Antique Engines and Old Iron
[Home] - [HELP] - [Forums] - [Library] - [Photo Gallery] - [Groups] - [Classified Ads] - [Subscribe] - [Links] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Shop Equipment Tools and Techniques > Machine Shop and Tool Talk
Forgot Password? Join Us!

Notices

Machine Shop and Tool Talk Shop Equipment, fabrication, repairs, how to fix it, which tool to use for the job. Machinist shop talk, straight to the point.

Machine Shop and Tool Talk

DIY Waterjet Cutter


this thread has 16 replies and has been viewed 1768 times

Reply
 
Thread Tools Display Modes
  #1  
Old 05-31-2017, 08:14:05 PM
dalmatiangirl61 dalmatiangirl61 is offline
Subscriber
 
Join Date: Feb 2010
Location: San Marcos, Texas / McGill, Nevada
Posts: 3,728
Thanks: 4,645
Thanked 3,074 Times in 1,516 Posts
Default DIY Waterjet Cutter

Saw this and thought some of you might get some ideas on building one, I know it would be a nice addition to my shop. This guy is doing sheet metal pretty easily with a cheap pressure washer, I'm thinking a bit more pump and 1/4" to 3/8" is not out of the question.
https://www.youtube.com/watch?v=Lg__B6Ca3jc
__________________
Those who can see the invisible, can do the impossible
Reply With Quote
The Following 4 Users Say Thank You to dalmatiangirl61 For This Post:
Sponsored Links
  #2  
Old 05-31-2017, 09:25:04 PM
Thaumaturge Thaumaturge is offline
Subscriber
 
Join Date: Mar 2014
Location: Beryl, Utah USA
Posts: 2,961
Thanks: 2,041
Thanked 2,846 Times in 1,214 Posts
Default Re: DIY Waterjet Cutter

Funny, I watched that as well just last night. Should you wish to try it stop by on your way to McGill and I'll give you a genuine CAT high pressure pump (300 series).
Doc
__________________
Still waiting for opportunity to prove that lots of money won't corrupt me...

Last edited by Thaumaturge; 05-31-2017 at 09:31:19 PM. Reason: Dislexia
Reply With Quote
  #3  
Old 05-31-2017, 09:25:40 PM
I like oldstuff I like oldstuff is offline
Subscriber
 
Join Date: Jan 2012
Location: Milwaukee, Wisconsin, USA
Posts: 4,489
Thanks: 944
Thanked 4,078 Times in 1,751 Posts
Default Re: DIY Waterjet Cutter

Smart articulate guy and an excellent build.
Reply With Quote
  #4  
Old 05-31-2017, 09:37:06 PM
PLCtech PLCtech is offline
Registered-I
 
Join Date: Dec 2015
Location: Maple Lake, Minnesota
Posts: 53
Thanks: 21
Thanked 33 Times in 21 Posts
Default Re: DIY Waterjet Cutter

Could slice bread or aluminum or sheet metal or fingers. You are smart to think of these ways of making money and wise enough to play it safe. I admire that.
Reply With Quote
  #5  
Old 05-31-2017, 10:09:33 PM
Vanman Vanman is offline
Subscriber
 
Join Date: Aug 2011
Location: Mission Viejo, California
Posts: 3,160
Thanks: 3,892
Thanked 1,292 Times in 875 Posts
Default Re: DIY Waterjet Cutter

YouTube must suggest similar things for you. I just watched that last night too!

Keith
Reply With Quote
The Following User Says Thank You to Vanman For This Post:
  #6  
Old 05-31-2017, 11:35:58 PM
akuna akuna is offline
Registered-III
 
Join Date: Jun 2012
Location: Central Oregon
Posts: 2,561
Thanks: 199
Thanked 878 Times in 671 Posts
Default Re: DIY Waterjet Cutter

The foam was cool. Wood, I have a band saw. The aluminum, I can cut about as fast with a hack saw. Bread, who needs soggy bread?

Did not get past that so have no idea if he cut steal with it.
Reply With Quote
  #7  
Old 06-01-2017, 10:25:27 AM
Odin Odin is offline
Registered-II
 
Join Date: Jun 2014
Location: Elmira, New York
Posts: 595
Thanks: 28
Thanked 416 Times in 225 Posts
Default Re: DIY Waterjet Cutter

The basic waterjet is just a pretty standard 3 axis gantry with the water process components attached.

All the magic happens in the high pressure intensifier and in the cutting head- where the high pressure stream is focused, mixed with abrasive, and directed onto the workplace.

I would not want to get my fingers that close to it though. The waterjet cutter where I work, 30 HP 55000 PSI, is capable of launching gritty water upwards of 30 feet. At 3 feet away, it stings like a windstorm at the beach from the garnet being thrown out of the spray. I've never dared to get closer while running, but a piece of 3/4" thick UHMW plastic mounted a few inches away from the cutting action as a blast deflector gets chewed through in a couple of weeks of regular cutting.

There are two ways to achieve the high pressure required:

A direct acting cam and plunger pump much like what a pressure washer itself uses and found in the smaller waterjets for its relative simplicity.

