Re: no thrust bearing - simple design ?

mcmaster-carr can be very helpful here and still be done cheap...I
just added new trust washers to my Y and they cost 5 bucks for the
12mm size...two needed

m-c also has acme leadscrews and even ballscrews at a pretty good
prices (5/8 i think is the cheapest for the leadscrews and nuts for
ballscrew parts)


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<davemucha@j...> wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "andrewyslee"
> <andrewlee@s...> wrote:
> > Hi Bob, list,
> >
> > While not impossible, it is not like walking into
> Walmart/RadioShack
> > when one wants to purchase things like linear rails, leadscrew,
> etc.
> > The plans I am looking at uses drill rods for guide. No one here
> > seems to know what a drill rod looks like.
> >
> > So, just to dip my toes in to find out what it is all about, I

may

> > try to make something simple with drawer slides and threaded rods
> > which one can easily pick up at the hardware stores, then perhaps
> > become more ambitious later. (I know there are lots
> of "professionals
> > here, but anyone else went down this road in their "formative"
> years?)
> >
> > How does one attach a leadscrew/threaded rod to a thrust bearing?
> > Does one just make sure that the diameters are a tight fit, or

are

> > there screws to tighten or something?
> >
> > Thanks
> >
> Hi Andrew,
>
> I'm not sure of the real question.
>
> It appears like you are in the design process.
>
> drill rod is a good quality steel, not particularaly straight and
> typically withing a few thousandths of it's listed size. I found
> that some one inch stuff I bought would not fit into some pillow
> block bearings.
>
> If you plan on making a table of some sort, my advice is to design

it

> in CAD and then figure your loads and use the spreadsheet in the
> files section (beamdeflection.xls ?)to verify the loads. then make
> sure that if you want, next year you can fit heavier stuff. real
> easy to do in design, real hard to do latter.
>
> There is absolutly no reason not to use all thread for testing, but
> it will not have the same life or thrust as ACME and ACME will use

up

> more energy than ball screws.
>
> There are lots of us using threaded rod, many use ACME and many use
> ball screws.
>
> There are lots of machines made of wood with gears or belts

forgoing

> screws altogether.
>
> Regarding thrust bearings, you can make a block with a bearing for
> the axial load, and attach plates then add thrust bearings. Thurst
> bearings are often very very inexpensive so if you have the ability
> to use them, do so.
>
> Dave