Need help on Estes Hyperbat

I bought this two stage rocket today and I am building it now and I can't figure out how the second stage motor is retained. I see how the first stage lights the second and falls away but how does the 2nd stage motor stay in place when the ejection charge goes off?
Maybe I left the cap off of the ca too long but I am confused :confused2:

https://www.estesrockets.com/rockets/by-engine/007217-hyper-battm

Here is a build thread on that rocket, done by one of our better looking forum posters:
https://www.rocketryforum.com/showthread.php?32620-Estes-Hyper-Bat-BATMAN-build

Basically the booster stage (short stage with the big fins that holds the -0 engine) has the engine block below the engine, so when the upper engine fires it will be pushed off and free fall away.

You tape the two engines together and slide them up into the main rocket body, leaving the -0 engine sticking way out the bottom. Then when you slide the booster stage onto the -0 engine it fits up against the main body.

Be careful when following the directions, as was pointed out in the build thread above there is an issue with them, and you could end up gluing things in wrong.

Friction fit is our friend......

https://www.estesrockets.com/media/instructions/007217_HYPER_BAT.pdf

The instructions show applying clear tape to hold the motors together for upper stage ignition and masking tape applied to both motors to make them fatter so they are retained by a "friction fit" in their respective stages.

The almost wordless instructions do not explain this well. Also, the masking tape on the upper stage motor is applied near the bottom end, which is swollen with nozzle and propellant. After firing, the propellant is gone and the casing can shrink, allowing the motor to eject. I always instruct and demonstrate applying the masking tape to the very top end of the motor and I have a bit extend off the top end so I can roll it down to form a "Gentle Glide Applicator" type interface. If the maksing tape edge is not rolled over, you may have it roll up on iteslef when installing the motor, which makes it get jammed.

https://www2.estesrockets.com/pdf/2845_Classic_Collection_TR-TN.pdf

See TR-2 for better explanation using plenty of pictures and words.

So one piece of masking tape is supposed to hold the upper motor inside the tube when the ejection goes off?
Sounds like a piss poor design to me. I'm guessing it will either not work or be a pain in the butt to install and remove the motor. I might have to design a retainer. Thanks for the help and advice.

burnout said:

So one piece of masking tape is supposed to hold the upper motor inside the tube when the ejection goes off?
Sounds like a piss poor design to me. I'm guessing it will either not work or be a pain in the butt to install and remove the motor. I might have to design a retainer. Thanks for the help and advice.

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Wow ! The lost art of friction fitting. Has worked for me up to 29mm F impulse. I'd say my experience is not unique, YMMV . If I'm not mistaken, all staged, black powder models that aren't designed as gap stagers work that way. If you can figure out a retainer for the sustainer with the engines taped together, cool on you. But Fred's attachments have all the relevant info, why not try it ?


One thing I always do that may be hard to see in the diagrams in TR-2: when you have the booster/sustainer motor combo inserted in the upper stage, put a wrap or two around the end of the sustainer motor tube and the end of the sustainer motor. Then slide the booster airframe on.

NO, it is not "one piece of masking tape".

You friction fit the motor. Every motor is different and every model is different and every roll of masking tape is different. You need to apply enough masking tape to make the motor fit 'snug' inside the rocket. That simply means that it will be tight enough to not eject - rockets with heavy nose sections like egglofters need tighter motors than models with loose easy-to-eject nose cones and recovery systems. If you ram-rod in wadding then the motor will eject and the rocket will crash (and it would rip out a motor retaining hook if it was that type of model).

you test fit the motor and see how it feels. It will be tighter as you push it in since the aft end of the motor is swollen, but if you have a glue blob or drip inside then the motor will get snug as it hits that spot. Anyway, simply wrap some masking tape around the motor until the fit feels right.

AND NEVER USE BLUE PAINTERS TAPE AS IT IS POOPY-STINKY. (and it costs 5 times as much)

burnout said:

So one piece of masking tape is supposed to hold the upper motor inside the tube when the ejection goes off?
Sounds like a piss poor design to me. I'm guessing it will either not work or be a pain in the butt to install and remove the motor. I might have to design a retainer. Thanks for the help and advice.

Click to expand...

I prefer friction fitting and use it on all of my own designs.

I used it for my level 1 HPR certification flight and subsequent flight with that same rocket.

For level 2 I used positive retention but that involved a metal ring and screws.

I appreciate your input. Personally,I would get more satisfaction out of building and using a mechanical device to retain the motor. It will also make motor changes quicker and easier. I don't mind the slight weight disadvantage, I'll have to see what I can come up with most likely I would need a larger diameter motor tube for the upper stage,maybe the next kit.

