Does the Shapeoko Pro controller have extra pins to use as gpio?

I see the inverter now supports the all new, very important ‘Wobbulating function’!.

Well, there’s nothing wrong with a little wobbulation on your spindle if it needs wobbling

However I do wonder what it would do to the vacuum, because thats a bit wobbly already

We’re trying to make less mess not more i guess

The supply frequency shouldn’t impact the spindle because the VFD rectifies the input power and turns it to DC which it then chops up again to make 3 phase AC for the spindle, that’s how it can do single phase in and three phase out. So the spindle sees the frequency the Variable Frequency Drive is creating, not the frequency of the incoming mains. So long as the VFD is rated for 50/60Hz everything should be fine.

On your breaker tripping issue, that’s common with large transformers and there’s an easy fix too, an inrush current limiter. You can either buy one in a package like this

Or you can just go buy a suitably rated NTC thermistor from somebody like Digikey and wire it in yourself.

They are mostly Negative Temperature Coefficient Thermistors which have a higher resistance when cold, i.e. when first switched on, but as they heat up their resistance drops to a very low value. This allows them to squash the peak in the turn on current without impacting normal performance of the load. These are commonly used on big motors etc. to avoid the problem you’re seeing.

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As you explain it like this, it sounds like how an inverter works…

Do you know if there are VFD’s that take in single phase 230V 50Hz, and then output 3 phase 110V?

in other words, can they do the stepdown themselves?

My guess is c3d would be better off supplying those, because it’s weird that the shapeoko itself happily eats 100-240 while the spindle Really Needs 110.

Thats also why i was taken by surprise a little.

I sounds like it could be possible, and that it would make the transformer obsolete…

I’m aware of those ICL’s i use them a lot in projects where a lot of LED driver and electronic PSU’s are used… We have to switch whole groups of that kind of electronics, and that gives inrush current problems without fail.

All those PSU’s switched on at the same time wanting to fill up their capacitors in a millisecond…

we use these but they are not cheap:

I should look into your idea to simply “make” them myself, because they’re so simple.
We do have a lot of trouble with them though… if they break down they stop relaying power… those ones we use anyway…

The reason I did not bother here in my home is because its an extra cost, and also i can simply leave the transformer on… I hope thats not a waste of energy though, but my assumption is that it shouldn’t use that much power idling.

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Yep, a VFD is an inverter, quite a few products claim “inverter drive” or similar to indicate that they have a VFD driving their motor, common on small chiller compressors etc. (larger ones you expect it anyway)

As for a VFD stepping down from 220 to 110V, you probably could, but it’s probably easier and cheaper to just buy a 1.5kW in 220V format. Then you can just use a 220V / 220V VFD which has a nicely matched set of AC / DC / AC voltages. The trick here is to use things that are already being manufactured in volume so that they’re reasonably cheap.

As for whether it wastes any energy, I’d just see how warm it gets doing nothing?


Yes all VFD’s do the rectifying of AC to DC and back to AC current but its not for just single phase in 3 phase out. You can have 3 phase in and 3 phase out as well, its the magic of DC converting back to AC at a different frequency making the motor run at different speeds. The VFD’s that I read about here are in principle the same that I would install on a industrial machine but thats about it.

My original reply was because I read the part about the house breaker tripping. That should not happen! Inrush peak current happens with all electrical devices, but most companies that make breakers already know this and build the breakers to handle the inrush (you can also purchase the correct type fuse to handle inrush). It would be terrible to read that someone had a fire, and I didn’t even try to make some sort of suggestion.
In the end enjoy your machine, but make sure your safe doing so. :slight_smile:

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Ah, mentioning the breakers reminds me, OP could also try a breaker rated for a higher inrush current, I forgot that I’d put a C curve breaker in my control enclosure for my HY VFD.

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