Re: Bridgeport retrofit servo questions

>I personally prefer the belts to be
> slightly undersized. In the event of a crash or runaway I would

prefer

> to snap a belt than break something expensive.
>
> Les
>

I have been worrying about this problem for a few weeks now....We all
want lots of power, but at what cost if there is a crash...

And as for belts, if you are relying on them for safety in a
crash...If you size them to small you get stretch...What size is just
right, were will they really break....

Then there is the question of steppers or servo's, which one would be
better to crash...Steppers just "slip" but have a lot of low end
torque to smash things before they slip. Servos have torque and or
current limits, but in a crash is the dammage already done before
these saftey features kick in....


Wally







--- In CAD_CAM_EDM_DRO@yahoogroups.com, Les Newell <lesnewell@h...>
wrote:

> Hi Brady,
>
> I have no idea why they made the belts so wide. There isn't that

much

> torque going through them. I used the same sized belt on the Z axis
> because of the difficulty of changing the Z axis pulley. On X and Y

I am

> using 15mm wide 8mm pitch HTD belts with a 60 tooth on the screws

and 24

> tooth on the motors. HTD belts have a round tooth profile and are

are

> smoother and quieter running. I personally prefer the belts to be
> slightly undersized. In the event of a crash or runaway I would

prefer

> to snap a belt than break something expensive.
>
> Les
>
> braidmeister wrote:
>
> >Thanks Les. Not sure yet if I am going with the Geckos or Rutex

servo

> >drives yet...If I stick to the original plan of 75v, then I should

be

> >good either way. If run 1:1, then it's best if run only to 75v

anyway

> >by your speed calculations.
> >
> >I noticed that the belts on the BP are pretty wide...what does the
> >HTD style offer? Is it trapezoidal or round toothed?
> >
> >-Brady
> >
> >
> >