For an advanced hobbiest -Which inverter/spindle?

[ericks]

There is only one reason to buy a more powerful VFD than the motor, that is to give you the possibility to change the motor to a more powerful one if you feel you need it at a later stage. That is assuming your VFD fulfils it's specifications. It has nothing to do with single phase or three phase mains.

The 0-10V issue I was talking about has NOTHING to do with screened or not screened cables. The cheap BoBs don't have a liner output voltage and because the D/A circuitry is a pretty simple one, the voltage is fluctuating. In an ideal world 25% pulse wide should give 2.5V out, 50% should give 5.0V and 100% should result in 10.0V but this is NOT the case, and the deviation is not linear. I measured this at the output of course, not just watched the spindle RPM meter.

Again i agree with you....you obviously know what you talking about

[A_Camera]

Anything I would consider to be "quality", would be non chinese, and $1000 and up.
If you want cheaper, then maybe one of these:
GMT Air Cooled CNC Spindle 0.8 kW 220 V 24000 RPM S | Air Cooled Spindles

According to this video at 2m51s...



...the Ugra is Made in China, which is what I suspected. It is just a higher quality, like so many other things. There is no such thing any more as Made in China = crap.

[mactec54]

There is only one reason to buy a more powerful VFD than the motor, that is to give you the possibility to change the motor to a more powerful one if you feel you need it at a later stage. That is assuming your VFD fulfils it's specifications. It has nothing to do with single phase or three phase mains

Again you talk with no experience but the one VFD install, you have done, it is a given in the industry that a VFD Drive that runs on Single Phase supplying a 3 Phase output need to have a derating, hence the larger VFD requirement, do some web searching you will find it everywhere, most VFD manufactures offer this information below

Single phase operation requires a derating factor of about 1.73 (square root of 3) because the INPUT current requirement goes up by not providing 3 phase power. If you are trying to operate a 5 hp motor and have single phase power, a 7.5 hp VFD drive would work marginally (1.5 times), a 10 hp VFD drive (2 times) would be preferred..

[mactec54]

Again i agree with you....you obviously know what you talking about

You should not agree to something that is incorrect, ( it could be correct with the Breakout Board, but also easy to fix, ) but with the VFD Drive that is incorrect, you clamming to be experienced with VFD Drives should know better, most VFD manufacturers offer this information below

Single phase operation requires a derating factor of around 1.73 (square root of 3) because the INPUT current requirement goes up by not providing 3 phase power. Example: If you are trying to operate a 5 hp motor and have single phase power, a 7.5 hp VFD drive would work marginally (1.5 times), a 10 hp VFD drive (2 times) would be preferred..

[Al_The_Man]

The whole crux of the matter over 1ph and 3 phase is the capacity of the DC supply and its ability to supply the demanded current.
The 1ph supply ripple into the typical 3 phase rectifier that is found in All VFD's, transitions from the peak through zero (100% ripple), this means that sufficient electrolytic capacity has to be provided on the rectifier output in order to maintain the load current demand and carry the required current through this zero transition..
In 3 phase, the electrolytic capacity can be considerably smaller due to the 3ph AC ripple being approximately only 5%, this is why in 3ph-only VFD's the electrolytic capacitor sizing is considerably smaller in spite of the larger motor size.
IOW, manufacturers size the DC supply (Capacitors) accordingly to accommodate both 1ph and 3ph inputs on the low HP convertors.
And of course the other edge that 3ph has is the rectified ripple frequency on 60hz supply is 360hz as compared to 120Hz for 1 ph.
Al.

[ericks]

You should not agree to something that is incorrect, ( it could be correct with the Breakout Board, but also easy to fix, ) but with the VFD Drive that is incorrect, you clamming to be experienced with VFD Drives should know better, most VFD manufacturers offer this information below

Single phase operation requires a derating factor of around 1.73 (square root of 3) because the INPUT current requirement goes up by not providing 3 phase power. Example: If you are trying to operate a 5 hp motor and have single phase power, a 7.5 hp VFD drive would work marginally (1.5 times), a 10 hp VFD drive (2 times) would be preferred..

