Tripoli allows 3 types of 'sugar' for use as the "primary fuel and binder" in
motors at their research launches. Because of that AND to stretch sometimes
limited amounts of sorbitol for making propellant, over the years, I've used a
60/40 fuel mix of sorbitol/sucrose in my own sugar motors thus keeping allowed
sorbitol as the primary fuel and binder. To keep the melted propellant fluid
enough to be poured into casting tubes, I use granular KNO3 (not ground or
powdered) and up to 40% of sucrose for the fuel portion but have had to
increase the temperature to 280 F to be pourable (I usually pour 100% sorbitol
at 230 F).
This is for minimum 75 mm grain size with 25mm mandrel core that makes pouring
into a casting tube practical...a large target for pouring and enough thermal
mass to prevent the propellant from thickening by being poured into a small
size tube.
"Tripoli Research Safety Code
Tripoli Rocketry Association - Research Safety Code April 2017 – Page: 3
3.2.2.6. Composite Propellant Rocket Motor Any device defined as a Rocket Motor
that
utilizes a propellant charge consisting primarily of an inorganic oxidizer
dispersed in
a carbonaceous polymeric binder.
3.2.2.7. Hybrid Rocket Motor. A rocket motor in which the fuel exists in a
different
physical state (solid or gaseous) than the oxidizer and that derives its force
or thrust
from the combination thereof.
3.2.2.8. Sugar Propellant Motor. A propellant charge containing potassium
nitrate as the
primary oxidizer, and containing either dextrose or sorbitol or erythritol as
the
primary fuel and binder."
Rick
On Tue Jun 25 2019 12:59:36 GMT+0000 (UTC), Juan Parczewski
<juanpamas@xxxxxxxxx> wrote:
Hello Richard
With regard to casting, unfortunately sugar plus sorbitol it is not a fluid
mixture. Difficult for casting. I used a vibrating table copied from your
vibrating table and with a pedal with electric switch to command it, I used the
direct casting system in the motor casing. I was passing portions of the candy
to the tube, giving it vibration and also using a polypropylene rod as a pison.
Once the casing was filled , I entered the central core. The working
temperature is of the order of 150 ° to 170 ° C.
Cheer
On Tue, Jun 25, 2019 at 2:08 AM FreeLists Mailing List Manager
<ecartis@xxxxxxxxxxxxx> wrote:
sugpro Digest Mon, 24 Jun 2019 Volume: 05 Issue: 041
In This Issue:
[sugpro] Re: sugpro Digest V5 #37
[sugpro] Re: Nozzleless motors
[sugpro] Re: Nozzleless motors
[sugpro] Re: Nozzleless motors
[sugpro] Re: Nozzleless motors
[sugpro] Re: 38 mm PVC liner for LOKI
----------------------------------------------------------------------
From: Richard Nakka <richard.rocketry@xxxxxxxxx>
Date: Mon, 24 Jun 2019 09:30:37 -0500
Subject: [sugpro] Re: sugpro Digest V5 #37
Nice work, Juan !
I notice you used a mixture of Sucrose and sorbitol. Shorter more powerful
burn. Good approach for nozzleless motors. How was this mixture to work
with, with regard to casting. Melt temperature? Pourable?
Richard
