How come no certified Sugar Motors

[NewEntity1]

From what I've heard, Sugar motors are some of the safest grains around, plus they perform decent as well...

How come no-one has ever tried to get sugar motors certified? If their performance can be made better than black powder, I would think they would even be useful in diversifying the rather spartan selection currently available in mid-power

 

[rbeckey]

My understanding is that they are ferociously hydroscopic, making them nearly impossible to store.

 

[DavRedf]

You got it Bob you almost have to make them on site. The slightest hint of water and they absorb it.

David

 

[Papa Elf]

The propellant is hard and brittle when new, and if any moisture finds its way into the propellant, it turns into puty.

 

[Ryan S.]

also, sugar isnt a very high performance propellant, so I would think that manufacturers are not willing to make the investment of having them certified unless they would make a good profit on them

 

[doxiedog315]

How about a dipped parrifin coating,you know ,wax? only puncture to install igniter?...........just wondered..jerry

 

[Papa Elf]

All it takes is one little hole or crack..... People that do make their own Sugar Motors do that, but it is still only a temporary solution.

 

[edwardw]

I actually fly exclusively sugar motors. I have never had a problem with them being Hydroscopic. If you go to www.inverseengineering.com and look at his casting method that is what I use. For some reason it cuts down on the hydroscopic nature. I have had a reload for a J engine sitting in my garage for over 3 months - not in a bag but just on a shelf and they are still in the exact same condition as when I cast them.


Edward

 

[wyldbill]

That may be true, but you (like me) live in Colorado where the humidity is notoriously low. Put the same load on a shelf in Houston and you'll have a puddle in a few days.

Some people will coat the grains will a nitrocellulose lacquer to seal them.. The lacquer is very flammable and will actually help ignite the grain. No poking holes in the sealant required.

-bill

 

[edwardw]

I have actually thought about coating them in NC laquer but have not yet. I didn't know how it would affect performance. I was thinking that it might be too hot at startup and hurt something. I know www.mbrocketry.com has a method of making your own NC laquer. I will try that.

 

[Johnnie]

I keep my grains in sandwitch, or Glad freezer bags, and add saltines in each bag as a desicant. I have grains that I made last winter still in storage. Granted these bags are also kept in a air & liquid tight military ammo can. I live in the Heart of Dixie in the State of Alabama, and we breath H2O down here...no problems yet.

As far as certifying...vacuum bag each grain for safe keep, and include an extra dessicant pouch like you find in electronics, and you might have a winning combo...but processes like that tend to drive the price up. As for performance, these motors burn as fast or faster than Blue Thunder, and produce more smoke than a White Lightning...but, unless you are launching at night, you will see no flame. The reloads I make for the Dr. Rockets 29/240 case are a full G were Aerotech loads for this same casing are mid to full H's. So AP will always be twice the power as well.

The single use might be a good way to certify these loads, as you can seal these up good for storage. Before Stanford Systems decided to take your money and run, he was coming up with a nice system of singleuse motors using "Candy" propellant.

I have attached a photo of my 54mm FWFG (Nightrider) rocket flying on a "Baby" J 10-grain 38mm Kn/Sorbitol load. The 6.5 pound rocket reached 3400 plus feet, burn time was 1 second...

Johnnie Paul

 

[wyldbill]

Originally posted by edwardw
I have actually thought about coating them in NC laquer but have not yet. I didn't know how it would affect performance. I was thinking that it might be too hot at startup and hurt something.

Check out Jimmy Yawn's experiments. NC lacquer is often used in finishing guitars. Stew Mac is one source if you don't want to make your own. Jimmy's recrystallizing technique is interesting also.

-bill

 

[edwardw]

Now that you guys mention it I will coat my next grains in NC Laquer. It will also help with startup because I have been adding a burn rate suppressant to the propellant to get longer burn times.

I have thought about making a bunch of grains ahead of time and putting them in my Foodsaver vacuum sealer machine with some rice and baby powder. The only problem with this (for me) is that every time that I make two or three sets of reloads for a motor somehow the rocket doesn't deploy a chute and I plant a tree. Hence the J reloads in the garage.

Edward

 

[marvSRG]

but, unless you are launching at night, you will see no flame.

