Estes Mini Honest John - First Flight

I launched my new Mini HJ yesterday on a A10-3T which is one of the recommended engines. Totally unstable immediately after leaving the rod. Luckily it was recovered with no damage. Need to do some calcs and add nose weight before the next flight.

Looks awesome.

Boosterdude said:

Totally unstable immediately after leaving the rod. Luckily it was recovered with no damage.[/IMG]

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Interesting. I've built one as well, and then made a OR file of it and it shows the same thing (unstable). OR says about .2 oz in the nose should give you a good margin.

FC

FastCargo said:

Interesting. I've built one as well, and then made a OR file of it and it shows the same thing (unstable). OR says about .2 oz in the nose should give you a good margin.

FC

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Excellent, that's close to what I came up with as well.

I can't beleive this is happening since I've never had this issue. Looks like a lump of clay will need to be added to future kits.


John Boren

That is strange, not sure why it's happening. It seems to me that .2 to .3 in the nose should resolve the issue. I'll try to get another flight sometime this weekend using the same A10-3T and report back.

The first flight basically got about ten feet of the ground, did some impressive turns, and landed ten feet from the pad. Just about as soon as it left the rod it was unstable. It was about 83 degrees, with zero wind.

Thanks for the heads up. I just bought this kit at the 30% Hobby Lobby sale this week.

Great looking rocket, btw.

Wow, I think that someone should ask/e-mail estes about this problem...
TRF :bangpan: Estes

We have built and flight tested several Mini Honest Johns as Estes and have had no problems at all with stability. In fact I was amazed at how stable the model is with such small fins. The only reports I have heard about the Mini Honest John going unstable is from this forum. To the best of my knowledge we have not gotten any calls into Estes about this issue either. We will however most likely add a piece of clay to future kits since it appears there is an issue even though we personally have not seen it.

John Boren
Estes R&D

Thanks for the the info because I plan on buying one of these

I finally flew the Mini HJ again today with the .25 ounces of nose weight added. I flew it with the A10-3, this time the flight was perfect. The boost was straight, and stable. Ejection was perfect, and I recovered the HJ with no damage.

The nose weight does the trick.

I got one a while ago.. flown only once. on a horribly undersized engine..
A 1/4A mini...

rookie mistake

she reached apogee at about 8 or so feet, nosed into the turf of the soccer field.. and its really nice turf! I can ROG with a light wieght electric park flyer off that turf!

anyways.. 8 feet in the air.. arches over. plops nose first in the turf about 10 feet from the pad... the tracking smoke starts to pour out of it, the POP! the engine ejects from the tail end of the rocket in a cute little arc.

it was actually really funny in a anti-climatic sort of way.

the nose cone did pop off, or shall I say, the rocket poped off the cone... the wadding stayed in and is intact, so I just stuffed everything back into the rocket...

so now I have 3 more little 1/4A minis laying around, so I made a wee little rocket by smearing a 3x6" index card with elmers glue, wrapped that around the spent 1/4A, sawed off 0.25 of that engine to use as a thrust ring, fashinoned a nose cone from blue foam, and fins from some scrap balsa..
painted the whole thing down with thinned elmers and painted it with leftover paint from the bertha...

havent launched it yet.. should be interesing.

Gotta use internet names cause you're both "John" and both last names start with "B".

Jumpet, when building and flying prototypes at Estes, what is the overall finish of the rockets flown? We all can see that Boosterdude has some skills in the finishing department as do you. Is it possible that sealing balsa and filling tube spirals, with all the different available products, as well as multiple coats of primer and paint used by many of the perfectionists in this hobby is what's causing this little diddy to be unstable?

I have experienced this with the Estes Hi-Flier. I couldn't even get it to fly on an A8-3 because I laminated the fins with card stock as well as painted the heck out of it to mach the Estes Placard. With the proper nose weight I've launched and recovered five times on C6-7's. Ballsy but fun.

It seams pretty plausible to me that Boosterdude did too good a job finishing the rocket and tacked on more weight than expected by designers.

That's a really good thought, but mine weighs 1oz which is less than the Estes estimated weight of 1.2 oz. Also, I was wondering about the weight of filling grain and spirals and built a second one. Number two had no fillings just shaped fins. First flight was totally unstable as soon as it left the rod.

They fly great with weight in the nose, easy fix!

Well, guess that myth is BUSTED :kill:

El Cheapo said:

Well, guess that myth is BUSTED :kill:

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Same thing I was thinking, it was a good idea. It made me build another one.

Sorry to hear that y'all's went unstable, but I appreciate you sharing so mine wont...

interesting. I just finished one too. Stock. I didnt even seal the balsa on this one. Last weekend was it's first and only launch. Seemed stable enough. We had a bit of wind and were only launching the smaller stuff so the flight was a bit of a rainbow. shoot popping out about 30 feet off the ground a few hundred yards down range. Flew on an A3-4 figured the flight was due to wind or a short rod. Ill try some weight and see if it changes but I really had not problems.

edit: i realized that i used that model for my frst future finish experiment. turned out great. thought i'd mention it since it could have changed some flight dynamic or something. I don't know enough yet to guess lol


-J

T-Rex said:

Sorry to hear that y'all's went unstable, but I appreciate you sharing so mine wont...

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No problem. Add the weight, install an A10 and watch it go.

JumpJet said:

We have built and flight tested several Mini Honest Johns as Estes and have had no problems at all with stability. In fact I was amazed at how stable the model is with such small fins. The only reports I have heard about the Mini Honest John going unstable is from this forum. To the best of my knowledge we have not gotten any calls into Estes about this issue either. We will however most likely add a piece of clay to future kits since it appears there is an issue even though we personally have not seen it.

John Boren
Estes R&D

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Martin Bowitz (our club president) told me he flew one built exactly per instructions at the recent Lucerne Dry lake launch that i wissed when my car got sdestroyed by debris on the interstate.

It was unstable on an A10-3T. he said it went unstable a bit into the flight, possible when the thrust ended or was well in the "tail" portion of the thrust. no defects in nozzle.

he said he reported it to Estes. I'm not sure if he e-mailed or used a web contact. He said he has not heard back yet.

He added clay nose weight and it flew fine yesterday at our Irwindale CA launch. I have seen at least 70% of them go unstable about 100 to 200 feet in the air.

You say you've test flown many with no problems. Have you test flown many with slight variations to determine how close to neutrally stable it might be, such as adding a tiny bit of weight in the back or slightly misaligning one fin? The average American consumer will not build perfect, so thre needs to be a decent safety margin.

Martin's model was perfect. I examined it very carefully yesterday.

Perhaps some flow visualization in a wind tunnel (with smoke). Maybe the bulbous nose turbulates the air and the fins are not in the reattached baoundary layer, so they are not effective.

Like with an egglofter, I like my fins to extend well out into "clean air" beyond the wake of the egg capsule.

just got this kit.
it has clay included now.

This was my first kit that I ever built... last summer. Flew it on A3-4T, both 1/2 and full and never had a problem. Fun little flyer! :fly: