[Tristar500]

I've been reading a few posts praising the G Penny spindles. Looking at this one but my inverter is only rated up to 400 Hz (Hitachi X200)

I'm in the USA so have access to 220 AC single phase.

I like the look of this one wit the ceramic bearings but it's a 800Hz unit. Anybody know of something similar that will work with my inverter?

https://www.aliexpress.com/item/3303...67891e53ISJtHB

I guess I could just bite the bullet and get the spindle/inverter kit?

Thanks in advance.

[mactec54]

I've been reading a few posts praising the G Penny spindles. Looking at this one but my inverter is only rated up to 400 Hz (Hitachi X200)

I'm in the USA so have access to 220 AC single phase.

I like the look of this one wit the ceramic bearings but it's a 800Hz unit. Anybody know of something similar that will work with my inverter?

https://www.aliexpress.com/item/3303...67891e53ISJtHB

I guess I could just bite the bullet and get the spindle/inverter kit?

Thanks in advance.

Yes you can get the same spindle in 400Hz the 800Hz is a 4 pole and the 400Hz is a 2 pole a 4 pole will have more torque, the G-Penny 2.2Kw 2 Pole is 10A with a speed range of 3000 to 24000 so one of the better spindles and has more torque than any other spindle in it's size

[Tristar500]

Yes you can get the same spindle in 400Hz the 800Hz is a 4 pole and the 400Hz is a 2 pole a 4 pole will have more torque, the G-Penny 2.2Kw 2 Pole is 10A with a speed range of 3000 to 24000 so one of the better spindles and has more torque than any other spindle in it's size

I use my homebuilt mill for many things but the most demand I put on it would be cutting 6061 aluminum. I make parts for the next CNC project and some bike parts etc. I mostly use end mills from 1/8 to 1/4 although I have collets and cutters larger and smaller.

Would you recommend the 2 pole motor for this kind of work or should I be looking at the 4 pole, 800 Hz and buy the VFD as well?

I'd rather put my money in a new spindle and use the VFD I have if it will work out well for me.

Thanks for taking the time to answer my questions Mactec54.

I'll poke around and see if I can find the 2 pole version you mentioned.

[Tristar500]

I'm having a hard time negotiating the "Chinelish" on the Ali Express site. If anybody can point me to the correct product I'd be most grateful. Not sure If I should be looking at the water cooled version or air? I have a water cooled laser cutter so I could tap into it's cooling system if need be.

[mactec54]

I'm having a hard time negotiating the "Chinelish" on the Ali Express site. If anybody can point me to the correct product I'd be most grateful. Not sure If I should be looking at the water cooled version or air? I have a water cooled laser cutter so I could tap into it's cooling system if need be.

What RPM are you using now for your aluminum cut this will give an indication which spindle will be best

Water cooled spindle is best

Here is the 400Hz with the option of Ceramic Bearings but before you buy we need to know what cutting speeds ( RPM ) you run at

https://www.aliexpress.com/item/3280...38211716mpu9Mg

[Tristar500]

I've never had any formal training as a machinist and have learned by trial and error over the years.
The spindle on the machine currently is a TAC Japanese unit I picked up off of Ebay 20 years ago. It's 3 phase 60 Hz spinning at 3600 rpm. I have it fitted with an ER-20 Collet chuck.

I don't know if a higher RPM would allow for faster cutting or not. As I said, It's all trial and error for me.

[mactec54]

I've never had any formal training as a machinist and have learned by trial and error over the years.
The spindle on the machine currently is a TAC Japanese unit I picked up off of Ebay 20 years ago. It's 3 phase 60 Hz spinning at 3600 rpm. I have it fitted with an ER-20 Collet chuck.

I don't know if a higher RPM would allow for faster cutting or not. As I said, It's all trial and error for me.

You won't be able to cut aluminum at those speeds with either of the 24,000 RPM spindles with the 2 spindles the 4 pole would be the best, but you would need a VFD Drive as well the 2 Pole will cut aluminum at around 4,500 to 7,200 RPM but light cuts at the 4,500 RPM

Yes your feed rates will be higher

[Dec0y]

I have owned a G Penny 800w water-cooled spindle coming up to 2 years and I have not had any problems with it.
When I purchased it I had problem with the VFD display but the speed controller worked fine.
I contacted the seller, they where very helpful, another display was sent out with a remote cable about 1.5m long.

Positive feedback from me.
I had a great experience with them pre sales and the experience continued with their after sales support.

[Dec0y]

You won't be able to cut aluminum at those speeds with either of the 24,000 RPM spindles with the 2 spindles the 4 pole would be the best, but you would need a VFD Drive as well the 2 Pole will cut aluminum at around 4,500 to 7,200 RPM but light cuts at the 4,500 RPM

Yes your feed rates will be higher

I would have to disagree with this statement, the quoted speeds are traditionally tested and recommended however the speeds are also dependent on the type and diameter of cutter.
Aluminium is being cut with high feeds and speeds exceeding 40,000rpm, I am personally looking at upgrading to the 400w 60,000 RPM water-cooled ceramic bearing spindle for that exact reason.
Trade torque for velocity.

