Hi all, first post and first lathe. Just bought a Clausing -Colchester 15x48 looks to be in good condition but missing the motor. Looking on line looks like these came with 3hp, 5hp or 7.5hp. Anyone know what motor frame type they are supposed to be? Also for hobby machining is the 3hp good enough? It’s clearly the least expensive motor and vfd choice.
Thanks in advance.
"Hobby" doesn't have a size on it. Some folk make railway locomotives, not always scale-model ones.
If I have an RPC, Phase-Perfect, (both, here..) or mains 3-Phase, I'd fit a 7.5 HP. LOT nicer to run underloaded that overloaded unless you are a Diesel prone to "wet stacking".
VFD comes down to whether you have any money left for a motor once buying a VFD rated for 1-P input on a larger motor.
Because...
When using electronic variable-speed it is wise to supply double whatever a single-speed is nameplated for. "Nameplate", after all, is a(ny) motor's BEST shot, not worst.
Either of DC Drive or VFD give-up power as they move away from nameplate "nominal".
- DC retains torque below nominal, loses it above, stability especially.
- VFD retains power and regulation above nominal, loses torque below.
Both are about the same when run closer to the nominal.
If using a VFD primarily to convert from single-phase to 3-phase, 1:1 is OK, but the VFD itself may need oversized.
If you intend to ALSO get best
use out of
variable speed? Then the motor should be upsized, and the VFD even more so.
Compromises are never really "free", y'see. [1]
TANSTAAFL
[1] 10EE (nominal 10") 3 HP run at as much as 4.3 HP, or 5 HP run at 5HP. AC+VFD downgrades generally use 5 HP for 3 HP better-yet 7.5 HP motors, and as much as 10 HP motors.
Cazeneuve HBX-360 (nominal 14") 7 HP is good - but it has a mechanical vari-drive inputing to a selectably geared head.
