Construction material Aluminum vs Steel

PSV5.II 2010

 Which is better? What is heavy duty? What will last? What makes sense?

ALUMINUM VS STEEL!!!!!!!!!!!!!!!

Unlike the "one hit wonder" surfboard machine builders here at Precision Shapes we have created a plethora of different machines from both a design and material stand point.  If you do some homework on us you will learn that we utilized different frame materials, different drives,  linear rail systems and finally both servo, stepper and encoded stepper motors creating quality working machines that are found world wide. We do extensive testing on all our products before we release them for sale..

Why?  Because I learned back in college the only way to be sustainable is to have a wide variety of experience in whatever you do.  You need not only be able to design a product and execute a build with your primary product selection, you really should know and understand what your competitions using understanding strength and weakness in order to find and position our product in the market place. Components and vendors change and you must always be ready to integrate new technologies without introducing risks for PSNW and its customer base.

First realize that the below paragraphs are really directed at Surfboard machines specific.  

Steel: Its heavy!  However this has nothing to do with being heavy duty. It does have excellent vibration dampening property's.  I will say that if you look at most the big bad steel machines they usually have aluminum board holding fixtures. So the vibration is still in play.. Also due to the weight of the machines gantry/car you need to use much larger motors to push and pull all that weight back and fourth. Is this heavy duty? Or just Heavy? lol.  Some of our competitors like to use the old Thermal Expansion scare tactic. " Aluminum will expand and contract".  Well lets see the truth is all metals face potential Thermal Expansion or the act of the metal increasing and decreasing in size during temperature change. Steel does this roughly 1/2 the amount of Aluminum. You would need to have a significant temperature change for this to come into play at all.. We are talking micro-inches of change through a major and fast temperature change. Our users just don't have this issue.  Is it our construction method? Maybe strategic leverage of design? Or maybe anyone who owns a machine  should provide a proper stable environment that coincides with protecting electronics and motor drives which quickly eliminates the micro-inch thermal expansion possibility?

In the end if you put your machine in the space shuttle traveled to the sun then back to the moon at warp speed after the machine expanded and contracted it would take minutes to make some adjustments getting her back to true.  HMMMMM??..   Besides even the steel machines have aluminum plates in critical area's they even use aluminum to hold their boards.. Tah Dah thermal expansion!! LOL.

Steel to me is just a hassle and really gives you no advantage. Lining up linears on a steel machine is a real hassle and unless you mill the frame and can control powder coating thickness binding or sticky spots is inevitable.. That's ok most hacks solve this by slapping some bigger motors on their machines to fight through the lack of precise build execution.

 I laugh harder when I hear my machine is "Heavy Duty" only to look at the machines design and understanding the designer fell into the excessive weight abyss.

 I wonder did anyone ever measure the amount of true cutting force needed per medium?? Guess what?  I know exactly how much force is seen at variable velocitys at different depth of pass on my system.  You see others may be forced to use steel due to the fact they hang a 5hp -60lb spindle on their z axis and in order to support that they have another 100+lbs of mass.

 Do they have the ability to code a software to create smarter tool paths that work within the machines traverse forces?? The answer is usually NO.

So IMHO steel just seems like a waste of time and weight causing no real advantage. More weight= bigger motors= more money and expensive repairs not to mention greater power consumption and adding upgrades is a major costly overhaul.

I really like working with Aluminum for most board related machines.  Balance and structure of design is really the key to using aluminum framing. Its easy to just start adding power and weight. The magic is designing and building efficient and as lean as possible while providing predictable performance.

  So remember bigger is not always better..

So to those building machines or may attempt to build their own machine remember the rule of "HEAVY DUTY".  Is your machine really heavy duty?  Or is it just heavy fighting to perform with all the excess weight you have added. Do you even know what forces and tolerances you are dealing with?   I suggest you learn those first before you break out the pencil and paper.. 


Good luck and have fun..