In a recent survey on home buying preferences, one out of every four respondents said they preferred a custom-built home rather than a new home already built or an existing home. There are many advantages to having a custom built home: unique finishes, custom floor plan, superior quality, and getting exactly what you want.
Whether it’s home renovation, auto repair, or assembling furniture from that famous Swedish retailer, doing it yourself is all the rage today. But when it comes to maintaining your waterjet equipment, you may want to think twice before making it a DIY project.
Standoff height, the distance between the tip of the mixing tube and the material you are cutting, is important when cutting parts on a waterjet. In a previous blog I provided recommendations for proper standoff height. In general, stand off height should be about 0.100” (2.5 mm), or as thick as a dime. When your jet is perpendicular to your part, straight up and down, then raising the standoff will increase noise, mess and round the top edge of the part. You will lose a little cut power as well.
It’s important to maintain stand off under conventional waterjet cutting.
It is true that waterjets are used for common materials such as steel, aluminum, gasket, and foam. But many people feel the tougher applications are where waterjet really shines. In this post I’ll highlight some that I believe best illustrate waterjet and abrasive waterjet capability.
- Exotic metal: Titanium and Inconel
- Thick insulation
- Cement board
The first three are abrasive waterjet related, and the last two use pure waterjet.
I’m pleased to say that we have a guest blogger today. Colleen Carnagey is a major part of Flow’s marketing group and she would like to introduce to you a new feature on our website that might be of real value to you as you become more educated on waterjet capabilities.
Over the years waterjet has created its own vocabulary. I’m fairly new to Flow (in Flow terms–4 years isn’t much on 20), and one thing I realized almost immediately is to feel confident in your understanding of waterjet technology as a whole, you must feel confident in your understanding of the terms used to explain it.
When the governments of the world undervalue manufacturing’s impact on Gross Domestic Product (GDP), the result can be detrimental to the economy. The results can include taxes and laws being put in place by governments without understanding the true impact on manufacturing. A recent study by Manufacturing Alliance for Productivity and Innovation (MAPI) suggests the US has been significantly undervaluing manufacturing’s contribution to GDP. If you are reading this post outside the US then I hope the topic at least has some relevance to you in your own country.
The Colorado River versus Waterjet
Waterjet gives the best edge. The surface is unaltered, exhibiting no heat or stress damage. This outstanding edge quality it is created by supersonic erosion.
Erosion is an extremely gentle form of material removal, however it achieves amazing results.
For example: the Colorado river can erode the one mile deep Grand Canyon in 35 million years, and the abrasive waterjet can erode over one foot thick of granite at 0.2 inch per minute (5mm/min).
Great machinists know the need for proper fixturing. And they also know the fixturing has to be true to the machine tool motion. I don’t pretend to be a great machinist, but I know quite a few, including Curtis Waffle pictured below in an old photograph. Curtis is a master machinist with 35 years at Flow. The large bed of a typical waterjet machine is an XY plane, and that plane must match that of the machine. If the worktable is not flat to the machine motion it creates ongoing headaches and part accuracy and quality issues for the operator.
What makes a technology take hold? Technologies come and go; even some that seemed so permanent at the time, such as kerosene lamps, typerwriters and record albums. One of the reasons waterjet has remained one of the fastest growing major machine tool processes in the world for the past 20 years is due to adaptability. The waterjet process was invented in the 50’s by Dr. Norman Franz, but it didn’t begin commercial use until the 70’s with the explosion of disposable diapers (which in this case is a good thing).
Then ultrahigh-pressure water was adapted to hard material cutting (metal, stone, composites, ceramics) with the invention of the abrasive waterjet in the late 70’s, really beginning industrial use in the mid 80’s. This important technology was invented by a team of engineers and research scientists led by Dr. Mohamed Hashish. Here is a brief excerpt of the abrasive waterjet master’s tale.
My first day on the job I met Duncan Murdock. It was 1989, and I sat in on a paper slitting meeting. I sat and listened and learned. Duncan was a senior tech (not a regional manager as he is today), and was clearly on top of the technology and the application. Although he was young, he explained to the engineers and designers exactly how to design the slitter’s cross beam, the redundant cutting heads (to ensure 24/7 operation) the catcher tank. He understood how the paper would flow at extremely high speed, across the top of the catcher, and how the catcher top would create the right airflow to keep the paper down and flat without billowing.