Re: Rotating Ballnut

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Marcus <implmex@...> wrote:

>
> Hi VR:
> Are you sure that using a rotating ballnut will work out cheaper

than a

> decent sized screw?
> Last time I looked, rotating ballnuts were horrendously expensive.
> Not only that, you now have to work out a way to make the motor and its
> cables traverse with the machine without snagging the cables or

fatiguing

> the connections.
> All are easily do-able, but not necessarily cheap.
> Also, when you get up to the 96 inch traverse range, are you sure

it's wise

> to try to go on the cheap?
> This sounds like more than a hobby class machine....wouldn't you be
> disappointed if you went through all that effort to build it only to

find

> you'd built a turkey because you got too focused on how much it

cost, and

> not enough on building it strong enough?
> Just a thought!!
> Cheers
>
> Marcus

Some of these issues are not that big. on my 10 ft axis, I had to
have 110 for the spindle, wires for home and end switches, air for the
solenoids and connections for the stepper on the Z.

Adding a rotating nut was only adding one more set of wires for the
stepper. All the kable-chain was already in place.

I do agree that the ball nuts can be pricey.

As for the costs, you do need to keep the screw in tension, and that
may require major frame reinforcement.

Dave

>