ddmobley

Ooo, look, a new propellant!

Designation: 8222
%Solids/%Metal: 82/0
Binder Type: HTPB
Isp (1000/14.7) 235.6
C* (ft/sec): 4817
Density (lb/in): 0.0589
T0 (oR): 4648
Gamma: 1.22
Molecular Weight: 23.33
Rate coefficient: 0.0687
Pressure exponent: 0.284

Just Jerry

What is the "market purpose" for this motor? Ultimate "cheater" motor?

It seems to be a minor modification of E6 propellant in a coreburner configuration.

Old is new again.

One wonders if "new" Apogee motors will suddenly have this propellant?

Just Jerry

UncleVanya

I'm dense. I'm not following what this means. What is a "cheater" motor?

This is a HPR motor from a certification perspective > 80 ns. I wonder about the market myself. Big average thrust very little total thrust for a G.

ddmobley

Look at the propellant weight.

UncleVanya

I did. Is that significantly smaller than the weight of a large F and a smaller motor? I haven't checked yet.

In a simplistic (and crude) calculation I took the weight and the newton's and it appeared that a 62.5g motor would not have any more total thrust than the newly formulated G80 - so by that measure the new motor isn't a whole lot better than what's out there. I would think a G80 - with lower average thrust and longer burn would take the same rocket higher - but I could be wrong.

My only thought had been that using this motor which barely is a G plus a long burn F would get you something...

NiallOswald

Did you get that information from the ISP portfolio? The specs look all but identical to Warp9 (8223AL) but with half the rate coefficient.

So, a fast-burning, SU, very small G motor - bit of a 'niche' product I'd have thought. If they shaved a few Ns and made it a full 'F' it'd be ideal for an 'F' boosted dart

Just Jerry

G142-6,10,14 (S)
29 x 113 mm
Single Use Motor
84.3 Newton-seconds total impulse
173.9 Newtons Peak Thrust
135.9 Newtons Average Thrust

Propellant mass: 38.6 gm.

Propellant Key:
8222ALF Propellant

Motor Type Key:
S = Single Use


Note being single use the propellant mass is 38.6g. Therefore it is not "mailable", but just barely. If it had been 30g it would be mailable.

At the propellant mass used it is about as small a G as you can get (cheater motor) [AT 29mm SU 84.3G135.9-10-8222ALF>. That makes it unsuitable for most NAR contests.

Not sure about TARC. Is this the sort of motor a TARC person might need?

Being over 80n average it is not a CPSC model rocket motor, and I believe is treated as HPR for purposes of consumer certification.

If I had to say what the purpose for this motor was, it would be to show an instance of the single most wildly regulated motor on the planet, and I'm not kidding.

On the other hand, it doesn't know it. It thinks it is a cool woosh generator! Ahhh, blissful ignorance!

Just Jerry

denverdoc

yea, I would have preferred a butt kicking F which would be very handy for staging, loadlifting, etc. That is a helluva an ISP at 230+ , particularly in such a small motor where efficiency can take a hit.

Art Upton

I used to use the RMS G104 for a few niche things, it was bearly a "G" as well.

This new G142 I will try a few.
Hey Red Arrow Dave; Got any yet?

You can't use a HPR motor in TARC or NAR contests, but you can for Tripoli records; but no boosted darts allowed there.

Adrian A

Yeah, given its 29mm diameter and short burn, it would get its butt kicked for the G altitude record attempts by the new AT G80 with 137 N-s or a 24mm Ellis G37. And it's just slighltly too much impluse to be able to boost an F10 sustainer for a 2-stage record while staying within a G total impulse limit.

But it should do well (much better than a G104) for getting top speed in a mach-busting 29mm rocket since it's nice and light and short.

Adrian A

Is the Isp just for the propellant, or net, including the whole motor?

ddmobley

As posted on TRF:

H_rocket

Sounds like

"If we could sell them on Overstock.COM we would and be done with it. Instead we'll sell tem off to the folks who will bend over backwards to find a use and if they sell, we will whip up a few extra in our next production run"

Hey it's another motor, slap it in something and see if it flies.

Just Jerry

Propellant ISP not system ISP.

Just Jerry

Art Upton

HI Adrian,

An F10 is listed as 74.26 total NS and the G142 as 84.3, that makes 158 and some change; the limit is 160


http://www.nar.org/SandT/pdf/Apogee/F10.pdf

Just Jerry

I used an E6 to an E6 2 stage to set an altitude record in the early 80's, shortly after the E6 was initially released as one of Aerotech's first products. It went 1992 M or 6534 feet (optically tracked).

I would think an F10 to F10 would go higher than G142 to F10 unless you delay staged the F10 so the G142 was an effective boosted dart initially.

One wonders if a lossy water (or tickle) vessel would be legal, to aid momentum before F10 burn?

Just Jerry

Art Upton

F10s to F10s tend to go off verticle and loose altitude that way, "sometimes". My thinking is a quick kick in the arse will keep it straighter. Current TRA G staged record is 7,672, F25 to F10; Douglas Gamber 10/27/02


Delay staging is a must and no issue since you need a micro timer anyway.

No TRA rule say lossy water is not allowed.
http://www.tripoli.org/records/overview.shtml

Anything strickly not allowed has to be allowed for competition to be fair around the country.

snaquin3

Looks like you figured out the intended use for this new motor! Looks to be just about perfect for such an application as G altitude.

I'm going to buy a few to try them out and the new G80's as well.

I wonder if this new propellant is a low smoke.

