I have an Emcoturn 120 3 ph cnc lathe am I am looking to convert to 1 ph Mach3. To make the project more manageable it is my intention to split the overall project into smaller lumps, so for the moment I am concentrating on the Spindle drive.
My electrical knowledge is very limited so any help from the forum would be greatly appreciated particularly at this early stage to stop me going off in the wrong direction.
Existing spindle setupThe current spindle drive is a 2.6kw DC Siemens motor (GL5104-OEZ40-6JU7-Z)
with integrated 3ph cooling fan. Direct belt driven (see photos) output speed 150 -4000 rpm max torque 17.6 NM and belt driven encoder (approx 300 slots)
I have noticed on the forum that a Parker ssd 514c unit would control this motor but I had a look at the manual and it didn’t look particularly straightforward also not sure how I would tackle cooling fan. Also not sure if this motor to powerful and costly to run for hobby needs.
Question 1 Do you think it is worth persevering with this motor ?
I was thinking of saving money by going for a smaller motor say 1.5 kw with ac inverter
Question 2 Is this a false economy ? ( I want to cut threads and not sure about torque level at slower speeds)
2,4,6 pole motors !!! I am not sure what would be better for my application relating to torque, running cost and surface finish
Question 3 For average working speed say 1500 rpm. Is it better to get a faster motor slowed down by inverter drive or slower motor speeded up by inverter?
I have noticed a massive price difference for ac inverters of the same power rating
as much as 300% the more expensive quoting vector control
Question 4 For my application is this extra cost justified? Does this just give more accurate speed control or are there any torque/ heat implications particularly at lower speed?
I have been looking at various breakout boards on the internet to see how the spindle controls are hooked up and many show inverter connections going straight back to BOB. But I have also seen speed controllers advertised and connected up to similar ac inverter drives. Eg
http://www.cnc4pc.com/Store/osc/product_info.php?cPath=25&products_id=303Question 5 What are the benefits of these controllers?
The lathe comes with its (very well made) own spindle encoder (see photo) approx 300 slots
Question 6 Is this too many slots for mach3 to handle and does single slot produce accurate threads?
Not sure what voltage output is for this encoder or of wiring details.
Question 7. Do you think I should change this for new or can anyone help with info?
Any comments from the forum would be greatly appreciated. Even if you only have answer for one of the questions. It all helps
Cheers George