Re: The new SX series SmartTabs
Well, I was going to let this go, but our buddy, Boomyal, forced me into this.
First, I would be nut's to bring out a product that would detract from what I feel is a good reputation.
Ain't nuts yet!
Second, there are many reasons for the plastic ( high density CO Polymer with no fillers). Number one is that Stainless cost are continuing to go up, and they are now twice the cost of two years ago.
Also, the installation is much easier, and faster with the deployment angle and actuator alignment built into the design.
Then, the maintenance and need for anodes in salt water is eliminated.
Also, the strength and durability is excellent without increasing cost.
To address the issue of "cheap plastics" we molded and tested the product with three different materials before we settled on the best for this application. Once the decision was made, we set up a "destructive cycle test" to determine the point of potential failure.
This was the criteria and method for the test:
1) Mount the assembled set to a fixture and a continuously rotating lever arm.
2) Align the arm to contact the plate two inches off center to create side loads which would torque the plate hinges and actuator end fittings (not a situation that would be found in normal usage).
3) Rotate the plate to compress the actuator 1.25" per stroke. The approximate distance require to bring the plate to horizontal in normal usage.
4) set the cycle time to (approximately) once every second (65 cycles per minute).
5) Install a 80 Lb. actuator in the highest pressure setting in order to create the maximum stress possible.
6) Run until failure occurred.
Results: after 48,812 cycles (12 hours of continuos operation) the Actuator "snap and lock pin" distorted at the transom bracket end, but did not break. Water cooling was required to keep the actuator below 210 degrees. No other physical damage was noted.
Prior to production the transom bracket tool was modified slightly to increase the load bearing surface.
The speed of test (16.25 times normal) created stresses and heat which would never be seen in actual use, however if this were translated into actual hour of operation it would be the equivalent of more than four years of starting and stopping the boat four times per minute.
The reason for loading the plate off center was to simulate stresses that may be caused by fork lifts during rack storage.
We are very comfortable with the design.
By the way, Minn Kota's new trim tabs are glass filled nylon.
