Mechatronics fixes

The scope was to fix the fragile plastic robot and pump designs while keeping the same controls and coding.

With this redesign, duty cycle went from 15% to 100%, reduced machine volume ~20%, eliminated assembly and break in issues, and passed 250,000 life cycle testing as well as IEC 60601 certification.

Touchscreen Integration

The scope of work was to take the touchscreen parts from a supply partner's bulky offering and make them look and feel integrated.  Their touchscreen, PCB's, and harnessing were all reused to fit the new mount and housing. The finished product was a flush fit that was integrated.

Fuse holders fix

This project was to reduce redundant options, fix problematic fuse holders that also had hard to find glass fuses, simplify the assembly, and merge the unnecessary BOM options that were created.  Fuses were swapped to circuit breakers. The 6 options were reduced to 2 options (110v or 220v outlet), reduced BOM cost by $17, and eliminated the end user's hunt for fuses. This is a picture of the prototype. The production version used snap in circuit breakers to further simplify assembly and meet higher electrical safety standards.

Part compatibility

Engineering used a sheet metal thickness in the design that was a mismatch to the thread size / available PEM nuts. The PEM nuts were popping out. Production was weld tacking the zinc plated pem nuts in place exposing welders to zinc oxide.  The pem nuts were distorting from welding, then had to be tapped.  Tapping was popping the welds and pem nuts out as was the assembly team.  The circle of struggle was consistent.  There were also problems in the field with cross threading and pem nuts were popping out.  

The solution was to switch to hex shaped rivnuts.  They are easily replaceable both in production and in the field.  This simple fix lowered BOM costs, rejects, assembly time, scrapped parts, and rework substantially. During this uprev the sheet metal box was made with the same flat pattern for both the left and right which simplified manufacturing. An _|R shaped cutout shows which way it was bent for reference.

Crushed foam

The original design was attempting to use foam as a cushion under offset rollers. But as designed it was completely crushing the foam with the fasteners.  This made the assembly wavy, would squeeze the foam out over time, made assembly challenging, and allowed the assembly to twist.  

The second picture shows the aluminum spacers that replaced the foam under the fasteners.  Foam was kept under the rollers for cushioning.  This solved all of the issues and made for a much smoother run. The spacers were planned to be incorporated into the injection molded parts to eliminate a part and reduce costs.

Grounding issues

The machine was repeatedly having static induced control board failures in the field.  Production was using a self threading screw into powdercoated steel.  These were making a weak connection that passed hipot testing during manufacturing but got corroded in the field and left the control board exposed.  The fix was to weld in a stainless screw and use a braided ground strap for a good ground connection that lasted.  This combined with 1 other fix eliminated the static induced control board failures.

Hose nut

The challenge was to connect a convoluted hose to a vacuum tip.  A prototype was made to work with manufacturer part specs.  The vacuum hose was found to be out of manufacturer's tolerance, a reworked thread was implemented and upreved.  This was a very simple and reliable solution that allowed quick replacement of all the vacuum tip and the hose.

Automotive suspension bushing flexing off axis

Some auto manufacturers are using bushings in their control arms that are flexing 90° to the bushing's intended flex direction.  These bushings fail quickly and allow suspension geometry to go way out of whack as they twist, rip, and mush. 

 Aftermarket polyurethane bushings bind the suspension as the control arm moves past parallel with the ground and quickly destroys the polyurethane. Some aftermarket suppliers offer "race" spherical bushings but their lack of seals means they act as a cup to collect water, salt, sand, and other road debris that quickly destroy the joint.

Atrick's solution was to weld in a collar then press in a sealed spherical joint.  This brought the handling up to the race aftermarket offerings without the downsides. These lasted years longer than all other options because the seals kept the grease in, the grit out, and allowed the required twist.