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The motor testing protocols now in place were developed when we were entirely dependent on the accuracy of the manufacturer's delay to safely recover our rockets. Thusly, it was entirely correct to test and verify that a 3 second delay is in fact 3 seconds. Longer than expected delays are bad, and shorter than nominal can be much worse. Testing and certification provided an independent check on delay accuracy. For motors where the delay composition is inaccessable, like an Estes BP the independent testion should continue.
However, there is a whole new class of motors available to us today. Reloadable designs *do* allow access to the delay element and can easily be modified with a simple twist drill. More high-tech approaches use an adjustable jig to repeatably drill the delay to the same depth.
But, we place an artificial (and unnecessary) restriction on ourself if we limit our ability to shorten delay times to only a few discrete quanta that mimic the delay steps which have historically been avaliable from the manufactures.
Specific example: the 5.5x Streak I am currently building for my Level-1 certification sims consistently with an apogee at eleven seconds. Without any modification the stock 13 second delay from the Pro38 I will be using is much too long, and the rocket is subjected to needless stress when ejection comes that long after apogee. Likewise, the next step on the DAT is 10 seconds, and the ejection charge goes off while the rocket is still going up, and I'd just be asking for a zipper. Nope, I need a delay of 11 seconds (trusting RockSim here pending flight tests).
Let's loop on this for a few iterations. An analgous situation exists in the FF airplane community regarding DT time. It is purely up to the discretion of the flyer what fuse length or timer setting to use to maximize the chance of maxing out, and still recover the model.
Shouldn't the HPR community have the same discretion ? We're not talking about somebody just starting out following an impulsive purchase at Wally-World. Someone going for HPR certification should know, and be able to hold a technical discussion about, the factors involved in making an informed delay time selection.
Relative to the testing and certification process, I would recommend the following change to the extant methodology; test the manufacturer's delay adjustment method (whether through the use of a jig or a simple depth to drill) to see if that process does produce accurate, repeatable variable time delays. The testing would thusly certify that the manufacturer's procedure consistently produces reliable delay times. Exactly what time delay to select should be up to the discretion of the flyer based on factors like specific rocket design considerations and flight weather conditions.
John