IGaging ez view woes

[Razzle]

Since I added my home brew x axis power feed to my Seig x2d minimill the igaging scales have started to act even more wonky than usual. to the point where I can't trust them anymore. I even went back to the original displays and am still having issues with lag, jumping and losing position. I wanted to solicit opinions on whether it is worth my time to implement some of the fixes (Eg shielded USB cables, isolation mounts, capacitors, etc) or just bite the bullet and upgrade to glass scales. I can get the scales for under 200. The drawbacks to new scales are (aside from cost): I have to build new mounts, and I have an iGaging touchdro adapter. So I will need to modify the connections to support the new scales. I welcome all opinions.

 

[markba633csi]

If your powerfeed motor is a brush type then it's probably broadcasting electromagnetic interference in all directions.
Try wrapping foil around the motor power leads and see if there's any improvement. If so then try adding foil to the dro leads also.
Those are the easiest things to try. Chasing problems like these can be frustrating

 

[RJSakowski]

I had problems with my TouchDRO on my G0602 lathe, using iGaging scales. The symptoms that I was experiencing was losing counts usually by multiples of .200 inches. The problem occurred when I turned off the motor. I installed chokes on the power lines for the motor and on the power supply for the TouchDRO and tablet which reduce the frequency but didn't eliminate it. The final solution was to add bypass capacitors to the iGaging pickups. That cured the problem.

I have another issue which is more an annoyance. The DRO will stop updating for a fraction of a second as I traverse the x or z axes. I suspect that this is an interrupt issue within the the tablet. I haven;t gone to any length to solve the problem yet.

 

[RJSakowski]

The power feeds that I've had experience with just use a simple full wave bridge rectifier to provide the d.c. for the motor. Adding filter capacitors will help to reduce motor noise.

There are two parameters which are used to measure compatibility of electrical devise; EMI or generated electrical interference and EMC or electrical comparability. Interference can be electrical in naturem carried through the wiring or elctromagnetic, travelling through the air. Generally, it is preferable to reduce or eliminate noise at the source. This is typically done with filter chokes and bypass capacitors, proper grounding and/or shielding. At the receiving end these strategies also work but they can be more difficult, particularly as an aftermarket solution.

 

[homebrewed]

Your choice really depends on your comfort level with messing around with those DROs. I had a hell of a noise problem too but took it up as a challenge. It didn't hurt that I'm an old hand when it comes to fooling around with electronics.

The most effective cure I found was to hardwire the scale to the DRO's internal ground. In the presence of electrical noise the scale acts as an antenna. The next-best cure was to add additional filter capacitors between Vcc and Ground inside the sensor box (the one that slides on the scale). You want to use a fine-tipped soldering iron for that.

Finally, when the batteries start to go flat the DROs get flaky, more sensitive to electrical noise. The external power supply option has its own problems because its power cable can pick up noise as well.

 

[Razzle]

Lots of good suggestions. My power feed is a 12 volt car seat motor driven by a PWM module. I am using an old laptop power supply as my power source. The Dro and scales are powered by a USB power distribution block. @RJSakowski I have also experienced your update lag issue. got worse after the power feed install. I am running touchdro on a 3rd gen kindle fire tablet. So all around I haven't done myself any favors. My x axis is basically useless right now due to lag and position loss. I am definitely comfortable troubleshooting things like this and have the skills to implement. But if I am doing that I am not machining. My question really is, do you think it is worth it or am I going to still have an unreliable dro at the end. My time is limited and so are my funds. I want to make the best choice I can within those limitations.

 

[ycroosh]

I had problems with my TouchDRO on my G0602 lathe, using iGaging scales. The symptoms that I was experiencing was losing counts usually by multiples of .200 inches. The problem occurred when I turned off the motor. I installed chokes on the power lines for the motor and on the power supply for the TouchDRO and tablet which reduce the frequency but didn't eliminate it. The final solution was to add bypass capacitors to the iGaging pickups. That cured the problem.

I have another issue which is more an annoyance. The DRO will stop updating for a fraction of a second as I traverse the x or z axes. I suspect that this is an interrupt issue within the the tablet. I haven;t gone to any length to solve the problem yet.

I suspect you have a Samsung tablet with Android 12? If that is the case, it's a bug in Samsung Android OS that crashes the wireless chipset for about 400ms (sometimes in quick succession). There is no fix for it yet (I filed a bug with Samsung, but they don't seem to care). The same hardware with Android 11 doesn't have the bug, so I hope that once they release Android 13, it will be fixed.

 

[ycroosh]

Since I added my home brew x axis power feed to my Seig x2d minimill the igaging scales have started to act even more wonky than usual. to the point where I can't trust them anymore. I even went back to the original displays and am still having issues with lag, jumping and losing position. I wanted to solicit opinions on whether it is worth my time to implement some of the fixes (Eg shielded USB cables, isolation mounts, capacitors, etc) or just bite the bullet and upgrade to glass scales. I can get the scales for under 200. The drawbacks to new scales are (aside from cost): I have to build new mounts, and I have an iGaging touchdro adapter. So I will need to modify the connections to support the new scales. I welcome all opinions.

With iGaging scales it's a bit of a "crap shoot". Some scales are rock solid and some are all over the place. I've seen cases where two out of 3 scales work perfectly well and one is jumping, loosing position, etc. Generally, earlier Mini-USB models were VERY flaky; latest Micr-USB EZ-View have been more stable. You can fix many of the problems with various tweaks. If you have a MSP430 based adapter, swapping to the new ESP32 model (DIY or pre-made) will help some (the firmware does a lot of shenanigans to work around glitches, like oversampling, etc.).

All that said, I personally would not use capacitive scales in a DRO these days. They made sense when iGaging DigiMag scales sold for under $50/piece and glass scales were $300-$400/piece. These days the price difference is not even 2x, but performance is not in the same ball park. With glass scales you get 2x the resolution, real-time position refresh (VERY important if you want to use a touch probe with TouchDRO, for example), and near bullet proof noise resistance. Unless you are on a tight budget or "love a good challenge", I'd swap the scales. To me, a DRO is a measurement instrument. If you have to re-check you DRO with a dial indicator or calipers, you loos one of the main benefits.

Hope this makes sense
Yuriy

 

[Razzle]

Thanks @ycroosh. That makes a lot of sense. I do have the micro USB scales and the ESP32 igaging adapter. The issues were tolerable before the power feed install. But now the Dro is useless. I enjoy a challenge but this isn't the challenge I want to spend my time on. Guess it's time to buy better scales. Might need a better tablet too. I want to run v3 and I can't get that on my old 3rd gen kindle fire. Besides, it's only a 7 inch. I want to move up to a 10.

 

[RJSakowski]

I suspect you have a Samsung tablet with Android 12? If that is the case, it's a bug in Samsung Android OS that crashes the wireless chipset for about 400ms (sometimes in quick succession). There is no fix for it yet (I filed a bug with Samsung, but they don't seem to care). The same hardware with Android 11 doesn't have the bug, so I hope that once they release Android 13, it will be fixed.

I am using an RCA tablet running Android ver. 6.0.1. I also experience the same problem with my LG G5 phone running Android ver. 7.0. Every 5.0 seconds, there is a short pause, less than 1 second. It doesn't appear to lose counts.

I haven't checked with my Samsung A53 G5 running Android ver. 13 as I don't recall the Bluetooth pairing code.