Re: Direction follower ? Water jet Re: [CAD_CAM_EDM_DRO]

> has anyone EVER done a homebrew waterjet cutter? are the pressures

involved

> just too dangerous? as far as i see it, they are just a preasure
> intensifier, attached to a saphire nozzle, right? over a water tank?
> wouldn't it the best way to cut glass? using abrasives in the water

(needed

> to cut glass) you'd even be doing the sanding!---Dave L.

The pressures involved are brutal. There can be no questions asked there.
4000 psi is enough to strip your skin when it's running with grit. The guys
I worked with used to take their metal stuff down to be blasted and they had
a 4000 psi grit jet which'd actually polish and erode away metal. 40kpsi is
beyond enough to remove a limb if it hits you close up. I'd be more worried
about pressures like that than I would be about running a big manifold of
gas cylinders on a flame table.

The pumping system to achieve the pressures is expensive but so is a lot of
the machine. Hoses to take that pressure are not easily bought. The nozzles
do wear fairly quickly, I think you can buy carbide ones. I read an article
by a man who ran these machines but I can't remember where it was now.
Please remember that you don't just blast water, you blast water with
sapphire grit to cut cleanly. You absolutely must have a recovery system to
collect the grit. The piston heads need very snug seals, all the gaskets
need checking regularly just in case, they also need changing once every now
and again.

If this is for a home sized job, or even small commercial, there is not
really anyway to you could justify such an expensive deal. It's like welding
your lawn mower with a Syncrowave TIG runner. I would have a bit of a read
around on pressures needed. At 40kpsi you are cutting metal and harder.
Glass, as I'm sure you'll know, is a lot softer than heat treated metals
(Which is one of the reasons for using water jets on such metal, so's not to
ruin the treat). I would be guessing but I would think you probably don't
need a huge amount of 4000psi to start working on glass.

It's something to have a look into anyway. I can't see glass needing
anywhere near 30kpsi+. And since you're not trying to chop a foot deep piece
of metal in half in under ten seconds you can always run it over a couple of
times. I saw one of these machines cutting some sort of soft volcanic rock
for a kitchen work top about 3 inches deep. The cutting was as if it were a
plasma torch on sheet.

Good luck, and remember, if you build it, you take photos of it!
John H.

P.S. Check the archives, we had a talk about this last year I think.