Re: Metal Working Spindle
Looking for the same recommendation.
Re: Metal Working Spindle
I use a similar water cooled 220v spindle for wood and am sure it will cut certain types of aluminum. It runs up to 400hz.
Steel cutting requires far lower speeds and much higher torques. Spindle and machine stiffness are much higher when cutting steel.
So I don’t think this spindle will actually cut steel, other then fine finishing. If that’s not what you intend to do, I would try to find torque specifications on these spindles at lower speeds.
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Re: Metal Working Spindle
Quote:
Originally Posted by
KiwiEngineer
Kia ora!
Ive been exploring this wonderful forum gathering information before i start my build.
I will be casting a gantry type cnc router with approximate build volume of 700mm x 500mm x 150mm out of cast iron from a local foundry.
I will be primarily cutting Aluminum, but of coarse i aim to try cut Steel. I am based in NZ and only have single phase electricity.
Can anyone help me choose the best spindle for this sort of application? I have found these 2 so far which i think will be good contenders as they are both 4 pole.
https://www.aliexpress.com/item/3298...archweb201603_
or
https://www.aliexpress.com/item/4001...archweb201603_
I have to admit im a little confused between the 2 as one is 800hz and one is 400hz. Which one would be better at low RPM?
I also noticed that the GDK80-12Z/2.2 spindle claims 1500 - 12000rpm in the link below. But doesnt claim it in the above link.
https://www.aliexpress.com/item/4000...%2315609%23235
Cheers,
Rohan
The G-Penny is the best spindle you have picked 400Hz verse 800Hz
800Hz 4 pole would be able to go up to 24,000 RPM
400Hz 4 Pole would only be able to go up to 12,000 RPM 400Hz 2 Pole will go to 24,000 RPM
The VFD Drives offered are not a good choice of VFD Drives to use so would buy the spindle separate
None of these spindle are suitable to mill steel, anything up to aluminum will be fine, you can do steel engraving though
Re: Metal Working Spindle
Hi Mactec54,
Thanks for the info!
Would you have a VFD you would recommend?
Is the main reason these are not suitable because of the peak torque being such a high speed or the build quality and bearings are not suitable?
Rohan
Re: Metal Working Spindle
Quote:
Originally Posted by
KiwiEngineer
Hi Mactec54,
Thanks for the info!
Would you have a VFD you would recommend?
Is the main reason these are not suitable because of the peak torque being such a high speed or the build quality and bearings are not suitable?
Rohan
I think you are talking about the milling of steel =Bearings, the Bearing arrangement and spindle design is the main problem, not the Bearing quality, High speed spindles built as cheap as these are have the 2 front AC Bearings with the cup facing out, the 2 top bearings are facing the opposite direction which are spring loaded, so as the spindles loads get higher, the front Bearing come off there faces of the AC Bearings and will chatter like mad until a thrust loading is applied
If you look at the G-penny you get more torque than any of the other spindles with the same Kw rating, because of the rotor is longer and a larger diameter, there is more copper in the stator plus if you see the Amp specs is also higher
The minimum speed is also better because of there design 3000 RPM all other water cooled are 6,000 RPM minimum
There are other seller selling this same spindle, under a different name, but be careful as there are some that look the same but are not
VFD Drive would depend on what Hz you went with the are many good VFD Drives for the 400Hz spindles not so many for the 800Hz to choose from
For what you want to do I would go with there best one with the Steel core, ceramic Bearings, the regular spindle has aluminum core
Re: Metal Working Spindle
Cheers again for the info!
I guess this seems like what im after.
https://www.aliexpress.com/item/4000...archweb201603_
As im not too concerned about 24k rpm and i think 12k should be plenty. I think a good 400hz would do me just fine.