A hydraulic intensifier system, which is what the machine I run uses. A hydraulic cylinder cycles back and forth at 3000 PSI, driving a smaller diameter plunger that pumps water from an intermediate 150 PSI booster pump up to the cutting head at 55,000 PSI. It works based on the diameter ratio of the hydraulic piston to the water piston, amplifying the force at the cost of flow. Ultimately the 30HP pump only moves 1-2 gallons per minute, but you don't need that much flow anyway at these pressures.

The high pressure water is then focused through a diamond orifice, 0.011" for a 30HP machine, giving you your cutting stream. The focused stream is then directed through a carbide venturi where particles of gemstone dust- garnet in this case, are sucked in. With the abrasive in the system it becomes possible to cut literally anything, and it is just a question of how long does it take to do. I have in the past cut inch thick silicon carbide with it for example, though it was extremely slow because of how abrasion resistant silicon carbide is.


Once you get this unstoppable cutting stream though, and have it positioned above a tank full of water to catch it and stop it so it doesn't cut things you didn't want cut, then its just a matter of computer software to position the gantry and perform the acceleration and corner calculations.

A waterjet in operation behaves like a wire-thin endmill. It deflects as the cutting head moves, to where the point at which the water exits the plate being cut lags significantly behind the point at which the water enters. Computer models are used to calculate the rate at which the material is abraded, and determine the correct feedrates and accelerations to produce square corners and curves that don't have excessive taper as a result of the jet being flung to the outside around the bend.

Its a really interesting process, and someone with sufficient time and effort could indeed make a DIY version. I might someday attempt it, but at the moment I don't need to: My boss lets me use his machine after hours as long as I am only making little stuff so as to keep the consumable costs down. The gasket set for my hit & miss was cut on it, and it is really handy for making brackets and quick fixes.
Reply With Quote
The Following 4 Users Say Thank You to Odin For This Post:
  #8  
Old 06-01-2017, 07:40:35 PM
dalmatiangirl61 dalmatiangirl61 is offline
Subscriber
 
Join Date: Feb 2010
Location: San Marcos, Texas / McGill, Nevada
Posts: 3,728
Thanks: 4,645
Thanked 3,074 Times in 1,516 Posts
Default Re: DIY Waterjet Cutter

Akuna
I agree the cutting bread part was a bit dumb, but the rest of the vid had some decent info. Watching some other waterjet vids last night there was mention of "food grade" waterjet machines being made/used, not sure what they are using it on. No, he never got to cutting steel.

Anyone know what the minimum pressure/flow rate for cutting steel would be? Considering the success he had with a cheapo pressure washer, I'm thinking a decent Triplex pump could do more, but not sure how much more pressure could be gotten out of one of them, safely.

Odin
I familiar with pressure intensifiers for gas, had never considered they were used for liquids too, but it makes sense that it would work on same principles.

Doc
I've got pumps and motors, what I'm really lacking in is time! Oh yeah, and the XYZ table, but those are into the DIY category too.
__________________
Those who can see the invisible, can do the impossible
Reply With Quote
The Following User Says Thank You to dalmatiangirl61 For This Post:
  #9  
Old 06-01-2017, 07:59:53 PM
I like oldstuff I like oldstuff is offline
Subscriber
 
Join Date: Jan 2012
Location: Milwaukee, Wisconsin, USA
Posts: 4,489
Thanks: 944
Thanked 4,078 Times in 1,751 Posts
Default Re: DIY Waterjet Cutter

Dal, consider using a little pressure washer ~ 6-800 psi. Run that output into a strong cast iron gear pump and you'll have unlimited pressure. Relief valves definitely required!
Reply With Quote
  #10  
Old 06-01-2017, 11:22:08 PM
Vanman Vanman is offline
Subscriber
 
Join Date: Aug 2011
Location: Mission Viejo, California
Posts: 3,160
Thanks: 3,892
Thanked 1,292 Times in 875 Posts
Default Re: DIY Waterjet Cutter

A couple friends of mine had the frames for their diesel hydraulic locomotives cut out on a Mitsubishi demonstrator unit, that was powered by a 60 hp motor. The frames were cut out of a two inch thick slab, but they had other parts cut that were four inch thick, I believe. I want to say that it could cut up to six or eight inch thick steel.


IIRC it ran at 60 kpsi. It used the hydraulic powered linear piston pump mentioned above, and had an accumulator on the high pressure side, which was enclosed in a thick steel blast shield, in case it failed.

They were not entirely impressed with the accuracy, and the Mitsubishi machine was discontinued, so they are having the frames for their current project flame cut and ground.

