I know both spiders and pistons have been flown without issue or protest at recent NARAM's. While it's clear that spiders, with the BP, to impart a bit more momentum/impulse/energy that without, it's debateable whether or not that's even a significant advantage. After all, technically an igniter imparts some energy, so a spider is viewed as simply a bigger, badder igniter.
If you want to PM me, and have about 18 MB free mailbox space, I can shoot you the draft of my article and pics.
--Chan Stevens
Chan, as Jay Leno would say , EXACTLY.
I think imparts a Bit is more likely imparts alot.... and yes that was part of the debate that went nowhere: an igniter can also impart some momentum to a modle rocket if launched from a piston because of the enclosed confined space; the igniter also generates x amount of gaseous byproducts.....
So the debate devolved into when is a BP igniter not a BP igniter anymore when its sole function is to add so much gaseous by product that it adds more than minimal impulse to the model; ie the launcher/igniter is now imparting velocity to the model which is not allowed by the NAR Pink Book.
I seriously doubt that an Estes solar igniter does all that much; I would also say that any amount of BP whether it be formed onto an igniter or just dumped into the motor nozzle end goes beyond what an igniter is or isn't; it's clear that in this case the sole purpose of the additonal BP is to enhance the momemtum of the model.
As a competitior the only recourse that you have is to ask for a on field ruling from the CD on Momentum 5.5; and then file a protest if you don't like the on field ruling; the other alternative is to follow Rule 6.12 prior to competing.
Historicaly, Rule 5.5 came into being circa 1964 because a model rocketeer by the name of Paul Hans devised a rubber band catapult system that could fling his model 150 up into the air. When the motor ignited, it burned through fishing line, pretty cool huh?
An analogy to this is something the HPR crowd does: they sometimes "paint" their cores with a pyrogen to enhance ignition. If this technique was used on composites in NAR competition, one could argue that this practice violates Rule 4.5 Alterations;: I think theres no doubt that painting the core results in the performance of the motor being different; if you painted the small core in an Estes BP motor, you would get the same result.
Chan, this would be a great R&D report for you to do.
you can shoot me your article
terry dean
nar 16158
I actually wrote an email to Tom Lyon on this subject maybe 2 years ago asking for a ruling and I can't find the email nor can he; I never bothered to follow up on it; I was told by BTC that If I was "caught" using BP igniters/powder in NAR competiton, that I would be "cheating". I guess its cheating only if you get caught? or in the eye of the beholder?