Torque / Speed curves for different Spindle Types

[Chaz]

i also have a denford triac with the standard sem servo motor, owned the machine for 3 years. ive never once managed to stall the spindle.

i do 1mm deep cuts in ally with a 20mm end mill no problem, i also do 2mm deep cuts with an 8mm end mill no problem. the motor has plenty of torque.

but i do agree it is pretty slow on the rpm front and i have also been looking at other options for new motors. although i can take 2mm of ally off at once with a good finish, due to the low rpm feed rate is pretty slow at about 250mm/m.

the current sem servo motor in the traic is £1200 new and brand new replacement with more speed is going to cost even more. the thing to bare in mind when looking at the high speed chinese spindles is the atc and bt35 tool holders are only rate to about 8-10k rpm.

Thanks. Maybe my feeds are a bit too agressive but wow 20mm, thats a lot.

It looks like my controller has died. Ill probably just get a newer version of the controller and then look at the high speed spindle options later. My brushes still look OK, perhaps a bit worn, looking to find some replacement ones to be sure.

Is your machine the same as mine? BT30 or 35? Mine is BT30. A good rpm speed is around 8K I think. So take the 24K Chinese spindle and gear it down by a factor of 3. I think that will give a good balance for speed / torque.