.

ddmobley

According to Gary, "[l>ow smoke, low visible flame."

snaquin3

Just like I like em ..... like my first composite Crown/SSRS motors I flew back in the 80's

I like colors too, but low smoke reminds me of the F67 (the first composite motor I ever used).

.

Art Upton

I talked to Dave @ Red Arrow Hobbies yesterday.

http://www.redarrowhobbies.com/

He ordered a batch, get them while they last, as like Gary said, they are "boutique"

I got mine on the way.

I'm pretty sure I saw Gary fly one of these at Black Rock a couple years ago

denverdoc

Question: where do the cited ISP values come from? You can search the net and get tables for your favorite fuel. But if I'm not mistaken these presume a nozzle and the better sources cite both sea level and vacuum ISP's owing to the different bumps in velocity one can get from optimal expansion into the respective ambient pressures. So AT cites 230+ for this propellant. This motor delivers closer to 210.

BTW, to compute ISP for a particular motor:

Isp=Impulse/(mass*grav constant) keeping the units consistent. In mks system, taht would be Newtons, Kg, and 9.8 m/s^2

Example a J motor of 1000N, .5 Kg of propellant: 1000/.5/9.8=204

Just Jerry

The most practical way to calculate an ISP (Impulse, subscript, specific, abbreviated SP or sp), is to find a static test report such as TRA TMT, NAR S&T, or CAR certification report.

Look at the delivered power they MEASURED. Then look at the propellant mass. Sometimes this is physically measured, sometimes from values stated by a manufacturer. This value should be net of thermal liners.

Divide power in Pound-seconds by propellant mass in pounds to get ISP in seconds.

Liquid motors use a calculated exhaust velocity method. This method is more grounded in hard data. A solid has the advantage of an absolutely fixed and known massflow.

By using a test report you are fixing a nozzle throat, exit area, altitude of test, temperature of motor, etc.
ISP varies with all these values.

Just Tech Jerry

denverdoc

So as I thought, one can use some specmanship to advertise an ISP that may have been delivered at say higher than normal pressures in a 150mm case, even if it bears little relation to the delivered ISP in the consumer products line. The reason I was wondering is I thought the big srb's in near vacuum deliver 240 something and none of my EX buddies are getting more than 220 and thats living on the edge.

Just Jerry

Back in the mid-80's I did a SU M static with a delivered ISP of 244. That was about 2000' altitude and as nearly perfectly expanded as possible, over 800 psi pressure and the flattest thrust curve you ever saw by carefully engineered BATES lengths intermingled. That propellant was certainly not pourable.

At least that's how I remember it

Just Jerry

Adrian A

Very cool. I'll have to sim that. I thought I remembered the F10 as being 78 NS or so, but I stand corrected. A 24mm Ellis G37-E6 theoretically could go to about 14k, though, so that's tough to beat.




That one is asking for an update, considering that an F10 has lofted a Parrot/Beeline combo over 8400 feet. But that was before the Parrot was certified, and I only recovered the nosecone anyway, since I went overboard on cutting the weight down.

Garoq

222.7 sec actually.

The new G80T delivered up to 229.2 sec during NAR certification testing. Not bad for a motor that operates at about 300 PSI average chamber pressure.

Just Jerry

That is technically impressive indeed.

Just Jerry

denverdoc

My bad 222 it is--which as Jerry says is damned impressive for such a small motor. Keep em coming!

Just Jerry

I would like to see GARY fly one. He says rockets are a necessary evil. That presumes they are necessary.

Just Jerry

denverdoc

Hey I'd love to see both Gary and Anthony fly--fabulous would be a drag race in the LDRS mach madness....

Steve_Shannon

I can attest to the fact that Anthony flies. I've seen him fly at RocLake in Canada. Great big, beautiful rocket, but bad luck.

ddmobley

I want to see Anthony fly his carbon fiber Black Brants.

Just Jerry

More people have seen me fly a rocket than Gary and Anthony combined.

Therefore I volunteer to provide free motors and airframes for Anthony and Gary in particular, and at "my" site in particular.

I will not only buy the drinks afterward, but the drinks for ALL COMERS.

Merely Jerry

http://v-serv.com/usr/motors/images.rr152-40960.htm

http://v-serv.com/usr/motors/images.rr152-88000.htm

I don't mean a piss-ant small motor either.

UncleVanya

Dang... I'll make that trip if it comes true.

denverdoc

Heck I think half the hobby would show up for that one.

No criticism intended: I think it would be great to see our leading manufacturers in the trenches more--not by sponsoring shots, which is a fantastic service/promotion of the hobby, or even demo flights--but by flying some bleeding edge pet projects or competing in a good natured way for bragging rights.

PS: Darrell, thanks for posting that pic of the BB. Reminds me I have a rocket to build by Sept.

ddmobley

I do what I can. But I would really like to see one of those BIG BBs hit the skies!

Just Jerry

Tripoli records rules SPECIFICALLY discourages that!!

Just Jerry

TRA #000012

denverdoc

Really, why? Seems like it would help promote the hobby.

snaquin3

Dave at Red Arrow Hobbies sent me an email to let me know the G142-6 motor shipment had arrived. I bought three and figured I'd try three of the new G80-13T for a near min. dia. scratch built I have that is based on the SSRS/Crown Lasor series of rockets with a hardwood cone and thick walled tubing. Not sure what I'm going to fly the G142-6 in yet but many of my smaller rockets would need to use an altimeter for deployment because of the 6 sec delay.

He told me about half of what he got in of the G142-6 shipment is already spoken for so I wouldn't delay if you want to get your hands on a few. He told me there wouldn't be another production run until sometime around fall .....

Anyone make a RockSim motor file from the .pdf data file yet?

.