Friction fitting is really very effective. I, too, have used it many times. In fact many of my clones are designed for friction fit simply because I did not want to use an engine hook. A little twist, and the engine comes right out. Blue tape works fine, I use it all the time. Perhaps you should hold judgement until after attempting it. But it is very reliable on the smaller motors.

I built it last night and it is already in paint now so I will probably try the friction fit anyway. I just don't understand why nobody wants to modify it and make it easier to use and safer. Can you say you have never had one pop out?I build race cars and If anything was held on with tape, after they stopped laughing they would not let me on the track.

burnout said:

I built it last night and it is already in paint now so I will probably try the friction fit anyway. I just don't understand why nobody wants to modify it and make it easier to use and safer. Can you say you have never had one pop out? I build race cars and If anything was held on with tape, after they stopped laughing they would not let me on the track.

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It actually is easier using the friction fit method, the odds of starting a fire from a pop out after bun out are very high, as in almost never.

Not trying to argue,but trying to learn. How exactly is having to apply just the right amount of tape to a motor and possibly test fitting it a couple of times easier than just sliding a motor in and screwing a retainer?
I was thinking maybe glue a small tube on the outside of the motor tube that contained a shaft with a thin tab on the end held together with a screw. Insert motor,slide tab over edge of engine case and tighten the screw. The tab would be thin enough so the booster is still snug against the upper stage.

burnout said:

Not trying to argue,but trying to learn. How exactly is having to apply just the right amount of tape to a motor and possibly test fitting it a couple of times easier than just sliding a motor in and screwing a retainer?
I was thinking maybe glue a small tube on the outside of the motor tube that contained a shaft with a thin tab on the end held together with a screw. Insert motor,slide tab over edge of engine case and tighten the screw. The tab would be thin enough so the booster is still snug against the upper stage.

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Hey man, your rocket, do what makes you happy. If you fly your brainchild at a club launch you might have some splainin' to do. At ours, stagers are heads-up flights anyway because of the extra parts in the air so I don't see any issue there. Some of us here just disagree with your interpretation of "piss poor design" and "simpler" and "easier" sustainer motor retention.

...and you say "tomaahto" and I say "tomaayto" !

FWIW as Fred explained there is the element of "feel" in friction fitting. Having a rocket buddy who has been there and done that is invaluable but maybe not practical in alot of cases. Look at it as another skill to learn.

Taping the motors together with clear cellophane tape is the most reliable way of getting the upper stage motor to ignite. If the motors are retained with a metal hook or a screw on retainer the upper stage will not ignite without some heroic design wizardry such as vent holes or the new whiz-bang Estes multi-stage funnel thing that I see in the 2013 catalog but have not seen in real life yet.

And that neat-o device is certain to add weight to a rocket and the friction fit method is the slimmest and lightest method.

See the TR-2.

Read the TR-2.

Then read the other TRs.

The motors will be touching and I'm pretty sure it will work. It will be safer and faster to load motors. Don't worry,I won't bother you guys with the details as I can see nobody is interested in experimentation here.

burnout said:

The motors will be touching and I'm pretty sure it will work. It will be safer and faster to load motors. Don't worry,I won't bother you guys with the details as I can see nobody is interested in experimentation here.

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Now, don't be like that. It's your thread, we all have our opinions and other body parts. Experiment away. Build a better mouse-trap. I think trying some of the old techniques is still valid if you care to. They are not less safe when done with care. Your initial post asked how the second stage motor was retained in the Hyperbat. As designed, it's done with friction fitting as described in TR-2.

Experimentation has already been done and we provided the results from 50+ years of experiments.
You are dismissing our advice based upon decades of actual launching. And it seems you have no interest in reading TR-2 or any similar reports of experiments from others.

I am confused why you would ask a question or start a discussion if you do not want to read or hear the answers of the opinions of others?