I have indicated that one should follow the relevant drive manufacturers instructions......Fortunately in my job i only work with higher end drives, started working with drives in 1994....seen and experienced the improvements in their design.

****** i think you are referring using a three phase input drive on single phase, then derating would apply.....personally i have never done this. If i have a single phase supply available in an application then i choose a single phased input drive only!! For a three phased system i would in most cases use a three phased input drive. Best practice is to use the proper drive for the available power supply. Yes using a larger capacity drive than the motor size has it's benefits but usually cost and space in the enclosure would dictate what size drive you can install.

[mactec54]

I have indicated that one should follow the relevant drive manufacturers instructions......Fortunately in my job i only work with higher end drives, started working with drives in 1994....seen and experienced the improvements in their design.

****** i think you are referring using a three phase input drive on single phase, then derating would apply.....personally i have never done this. If i have a single phase supply available in an application then i choose a single phased input drive only!! For a three phased system i would in most cases use a three phased input drive. Best practice is to use the proper drive for the available power supply. Yes using a larger capacity drive than the motor size has it's benefits but usually cost and space in the enclosure would dictate what size drive you can install.

There are not a lot of Single Phase Only Drives that could run a 2.2Kw Spindle the most used spindle size

The Drives that are for true Single Phase use only have ( 2 ) input terminals, and have low Hp ratings, any other VFD drive even though they can be used / run on single Phase, they all have a 3 Phase input rectifier with the R- S- T Terminals, these where designed to run on 3 Phase, they where not designed to run on Single Phase, even though they have and say for Single Phase use, so any user has a choice to use a larger capacity Drive or Derate the one they have

This is one of the reasons why the Chinese Drives are unreliable, they are not being sized or derated for the Motor they are driving, everyone says there spindle is not 2.2Kw this is the reason, the VFD can not supply enough input current to drive the spindle to is max

As for a drive size being big these small Drives up to 5Hp rated are all much the same size

[Dan911]

Again you talk with no experience but the one VFD install, you have done, it is a given in the industry that a VFD Drive that runs on Single Phase supplying a 3 Phase output need to have a derating, hence the larger VFD requirement, do some web searching you will find it everywhere, most VFD manufactures offer this information below

Single phase operation requires a derating factor of about 1.73 (square root of 3) because the INPUT current requirement goes up by not providing 3 phase power. If you are trying to operate a 5 hp motor and have single phase power, a 7.5 hp VFD drive would work marginally (1.5 times), a 10 hp VFD drive (2 times) would be preferred..

What you posted makes perfect sense but I have to add.... I purchased a 3KW Huanyang VFD and 3KW spindle several years ago, changed the upper bearing on spindle a year later and changed the lower paired bearings on spindle the following year after that. Same Huanyang single phase VFD still going.

Dan

[mactec54]

What you posted makes perfect sense but I have to add.... I purchased a 3KW Huanyang VFD and 3KW spindle several years ago, changed the upper bearing on spindle a year later and changed the lower paired bearings on spindle the following year after that. Same Huanyang single phase VFD still going.

Dan

All the Huanyang Drives I have repaired, have never had a rectifier fail, because of running on Single Phase, this part of there drive is quite robust, your 3Kw has the same parts as a 4Kw from 1.5Kw up to 4Kw are the only ones I have looked /worked on, and they all have the same front end rectifier, so there is not much chance that running on Single Phase is going to affect any of them, bigger is always better as your VFD drive has more capacity to be able to draw more Current when needed, most drives can not handle the extra current draw that these spindles can draw, and this is one of the reasons why they fail, even Hitachi also fail with the same problem, so it is not a single manufacture that has this problem, they all do, sizing is key, and the correct spec Drive for Spindle or Motor being used

The correct sizing of a VFD Drive is important, every manufacture has a list of what each drive is capable of doing with Single Phase and 3 Phase connection, if everyone followed what the manufacturer's recommend then we most likely would have a lot less problems with VFD Drives

So basically there are 3 things that are needed for a successful VFD install, Drives Sizing, Wiring and Parameter setting

[automationtechinc]

You are right " So basically there are 3 things that are needed for a successful VFD install, Drives Sizing, Wiring and Parameter setting "
https://www.automationtechnologiesin...e/cnc-spindle/

[Goemon]

According to this video at 2m51s...



