Re: Smallish CNC Miller

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "xj5373" <ian.c.haynes@b...>
wrote:

> Hi Folks,
>
> Firstly thanks a lot to all the people who replied to my first

post.

> I learned a lot from the replies and a lot more from all the other
> traffic in the group, thanks again.
> I may regret this decision but based on the info I have gleaned I

am

> going to attempt a conversion of my Bridgeport.
> The strategy is to firstly get hold of some software for a play.
> Based on what I have read and seen I conclude pragmatically that
> Mach2 looks a good choice, the manual alone is a great piece of

work.

> Step 2 is to get some servo motors working on the bench. Gecko 210s
> seem to be a good choice for the drives but I could do with a bit

of

> guidance on stepper motors. Nema size 34 motors look like the right
> choice for the X and Y motion (might hold off on Z until X and Y

are

> installed) but there seem to be options within this spec. I am UK
> based so any suggestions for suitable suppliers and more specific
> spec would be welcome. Radio Spares do motors 2.5V 4.5A with a
> holding torque of 2200mNm (part 440-470), Mclennan have other

options.

> What do you think about a break out board between the PC and the
> Geckos?

Does Graham still have drivers over there ? He is on your side of
the pond IIRC. His site had some drivers for sale last time I
looked.

As for the breakout board, there are a few good choices. check the
links section.

if you are electronically capable they are very easy to make. if you
just want to get the thing done, buy one.

As for servos or steppers, I think you should make sure you get big
enough steppers the first time. This list is loaded with people to
compromised and got smaller steppers than were required and then
swapped them out for servos. I have never heard of anyone going the
other way though. from what I gather, big servos are much easier to
find so most people have oversized servos, but who really cares when
it works !

I think for a Bridgeport sized mill it is at the upper end of
steppers and lower end of servos.

In my opinion, getting good drives and powerful motors is the key and
which way you go doesn't matter.



Dave