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Jonny:
Thats assuming his motors dual voltage regarding VFD.

Mines not and a 5.5hp 400V 3ph wont run a 3hp motor without a helping hand. Even a Transawave 5hp convertor mines like no tomorrow when putting a minor cut on.

I have to run my 3hp 400V motor from a single phase 240V supply to 400V 3ph output, best part of £1100.

Rather defeating the object not using the Master clutch, its the best part of the lathe like Harrison 11"/140. Motors permanently running, so real easy to convert.

philf:

--- Quote from: Jonny on November 16, 2012, 03:56:31 PM ---Rather defeating the object not using the Master clutch, its the best part of the lathe like Harrison 11"/140. Motors permanently running, so real easy to convert.

--- End quote ---

Hi Jonny,

The problem is that the instantaneous current when dropping the clutch in is going to be huge and thus the VFD trips - not a problem when you let the VFD accelerate the load.

I didn't consider that the motor may not be wired Delta for 230v but if it wasn't I don't think it would trip the VFD - it just wouldn't have any torque if it was a 230V inverter.

Phil.

rotorhead:
Luckily all my motors are dual voltage, I certainly now like the ability to raise or lower the frequency/speed of the motor, since assembling the remote control box.

I don't use that feature with the Clarkson, I usually run it at just 50Hz, that seems plenty fast enough with the pulley gearing.

It's only since fitting the 250 mm/10" Griptru that I've experienced the startup overloading, but it IS far larger/heavier even that the 10" 4 jaw.

Also I'll tighten the rear body countersunk screws, to see if that eliminates the juddering whilst parting off.

Time will tell, I'll give the suggestions a tryout this next week or so, and give an update of what I find to be best for myself and equipment.

Once it's running, taking a 50-75 thou cut on a 75mm dia 24T bar, with an 08 tip I have no problems.

I received a warning whilst posting this reply, it appears Phil had posted more or less at the same time.

After reading Phil's message, I'll mention that the motor voltages are 220/230 /380/440, and the VFD is 220/230v 3Ph out

mattinker:

--- Quote from: rotorhead on November 16, 2012, 05:11:47 PM ---

I don't use that feature with the Clarkson, I usually run it at just 50Hz, that seems plenty fast enough with the pulley gearing.



--- End quote ---

Just a thought, the MKI Clarkson runs at 4000rpm, the MKII has two speeds, 4000 and 6000rpm, the latter being used for smaller diameter wheels, running at up 75hertz might be worthwhile. Without off course over-speeding the wheel.

Regards, Matthew

krv3000:
well dun

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