I had a question as to how it works. I obviously read your replies and to say I didn't is just lame. The fact I want to try something different does not mean I didn't listen to your advice. You seem upset because I don't want to do things the way you or most other people do it. It also seems you are stuck in the 60's and convinced their is nothing more to learn or improve in this hobby. If everyone thought the way you do we would still be driving aspirated engines with no computers.:gavel:
Even If I fail at my attempt(which I won't) I am still a better person for trying.

just built this with my daughter last week... painted pink... anyway, used the friction method and was able to keep motor in rocket in second stage. that worked great.


my daughter and i are newbies so could use some advice though.... the nose popped off but the parachute didn't come out. it looked like maybe there wasn't enough force to pull it out as well.. any ideas on how to make that work better?

it actually worked out for the best... shot it off at a launch site here in hawaii which is reasonably close to the beach... i think if the parachute deployed correctly it would have ended up in the pacific ocean. this rocket took off literally like a bat out of hell... i'm guessing my fins weren't exactly right as she took a hard left. anyway, she ended up landing right at the oceans edge... got a little sandy and wet from waves rolling in but didn't get submersed. she will fly again.

any thoughts on set up for parachute would be appreciated. thanks!

Make sure your parachute isn't too tight in the body tube. It should be wrapped small enough that it can easily slide out when the nose cone ejects. Also, where do you have it attached? Is it attached to the nose cone or the shock cord? If it's on the shock cord, make sure it's near the top of the shock cord (nose cone end) so not much cord needs to come out to get the parachute out.

Other thought - if it lands lightly, might be worth putting a nice big streamer in it instead of the 'chute so it doesn't go surfing...lol

808rocketman said:

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any thoughts on set up for parachute would be appreciated. thanks!

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Welcome to the forum to you and your daughter and congratulations on flying in HAWAII !! (just a little jealous ) Here's my two cents on parachutes and stagers and wind.

There are many techniques for folding parachutes but as Loopy correctly stated the end result should be a package that is smaller than the diameter of the body tube (about 1 inch in the case of the Hyperbat).
You want to avoid stuffing the chute into the space. Here's a video of one technique used by Tim Van Milligan of Apogee Rockets: https://www.apogeerockets.com/index.php?main_page=page&id=44
One of Tim's newsletters has some good info on folding, spill holes, and swivels: https://www.apogeerockets.com/education/downloads/Newsletter184.pdf

Dusting a plastic chute with baby powder (talc) will help keep it from becoming a plastic wad.
When the winds kick up around here I reef the shroudlines by wrapping tape around them about half way up the length. This keep the canopy from opening all the way, in effect, reducing the parachute diameter.

How hard a left are we talkin' about ? Stagers have a tendency to fly into the wind because of the added fin area which may be what you experienced. I would try flying the rocket single staged and see if the left turn tendency is still there.

Hope this helps.

thanks for the advice on the parachute! we'll shoot for some modifications this weekend before firing off again.


it was a pretty hard left... and what you're saying about the wind makes sense. we set up at the far end of the park in anticipation that the wind would drag it right down the park when the parachute went off... what happened instead was it went left right into the wind and ended up on the beach... haha.

we shot a small one stager off right before and it went straight up and then drifted right once the parachute opened up. so maybe the added fin area took it into the wind. i didn't anticipate that. good to know... i will have to account for that next time we go out.

it sure made for an exciting couple of second though... that thing was moving and we thought for sure it was headed into water... saw the nose pop off and it just fell pretty rapidly down towards the water.... we ran over there and found it right where the water meets the sand... made for an exciting morning. thankfully the beach was pretty empty so the chances of it landing on someone was slim.

Generally, models with smaller fins and moving faster won't weather-cock (turn into the wind) as much, and that's why the first one you launched went straight.

808rocketman said:

thanks for the advice on the parachute! we'll shoot for some modifications this weekend before firing off again.


it was a pretty hard left... and what you're saying about the wind makes sense. we set up at the far end of the park in anticipation that the wind would drag it right down the park when the parachute went off... what happened instead was it went left right into the wind and ended up on the beach... haha.

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That's the weathervaning (or weathercocking) effect of big fins or multiple sets of fins and the accel from the rocket motor. You'll learn to judge it better the more you fly and compensate for it with launch rod direction (straight up or slightly with the wind) and more accel (bigger motors !)

...

808rocketman said:

it sure made for an exciting couple of second though... that thing was moving and we thought for sure it was headed into water... saw the nose pop off and it just fell pretty rapidly down towards the water.... we ran over there and found it right where the water meets the sand... made for an exciting morning. thankfully the beach was pretty empty so the chances of it landing on someone was slim.

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Yep, a little velocity multiplier goes a long way. On most flights the booster phase is pretty deliberate, slow even. Then the second stage lights and POW, ZOOM, where'd it go ? Ain't no accident that staging is still the way to orbit.

I am VERY interested in how this Hyper-Bat turns out for you. Between being painted pink (did I read that right?) and launching in Hawaii (which island?), I think you may have a challenge on your hands.

