[allaces]

Hi,

A few questions:

1 - I want to use a 2.2kw water cooled Chinese spindle and gear it down 4:1 to an R8 spindle on a milling head I'm building.
The Chinese spindle can run at 20,000 RPM, so the R8 spindle would be 5000 RPM max.
Does anyone know of possible problems with that idea?

2 - Would it be possible to index and hold the R8 spindle in that indexed position using an encoder on the R8 spindle end?
Does the 2.2kw water cooled Chinese spindle have the ability to brake and hold a position?
If this could be done... how would it need to be wired and setup in Mach3?
Please explain any suggestions or problems with the above...

Thanks,
Ray

[mactec54]

Hi,

A few questions:

1 - I want to use a 2.2kw water cooled Chinese spindle and gear it down 4:1 to an R8 spindle on a milling head I'm building.
The Chinese spindle can run at 20,000 RPM, so the R8 spindle would be 5000 RPM max.
Does anyone know of possible problems with that idea?

2 - Would it be possible to index and hold the R8 spindle in that indexed position using an encoder on the R8 spindle end?
Does the 2.2kw water cooled Chinese spindle have the ability to brake and hold a position?
If this could be done... how would it need to be wired and setup in Mach3?
Please explain any suggestions or problems with the above...

Thanks,
Ray

No the spindle does not have the ability to hold a position, they can do braking with a VFD Drive that has a braking Resistor ( normally extra for this ) not a good choice of motor to do this with, if you got a AC servo motor you would solve all your problems 5000 is what some will run at depending on size and you can position it how ever you want , in Mach3 you could set it up as an axes

[allaces]

Mactec54,

Thank you for your reply. I need more help!

Keeping in mind the "cost" and the "resulting torque" value at the R8 spindle from the 4:1 reduction of my flawed 2.2kw setup...

Can you direct me to a "110 VAC Servo" that can handle the "5000 RPM" and provide similar "Torque" to the R8 spindle for similar "End Price"?

Ray

[joeavaerage]

Hi,
I bought a second hand 1.8kW 3500 rpm Allen Bradley AC servo and matching drive for about $600 USD (delivered) in New Zealand. Still had to buy cables and
the Rockwell setup software for use as a directly coupled spindle motor, all up about $900USD. Absolutely delighted with how it works.

Quite frankly a lot of that Chinese stuff is that junky that second hand US/European/Japanese stuff is better. AC servos when used as spindles can be indexed very
accurately, programmed in velocity OR torque OR position modes, or maybe a primary mode (velocity) with a secondary mode (position),they are almost too good!.

Have a closer look at secondhand servos and matching drives on EBay. If you are unfamiliar with AC servos I would get a servo and matching drive from the same
manufacturer. You can mix and match servos and drives IF you know what you are doing. I'm glad I have a matching drive...I think I would have struggled
to adapt my servo to another manufacturers drive.

Delta and Teco are good Chinese/Taiwanese brands but I wouldn't trust any of the cheaper Chinese stuff. Beware also that cables and setup software
(depending on the brand) may not be included if buying second hand.

You might like to look at new DMM servos, although I think all the higher power ones are 230V. The company is Canadian and have a good reputation for support
but they manufacture in China so the prices a pretty compelling. Quality at a good price.......

https://store.dmm-tech.com/products/...ac-servo-motor
https://store.dmm-tech.com/products/...nt=20981907526
https://store.dmm-tech.com/collectio...Servo%20Cables

Craig

[allaces]

Hi,
I bought a second hand 1.8kW 3500 rpm Allen Bradley AC servo and matching drive for about $600 USD (delivered) in New Zealand. Still had to buy cables and
the Rockwell setup software for use as a directly coupled spindle motor, all up about $900USD. Absolutely delighted with how it works.

Quite frankly a lot of that Chinese stuff is that junky that second hand US/European/Japanese stuff is better. AC servos when used as spindles can be indexed very
accurately, programmed in velocity OR torque OR position modes, or maybe a primary mode (velocity) with a secondary mode (position),they are almost too good!.

Have a closer look at secondhand servos and matching drives on EBay. If you are unfamiliar with AC servos I would get a servo and matching drive from the same
manufacturer. You can mix and match servos and drives IF you know what you are doing. I'm glad I have a matching drive...I think I would have struggled
to adapt my servo to another manufacturers drive.

Delta and Teco are good Chinese/Taiwanese brands but I wouldn't trust any of the cheaper Chinese stuff. Beware also that cables and setup software
(depending on the brand) may not be included if buying second hand.

