Re: [CAD_CAM_EDM_DRO] Re: Cold rolled steel, flats or square for use as rails.

On Saturday 09 August 2008 02:19:09 apples0_17 wrote:

> So that brings me to another question.
>
> Firstly yes the stainless steel seems to be the most logical so far.
> How will stainless steel go for a bearing surface. I think from
> memory SS is harder than normal mild steel? Yes??

In general terms yes, it gets a lot more complicated with flexing and
stretching though. Shouldn't matter on a rigid structure but worth bearing in
mind if using thinner materials.
If your using rollers then just try and get the widest contact area reasonably
possible and consider harder materials if your design creates a very high
loading anywhere. A good design shouldn't have very high loads anywhere but we
all know the world isn't perfect :)
Watch out for stainless if using slides, it's not bad with plastic guides but
metal to metal guides with stainless can cause big and unpredictable problems,
it has a horrible tendency to stick and pick-up.

>
> And then why do all the other manufacturers use either mild steel
> unground ( cold rolled flats,torchmate) and then others use hardened
> and ground steel.

Mostly a matter of getting what you pay for and the intended application, if
you want a highly accurate 24/7 machine then the price goes up. Fast.

>
> I can't say that I have seen any stailess steel rails made out of flat
> or square stock. Maybe the Hiwin type and thompsons are all SS, I
> don't know.

Ground finish sections are fairly easy to get for decorative and visible
structures, they don't claim to be precision finished but are very accurate,
certainly good enough for an initial design and can be precision ground later
if needed. Only trouble is clamping the damn stuff down as it doesn't stick to
a magnetic table :)