...the Ugra is Made in China, which is what I suspected. It is just a higher quality, like so many other things. There is no such thing any more as Made in China = crap.

I would prefer to buy a Teknomotor spindle over a GMT. The prices are the same or better, they are made in Italy, not China and they have better entry level options.

Their 2.2kw electric fan cooled model and their manual quick tool change HSK32 models were among the best value I saw with industrial brands. Their basic entry level air cooled models between .8kw and 2.2kw are very affordable with current Euro / dollar exchange rates. I have seen them in the $400-$500 range.

[ger21]

I know someone with a Teknomotorspindle. The bearings went after about 2 years of use, though it was used a lot. Not sure if they are any better than the GMT??

[ericks]

I have been looking into these Teknomotor spindles for my new build. There are different models, obviously with a price difference

[A_Camera]

There are not a lot of Single Phase Only Drives that could run a 2.2Kw Spindle the most used spindle size

2.2kW is a sort of a "reasonable limit" because of the current limits of most 1phase homes. After that it is regarded as purely industrial usage where three phases are always available (at least in Europe). Never the less, it isn't a big issue to find 2.2kW single phase VFD, though the subject here is 1.5kW.

The Drives that are for true Single Phase use only have ( 2 ) input terminals, and have low Hp ratings, any other VFD drive even though they can be used / run on single Phase, they all have a 3 Phase input rectifier with the R- S- T Terminals, these where designed to run on 3 Phase, they where not designed to run on Single Phase, even though they have and say for Single Phase use, so any user has a choice to use a larger capacity Drive or Derate the one they have

This is one of the reasons why the Chinese Drives are unreliable, they are not being sized or derated for the Motor they are driving, everyone says there spindle is not 2.2Kw this is the reason, the VFD can not supply enough input current to drive the spindle to is max

As for a drive size being big these small Drives up to 5Hp rated are all much the same size

What you are saying is the same as I have said before. There is a need to buy a more powerful driver if you buy the cheap Chinese drivers because they are not capable of delivering what they promise in the specs. That is NOT necessary with quality VFDs, a single phase 1.5kW VFD can drive a 1.5kW motor with full power just as well as a three phase 1.5kW VFD can. The only difference is that the single phase VFD will draw more current than a three phase would, but you would NOT notice any other difference if you have a quality VFD.

[A_Camera]

Again you talk with no experience but the one VFD install, you have done, it is a given in the industry that a VFD Drive that runs on Single Phase supplying a 3 Phase output need to have a derating, hence the larger VFD requirement, do some web searching you will find it everywhere, most VFD manufactures offer this information below

Single phase operation requires a derating factor of about 1.73 (square root of 3) because the INPUT current requirement goes up by not providing 3 phase power. If you are trying to operate a 5 hp motor and have single phase power, a 7.5 hp VFD drive would work marginally (1.5 times), a 10 hp VFD drive (2 times) would be preferred..

I think you are mixing apples and oranges. I am talking about single phase, quality VFD designed for single phase use, not eBay quality three phase VFDs run on single phase. Also, nobody here except you, are talking about 10hp machines. The OP was talking about 1.5kW and that's what I am talking about as well.

Yes, the current goes up if you have a single phase 1.5kW VFD compared with a 3 phase 1.5kW but that doesn't mean you have to use a 2.2kW to run a 1.5kW motor on single phase.