Keith
Reply With Quote
  #11  
Old 06-02-2017, 04:40:29 AM
tdmidget tdmidget is offline
Registered-I
 
Join Date: Nov 2012
Location: Tucson, Arizona
Posts: 136
Thanks: 35
Thanked 41 Times in 32 Posts
Default Re: DIY Waterjet Cutter

Quote:
Originally Posted by I like oldstuff View Post
Dal, consider using a little pressure washer ~ 6-800 psi. Run that output into a strong cast iron gear pump and you'll have unlimited pressure. Relief valves definitely required!
Uh, no. The only pump that makes use of incoming pressure is the centrifugal pump. Positive pressure pumps cannot take advantage of incoming pressure. Ask a fire fighter engineer.
Reply With Quote
  #12  
Old 06-02-2017, 05:00:25 AM
Thaumaturge Thaumaturge is offline
Subscriber
 
Join Date: Mar 2014
Location: Beryl, Utah USA
Posts: 2,961
Thanks: 2,041
Thanked 2,846 Times in 1,214 Posts
Default Re: DIY Waterjet Cutter

Not so... the Cat high pressure pumps use staged pistons.
Doc
__________________
Still waiting for opportunity to prove that lots of money won't corrupt me...
Reply With Quote
  #13  
Old 06-02-2017, 08:53:47 AM
Odin Odin is offline
Registered-II
 
Join Date: Jun 2014
Location: Elmira, New York
Posts: 595
Thanks: 28
Thanked 416 Times in 225 Posts
Default Re: DIY Waterjet Cutter

Quote:
Originally Posted by tdmidget View Post
Uh, no. The only pump that makes use of incoming pressure is the centrifugal pump. Positive pressure pumps cannot take advantage of incoming pressure. Ask a fire fighter engineer.
I think it would depend on the geometries of the pump and what mechanism drives it.

A simple plunger pump will not pass on forward pressure, although said pressure will help it on the return stroke by making sure the check valves seal properly.

A balanced-pressure plunger pump, with water on both sides of the piston, will benefit from upstream pressure. The water behind the piston provides force to expel water as well as the pump rod pushing it along, and this can be achieved in both directions.


Gear type pumps probably can be constructed in a way that lets them boost pressure in stages, again by balancing the design so that the incoming pressure helps drive the output.

Which makes me wonder what kind of pump the fire department was using that couldn't boost pressure in this way. Probably a pump designed to operate with its intake at a vaccum lifting water from a pond into a truck.
Reply With Quote
  #14  
Old 06-02-2017, 08:58:20 AM
I like oldstuff I like oldstuff is offline
Subscriber
 
Join Date: Jan 2012
Location: Milwaukee, Wisconsin, USA
Posts: 4,489
Thanks: 944
Thanked 4,078 Times in 1,751 Posts
Default Re: DIY Waterjet Cutter

Quote:
Originally Posted by tdmidget View Post
Uh, no. The only pump that makes use of incoming pressure is the centrifugal pump. Positive pressure pumps cannot take advantage of incoming pressure. Ask a fire fighter engineer.
Good point. But an increase in input pressure even to a gear pump will help somewhat. Yeah technically a gear pump has losses from internal leaks therefore can't be considered positive displacement. +1 on the centrifugals benefiting from multiple stages such as a submersible well pump.
Reply With Quote
  #15  
Old 06-02-2017, 12:08:27 PM
akuna akuna is offline
Registered-III
 
Join Date: Jun 2012
Location: Central Oregon
Posts: 2,561
Thanks: 199
Thanked 878 Times in 671 Posts
Default Re: DIY Waterjet Cutter

All I know about pumps on fire fighting equipment is you do not want to pull a vacuum when connected to a hydrant.
Reply With Quote
  #16  
Old 06-02-2017, 12:25:57 PM
Power Power is offline
Registered-III
 
Join Date: Aug 2011
Location: New Jersey
Posts: 4,011
Thanks: 946
Thanked 2,281 Times in 1,329 Posts
Default Re: DIY Waterjet Cutter

That is to prevent damage to connected customer equipment.

Nearby municipalities do not have city water. Every residence has it's own well. When there is a fire, they come with a tanker truck, and then lay hoses to nearest pond or source of water. Often hundreds of feet away. I have seen inlet pressure gauges showing substantial vacuum.
Reply With Quote
  #17  
Old 07-04-2017, 12:23:42 AM
WidgetAU WidgetAU is offline
Registered
 
Join Date: Jul 2017
Location: Pearce, Australian Capital Territory, Australia
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Default Re: DIY Waterjet Cutter

Hi All

noob user questions on there way

watched the video and read the posts, and have been looking at a lot of waterjet sites and found that there is a lot our there for the pros, but not a lot for the low budget hobbyist

thinking

Pump

Will this have enough pressure/flow to be of any use?

Mach3 USB 3 Axis CNC Motion Control Card

Has anyone used Mach3 to control a waterjet?

if the pump is up to the task what nozzle (mixer?) would suit?

this is for "desktop" hobby use, so speed is less important than cheap

more questions to follow I am sure
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
New Day Cutter 41Briggs Maytag Engine Collectibles 1 10-05-2014 11:25:06 PM
Sickle Bar Cutter IronworkerFXR Antique Farm Tractors 8 09-16-2014 12:11:15 AM
Bone Cutter oldironlindy Farm + Industrial Antiques and Collectibles 10 12-07-2011 06:16:16 PM
brush cutter keith york Antique Engine Archives 2 04-22-2003 08:18:45 AM


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 05:12:54 AM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark - A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2016 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277