Does a bear crap in the woods?
Nice. What pressure and size nozzle is it using? Is the cut smooth the whole width?
I’m running at 44,000psi and using a .042” nozzle. The quality all depends on the speed. If you go too fast you’ll get a little washout on the back side but at higher quality/lower speed you get a nice finish. It ends up looking like a sand blasted part. The beauty of the waterjet is that it doesn’t put any heat back into the part so you won’t warp anything or ruin hardness or temper.
That’s just cool.
44000 PSI. Man thats high pressure. I work up to 6000 PSI with hydraulics. I cant imagine 44000 going through a 1mm hole. This must have some sort of amazing pump, hoses and filtration.
It’s a Flow 60k hydraulic intensifier setup. A 25hp electric motor runs a hydraulic pump that supplies 3200psi to the intensifier unit which shifts a puck back and forth in a cylinder to drive ceramic “pistons” to make the water pressure. Then it goes through an attenuator to smooth out the stream and out to the nozzle through SS316 tubing with UHP fittings. The filtration system is just an ebbco closed loop unit with a deionizer.
It’s an old machine. The new ones kill me. 90,000 psi, possibly more now.
Thanks for the info. 90,000 PSI. Thats a lot of pressure. 
Wow, that is impressive.
I got a couple parts waterjet-cut for my 7xC8 reflector build. 1/4” aluminum. The cut was not straight, as if the water jet expanded as it went through the material. Is this something that one has to consider in waterjetting?
All parts cut with a waterjet will have a taper to some degree. Slower cutting speeds can minimize it to some degree. This of course only applies to an older or simpler machine that only has x and y axis. Some equipment has a head that will compensate and some are even full 3D these days.
My father worked as a maintenance supervisor at an alcohol production facility… they often cut reactors apart from the inside with semi truck hydro jets, usually 2 trucks to form the system. I will never forget the day he came home and reported that there was an accident with the hydro jet… the man died instantly when he was hit with the jet. They are amazing things, but holy crap dangerous when they are operated by a person and the nozzle is portable. I felt very fortunate when I cut myself with oil once, only have a couple of scars left now 30 years later.
One just never thinks about water being able to do this kind of work…
Actually the water doesn’t do the work. The 80 HPA garnet from MRsDNFs’’ back yard does the work.
You know your going to get me in trouble with the good wife talking about my backyard and what I haven’t done. 
Waterjets are great and all, but I really hate how large the taper is on any thick materials. 
EDM wire or CNC is a better option for cutting stuff that thick if you care about edge quality.
Yeah the taper can be a pain but it is what it is. You’ll grow old waiting for a part like that to come off a wire EDM or CNC. It’s all about the application I guess. I very rarely ever cut thick stuff like that, I generally work with 1/2” and thinner.
Update regarding taper. I did the sister part today and decided to have a measure. I got .003” taper per side over 2.75” running at 3 quality out of a possible 5. Better results than I expected honestly.
That sounds pretty good to me. More accurate than I could ever hacksaw. 
Impressive…………. :+1:
Imagines MRsDNF using a hacksaw to cut a 2.75” thick piece of steel
“This could take awhile”
You’d be surprised what this old fool did as a kid on the farm with little more than a hacksaw, hand drill and acr welder. 