H97J - Does it exist?

I am simming a rocket in rocksim and the motor H97J is listed. That motor would make a great flight in my rocket but I can't find whether or not it still exists.

bigone5500 said:

I am simming a rocket in rocksim and the motor H97J is listed. That motor would make a great flight in my rocket but I can't find whether or not it still exists.

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Absolutely it still exists. Fits the 29/240 casing. Wildman rocketry has them - at least according to his website.

So does Al's Hobby shop.

They're readily available.

yes! I flew (one ) in my Deuce and I am planning to get both this time to light. I will get pics up sometime.

Ben

I flew one two weeks ago in my Sumo. Nice motor

Flew 2 at RedGlare4 and 1 at Culpeper.

You can download a current list of motors available from the manufacturer. I check that list frequently to see if the motor is still available.

Mike

ben said:

yes! I flew (one ) in my Deuce and I am planning to get both this time to light. I will get pics up sometime.

Ben

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If you have any extra pyrogen available, apply a thin layer to the core of the top grain of each motor. That should get 'em both lit.

I once lit a very stubborn E16W this way. Anyone who has or tried to fly one of these motors will tell you they're a pain in the (insert random sound effect here) to light.

Lit on the very first try.

MarkM said:

Absolutely it still exists. Fits the 29/240 casing. Wildman rocketry has them - at least according to his website.

So does Al's Hobby shop.

They're readily available.

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isn't that a 29/180 three grain?

either way cool motor.

Jim Shue said:

isn't that a 29/180 three grain?

either way cool motor.

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No, its definitely a 29/240. I can't remember the number of grains.

The 3 grain 29/180 load is a G75J
The 4 grain 29/240 load is a H97J.

The H97J has a propellant weight exceeding 125 grams, so it can't be flown at launches using the FAR 101 notification process.

John

Donaldsrockets said:

If you have any extra pyrogen available, apply a thin layer to the core of the top grain of each motor. That should get 'em both lit.

I once lit a very stubborn E16W this way. Anyone who has or tried to fly one of these motors will tell you they're a pain in the (insert random sound effect here) to light.

Lit on the very first try.

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This is always a good idea. I'm surprised that I don't hear more about "painting grains".

Shameless plug:
QuickDip is an excellent choice for doing this.

yes, i have two in my box.
Although IMHO, its a pretty crappy motor. The black smoke is cool, but it just doesn't have any oomph.

QuickBurst said:

This is always a good idea. I'm surprised that I don't hear more about "painting grains".

Shameless plug:
QuickDip is an excellent choice for doing this.

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That was my plan.

Not to put QB down but it was the 2nd twiggy in the fresh pack (opened a weekor two before and kept inside controlled) to not light. I did test it with an E-match tester (all I had) and it was good. The other one lit in the cluster.

Ben

Necromancer said:

yes, i have two in my box.
Although IMHO, its a pretty crappy motor. The black smoke is cool, but it just doesn't have any oomph.

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It's not supposed to have a lot of oomph, and it burns pretty long for a 29. I like it a lot.

I want one for my BT80 Bullpup. Will put it to about 2000'. Which is just right.

ben said:

That was my plan.

Not to put QB down but it was the 2nd twiggy in the fresh pack (opened a weekor two before and kept inside controlled) to not light. I did test it with an E-match tester (all I had) and it was good. The other one lit in the cluster.

Ben

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Very sorry to hear that. Did the igniter fail or did the igniter fail to light the propellant?

Sometimes there are other issues.

Old motors for one. Was it an old motor? BJ propellant is always hard to light, if it was old BJ propellant, then it would have been even harder to light.



FYI

I never take failure reports as insults, I take them as learning experiences.

skycopp said:

Flew 2 at RedGlare4 and 1 at Culpeper.

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Where were you at Culpeper? I must have missed you, or just didn't get the person connnected with TRF. Maybe we should have name tags with our TRF tags when we're at the launches.

I flew 2 of the H97J on Sunday at Culpeper, before helping Will with the Saturn V. Mike said they were the original Smokey H100s from a few years back.

Nice motor, but the effect is better then the oomph! But why fly them if not for the effect? If you want oomph, fly something else. It's all about choice.

Handeman said:

Nice motor, but the effect is better then the oomph! But why fly them if not for the effect? If you want oomph, fly something else. It's all about choice.

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Nicely said. I have always liked the black jack propellant. Which is one reason for wanting this motor. Firstly though because my rocket is small.

Handeman said:

Where were you at Culpeper? I must have missed you, or just didn't get the person connnected with TRF. Maybe we should have name tags with our TRF tags when we're at the launches.

.

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Yes, I was at Culpeper, but only on Saturday.

Guess you got a chance to see my L1 flight then. Too bad you couldn't have gotten back on Sunday. Will Marchant's Saturn V flight was really cool with the K and 4 Js.

QuickBurst said:

Very sorry to hear that. Did the igniter fail or did the igniter fail to light the propellant?

Sometimes there are other issues.

Old motors for one. Was it an old motor? BJ propellant is always hard to light, if it was old BJ propellant, then it would have been even harder to light.



FYI

I never take failure reports as insults, I take them as learning experiences.

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The ignitor actually failed to ignite. I figured after the 50-75 ignitors and E-matches I have went through and got 2 that failed. I think I am doing ok

Ben

You've had two fail?

Wow - I've gone through at least a hundred (quickbursts) with exactly one failure.

So what is the smallest H 29mm motor available? I see rocksim has an H55 in the motor selection.

Impulse wise, the H165 is the weakest 29mm H motor. The H55 is OOP.

jj94 said:

Impulse wise, the H165 is the weakest 29mm H motor. The H55 is OOP.

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H128?

Ben

ben said:

H128?

Ben

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From Aerotech's catalog, the H165 is listed as 170 Ns. The H128 has 175 Ns. But any of the H motors for the 29/180 will be good. Those are as weak as they get from AT.

jj94 said:

From Aerotech's catalog, the H165 is listed as 70 Ns. The H128 has 75 Ns. But any of the H motors for the 29/180 will be good. Those are as weak as they get from AT.

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That is true. With the WL you get a tad longer burn time than the Redline

Ben

Would it be a better trade off going with shorter burn and higher thrust or longer burn and less thrust in order to get a lower alt. flight?

It seems to me that the one with higher thrust/short burn would be the answer. H128W is 175Ns and the H165R is 170Ns. The propellant in the H128W weighs almost 1g more than the H165R.

You're almost always better going with the long burner for altitude, except when you're under about 7 or 8 to 1 liftoff thrust to weight ratio.

bigone5500 said:

Would it be a better trade off going with shorter burn and higher thrust or longer burn and less thrust in order to get a lower alt. flight?

It seems to me that the one with higher thrust/short burn would be the answer. H128W is 175Ns and the H165R is 170Ns. The propellant in the H128W weighs almost 1g more than the H165R.

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As a rule of thumb, the lower average thrust will burn longer and get you a higher altitude. An extreme example is my L1 rocket. It simmed to almost 4200 feet @.52 mach on a Loki I110 with 4+ sec. burn, it sims to about 3800 feet @ .62 mach on a I1299 with a 0.3 sec burn.