Axis load meters?

[DAB_Design]

I was having a conversation with the voices in my head the other day, and we may have come up with something that may be of some use to someone.

Has anyone ever tried to incorporate axis load meters? A couple of machines we have work have meters for each axis.

Me and electronics aren't very friendly, unless it's all already drawn out and proven to work. So my idea is....can you use maybe some cheap (analog wal-mart type) multimeters inline with your motors to monitor the power going to them. Most industrial machines have safeguards builtin to prevent harming the motors/machine if the motors are pushed too hard. Most DIY/conversions don't have this. So maybe this is something that could help especially those that are new to machining.

If the power is nearing peak motor specs, you know to slow things down a bit. If it's too low, you can push it a bit harder. Of course other things would dictate how to run the machine, but this could take one of those things out of the equation.

Would this work, or am I just too electronicly uneducated? If this would not work, please do not reply in red text.

[High Seas]

Originally Posted by DAB_Design I was having a conversation with the voices in my head the other day, and we may have come up with something that may be of some use to someone.

Me too! Glad to hear others do as well.

Originally Posted by DAB_Design Has anyone ever tried to incorporate axis load meters? A couple of machines we have work have meters for each axis.

I've looked at doing this as well and like you - I'm not too electronically inclined. There was a thread on setting this up with a Xylotex Driver - Ynneb had a good post and picture - on 06-02-2004. - search the Xylotex Forum.

Originally Posted by DAB_Design ...can you use maybe some cheap (analog wal-mart type) multimeters inline with your motors to monitor the power going to them.

Buy them from Harbor Freight at a deep discount price - I got 6 digital ones for about 20 bucks. Haven't hooked 'em up yet - will have to wait till my return.

I was also freaking over temps too and picked up a couple of cheapo temp probes - (they're degrees C only - but close enuf. They were called Computer Baby Sitter/Nanny/Nurse - or something silly like that. Came with 2 probes each - a pair - or 4 probes was also about 20 bucks.
Jim

[ESjaavik]

With steppers, I think you can forget it.
With servo's there may be an output for that so you just need a meter. I have several different types of 3ph BLDC drives and all of them have such an analog output. It can be configured to monitor different conditions where momentary motor current is one of them. Another that could be of interest is momentary following error. Especially if what you want to know is if you can go faster / accelerate harder. Then the following error is what you want to monitor, not the current.

But on your spindle drive, the momentary current is of interest. If you know that cutting this part and on that certain point you usually see 60% and now you see 80%, then you know you need to check if your tool should be changed.

Or it could even be used as input to your path controller telling it that the spindle can take some more load, go faster please. Uhh..don't think the controllers used in hobby machines would understand that.

[davesaudio]

hmmm
current transformer - use the output to drive an xy type plotter
program? would give some useful info on a "run"