Do manual pulse generators go bad?

Hi, I have an iMach P1A-S pendant running on a Windows 10 64 bit version of UCCNC however the jog wheel only seems to work correctly with each axis traveling in one direction only. So for each axis, the jog wheel moves the axis correctly in say, X+ but running the jog wheel in X- the axis will not move at all or move intermittently. All three axes are the same. I have updated the firmware on the pendant to the correct version for UCCNC and I have enabled the plugin for UCCNC. Prior to using UCCNC I was using Mach3 and Mach Standard Mill with the same issue. Each time I updated the firmware for the pendant but the result was the same.
This problem has been steadily getting worse but when I first purchased the pendant it worked fine.
Could this be a problem with the jog wheel itself? Is there a way of testing the jog wheel to check for pulses in both directions?
Regards,
Mark Presling

It's possible for the encoder (wheel) to go bad. I drop tested mine one too many times over about 4 years and it finally failed. I replaced the encoder and was back in business in a few minutes. I suppose it could be a loose wire inside also.

https://www.ebay.com/itm/29352236337...3ABFBMsNm3u8tf

Jim,
thanks for your reply. This reminds me that I did drop the pendant hard enough to break the D handle on top. I 3D printed a new one but it's possible this was about the same time that I noticed the issue with the failure to move the axes in one direction. I took the cover off the pendant this morning and unplugged and replugged the encoder but it made no difference. I think I will replace the encoder wheel and see if that resolves the problem. I did contact iMach but so far they haven't got back to me.
Regards,
Mark Presling

Hi,
I have until recently used a VistaCNC P1A pendant and have used it for seven years on my Mach4 mill, its been great....until recently.

It has started playing up, where one or another axis would stop pulsing, and even more recently where all axes would stop. I too wondered whether
it was the MPG itself of maybe the USB comms back to the PC. This problem has been getting worse...and is particularly troublesome in warm weather.

I pulled it to bits and measured the MPG output, it appeared OK, and so I concluded that it was the USB side. Note that given this is an intermittent problem
I have only moderate confidence that my conclusion is correct.

Over-all the pendant has been so good I should just buy another.....it's proved it's worth many times over.

What I decided to do however was to make my own wired MPG. Many of the features of the P1A I never, or hardly ever used, so I have simplified my
pendant to what I use and nothing else. I bought a (second hand) Sensei MPG unit off Ebay....and despite being old is superb. Two toggle switches and
a box and I'm up and running.

Due to the simplification of the design my wiring scheme is:
2 wires........+24VDC, 0VDC
2 wires.........A,B MPG outputs
2 wires.........Axis select
1 wire...........Incremental/Velocity select.
7 wires Total

The MPG cost $60USD delivered to New Zealand. The plastic box and two toggle switches cost $60NZD, about $40USD. I spent a few hours designing and making
the very rudimentary electronics inside the box. So for a little less than what I might have paid for a new P1A I've built my own....albeit with less features. I use what I use
and can't be bothered with the rest.

Craig

Craig, thanks for the info. I must say I am not comfortable with customising electronics on my machine. Your approach would be great though. I also rarely use a lot of the functions on the pendant. I really just want to be able to jog X,Y,Z and A and maybe use the E stop function. I did hear back from VistaCNC and they said that they suspected the encoder had failed and that they could replace it but the cost of the repair and the shipping was more than almost the same as a new pendant. I have ordered a replacement MPG from China and it will take the mandatory 6 weeks to receive it but I can use the pendant as it is and of course the keyboard shortcuts.
Regards,
Mark