[canman77]

Hi everyone,

I've been doing a lot of research and asking a couple members about VFDs and spindles and right when I think I'm making a breakthrough as to what to get for my machine (Chinese 3040, upgraded drivers) I feel like I've gone two steps back.

I have a few questions I'd like to ask, hopefully you all can help in my quest for knowledge. I'm limited on budget, so I'm stuck with the Chinese spindles/VFD. Which I'm OK with, people seem to have great success with these. I'm also limited to 110v, I don't have easy access to a 220v circuit.

It was explained to me that the current and the frequency are the important factors in spindle/VFD operation. I've seen spindles on eBay that are rated 1.5kw, 220v (not referring to a VFD, just spindle). This may be a dumb question, but can a spindle rated at 220v work with a VFD that uses 110v input mains? I keep reading that these VFDs output 220v, but the specs on eBay indicate that the output is the same as the input. (To those who gave me this information, don't take anything personally...I'm just trying to wrap my head around everything)

Similarly, what is the benefit to a 220v vs. 110v VFD/spindle? I know that current = power/volts, so would a 110v 1.5kw spindle draw more current than a 220v? (I'm sorry I don't know how to correctly phrase any of this...I somewhat understand the relationship between current, power, and volts, but then the one phase/three phase stuff I haven't researched)

Now, as far as what my machine can handle, I'm torn between the 1.5kw and the 0.8kw. I cut lots of wood using a trim router now and the bearings just can't handle deeper passes. Using a 1/4" downcut spiral bit, around 1500mm/min, how deep would these spindles be able to cut? I don't care about full depth cuts...it would be pretty cool, but it isn't the goal. I'd be really happy if I could do 4-6mm passes without taxing the spindle. Would a 0.8kw spindle be able to handle cuts like that, or would the 1.5kw be the better option? I know it all depends on the machine's rigidity, etc, but I'm mostly just looking for the capabilities of each spindle, not the capabilities of my machine.

Thanks everyone for your patience with me...I'm trying to find out as much as I can but like I said, I'm just getting more and more lost. I think these questions will hopefully clear up my confusion and not make it worse!

[A_Camera]

Hi everyone,

I've been doing a lot of research and asking a couple members about VFDs and spindles and right when I think I'm making a breakthrough as to what to get for my machine (Chinese 3040, upgraded drivers) I feel like I've gone two steps back.

I have a few questions I'd like to ask, hopefully you all can help in my quest for knowledge. I'm limited on budget, so I'm stuck with the Chinese spindles/VFD. Which I'm OK with, people seem to have great success with these. I'm also limited to 110v, I don't have easy access to a 220v circuit.

It was explained to me that the current and the frequency are the important factors in spindle/VFD operation. I've seen spindles on eBay that are rated 1.5kw, 220v (not referring to a VFD, just spindle). This may be a dumb question, but can a spindle rated at 220v work with a VFD that uses 110v input mains? I keep reading that these VFDs output 220v, but the specs on eBay indicate that the output is the same as the input. (To those who gave me this information, don't take anything personally...I'm just trying to wrap my head around everything)

Similarly, what is the benefit to a 220v vs. 110v VFD/spindle? I know that current = power/volts, so would a 110v 1.5kw spindle draw more current than a 220v? (I'm sorry I don't know how to correctly phrase any of this...I somewhat understand the relationship between current, power, and volts, but then the one phase/three phase stuff I haven't researched)

If you have two motors, one is 1.5kW 110V and the other is 1.5kV 220V then you have two equivalent motors, but the 110V motor will need twice the current. So, assuming your VFD can handle that current and is made for 110V and you have a 110V 1.5kW motor then you can use that. But... if you have a 220V motor then you can't run that from 110V, unless you have split phases (I think that's what it is called in USA) and you feed the VFD with two phases 180 degrees apart, and not one phase and a neutral. Your 110V will remain 110V even after leaving the VFD, since the VFD maximum output voltage is equal to the input voltage. If you run a 220V motor from 110V then you will get half the rated power out, so a 220V 1.5kV motor will only work as a 110V 0.75kW motor. The other issue is that if you connect a VFD designed for 220V to 110V then it may not work at all, at least the one I have would definitely not be usable, since it is specified for power input 200...240 VAC (-10 % / +10 %), so 110V is far too low for that.

Now, as far as what my machine can handle, I'm torn between the 1.5kw and the 0.8kw.

If you can handle 1.5kW motor then no doubt, get the more powerful one. There is no disadvantage in having twice the power except that it will draw more current.

I cut lots of wood using a trim router now and the bearings just can't handle deeper passes. Using a 1/4" downcut spiral bit, around 1500mm/min,

Why downcut? I think upcut is what you should use because that cleans the tracks as the spindle rotates. Also, I am not an expert on wood, but 1500mm/min seems pretty slow to me, so with the 1.5kW VFD controlled spindle you could probably cut at least twice as fast, perhaps even faster, depending on the depth and the type of wood you are cutting, but like I said, I don't work with wood.

how deep would these spindles be able to cut? I don't care about full depth cuts...it would be pretty cool, but it isn't the goal. I'd be really happy if I could do 4-6mm passes without taxing the spindle.

Again, not a wood expert, so take my answer with a grain of salt, but 4-6mm isn't very deep in my opinion if you have the right spindle RPM and cutter. In fact, I am surprised that you can't cut that deep with your router today. Never the less, wood can be very hard, so it may depend on the wood you are cutting.

Would a 0.8kw spindle be able to handle cuts like that, or would the 1.5kw be the better option? I know it all depends on the machine's rigidity, etc, but I'm mostly just looking for the capabilities of each spindle, not the capabilities of my machine.

As I said, the more power the better, so there is no doubt in my mind that 1.5kW is better than a 0.8kW, even if it may be able to fulfill your requirements for now. Remember that there might be a day when you want to cut deeper, or harder wood, or at higher speed or whatever else where more power would mean you can do things you can't do with less power. The rigidity of your machine is just as important, regardless which spindle power you have. I don't think that there is a big weight difference between 0.8kW and 1.5kW, but if your machine is generally not rigid enough then that is a more important issue than buying a new spindle. Perhaps the current struggling is due to rigidity issues? In that case you should do something about that first, before buying a new spindle. Start with using upcuts so you get better chip removal.