You might like to look at new DMM servos, although I think all the higher power ones are 230V. The company is Canadian and have a good reputation for support
but they manufacture in China so the prices a pretty compelling. Quality at a good price.......

https://store.dmm-tech.com/products/...ac-servo-motor
https://store.dmm-tech.com/products/...nt=20981907526
https://store.dmm-tech.com/collectio...Servo%20Cables

Craig

Craig,

For whatever reason, I COMPLETELY missed this post!!!
My apologies for that... I clearly need to pay more attention to how forums work. I'll try to blame it on age, but that hurts!

It seems you provided me with everything I needed "right from the start". I don't think DMM is more that 15 miles from me! NO Shipping issues!

As you already know... electronics are NOT my thing but your help is getting me on track.

I don't think I will do better for prices... and I can get support from them for my shortcomings...

I will contact them directly for equipment in the links you provided.

Thanks again Craig for taking time on me!

Ray

[joeavaerage]

Hi Ray,
DMM have carved out a good reputation for themselves in a short time.

You will have seen that a new DMM servo and drive can be had for about the same money or even less than a second hand Allen Bradley
servo and drive.

Craig

[mactec54]

Mactec54,

Thank you for your reply. I need more help!

Keeping in mind the "cost" and the "resulting torque" value at the R8 spindle from the 4:1 reduction of my flawed 2.2kw setup...

Can you direct me to a "110 VAC Servo" that can handle the "5000 RPM" and provide similar "Torque" to the R8 spindle for similar "End Price"?

Ray

If you only have 120v supply then forget the 2.2Kw they are junk when run with 120v NA supply they need 240v to be anywhere half decent

Dmm can run on 120v/240v so check them out to see what they have to offer DMM | Technology Solutions | AC SERVO DRIVE | AC SERVO MOTOR | ROTARY ENCODER

[allaces]

If you only have 120v supply then forget the 2.2Kw they are junk when run with 120v NA supply they need 240v to be anywhere half decent

Dmm can run on 120v/240v so check them out to see what they have to offer DMM | Technology Solutions | AC SERVO DRIVE | AC SERVO MOTOR | ROTARY ENCODER

I checked the link you provided. They do look like high end and very suitable for the application, but the price is probably over my budget for a hobby machine (I could not find any prices).

I appreciate your input even though I may be on the lower end of the price scale.

120VAC or 240VAC is not a problem if a 240VAC spindle is a better choice.

I know I could buy the "best of the best" if the end price is not an issue...

What do you think about the other questions I asked?
- Total comparative cost for both
- Encoder on the R8 spindle to achieve indexing of the 2.2kw spindle
- Torque comparison for both at all RPM range - using 4:1 on the 2.2kw spindle

I'm trying to get something priced reasonably that would fit my hobby needs.

Thank you,
Ray

[he1957]

Have a look at the ClearPath servo motors. They have a wide set of ratings, operating parameters and modes including the ability to set them to move to one of 4 pre-programmed positions (depending on modes). They might not give the RPM's you need however.

How you would integate this into what you are building might be a different question.

[joeavaerage]

Hi,
Clearpath servos are nice but expensive, The dollars per watt is almost double Delta or DMM. They capture sales by marketing them as a 'replacement
for a stepper' and that attracts a lot of new customers, who pay too much for them.

If you need an indexing spindle of moderate torque then there is NO ACCEPTABLE low cost solutions. Any of the low cost solutions like
cheap Chinese asynchronous motors and VFDs are not indexable and still would need significant gear or belt reduction (did you say transmission loses?)
to drive an R8 spindle.

I suspect that if you buy something like this then you'll find it does not do the job you wanted and that makes it VERY EXPENSIVE even if it did not cost
a great deal.

Genuine indexing requires a servo with an encoder. New AC servos of good quality but still fair prices are Delta and DMM. My Allen Bradley servo
is very similar to this:
https://www.ebay.com/itm/ALLEN-BRADL....c100005.m1851
And the servo drive:
https://www.ebay.com/itm/Allen-Bradl...53.m1438.l2649

So even second hand, really good quality from the US, Japan and Europe are expensive, on the other hand they work REALLY WELL.

I think Matec54 is right, expecting 2.2kW from a 120V supply is unrealistic.

I think also you have to revise your budget upwards somewhat or risk buying what you hope is a cheap solution only to find it doesn't work as well as you hoped.
A close inspection of EBay may result in a good buy. Baldor servo motors are well represented often at good prices and are great motors. Unfortunately the matching
servo drives are very expensive. You might alternately find a brushed servo for which there may well be cheaper DC servo drives.

Craig

[allaces]

joeavaerage,

Thank you for taking the time to explain this to me.
I appreciate input from those with experience in areas I don't have.
I now have a better chance of selecting a better solution for my projects.

