Re: [CAD_CAM_EDM_DRO] Re: Is it possible to change the BP motor to eliminate shifting?

Perhaps the best way to think about it is with an analogy. Could
you have a car without a transmission? The answer is yes. However,
you would have to make some choices. If you pick a fixed ratio
that allows you to go highway speed then you will accelerate very
slowly to get to your desired speed. There are some hills that you
could not climb.

If you choose a ratio that allows you to go up any hill then you would
not be able to reach highway speed. Driving around town would be
fine.

Of course you could install a very large engine that would have enough
torque for any hill but would still reach highway speed. The downside
is gas mileage and cost.

The transmission in your car like the transmission in your Bridgeport
gives you the ability to use a motor of reasonable size to do most
any job that you want.

In the early days of automatic transmissions for cars they used a
torque converter but few gears. Some cars had two speed transmissions
or even one speed. They depended on the torque converter to
multiply the engines torque. Torque converters, then and now, cannot
produce the torque range that a gear box can. These cars accelerated
at a majestic (slow) rate as my father remembered. He recalls driving
some way back then. This probably slowed the acceptance of automatic
transmissions. Most people bought standard transmissions.

Pete.

----- Original Message -----
From: "Keith Clark" <mail@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Sunday, April 10, 2005 11:14 AM
Subject: [CAD_CAM_EDM_DRO] Re: Is it possible to change the BP motor to
eliminate shifting?


>
> I was wondering if there some more powerful motor or other way to
> gear it to maintain the torque in the low range?
>
> Thanks
> Keith
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Lance Hopper"
> <snaggletto@c...> wrote:
>>
>> Yes, you can use a VFD, to control the speed of the motor.
> However,
>> you will lose tons of torque (cutting power) at lower RPM's by not
>> using the backgear (low gear range). This would render the
> Bridgeport
>> nearly useless while using larger diameter cutters at low RPM.
>>
>>
>>
>>
>> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Keith Clark" <mail@t...>
> wrote:
>> >
>> > Is it possible to change the 2 HP motor on my (Series 1
> originally
>> > Boss controlled) Bridgeport spindle during conversion to control
>> > spindle speed, to a motor that could have the entire speed range
>> > needed and thus obviate the need for the gear shift?
>> >
>> > Thanks,
>> > Keith
>
>
>
>
>
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