As I recall, I was a bit puzzled by some of the instructions when assembling the motor mount and second stage....as someone noted much higher up on this thread. I believe I called Estes to clarify, and got confirmation that they've got something mis-illustrated, and they knew they were going to have to fix that as they went back to re-print with five languages on their international instructions. But the point is that they are aware of it, and if you think about it, you can figure out what's wrong as well. There were at least to "stickies" or glue bottle illustrations that had come free and reattached elsewhere on the galley sheet paste-up for this run of instructions.

My hyper-bat flew well once or twice, and then I set it asside on a very windy day, and have not gotten back to it again....distracted by larger and better rockets.

If you can, please attach a few photos of your pink bat, and where you fly. (I'm just having a hard time imagining a large flat spot near the beach, but i suppose it depends on which island and which side (dry or wet) you were launching from.)

https://maps.google.com/maps?oe=utf...n4CwAQ&ved=0CIQBEPwSMA4&output=classic&dg=brw


right across sandy beach on oahu is a beach park... it's one of the few parks here on oahu that it's legal to launch rockets... there's a bunch of folks doing kites on windy days or other RC type stuff there. it isn't huge but it definitely isnt small. with the wind running east across the beach i didn't think it would be too much of an issue. there was a slight on shore breeze as well, so we just aimed a bit towards the highway too and that seemed to do the trick on the first launch.

i'll have to try and snap a photo of it and get it uploaded... it's pink and we did a lot of flowers and hearts on the fins... my daughter is 4 so she really likes anything pink or with flowers on it. we call it the pink flamingo. if you have a little girl you will quickly learn that you can get her to take part in these sorts of activities if you make things pink and have flowers... same thing with soccer... we got her pink soccer socks and a pink ribbons for her hair and she loves soccer.

she's the decorator and i do the gluing. then at the launch she's the ignition and recovery specialist (she presses the button and then runs off after the rocket...)

i'm gonna be honest... i wasn't sure if the instructions were confusing or i was just in over my head... or maybe a little bit of both. this was our second rocket build so i might have chewed off more than i could handle. for me i thought the most confusing part was trying to identify which tubes were which in the instructions... other than that i thought it went ok. we did an easy one stage previous to this and it was a piece of cake compared to this thing.

totally worth it though. seeing the second stage ignite was pretty cool... it was moving at a pretty good pace. we started with a C6-0 and the second stage was a B6-6.... i was gonna put a C6-7 in for the next flight but she was too wet and i didn't want to risk it.

Kirk G said:

I am VERY interested in how this Hyper-Bat turns out for you. Between being painted pink (did I read that right?) and launching in Hawaii (which island?), I think you may have a challenge on your hands.

As I recall, I was a bit puzzled by some of the instructions when assembling the motor mount and second stage....as someone noted much higher up on this thread. I believe I called Estes to clarify, and got confirmation that they've got something mis-illustrated, and they knew they were going to have to fix that as they went back to re-print with five languages on their international instructions. But the point is that they are aware of it, and if you think about it, you can figure out what's wrong as well. There were at least to "stickies" or glue bottle illustrations that had come free and reattached elsewhere on the galley sheet paste-up for this run of instructions.

My hyper-bat flew well once or twice, and then I set it asside on a very windy day, and have not gotten back to it again....distracted by larger and better rockets.

If you can, please attach a few photos of your pink bat, and where you fly. (I'm just having a hard time imagining a large flat spot near the beach, but i suppose it depends on which island and which side (dry or wet) you were launching from.)

Click to expand...

808rocketman said:

https://maps.google.com/maps?oe=utf...n4CwAQ&ved=0CIQBEPwSMA4&output=classic&dg=brw


right across sandy beach on oahu is a beach park... it's one of the few parks here on oahu that it's legal to launch rockets... there's a bunch of folks doing kites on windy days or other RC type stuff there. it isn't huge but it definitely isnt small. with the wind running east across the beach i didn't think it would be too much of an issue. there was a slight on shore breeze as well, so we just aimed a bit towards the highway too and that seemed to do the trick on the first launch.

Click to expand...

Oh, I see from your map where you're talking about on the eastern shore.
I have toured Oahu twice, and snorkled at Hanauma Bay near the "toilet bowl" just a little SW of your Sandy Beach park.
You're near the famous blow hole also... (isn't Eternity Beach nearby?)
Looking forward to your photos!
PS: My little girl is now 20 yrs old, and continues to decorate my rockets with crayons, paint, etc. "Creative decorator" indeed...)

Hey. Check out my bat rocket 29mm 980 feet.
https://youtu.be/TkzZIGbx--8 night flight