anyone used vevor scales? do they have a home signal

[mtraven]

FYI-- this marks the first time I've had need to post in the digital machinist section, feels good, like I'm progressing.

In an attempt to bring myself into the 21st century, I recent purchased my first scale(glass)...a vevor 10"

I am building the interface for it myself (seemed like a fun project). Documentation is scarce (that link is all I have).

I had no difficulty picking up the two primary signals (A &B)--digital pulses half a cycle out of phase. There should also be a "home sign", sometimes called "z" or "r1". From a pic I have, it should be just a single pulse, 1/4 cycle length (no pattern or anything). I have meticulously scanned up & down this thing in every way I can: dmm, micro controller interrupt, analog polling & a scope. All of which work to read the primary encoder signals. What i do have is, on the pin that is suppose to be the home signal, is a very low, constant voltage(0.190vdc). Constant is not quite right, as there is about a 30 mVDC variation in that line, which comes only with movement of the scale (at rest it is dead constant).

am I doing something wrong? did I get a bad scale? was a home signal every actually built into the thing? (the sensor head is potted, so I can't peak under the skirt)

so anyone who has one of this scales: does your home signal work? ie after power loss, are you able to move your scale to find absolute 0 ?

at this point, I've exhausted all my testing options, I have an email into the manufacturer & I'm all ears to any suggestions y'all might have. Thanks for your time.

[djc]

Have you tried all the pins in the connector? There is some discussion on the TouchDRO site that pin outs are inconsistent between brands. There is a comment on the Vevor one that the pinout shown in their diagram is for the display rather than the scale. You might not need to look at the head, but at the scale itself - if it is a glass scale, there might be some visual indication (or not) of the home marker.

[mtraven]

Have you tried all the pins in the connector? There is some discussion on the TouchDRO site that pin outs are inconsistent between brands. There is a comment on the Vevor one that the pinout shown in their diagram is for the display rather than the scale.

yes I have tried every wire in the array, multiple times, multiple methods of detection. And I did see that note, after scratching my head for 30 minutes wondering why the pin numbers where wrong...But yes I have it right & have checked all the connectors.

You might not need to look at the head, but at the scale itself - if it is a glass scale, there might be some visual indication (or not) of the home marker.

oh man, how tempted I've been...I usually don't hesitate to dismantle something, but I can't see a clean way to get into this thing...and I still might be in my return window.

I'm correct that this a pretty critical feature for a dro, right? I've never had one so I can't say for sure, but I imagine it is.

[djc]

I'm correct that this a pretty critical feature for a dro, right?

To me, it is a minor inconvenience rather than a show stopper. I am guessing you are installing it on a manual machine. Just return it to work coords. of (0,0,0) before you switch it off and do not touch the handles while it is off. Use hard stops on each axis to get back to -273C.

[Peter.]

I have some on the shelf ready to install with the vevor interface but I'm nowhere ner ready to do that yet. I will ask someone who I know has a setup in use.