I am upgrading the spindle motor for a 2HP PM833-TV benchtop mill. The stock motor is as loud as a vacuum cleaner. I have decided to use a JMC 1.5KW AC servo for the new spindle motor. This servo has a max speed of 3000 rpm and torque of 4.78 Nm. My goal is to increase the spindle speed to 5000 - 6000 rpm with a pulley ratio of somewhere between 1:1.80 or 1:2.0.
While I have no immediate needs for rigid tapping, I would prefer to use some form of timing belt for this task. To see if the required pulleys would fit inside the milling machine cavity I proceeded as follows:
The spindle pulley requires a 40mm bore. A small timing pulley with a 40mm bore will have an outside diameter of approximately 67mm. For a 1:1.90 pulley ratio, this would require the larger pulley to be about 127mm. See drawing below. These numbers are just estimates for feasibility.
I have limited knowledge of what sizes are available for types of timing pulleys. I looked at SDP/si website and several others and was not able to find timing gears close to these sizes. A few questions:
1. Should I be looking for a particular style of timing pulley that may be available with this size range (HTD, GT3 etc.)?
2. I found some a fairly expensive option using taper lock pulleys on McMaster Carr. These are available in the correct size and would offer a 1:2.05 ratio. They are offered for belt widths of up to 12mm or 21mm. The stock belt is 15mm wide. Do you think the 12mm would be sufficient? Do you know of another source for these taper lock pulleys?
3. If rigid tapping is not of main concern, would a poly v belt be a viable option. I only just started using my lathe, but I may be able to turn my own pulleys.
Please let me know your thoughts... Richard
While I have no immediate needs for rigid tapping, I would prefer to use some form of timing belt for this task. To see if the required pulleys would fit inside the milling machine cavity I proceeded as follows:
The spindle pulley requires a 40mm bore. A small timing pulley with a 40mm bore will have an outside diameter of approximately 67mm. For a 1:1.90 pulley ratio, this would require the larger pulley to be about 127mm. See drawing below. These numbers are just estimates for feasibility.
I have limited knowledge of what sizes are available for types of timing pulleys. I looked at SDP/si website and several others and was not able to find timing gears close to these sizes. A few questions:
1. Should I be looking for a particular style of timing pulley that may be available with this size range (HTD, GT3 etc.)?
2. I found some a fairly expensive option using taper lock pulleys on McMaster Carr. These are available in the correct size and would offer a 1:2.05 ratio. They are offered for belt widths of up to 12mm or 21mm. The stock belt is 15mm wide. Do you think the 12mm would be sufficient? Do you know of another source for these taper lock pulleys?
3. If rigid tapping is not of main concern, would a poly v belt be a viable option. I only just started using my lathe, but I may be able to turn my own pulleys.
Please let me know your thoughts... Richard
