Re: [CAD_CAM_EDM_DRO] Converting a Bridgeport Clone

Hi Roland,

This alters the problem but I have just bought off Ebay and air ram of 1.5" diameter but with 300mm of movement, maximum working pressure 150 psi. I assume this will reduce the size of stepper needed?

Regards, Terry

>I would seriously look at assisting the knee before attaching motors. You
> want to perform a milling operation, not a hoisting exercise. An air
> cylinder either side of the column, hooked to an air tank, and fed with
> regulated air gives an adjustable solution.
>
> Gas struts are OK too, but matching the weight might be a problem, and they
> are a bitch to compress if a bit too long to install. Counterweights would
> work too, but they add too much to the moving mass.
>
> Regards
> Roland
>
> On 19 April 2011 14:06, wotisname <wotisname@...> wrote:
>
>>
>>
>> It has been a long time since I posted on this group and I notice there is
>> not so much activity these days. Anyway on to my question:
>>
>> I have a Bridgeport clone and want to fit a stepper to the knee and I am
>> unsure of the size of stepper motor to do the job properly. I was thinking
>> of buying the motors from Arc Euro Trade here in the UK along with their
>> drivers:
>>
>> http://www.arceurotrade.co.uk/Catalogue/Stepper-Motors/Stepper-Motors
>>
>> If it takes 11.5 foot lbs of force to lift the knee and there are
>> 135.581795 newtons centimetre to one foot/pound, and I am thinking of a 6:1
>> reduction ratio on a toothed belt, what size motor would I need for reliable
>> operation? I am confused about holding torque and moving force.
>>
>> Would I need the stepper 160-010-00500 @ 4.2A 650Ncm or will 160-010-00450
>> @ 4.2A 350Ncm do the job?
>>
>> Regards, Terry