10EE spin down time

My 1963 5 hp DC motor 10EE had the DC drive replaced with a modern 2 quadrant DC drive (not 4Q), which means no powered braking. How long should I expect the spindle to take to spin down once depowered from just friction? I'm trying to determine if the extra complexity of installing a DPDT contactor/braking resistor (which the modern DC drive supports) is worth it. Thanks!

thermite said:

Does "coast down" even matter? Take a stop watch to it. It is what it is.

More useful is how fast do you NEED it to stop? Braking resistor is maybe 2 seconds, "average" RPM and workholder+work mass, IF, repeat IF, you are not to risk over-stressing sumthin'.

Child's play to add a MECHANICAL friction brake to a 10EE. Any of those can EASILY beat even the best 4Q drives for a fast stop.

Click to expand...

If you are trying to make a living with a manual lathe coast down time matters big time.

bmazin said:

My 1963 5 hp DC motor 10EE had the DC drive replaced with a modern 2 quadrant DC drive (not 4Q), which means no powered braking. How long should I expect the spindle to take to spin down once depowered from just friction? I'm trying to determine if the extra complexity of installing a DPDT contactor/braking resistor (which the modern DC drive supports) is worth it. Thanks!

Click to expand...

A factory Modular drive in good condition will accelerate or stop smoothly in about 2 seconds.
The Mentor drive has programmable start up and braking ramps, suggest you try setting those parameters and then see what happens. You may notice a difference in accel/decel ramps depending on what you have attached to the spindle--ie; big heavy chucks or faceplates vs a lightweight collet nose.

I find it a lot easier to integrate braking resistors into the drive system (and there is more room for it) than engineer a mechanical brake to fit a 10EE. Pretty sure a 4Q Regenerative drive will stop the spindle faster than a human can reach for a mechanical brake after turning the spindle off.

My mentor drive is not 4Q - the 4Q ones have a part number ending with R (regenerative), so it is a braking resistor or nothing.

Now that foot switches were mentioned, what do you think of a foot pedal deadman switch for the low/medium skill machinist working solo in his garage?