I notice these seem to be very popular. I guess it isnt because their so cheap.
https://www.aliexpress.com/item/1689...5a1c1e74KMlqZQ
Rohan
Re: Metal Working Spindle
Quote:
Originally Posted by
KiwiEngineer
Correct the 4 pole 400Hz is all that most need unless you are using very small diameter cutters then the extra spindle speed can be a good thing
With that VFD Drive yes it is one of the most popular in the 400Hz range, for single phase, go a little larger so like 3Kw you will want a 25A / 30A circuit for your machine power supply
Re: Metal Working Spindle
Hi Mactec54,
The G-Penny customer support have been messaging me concerned about my choice of VFD. (3.0KW HUANYANG). I mentioned to them that i am not concerned about going 24k rpm and 12k rpm will be fine with me. They then replied and said that the torque would also be reduced and suggested i swap it out for one of these. https://www.aliexpress.com/item/1005...30693e5ffzJpBx
Is this correct? Would there be much torque loss if running both VFD at similar rpm?
Rohan
Re: Metal Working Spindle
Quote:
Originally Posted by
KiwiEngineer
Hi Mactec54,
The G-Penny customer support have been messaging me concerned about my choice of VFD. (3.0KW HUANYANG). I mentioned to them that i am not concerned about going 24k rpm and 12k rpm will be fine with me. They then replied and said that the torque would also be reduced and suggested i swap it out for one of these.
https://www.aliexpress.com/item/1005...30693e5ffzJpBx
Is this correct? Would there be much torque loss if running both VFD at similar rpm?
Rohan
You are talking with sales people that have no clue as to what VFD would be best, they will sell you anything to make a sale, the one they suggested is only 7A output your spindle has 10A plus so go figure as to what they are talking about, would the Torque change not a chance, not unless they are talking about using vector mode and that can give you better low speed torque, but this does not change the overall torque of the spindle
For your spindle you want the 4 Pole ceramic bearings 12,000 or 24,000 your choice when you go with 4 Pole your VFD Drive choices change
12,000 RPM 400Hz
24,000 RPM 800Hz
So which Spindle you get will determine which VFD Drive you need to get, Fuling is not what I would be buying, as I said they want to make a sale and that is the only VFD Drive they have that will do the 800Hz Spindle, But also what they suggested would not be suitable for either of those spindles @10A
What ever VFD Drive you end up getting it still needs to have more capacity for single phase power supply so 3Kw is the minimum
Re: Metal Working Spindle
Thanks again for the fast response! As i have already made the purchase and they were trying to change my order. (which is nice they are thinking of me)
I had chosen the following.
https://www.aliexpress.com/item/1005...61b64c4druejlj
and
https://www.aliexpress.com/item/4000...61b64c4druejlj
Which from what i understand should work fine being. But would only run at 12k rpm max? Which i am more then happy with.
So i should reply back to the support and ignore there suggestion and carry on with my order?
Rohan
Re: Metal Working Spindle
Quote:
Originally Posted by
KiwiEngineer
The spindle you have the link to is 800Hz this will not run with the 400Hz VFD Drive
Re: Metal Working Spindle
ahh right. I guess i didnt understand correctly..
Would it be easier to find a better VFD or to find a 4 pole 400hz spindle?
Rohan
Re: Metal Working Spindle
Quote:
Originally Posted by
KiwiEngineer
ahh right. I guess i didnt understand correctly..
Would it be easier to find a better VFD or to find a 4 pole 400hz spindle?
Rohan
There are not a lot of choices in the cheaper VFD Drives, that do 800Hz, the one they offer Fuling is border line but will do the job, for the 800Hz spindle, it is a little low in power rating for single phase use, the best VFD Drives are expensive Yaskawa Delta Etc. the next up Fuling is 3.7Kw this would be better but make sure it has 800Hz or more in the spec's if you buy this one
I thought the spindle you had found was 400Hz 4 Pole
Re: Metal Working Spindle
I dont mind spending more to get a better VFD. But i cant find any any delta,yaskawa or hitachi VFD's that will output 800hz. Do know any of the better models that will do this?
The fuling VFD's seem a little miss leading in there title as they claim 10A output for the 2.2kw and 15A output for the 3.7kw in their descriptions.
