[sugpro] Re: PVC Delay Grain Trouble
- From: Bill Kuker <bkuker@xxxxxxxxxxxxx>
- To: SugPro <sugpro@xxxxxxxxxxxxx>
- Date: Sun, 8 Mar 2015 22:53:13 -0400
Well, I've used electric igniters with a BP/NC mixture, the same but with
Mg added, the same but with an extra half teaspoon boost of BP to try to
remedy the problem, cannon fuse and cannon fuse with BP. The cannon fuse is
still head-end ignition, but I have found that since I generally fly in
sub-zero temps (fahrenheit!) cannon fuse is more reliable, lighter and more
convenient than dealing with wires and batteries.
I guess I'll try some kind of pyrogen on it. Any suggestions?
As far as electronic recovery, I like to be able to prep N full flights
ahead of time (airframe, motor and recovery). For "religious" reasons I
only fly scratch built everything, so that many electronic recovery systems
would be a big investment, although it is probably the right solution, also
if I go any higher I'll need dual deployment, but even then I'll keep the
pyrotechnic deployment in place as a drogue backup even if I can't get it
more than 50% reliable.
-Bill
On Sun, Mar 8, 2015 at 9:50 AM, steve ghioto <ssmgg@xxxxxxxxxxx> wrote:
> Bill,
> I don't use this style but my first question would be what type of
> igniters are you using? Second, can you coat the bottom of the delay grain
> with a pyrogen to aid in the starting of the grain? Third, can you switch
> to some type of electronic recovery?
>
> Steve
>
> ------------------------------
> From: bkuker@xxxxxxxxxxxxx
> Date: Sun, 8 Mar 2015 08:47:47 -0400
> Subject: [sugpro] PVC Delay Grain Trouble
> To: sugpro@xxxxxxxxxxxxx
>
>
> For a few years I have been flying PVC motors with great success. I
> started with designs similar to Richard Nakka & Chuck Knight, and have
> simplified some steps in construction by using the right fittings, and
> changed to machined steel nozzles.
>
> Ignition, flight, and overall performance have been spot on and very
> reliable, I am working on drawing up all of the details to share.
>
> My recovery rate is 50% at best. My delay grains are exactly as described
> here: http://www.nakka-rocketry.net/pvcmot7.html
>
> Each flight either works perfectly, with ejection at just the right time,
> or I dig an unlit delay grain out of the wreckage. Does anyone else use
> this style? Any tips on how to make it reliable?
>
> -Bill
>
>
>
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