Tool post grinder

[Shawn_Laughlin]

Does anyone see me running into problems if I were to make a tool post grinder with a 1.5kv er20 spindle motor 220v 3 phase? I have a vfd and 1.5kv -2hp should be more than enough hp for any wheel or at least bigger than practical on my machine, and it would take up much less room.

I was going totry a servo motor but since I have a vfd already the spindle motor seems to be the best route for me but I have zero experience with spindle integrated motors

 

[JimDawson]

The router spindles might work OK. I would be looking for one with a 4 pole motor, normally 18,000 RPM. The reason for this is that you don't need the high rpm for grinding, and you need to stay within the rated RPM of the wheels. In some cases that may be as low as 3600 RPM. The low speed performance of most of the router spindles is very poor below 6000 RPM, using the 4 pole motor will increase the low speed performance.

I would also recommend a water cooled spindle to run at slower speeds, the air cooled ones tend to get hot below about 12,000 RPM due to lack of airflow. A sensorless vector VFD would be required the get the low speed performance.

A quick EBay search turned up nothing with these spec's.

I just used an air grinder for my tool post grinder.

 

[Shawn_Laughlin]

I was worried about that with then lower speeds. I have slv vfd i bought for a tube axial exhaust fan I never used that’s up for the job. I have a air reamer but it’s so dang loud I hate using them. I machined a housing for an er11 swindle and got bearing and put it all together and even have a dc shunt 1/8 hp motor with a. Dart controller but come to find out the motor was damaged during the floods we had in Texas from hurricane Harvey a couple years back. I might just buy another one bc the spindle motor might be more of a problem then I originally thought. So thanks bc I might’ve spent money I shouldn’t have.

 

[Shawn_Laughlin]

I found a servo motor it’s like 3600 rpm but I believe the guy had the specs wrong,maybe. He has it as being 7.08 in lbs of torque and I’m wondering if he meant in oz? And I can’t find any specs when I search the model number he gives. I’m bout to shoot him a message. It’s a NEMA 23, 3600 rpm, 36 or 40 something volts.