Note that the manufacturer recommendations are MATCHING the VFD and the motor power. Never have I read anywhere that there is a need or recommendation to use a more powerful VFD than the motor, though I'd definitely believe that is the case with the low end VFDs.

Yes, I talk with experience from only one VFD, that is hardly a secret. But before I bought the one I have, I have read quite a few manuals and looked at different options. It was very easy for me to dismiss the HY and would not hesitate dismissing it even today. I think, as I said before, that spending a little more on the VFD is well invested money, saving a lot of headaches and questions. I know you disagree with many of my comments, but I can live with that.

[A_Camera]

I have indicated that one should follow the relevant drive manufacturers instructions....

Exactly. But the problem is that you can only trust the serious manufacturers, not the ones which mass produce half baked copies or sell under invented "brand" names. With those it is a bit of a lottery.

[ericks]

Exactly. But the problem is that you can only trust the serious manufacturers, not the ones which mass produce half baked copies or sell under invented "brand" names. With those it is a bit of a lottery.

I agree....

[Goemon]

I know someone with a Teknomotorspindle. The bearings went after about 2 years of use, though it was used a lot. Not sure if they are any better than the GMT??

The bearings on any spindle go after heavy use. I am sure the cheapest Teknomotor spindles have lower quality bearings than their more expensive models which have dual super precision bearings at the tool end (like other industrial models). I assume the longevity is priced in.

I just have more trust in the Teknomotor brand than any Chinese ones. They have been established a lot longer than GMT and they are sold in places that sell other industrial brands like Colombo (places that wouldn't touch Chinese spindles). They are also well supported with accessories and good availability of affordable replacement parts.

The GMT spindles are not cheap enough to be worth taking a chance on for my taste. I considered it but their prices were creeping into HSD teritory. I can understand taking a chance on a no-name Chinese brand if they are so cheap that the risk doesn't matter. I see no reason to buy one if there is no meaningful saving at all. A 4.5kw GMT costs about the same as a new 4.5kw HSD...

I couldn't find any track record at all for GMT spindles (good or bad). I don't think there are many out there.

It's just one man's opinion though. I just haven't had very good luck in the past with products from China.

I am surprised the GMT spindles get a pass from you. It was largely because of your advice I stayed away from Chinese spindles and invested in an industrial model. Would you really spend $800-$1000 on a 2.2kw shaft fan cooled GMT over a 2.2kw electric fan cooled Teknomotor for $800, or a rebuilt 4.5kw PDS ADEV 90 (with 6 month warranty) for $950?

This guy reviewed his 2.2kw electric fan Teknomotor as part of his build log:

https://www.wadeodesign.com/design-details.html

He has a bunch of videos on YouTube showing it milling nice looking aluminum parts too. It's worth a look if you haven't already seen it.

[ericks]

I have been looking/searching for a while. The higher end Teknomotor seems to be a very good option, its on my list for sure

[Goemon]

2.2kW is a sort of a "reasonable limit" because of the current limits of most 1phase homes. After that it is regarded as purely industrial usage where three phases are always available (at least in Europe). Never the less, it isn't a big issue to find 2.2kW single phase VFD, though the subject here is 1.5kW.



What you are saying is the same as I have said before. There is a need to buy a more powerful driver if you buy the cheap Chinese drivers because they are not capable of delivering what they promise in the specs. That is NOT necessary with quality VFDs, a single phase 1.5kW VFD can drive a 1.5kW motor with full power just as well as a three phase 1.5kW VFD can. The only difference is that the single phase VFD will draw more current than a three phase would, but you would NOT notice any other difference if you have a quality VFD.

Most homes here can accommodate a 50 amp 240v breaker and some even higher (depending on what type of heating system they have).

My 5.6kw spindle draws 19amps 3ph which means it needs just under 40amps from a 1ph outlet (according to my VFDs manual). I wouldn't want to go up in power from that where I live but others do. There is no need to limit yourself to 2.2kw if you need more.