When I contacted a supplier of these Chinese spindles. they told me that the performance of 120V or 240V would be similar except that the amp requirement would be double for 120V system. I have a 12" radial arm saw that I bought many years ago that can run on either 120V or 240V and... to me... the performance is not noticeable either way it's wired, except that you need double the amps on the 120 line when you run it on 120V. I thought the same would be the case for the 2.2kw spindles.

Thanks for your input,
Ray

[joeavaerage]

Hi,

except that you need double the amps on the 120 line when you run it on 120V. I thought the same would be the case for the 2.2kw spindles

That is essentially correct. The problem is that with the 0.5-0.6 power factor common with VFDs the even at 240V 2.2kW could take 20A or more. Now you want to double
the current to run at 120V is quite an ask!!. At about 2kW and above the majority of servo drives require three phase and 400V line-line at that. I suspect genuine 120V servos are very
rare indeed beyond 1kW. Your choice would be limited and probably expensive.

AC servos get their torque by having more pole-pairs, or how they are wound. 24000 rpm asynchronous spindles have one pole pair per phase, called two pole
in the US, with a 400Hz VFD. A typical AC servo will have four pole-pair per phase, or 8 pole in US speak, with a servo drive capable of 400Hz. The servo
will have four times the torque of the asynchronous spindle but 1/4 of the revs.

You can get asynchronous spindles with two, three and four pole-pair per phase but they tend to be specialized and built for industrial applications and very
expensive, even more than a servo. Even then asynchronous spindles would need to be fitted with an ecoder or resolver to be indexable, way WAY out
of your budget.

I recommend you try an AC servo, I suspect you would be surprised just how much grunt a 1kW or 1.3kW Ac servo can have. Servos commonly have a short term
torque overload of three or four times their rated torque. Obviously they will overheat if you attempt to get more than their rated torque continuously but that
short term overload can certainly make you believe that the servo is much more powerful than the rating suggests.

Craig

[allaces]

Hi,

... I recommend you try an AC servo, I suspect you would be surprised just how much grunt a 1kW or 1.3kW Ac servo can have. Servos commonly have a short term
torque overload of three or four times their rated torque. Obviously they will overheat if you attempt to get more than their rated torque continuously but that
short term overload can certainly make you believe that the servo is much more powerful than the rating suggests.

Craig

Craig,

I will definitely consider your recommendation for 1kW or 1.3kW Ac servo. From what you explained... it probably would be very sufficient for my project and clearly makes more sense that my original idea , not that my original idea made any sense to start with. I'm amazed that people like yourself with the knowledge you have... take the time and can be even be bothered to advise people with shortcomings like me.

TOTALLY APPRECIATED!

---------------------------------------

Craig,

I already have a VFD like this one:

https://www.ebay.com/itm/2-2KW-3HP-V...JHDP:rk:3:pf:0

Would the following servo be a good match for this VFD and my project?

https://www.ebay.com/itm/ALLEN-BRADL...frcectupt=true

My project being a small CNC lathe with a custom R8 spindle which would be used for machining small shafts and being able to index the spindle for machining grooves, keyways, drill holes, etc... using live tooling.

Thanks,
Ray

[Jim Dawson]

The step pulleys will work fine. I'm having a bit of trouble getting my head around what you are saying about the geared indexing shaft.

[allaces]

The step pulleys will work fine. I'm having a bit of trouble getting my head around what you are saying about the geared indexing shaft.

I'm looking at the spindle to only have the driven gear, position/speed sensor, and bearings on it.
Next to it will be what I'll call the driving gear/index shaft for this spindle.
One end of this shaft will have the 2 clutches and Nema 34 connected to it for indexing.
The other end of that shaft will be the driving gear, support bearing, and external driving step pulleys I mentioned.

- I'm revising this above idea to using a timing belt instead of gears inside the head. Now days... you can get pretty rigid setups using them with pretty much 0 backlash. I already use that setup on my converted to CNC mill/drill, to operate a second spindle. Adjusting and maintaining C/D is also easier, plus no oil lubrication required.
- I'm also looking at putting the "brake" using a mag clutch on the spindle shaft instead of the driving gear/index shaft I mentioned above. This would eliminate milling force vibrations created from the connection between 2 shafts. I ordered a few mag clutches... I'll see if can somehow fit one on the 2" diameter spindle shaft... I doubt I will be able to... then a disk brake may be the best way to go.

Again... this is still work in progress, so learning and changing my mind is part of the process

Any suggestions are greatly appreciated.

Ray

[allaces]

Would you happen to know what the field coil bore diameter for this clutch is, it more than 2"?
https://www.ebay.com/itm/AC-A-C-Comp...1/223097334901
I can't seem to get an answer from anyone for that..
If it's over 2" then that could possibly allow me to use it for a spindle position brake right on my main spindle.

Ray