Re: Acme, ball screw or rack for wood router?

since we usually agree that when one says someting can't be really
tosses down the gaunlet.

If I may, I'll pick it up.

Back in the pre-politically correct days when science proved that
ther is no corelation between second hand smoke and illness, the
tabacco industry designed a simple method of creating a whole smoking
office heating and ventilationg design.

The idea was that the hung ceiling was really the supply duct and the
floor, the entirety of the floor, was the return duct.

you could smoke a cagarette and watch the smoke go straight down.

when you exhaled, it looked like the smoke was acted upon by gravity.

Not that this is in the home shop budget, but by using the floor and
ceiling as the supply and return, all the dust would be immeadiatly
exhausted.

of course the carpet needed to be selected for the pressure drop of
the flow thru it and it needed to be cleaned regularly.

Although this is only slightly aligned with the topic, most machines
can be 'contained' by an air wall. blowing air down from the ceiling
and sucking it up at the floor.

in addition, there is an electro static air filter that will remove
submicron particles from the air. These are very inexpensive and can
be had at Home Depot.

Be that as it may, the idea that it 'can' be done is a far cry from
the can you affort it, or the do you even want it questions.

as always, the best method of reducing dust is at the source of
production.

Dave










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

> Considering that rack, belt and chain drive will all hold .002 and
> perhaps down to .001, while you only need .010 means that the

expense

> and added complexity of ballscrews isn't warranted. Ballscrews and
> leadscrews really belong in the non dusty environment of

metalworking

> machines. In the list archives somewhere is a description of a
> commercially made chain drive large gantry router capable of high
> speeds at .002. The manufacturers of this well reputed machine
> eventually went to rack drive, despite comparable accuracy between
> chain and rack. They only changed due to marketplace perceptions

that

> rack was better. That decision was purely a marketing choice.
>
>
>
>
> As for dust extractors, none are technically perfect and some
> ultrafine dust will occur. Not only is this a mechanical nuisance

but

> its also a health hazard, which can be extremely hazardous

depending

> on specific wood species (or resins present in manmade boards).

Have a

> look at any commercial woodshop with the huge inbuilt extractors,

they

> are all dusty to some extent.
>
>
>
>
> Regards
>
>
> Bob thomas
>
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "caudlet" <info@t...> wrote:
>
>
> > --- In CAD_CAM_EDM_DRO@yahoogroups.com, "ddgman2001"

<sheldon@d...>

>
>
> > wrote:
>
>
> > > What is the best drive system for a wood router considering the
>
>
> > dusty
>
>
> > > environment?
>
>
> >
>
>
> > Totally depends on your objectives. I use my wood router to do
>
>
> > complex carving and sign work. Deep carves require several

passes

>
>
> > that have to register pretty close. So in thousands of moves I

have

>
>
> > to be able to hold .010 or better or it will show in the carving

and

>
>
> > take a lot of handwork to clean it up. If on the other hand you

are

>
>
> > cutting out furniture parts and large panels then less tolerance

is

>
>
> > acceptable. You need to select your drive mechanism based on the
>
>
> > finish product you want to turn out.
>
>
> >
>
>
> > I agree with the other members about using rack and pinion or

even

>
>
> > chain drive for lower tolerance applications. Yes, dust is a
> problem
>
>
> > but with adequate dust extraction at the cutting point and proper
>
>
> > shielding of the drive mechanisms and ways, its a problem that

can

> be
>
>
> > solved. They make bellows and way covers that accordian up for

both

>
>
> > the ways and/or the ballscrews themselves. The material is not
> cheap
>
>
> > running 30 to 35 bucks a linear foot but for extreme environments
> its
>
>
> > cheap insurance.
>
>
> >
>
>
> > Giving some thought to where you mount the ways and drive

components

>
>
> > out of the direct path of flying chips will go a long way in
>
>
> > reducing problems.
>
>
> >
>
>
> > As for speed, I found that while it's nice to have rapids that

are

> as
>
>
> > fast as possible the type of cutting (often using .125 or .0625
> bits)
>
>
> > I am doing limits my speeds to 60IPM or less except for large

areas

>
>
> > doing roughing cycles.