Cable stuff was Re: Stuttering stepper- cables and flex

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "ballendo" <ballendo@y...>
wrote:

> Hello,
>
> Jon has covered the basic things already, but let me add something:
>
> The cables themselves. Inside the insulation. Broken wire(s). A

cable

> not expressly made for continuous motion can fail VERY quickly. And
> it/they can take out one or more drives as they go...
>
> Very few homebuilt cnc machines I see on the net use anything NEAR
> proper cables or cable "management".

Then you'd be proud of mine. For around $100.00 including shipping,
I purchases machine flex cables, multi conductor, shielded. one
cable for 110 spindle voltage, one for steppers, the third for the
home switches and signal outputs. INGUS rolling trays.

cables are the nicest part of my home made machine.


Okay, but get this: the SAME cable use in a "rolling"

> way (as in a cable track, or supported so that it works similarly),
> will have a life in excess of 6 million cycles! That's 200 times

the

> life, just by using the cable properly.
>
> Recently I was looking through the Olflex catalog, which says that
> there should be 15x cable diameter from the fixed points to the
> rolling part...

I think we get an idea of this with flex adapters on cords like hair
dryers.


a 1/2 dia cable bundle should have a minimum curve of 7.5 inches.
Seems that is what the INGUS tray does. but, it is the first inch
out of the box or flex, that first unsupported inch that gets like
90% of the strain.

I think this ratio is about what a cable would do naturally when you
roll it up, like putting away an extention cord. there is a natural
minimum circle the wire will easily achieve.


And to our friend with the current problem.

disconnect the power.
solidly connect an ohm meter.
flex the cables by hand to their natural movement, don't over flex
them or kink them.
move the cable slowly in all the directions it would see under normal
conditions.

Dave