Re: Timing Belt styles/sizes

--- In CAD_CAM_EDM_DRO@y..., ccs@m... wrote:

>
> While trying to pick a timing belt style for the long feed leadscrew
> drive on my lathe, I downloaded a manual from Gates.
>
> In this, they mentioned that the HTD style of belt is designed to
> be stronger, but the tooth shape used to accomplish this requires
> greater clearence than trapezoidal belts, which results in backlash.
> In short, they do not recommend HTD belts for precision positioning.
>
> I had the sense that some here did like these belts for this
>purpose.
> Gates may have a vested interest - they are trying to sell their
> new shape, the GT2, but that does not necessarily void their
>argument.
>
> What belt series in practice is good for a 600 oz-in motor? A 1000
> oz-in? I used XL on the crossfeed stepper, but assume I need
> something bigger such as H or L for the long feed given that I'm
>using
> servo with much more power. I've been able to find a few figures
>for
> allowable working tension, but it is unclear if that is installation
> pre-tension, or the tension due to power transmission.
>

Chris
The L series belts 3/8" pitch can take up to 2000 oz-in on a 1" wide
belt with ease.
There are formulae for working all this out but there are a lot of
variables.
A 2,000 oz-in motor running at 1,000 rpm will need a belt rated at
0.5Hp but if running at 500 rpm it then needs 1.0 Hp.
Effective tension, expressed in in-lbs, is worked out by multiplying
33,000 by the HP and divinding by the belt speed in ft-min.

John S.