Ditron vs Sino...wich is better in your opinion

[WobblyHand]

@ycroosh - Any thoughts on my Ditron read head with 6 wires? I do not see this variation listed on your website? Is it RS422 without reference?
@WobblyHand ?

With only 6 wires, I'd guess it was A+, A-, B+, B-, +5V, and GND. However, I'm not an expert at this at all.

 

[rwm]

That's my guess as well. I have identified the + and - and they match Yuri's pin out. I will check the other wire with a voltmeter.

 

[mksj]

I should mention; I called PM. They only sell kits which include the scales. They do not have the Magna Slim so I cannot go that route. Also their DRO displays are software specific for lathe or mill. So you could not but a 3 axis and later put in on a mill. Well you could but it would not have features for milling.

That will cost you an extra $500. Some DROs are universal, so can be set for different types of machines, others are machine specific in the firmware. I have the EL-700 form the DRO pros, I have installed the same DRO on both the mill and lathe, same goes for the Easson ES-12B/C, you specify the type of machine. Also, although the boards maybe the same for 2, 3 or 4 axis, they may not have the port sockets or the firmware activated.

 

[rwm]

Somebody should write a Primer on DROs for this site. (among other subjects!)
Yuri's website is outstanding and a great reference for anyone in the market for a DRO, Touch DRO or otherwise.

 

[rwm]

Well just to complicate things further, I checked the wiring to DB9s on the back of the display. Turns out that there are wired pins that connect to unwired pins on the other side of the connector in both directions! In other words, they connect to air. From what I can tell, there are only 4 pins truly in use. So this is the most basic TTL with V+, Ground, A, and B. That makes it easier to deal with. I will make an adapter for the Electronica scale based on this. Looks like I will only need 4 wires to the correct pins and the + and Ground are easy to identify. Even if A and B are backwards that will just change the direction of the scale.

 

[WobblyHand]

Well just to complicate things further, I checked the wiring to DB9s on the back of the display. Turns out that there are wired pins that connect to unwired pins on the other side of the connector in both directions! In other words, they connect to air. From what I can tell, there are only 4 pins truly in use. So this is the most basic TTL with V+, Ground, A, and B. That makes it easier to deal with. I will make an adapter for the Electronica scale based on this. Looks like I will only need 4 wires to the correct pins and the + and Ground are easy to identify. Even if A and B are backwards that will just change the direction of the scale.

Actually, it makes your life easier. As you can see, they only used A+ and B+, otherwise known as A and B. Save for wonky tape and readers, this is pretty simple stuff.

 

[rwm]

I made this adapter which goes from Ditron wiring on one end to EMS wiring on the other using the basic TTL (V+,V0,A,B, Shield to housing.) I checked the Vcc out on my EL400 and It does correspond to Yuri's pinout diagram. I think connecting Vcc to the wrong pin would be the main way to fry something. My new scale should be here on Thursday. Fingers crossed this is the fix.

 

[rwm]

I got the Electronica Magna Slim scale today. I did a quick test to see if the Ditron could read it with the adapter. That works! I can't really tell anything about accuracy yet until I get it mounted. I have to say I am a little disappointed with the Slim scale design. It is definitely small but the mounting holes in the read head are in a dumb location that makes adjustment difficult. Also the scale does not mount with typical end caps and kind of floats in the middle. It looks like this design is not ready for prime time yet. I am going to have to remake all the mounts for this new scale. That won't be until next week.
Why would you put the mounting holes so close to the reader surface???? (This is not my machine-stock photo)

Dumb...

 

[pontiac428]

@ycroosh - Any thoughts on my Ditron read head with 6 wires? I do not see this variation listed on your website? Is it RS422 without reference?
@WobblyHand ?

That is the TTL configuration. I talked to Ditron this week, they said the heads can read either TTL or RS-422-A (8 wires plus shield). The difference is TTL degrades in long cable runs, where the twisted pair bucks noise. By long runs, I'm talking upward of a hundred meters.

 

[rwm]

I GOT IT WORKING! Success...
Here is the EMS read head mounted:

I still don't like how close the mounting screws are to the read surface but it works.

Here is the scale:

This plugs right into the Ditron display with the adapter I made and it works fine.
Accuracy testing shows it to be dramatically better than the Chinese scales. I did find a small linear error of about .002" over 1". Previously I was seeing non-linear errors of .002" over .1" with the Ditron scales. I turned on the linear comp and it is now almost dead on! I can report and error of .0003" over 1". I am very pleased to say the least. This has been a journey and I thank you all for the guidance!

In summary I would say the following:

I would avoid the Chinese scales as they have significant inaccuracy as described by Yuri https://www.touchdro.com/resources/scales/magnetic/overview.html]
Electronica is a better system. (Made in India)
The Magna Slim is small but the mounting is a little sketchy. Use it only if you must. The regular scales are easier to mount
If you already have a Chinese display head you could consider replacing the scales to gain accuracy.