Re: [CAD_CAM_EDM_DRO] Re: Stepper Motor size

Hi how can we calculate lead screw efficiency??

SHABBIR
At 02:43 PM 10/3/01 +0000, you wrote:

>Hi,
>
>A handy equation to convert in-oz torque to Lbs of "push" or thrust
>on a leadscrew is:
>
>Lbs = (in-oz times 2pi times TPI times %) / 16
>
>Where TPI is leadscrew turns per inch and % is leadscrew efficiency
>
>If you have a 5 TPI leadscrew with 85% efficiency and a 2,000 in-oz
>motor, then push is:
>
>(6.28 X 5 X 2,000 X 0.85) / 16 = 3,336 Lbs, or over 1.5 tons. That's
>a lot isn't it?
>
>Mariss
>
>
>
>--- In CAD_CAM_EDM_DRO@y..., karl@c... wrote:
>> I'm looking for stepper motors for my second CNC mill. My
>Bridgeport
>> Series 1 has LARGE steppers. I don't have the specs. but I guess at
>> least 2000 oz/in.
>>
>> My second mill is a full size bridgeport type knee mill which needs
>a
>> CNC upgrade. I'm using Ahha Artisan FWIW. The control uses 48 volts
>> and needs 8 pole motors.
>>
>> Anyway, I'm looking for large steppers and can't find any. My first
>> question is what size do I really need? I do the conversion from
>> oz/in to foot pounds and steppers seem really puny. For example,
>540
>> Oz/in. = 2.8 foot pounds. A typical power feed is 35 to 70 foot
>> pounds.
>>
>> Anyone have a source for large steppers? Preferrably used, or at
>> least inexpensive.
>>
>> Karl
>
>
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