Yeah, that's the downside of Sugar motors, but haven't you
-Johnnie- done some testing of KNO3 Epoxy motors with Mg in them? Did you get any flame then? Sorry if I'm getting too EX, I just want to see if some flame has been gotten out of any type of KNO3 oxidized motor.

 

[Johnnie]

The only flame I was able to get came from a 9 second burn Kn motor that was 76mm w/ 4 grains. It had a 12" long flame, that was it, kno3 is a flame suppressor.

We are getting a little to EXy in here, so I will try to get us back on topic...

If you could get "Candy" propellant certified, then that would mean you have nailed a process that would allow these motors to be stored for at least a year without being in an ammo can.

But look at the upside, cost would be lower than AP, and Sorbitol can be bought by the pallet. This is assuming you developed Kn/Sb as opposed to any other types of "candy."

To me the flame is not the go getter in a propellant. Look at Blackjack motors, the likeability of these certified motors, is there long burn and black smoke...no flame. The "candy" burns like Blue Thunder, only with a white smoke exhaust...this could be touted the carbon copy of Blackjack, it could be called "White Thunder"



LEUP's??? Not yet, could be a short term fix for big reloads that do not require a LEUP if "candy" were certified...definetly do not want to get political in here either.

I can envision single use G motors of this propellant selling for $6 or $7 bucks a pop...I would buy singleuse White Thunder, and alternate Blackjack and White Thunder every other flight...

 

[edwardw]

Just to confirm some stuff briefly.

No flame - only time I had flame was at 3000psi motor pressure.

Sorbitol/KNO3 has been characterized by Richard Nakka. www.nakka-rocketry.net

Has a wierd triangular thrust curve for sorbitol. By nature Sorbitol burns longer than regular sugar. Less powerful

Why doesn't someone start a company and make reloads then?
Anyone want to partner up with me? I'm game.

Edward

As a side note - red copper oxide turns the smoke pink - but makes it burn faster. A burn rate catalyst.

 

[Papa Elf]

Do you mean less thrust when you say less powerful? If it burns longer than sugar, it may produce less thrust? I thought Sobitol was more powerful than sugar because of its two additional Hydrogen atoms...

Its kind of like comparing Redline with White Lignthing.

H128W and H168R. The H168 has a lot more thrust than the H128, but the H128 has more total impulse....


or am I just blowing smoke?

 

[edwardw]

Two engine comparisons
Exact Same specs on engine - core, grains, throat


Sugar
K1082 Total Impulse is 1438 n*s Burn time = 1.3

Sorbitol
K593 Total Impulse is 1312 Burn Time = 2.2 Seconds

 

[Papa Elf]

Are those at simular PSI? Is suggar motors simular to APCP, where the higher the PSI (Up to a certain point), the more efficient the propellant burns (making more energy)?

 

[wyldbill]

BTW, if you don't wanna commit a faux pas whilst confabbing amongst your Rocket Scientist brethren, the word is
hygroscopic
Not:
hydroscopic
FWIW,
-bill

 

[Johnnie]

Are those at simular PSI? Is suggar motors simular to APCP, where the higher the PSI (Up to a certain point), the more efficient the propellant burns (making more energy)?

The higher the PSI, the better the Isp, so yes, to a point PSI will enhance your motors performance...too much, and that pressure will probably let the end closures go. APCP will run KN value between 180 and 220 sometimes more or less depending on formula...My KNCP will run KN's between 275 and 300 conservatively.

APCP withdrawl?...KNCP fix

 

[edwardw]

No, but I did do some at the exact same PSI.

The total impulse of the sorbitol was 1350 while the sugar was 1438.


The soritol burned for 2.1 seconds while the sugar burned for 1.2 seconds.


Edward

 

[gerbs4me]

Sugar motors rock!!!!

BTW:I don't think we are supposed to discuss EX on this forum, maybe I'm wrong

 

[Ryan S.]

I think we are safe right now Gerbs. I dont think this thread had crossed the line but I may be wrong

 

[MarkABrown]

Originally posted by Ryan S.
I think we are safe right now Gerbs. I dont think this thread had crossed the line but I may be wrong

You're all still good to go. As long as there are no exact formulas posted, you're within the guidelines.