What is the physical difference between and 4 pole 400hz spindle and a 4 pole 800hz one?
Rohan
2 Attachment(s)
Re: Metal Working Spindle
Quote:
Originally Posted by
KiwiEngineer
I dont mind spending more to get a better VFD. But i cant find any any delta,yaskawa or hitachi VFD's that will output 800hz. Do know any of the better models that will do this?
The fuling VFD's seem a little miss leading in there title as they claim 10A output for the 2.2kw and 15A output for the 3.7kw in their descriptions.
What is the physical difference between and 4 pole 400hz spindle and a 4 pole 800hz one?
Rohan
There would not be any physical difference between the 2 spindles inside will be different, there is always conflicting numbers in there description's
This is a Delta VFD11AMS21ANSHA High speed Model and Yaskawa the best of all but a high cost V1000 High speed model
Yes you have to put in High speed when you try and find these VFD Drives, then you will get the spec's for that VFD Drive the Delta High speed goes up to 1500Hz
The Delta will be better priced of these 2 VFD Drives
Re: Metal Working Spindle
Hi,
I've found that high speed low torque spindles are very poor choices for milling steel.
You can engrave, light finish cut with small diameter (3mm or less) endmills but that's it.
I made a second spindle especially for steel. I used a 1.8kW Allen Bradley servo (3500rpm/6.2Nm cont) and
cylindrical ER25 toolholder and P4 angular contact bearings. Just the 'bees knees' in steel.
The majority of time (90%) I use my highspeed spindle and only swap over to the 'grunter' when I need it.
Where-abouts in NZ? I'm just out of Christchurch.
Craig
Re: Metal Working Spindle
Quote:
Originally Posted by
joeavaerage
Hi,
I've found that high speed low torque spindles are very poor choices for milling steel.
You can engrave, light finish cut with small diameter (3mm or less) endmills but that's it.
I made a second spindle especially for steel. I used a 1.8kW Allen Bradley servo (3500rpm/6.2Nm cont) and
cylindrical ER25 toolholder and P4 angular contact bearings. Just the 'bees knees' in steel.
The majority of time (90%) I use my highspeed spindle and only swap over to the 'grunter' when I need it.
Where-abouts in NZ? I'm just out of Christchurch.
Craig
He has a 4 pole not a 2 pole motor, the 4 pole motor is much better so has some ability to mill steel still not the greatest, what he has is not the normal 6,000 to 24,000 spindle
Re: Metal Working Spindle
Quote:
Originally Posted by
joeavaerage
Hi,
I've found that high speed low torque spindles are very poor choices for milling steel.
You can engrave, light finish cut with small diameter (3mm or less) endmills but that's it.
I made a second spindle especially for steel. I used a 1.8kW Allen Bradley servo (3500rpm/6.2Nm cont) and
cylindrical ER25 toolholder and P4 angular contact bearings. Just the 'bees knees' in steel.
The majority of time (90%) I use my highspeed spindle and only swap over to the 'grunter' when I need it.
Where-abouts in NZ? I'm just out of Christchurch.
Craig
Hi Craig,
As Mactec54 said ive brought a 4 pole spindle which from what i understand is "double" the torque. So giving it a go anyway, will at least be good for cutting plastic and light cuts of aluminium.
Do you have anymore information about your custom spindle? Might have to go down the route in the end haha.
Im based in Tauranga.
Rohan
Re: Metal Working Spindle
Quote:
Originally Posted by
mactec54
He has a 4 pole not a 2 pole motor, the 4 pole motor is much better so has some ability to mill steel still not the greatest, what he has is not the normal 6,000 to 24,000 spindle
Another dumb question incoming haha.
I cant seem to find the physical difference inside between a 800hz spindle and 400hz one. I thought i could possibly get G-Penny to modify my one? Would this this benefit me how? Or would it have the same torque curve at the same rpm as the 800hz spindle but with a lower top speed?
Rohan