I recently flew my honest john (estes) on a D 12-5. I attached my jolly logic altimeter 3 to the nose cone with a fishing swivel and placed 4 holes below the nose cone shoulder but above where I pack the parachute. It says my rocket only went to 512 ft, but I thought that wouldn’t be right given the rocket and engine. It also said my sky lofter (estes) went 644 ft on a C 6-5. This does not seem actuate given the estimated altitudes by the manufacturer. What could the problem possibly be? Are my holes too small?
Jolly Logic Altimeter 3 Barometric Pressure Holes
- Thread starter Jack Arne
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The Estes HoJo is a heavy rocket...so that seems reasonable. I'm less familiar with the Sky Lofter. Can you post photos of both rockets? Lots of factors can affect this. Paint, smoothness of finish, wind conditions, etc.
The pressure holes you describe sound like more than enough. I normally only drill two for my JL3. How large were the holes? Are you sure that the nose cone shoulder didn't cover them?
The pressure holes you describe sound like more than enough. I normally only drill two for my JL3. How large were the holes? Are you sure that the nose cone shoulder didn't cover them?
Estes’ estimated altitudes are generally quite optimistic. This comes from someone who has literally hundreds of flights of models with various altimeters (including AltimeterThree) in them.
I’m not too familiar with that Honest John. A quick look at what a Sky Lofter is tells me that 644 feet on a C6-5 is plausible.
It sounds to me like you’re reasonable data.
I’m not too familiar with that Honest John. A quick look at what a Sky Lofter is tells me that 644 feet on a C6-5 is plausible.
It sounds to me like you’re reasonable data.
Well, the readings you get after ejection should be pretty accurate, right?
I'd trust the Alt3 over manufacturer estimates here. Also note that you've added a third of an ounce of weight by including the Alt3 in there, that'll cut down your altitude as well.
As for whether your holes are too small: how big are they?
Those holes should be fine. If it were me, I‘d have put the ones in the Sky Lofter’s payload section much closer to the bottom (further away from the nose cone/payload tube joint) but what you have should be fine.
Your graphs both look good with no odd spikes or anything....I’d say trust your instrumentation!
Your graphs both look good with no odd spikes or anything....I’d say trust your instrumentation!
First of all, that's a great looking Honest John--and I'm a connoisseur of America's first nuclear capable missile. Nice work!
The placement of the holes is fine, and so is the size. I concur that Estes altitude estimates are mostly marketing. Given the weight, wind, etc. I suspect your data is spot on.
Lower is better anyway--you can see the whole flight, and admire that beautiful rocket in flight.
BTW, Jolly Logic rules. John Beans is a natural treasure. Hoping that both he and Betty White are quarantined in a secure undisclosed location until this pandemic is over. We're all waiting on the smaller JLCR and can't risk the fate of the free world.
The placement of the holes is fine, and so is the size. I concur that Estes altitude estimates are mostly marketing. Given the weight, wind, etc. I suspect your data is spot on.
Lower is better anyway--you can see the whole flight, and admire that beautiful rocket in flight.
BTW, Jolly Logic rules. John Beans is a natural treasure. Hoping that both he and Betty White are quarantined in a secure undisclosed location until this pandemic is over. We're all waiting on the smaller JLCR and can't risk the fate of the free world.
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