co.uk/docs/mdro/console-encoder-compatibility_techincal.pdf. I am just about to order an Electronica 1uM magnetic scale and adapter from M-DRO to use on my Lathe cross slide with an Easson ES12 Display. I am awaiting them to get back to me with a price. The Z axis will remain a 5uM glass scale

Ron

Hi Ron. I replied a couple of days ago but I see my post did not post. Not sure why. Anyway, thanks for the info, just what I needed. I will definitely check out the backing plates. They look like they could really help.

Looking at the pinouts on my scales, the glass scales have 5v TTL A and B quadrature while the magnetic appears to have RS-422 A A', B B' quadrature output. After some investigation, it looks like the RS-422 magnetic scales can be used in TTL mode with just the A and B signals. I'll put the scope on them and report back.

 

[hvontres]

Hi Ron. I replied a couple of days ago but I see my post did not post. Not sure why. Anyway, thanks for the info, just what I needed. I will definitely check out the backing plates. They look like they could really help.

Looking at the pinouts on my scales, the glass scales have 5v TTL A and B quadrature while the magnetic appears to have RS-422 A A', B B' quadrature output. After some investigation, it looks like the RS-422 magnetic scales can be used in TTL mode with just the A and B signals. I'll put the scope on them and report back.

Actually, your best bet would be to put a differential reciever chip close to your readout. That way you can run the A A' B B' signals for improved noise immunity. Something like this http://www.ti.com/lit/ds/slls115e/slls115e.pdf will handle two scales and can be had for a whopping $0.96 at mouser

 

[frostheave]

Actually, your best bet would be to put a differential reciever chip close to your readout. That way you can run the A A' B B' signals for improved noise immunity. Something like this http://www.ti.com/lit/ds/slls115e/slls115e.pdf will handle two scales and can be had for a whopping $0.96 at mouser

Thanks for the heads up Henry. It may come to that. To start with I will be using AB glass scales with the following interface chip

http://www.usdigital.com/products/interfaces/ics/LFLS7183

to count interrupt driven edge triggers with an Arduino. The 7183 relieves the MCU from processing the quadrature signals, including direction, and it just has to count up or down and display the position. In my simulation on the Arduino, it should be able to handle at least 200 inches per minute. I'll see what happens.

Bob

 

[ronboult]

Hi Bob
I have just received an Electronica 1uM magnetic scale from Allendale ( Machine DRO) in the UK along with the Type 10 adapter cable required to connect it to my Easson ES12.

Plugged it in , adjusted the resolution and it works perfectly. I suspect that if you just rearranged the connection in the DB9 plug to match those of glass scale connections you would not even need the connector.

Clearly the output of the magnetic scales include the 5 volt TTL Quadrature signal similar to glass scales
Cheers
Ron

 

[frostheave]

Hi Bob
I have just received an Electronica 1uM magnetic scale from Allendale ( Machine DRO) in the UK along with the Type 10 adapter cable required to connect it to my Easson ES12.

Plugged it in , adjusted the resolution and it works perfectly. I suspect that if you just rearranged the connection in the DB9 plug to match those of glass scale connections you would not even need the connector.

Clearly the output of the magnetic scales include the 5 volt TTL Quadrature signal similar to glass scales
Cheers
Ron

Hi Ron,

Thanks so much for the great info. I had read somewhere that the magnetic scales could be used by connecting only the A, B, and GND pins, i.e. not using the scales in differential mode. You have confirmed this is true, and saved me some time!

Bob