[BigGinge]

Hi,

I'm starting to spec out a new bench top machine build that I'm hoping to put together for some small scale project work in various different materials, though probably with a focus on aluminium plate. Realistically I'm probably looking at the more budget friendly spindles and VFDs available on AliExpress to get this moving so budget is something I'm keeping in mind when making my parts choices.

One of my first questions on this is what I should be looking for in terms of power and features for my spindle and VFD choice, so I was hoping some people with a bit of experience on this could provide some guidance.

I guess the easiest point to address is probably what spindle power I should be aiming to go for. I'm guessing that in general more really is more in this regards and that going for the highest power spindle I can support on my existing wiring system (230V, single phase). This probably means I'm looking at a 2.2 kW spindle and VFD at the top end but see other 1.5kW and 0.8 kW options that I could consider if the lower power doesn't have too much of an impact when cutting aluminum at the sorts of speeds that most of the spindles seem to run at.

As a bit of background to the above, the prices for the spindles I've seen are around £130, £170 and £200 respectively for a 0.8kW, 1.5kW and 2.2 Kw spindle from G-Penny.

The next point I've been considering is linked to the previous question and is whether it is worth trying to pick up a 4 pole spindle, rather than a standard 2 pole spindle. As I understand things this should let me get a bit more usable power/torque at the lower spindle speeds but again I'm not sure of how much real world difference this would make. Is it worth the extra to go for the 4 pole spindle of a 2 pole variant of an equivalent power? Going for the 4 pole spindle would probably take me from £200 ish for a 2 pole 2.2kw spindle all they way up to £300 for a 2.2kw 4 pole motor (though this does look to have a few additional improvements in build too)

My final question (for now) is if it is worth trying to go for an inverter that offers sensorless vector control of the spindle rather than the standard V/F drive used on most of the common units? I've seen that it is possible to pick up a Huanyang GT-2R2G-2 vector control inverter for around £150 which isn't a huge amount more that the more common HY02D223B which would probably cost me £120. I suspect on this one (unless someone advises otherwise) its is fairly easy to justify the GT series inverter as the price difference isn't huge and I can always just run it in V/F mode if the vector control mode doesn't play nice with the spindle I end up buying.

[mactec54]

Hi,

I'm starting to spec out a new bench top machine build that I'm hoping to put together for some small scale project work in various different materials, though probably with a focus on aluminium plate. Realistically I'm probably looking at the more budget friendly spindles and VFDs available on AliExpress to get this moving so budget is something I'm keeping in mind when making my parts choices.

One of my first questions on this is what I should be looking for in terms of power and features for my spindle and VFD choice, so I was hoping some people with a bit of experience on this could provide some guidance.

I guess the easiest point to address is probably what spindle power I should be aiming to go for. I'm guessing that in general more really is more in this regards and that going for the highest power spindle I can support on my existing wiring system (230V, single phase). This probably means I'm looking at a 2.2 kW spindle and VFD at the top end but see other 1.5kW and 0.8 kW options that I could consider if the lower power doesn't have too much of an impact when cutting aluminum at the sorts of speeds that most of the spindles seem to run at.

As a bit of background to the above, the prices for the spindles I've seen are around £130, £170 and £200 respectively for a 0.8kW, 1.5kW and 2.2 Kw spindle from G-Penny.

The next point I've been considering is linked to the previous question and is whether it is worth trying to pick up a 4 pole spindle, rather than a standard 2 pole spindle. As I understand things this should let me get a bit more usable power/torque at the lower spindle speeds but again I'm not sure of how much real world difference this would make. Is it worth the extra to go for the 4 pole spindle of a 2 pole variant of an equivalent power? Going for the 4 pole spindle would probably take me from £200 ish for a 2 pole 2.2kw spindle all they way up to £300 for a 2.2kw 4 pole motor (though this does look to have a few additional improvements in build too)

My final question (for now) is if it is worth trying to go for an inverter that offers sensorless vector control of the spindle rather than the standard V/F drive used on most of the common units? I've seen that it is possible to pick up a Huanyang GT-2R2G-2 vector control inverter for around £150 which isn't a huge amount more that the more common HY02D223B which would probably cost me £120. I suspect on this one (unless someone advises otherwise) its is fairly easy to justify the GT series inverter as the price difference isn't huge and I can always just run it in V/F mode if the vector control mode doesn't play nice with the spindle I end up buying.

It all revolves on your Power supply and Amps available as to what spindle you can use, for a whole machine with a 2.2Kw spindle you want a minimum of 25A circuit.

G-Penney is the best choice for a spindle, 4pole don't seem to have a good speed range as one would think they should, and require a 800Hz VFD Drive if they are 24000 RPM

[BigGinge]

I'm not at home to check just now but I'm reasonably sure that circuit is on a 32A breaker so should be ok. If it's only 16A then the spot the machine will live is only about 5m from the consumer unit so it wouldn't be too difficult to run a dedicated 32A spur out for it.

I had noticed that the 4 pole motors were still specified as being rated to 24000 RPM, I was kind of hoping that was just a mistake and that they would deliver full power at 12000 RPM but guess that doesn't sound like it is the case for these particular spindles. Shame.

[mactec54]

I'm not at home to check just now but I'm reasonably sure that circuit is on a 32A breaker so should be ok. If it's only 16A then the spot the machine will live is only about 5m from the consumer unit so it wouldn't be too difficult to run a dedicated 32A spur out for it.

I had noticed that the 4 pole motors were still specified as being rated to 24000 RPM, I was kind of hoping that was just a mistake and that they would deliver full power at 12000 RPM but guess that doesn't sound like it is the case for these particular spindles. Shame.

Here is one spindle that is an ok brand, Ceramic Bearings would be good, but they don't seem to offer it. the amps rating seem low it should be around 8.5A plus

It seems you have enough Power so a 2.2Kw work very well if the VFD Drive is Programed correctly, most of the Vector control VFD Drive can only work up to 300Hz so even less, the higher end VFD Drives vector control works through the whole range.

https://www.aliexpress.us/item/22518...d=JtGZGlFqUpdR

[BigGinge]

Do ceramic bearings make a big difference in use with these? They seem to be a relatively inexpensive option on a lot of the 2.2kw motors.

[mactec54]

Do ceramic bearings make a big difference in use with these? They seem to be a relatively inexpensive option on a lot of the 2.2kw motors.

Yes, they do make a difference they will last 3 times as long as a steel Ball Bearings sometimes more, they run smoother, just in general a much better Bearing to use. they also prevent any Rotor voltage going through the Bearings which causes most Bearing failures, a snip of what happens inside an AC 3ph motor.

When using single phase supply, it is worse, unbalanced this problem gets quite bad, so Bearing life can be quite short, depending on use, any Ac motor whether it's a spindle motor or just an Ac motor being driven with a VFD Drive, have this problem.