[v0dka]

Here is the same but in 400hz version : https://fr.aliexpress.com/item/32947...%2315613%23403

[mactec54]

I would have to disagree with this statement, the quoted speeds are traditionally tested and recommended however the speeds are also dependent on the type and diameter of cutter.
Aluminium is being cut with high feeds and speeds exceeding 40,000rpm, I am personally looking at upgrading to the 400w 60,000 RPM water-cooled ceramic bearing spindle for that exact reason.
Trade torque for velocity.

You have no understanding of these spindle designs if you want to use very small cutters then yes you can use much higher RPM and cut Aluminum , but the average 400Hz spindle the bearing arrangement is not designed to cut aluminum so if your 60,000 spindle is of the same design then it would be a wasted upgrade as the outcome would be the same, these spindles can only run at these speeds because of the Bearing arrangement which in general is only good for engraving and not milling away metal like a normal mill will do

[broken003]

Yes you can get the same spindle in 400Hz the 800Hz is a 4 pole and the 400Hz is a 2 pole a 4 pole will have more torque, the G-Penny 2.2Kw 2 Pole is 10A with a speed range of 3000 to 24000 so one of the better spindles and has more torque than any other spindle in it's size

mactec54,
You mention that the G-Penny 2.2Kw 2 Pole is 10A spindle can run as low as 3000RPM?

Will there be useable torque at that low of RPM?

Is there anything I should watch out for when using it at lower RPMs?

[mactec54]

mactec54,
You mention that the G-Penny 2.2Kw 2 Pole is 10A spindle can run as low as 3000RPM?

Will there be useable torque at that low of RPM?

Is there anything I should watch out for when using it at lower RPMs?

They can run as low as 3000 RPM how much torque to do any useful cutting would be the question, it would be try and see, stalling would be your biggest concern, it would only be very light cutting at that speed, as max torque is at 24000 RPM so won't have very much torque at 3000 RPM

Set the readout on the VFD Drive for Amps and see what it is doing at each RPM level with a cut

[Tristar500]

I need to get out the manual for the Hitachi VFD and figure out how to display the Hz and or Amps.

Been using it for a few weeks now and am very pleased. Cutting mostly aluminum, brass and some plastics.

[mactec54]

I need to get out the manual for the Hitachi VFD and figure out how to display the Hz and or Amps.

Been using it for a few weeks now and am very pleased. Cutting mostly aluminum, brass and some plastics.

Not everyone is using a Hitachi VFD Drive, some it is just a press of a button on the VFD Drive KeyPad to change from RPM Amps Etc. nothing to look up in the manual

[planebuilder]

I have been using a Porter Cable 7518 for many years on my CNC gantry table. I have rebuilt it 3 times, new bearings each time, I don't think it's worth rebuilding again, getting loose and runout is increasing.
I cut wood, plastic, and mostly 6061T6 thin sheet (.020) up to 1" plate (multi pass). Most work is with 1/4" 2F bits @21,00 rpm. I'm thinking it's time to buy a spindle. I have 220 single phase power.
I'm thinking ceramic bearings, water cooled.
What G-Penny spindle size would you recommend, 2.2 kw or 3.5 kw to be as good or better than the PC7518?

[mactec54]

I have been using a Porter Cable 7518 for many years on my CNC gantry table. I have rebuilt it 3 times, new bearings each time, I don't think it's worth rebuilding again, getting loose and runout is increasing.
I cut wood, plastic, and mostly 6061T6 thin sheet (.020) up to 1" plate (multi pass). Most work is with 1/4" 2F bits @21,00 rpm. I'm thinking it's time to buy a spindle. I have 220 single phase power.
I'm thinking ceramic bearings, water cooled.
What G-Penny spindle size would you recommend, 2.2 kw or 3.5 kw to be as good or better than the PC7518?

It would depend on the Amperage you have with you 240v supply you need a 30Amp circuit for a 2.2Kw spindle

[planebuilder]

I have lots of amperage available, up to 60 amps. Would the 2.2 kw spindle be as powerful as the PC Router or would I need the bigger one?

[mactec54]

I have lots of amperage available, up to 60 amps. Would the 2.2 kw spindle be as powerful as the PC Router or would I need the bigger one?

Hp is Hp no matter what spindle 2.2Kw is around 3Hp if you are running at the near top end of the RPM then that is where you have max Hp and torque if you run at low RPM then the Hp and torque of the spindle will be less

So what is the rated Hp of the Router you are using, these spindles normally perform better than a normal Router

This spindle brand G-Penny is better than the rest as far as torque goes just a little better built and 10A for the 2.2Kw

[planebuilder]

They list the PC at 3 1/4 hp. You can hear the rpm drop a bit when cutting so probably getting less then full hp? I had heard the spindles maintain rpm better, more torque, so more hp when cutting, is that true? If so then it sounds like the 2.2kw would be a close replacement unless I'm missing something? Or would the 3.5kw give a machine more ability? I know it's hard to make specific recommendations when you don't know my machine.