You can also modify a CTI for HEI if you use the right epoxy like CO4525
On Tue, Sep 5, 2017 at 8:55 PM, James Dougherty <jafrado@xxxxxxxxx> wrote:
Putting blue-tape over the cavity will give a small amount of smoke, but
no ejection charge.
The easiest way to fly one of those with electronics is to dump out the
charge; and use your altimeter chargers.
You will still get blow-by.
If you don't want blow-by, use epoxy.
Yes, it is pricy though.
On Tue, Sep 5, 2017 at 8:50 PM, Dave M <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
Eric,
So to clarify you are removing BP and putting blue tape over the cavity?
Sent from my iPhone
On Sep 5, 2017, at 8:36 PM, Eric Melville <eric@xxxxxxxxxxxxx> wrote:
I put blue tape over the touch hole. It might sound ridiculous but I have
not seen a single burn through, on at least a dozen flights now.
- iPhone mail
On Sep 5, 2017, at 7:40 PM, Dave M (Redacted sender "muldavea" for DMARC)
<dmarc-noreply@xxxxxxxxxxxxx> wrote:
So what should I do otherwise with the BP cavity? Is there a better way
than filling with epoxy?
Sent from my iPhone
On Sep 5, 2017, at 6:47 PM, Dave M (Redacted sender "muldavea" for DMARC)
<dmarc-noreply@xxxxxxxxxxxxx> wrote:
I just emptied the cavity of the BP.
Sent from my iPhone
On Sep 5, 2017, at 6:12 PM, Dave Barr <dhbarr@xxxxxxxxx> wrote:
To clarify: did you keep the delay grain or was that epoxified as well?
On Tuesday, September 5, 2017, Dave M <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
54mm. I believe they were a J295 and a K570.first I thought I was cutting off the oxygen supply somehow at the base of
Good point Kurt. Maybe I was just unlucky with those two launches. At
the motor (I helped a guy who was down to his last igniter when I noticed
he had heavily taped up the bottom of the motor) but I just had the red cap
on and even cut an X cut into it after igniters failed. It was only later
that I realized it was the motors I filled with epoxy so I got suspicious.
Now I'm paranoid to do that again. On some small Aerotch motors I've just
used Vaseline instead of BP with some tape over it, but figured epoxy is a
better alternative?
wrote:
Sent from my iPhone
On Sep 5, 2017, at 4:54 PM, Kurtgug@xxxxxxxxx <kurtgug@xxxxxxxxx>
always harder to light it with the second, and even harder with the third.
Once you burn the first igniter without lighting the motor, it is
The core gets coated with soot which acts as an insulator. If you had the
pyrodex pellet in there, it is hard to imagine that not lighting. Maybe it
did light but fail to light the fuel. That would really coat the inside
with soot.
DMARC) <dmarc-noreply@xxxxxxxxxxxxx> wrote:
Sent from my iPad
On Sep 5, 2017, at 4:44 PM, Dave M (Redacted sender "muldavea" for
so quickly that I didn't think it would have any chance to soak thru
No I was very careful next not to disturb anything. And the epoxy dries
anywhere.
DMARC) <dmarc-noreply@xxxxxxxxxxxxx> wrote:
Sent from my iPhone
On Sep 5, 2017, at 4:36 PM, Gregory Lyzenga <lyzenga@xxxxxxxxx> wrote:
On Sep 5, 2017, at 4:22 PM, Dave M (Redacted sender "muldavea" for
A while back, I had two Cesaroni motors that were not plugged but Ididnt want the motor to blow the BP charge. So I removed the BP and filled
up with epoxy. Problem was, in each case, it took maybe three attempts to
launch. Kept burning out igniters. Any thoughts?
damage the igniter pellet at the top of the grain? Since Cesaroni igniters
In the process of removing the ejection charge, did you disturb or
are basically just e-matches without a bunch of pyrogen, there is a pyrodex
pellet at the top of the motor to get the ignition going. If the epoxy ran
onto that, it might explain your problem. But on second thought that seems
unlikely, since there would be a delay grain between it and the ejection
charge well. Hmmm… I’m not sure...
- Greg
----------------------------------------------------------
Gregory A. Lyzenga <lyzenga@xxxxxxx>
Dept. of Physics, Harvey Mudd College (909) 621-8378
Claremont, CA 91711-5990 mobile (626) 808-5314
