Super Hi-Flier: Estes Hi-Flier Two-Stage Conversion

[smstachwick]

This isn’t a build that I have been photographing or documenting much, mainly because it is a bit of a rush job. I’m trying to get it in flight ready condition before flying with DART on 5/14. I do think it’s cool enough to be worth sharing though. The completed sustainer looks like it could be a weapon, a real rockety-looking rocket.



To accept the booster, I omitted the motor hook and the motor hook retainer ring. I changed my mind halfway through the build and instead of interrupting its sleek looks by mounting the shock cord externally with a knot and running it through a slit in the body tube, I slowed down a bit and mounted it with the standard internal tri-fold.

I eyeballed the fin alignment and got them darn near perfect after 30 minutes of patiently (impatiently) adjusting them. The launch lug is split and mounted at the leading and trailing corners of one of the fins.

I ended up not making the glue joint between the nose and its base very strong. OpenRocket predicted negative stability with the booster but I’m not sure that the file I downloaded took the clay weights into account. If it spins, I’ll cut the bottom out and put in the clay that came in the second kit. I have to get myself a scale and get the correct weight so I can override that and the CG.

The fins will go on the booster today, with shortening of the tube and vent holes coming quickly after. With any luck, it will fly at DART’s field with an A8-0 loaded into the booster and the B6-6 that I rescued from my busted Generic E2X. Hopefully that sucker will light.

 

[BEC]

Hopefully that sucker will light.

Take 1/8 inch twist drill bit in your fingers, put the point up the nozzle of the B6-6 and twist while pressing into the fuel grain moderately. Twirl it a couple of times, then shake the powder out on the palm of your hand and look at it. If it’s nice and black, you’re good. If it’s grey, repeat until you get black.

Occasionally the nozzle of an Estes motor has some residual clay from the nozzle formation in the way of the bottom of the propellant and these don’t want to light, either as an upper stage or with a regular igniter. Getting that clay out of the way solves the problem.

 

[smstachwick]

Take 1/8 inch twist drill bit in your fingers, put the point up the nozzle of the B6-6 and twist while pressing into the fuel grain moderately. Twirl it a couple of times, then shake the powder out on the palm of your hand and look at it. If it’s nice and black, you’re good. If it’s grey, repeat until you get black.

Occasionally the nozzle of an Estes motor has some residual clay from the nozzle formation in the way of the bottom of the propellant and these don’t want to light, either as an upper stage or with a regular igniter. Getting that clay out of the way solves the problem.

Yes, I’ve seen that bit of advice, in the silly “decline of Estes” thread a while back when there was a bunch of complaining about the igniters.

I suspect that weak staging tape was to blame for that not going, but before I came to that conclusion I did dig around in the nozzle a bit trying to loosen up any clay that may have been in there. I’m fairly certain that any clay from manufacture or burned grain residue from the booster is gone now, although I am a bit concerned that I may have damaged the nozzle with my ham fisted attempts to clean it.

Also on my mind is that removing the tape and peeling a layer of paper close to the nozzle may have weakened the casing. This is a questionable motor at best and I’d prefer to be rid of it, one way or another. If it doesn’t go, I’ll likely soak it and try another one from the pack.

Regarding the booster airframe though, I got the fins on just now. I astonished myself by getting the alignment right with my initial attachment, no adjustment needed, confirmed visually from the end and sides of the body tube in all three orientations. Well-marked tubes and double glue joints work.

 

[BEC]

I don’t think the occasional clay issue is any sign of “decline”. I agree that thread was just silly.

 

[smstachwick]

The rocket is complete.


The booster has an additional lug attached at the correct spot to interdigitate the fins, and I’ve got three vent holes messily drilled into the booster and cleaned out as much as I dared with my knife. Worst-case scenario stability with a pair of C6s isn’t quite to my liking, but at least it’s a positive stability margin if OpenRocket’s calculated CP is correct. I may end up needing some more nose weight for that flight, but the A8-0 / B6-6 stack should be alright.

 

[GlenP]

One technique for cleaning up vent hole edges is to wrap some fine grit sandpaper around a dowel small enough to fit and just spin that by hand in the cut holes until you smooth out the cuts from the blade. Looks like a cool missile design, nice kit bash stager conversion!

 

[BEC]

They will also be more amenable to "cleaning" if you harden the edge of the hole with a little thin CA glue.

I'll be looking forward to hearing how well this model flies. It does look cool, as Glen says.

 

[boomtube-mk2]

I scratch built a two-stage rocket that looked very much like yours based on the bt20 tube and using 18mm motors.

It flew nicely with an A8-0 A8-6 combo but became unstable with any larger motor combination.

Good luck with yours.

 

[BABAR]

Looks great! Hope you get some paint on it before it flies. With an A8-0 in the booster, it should stage fairly low, but I don't know about the height of the grass or bushes in your launch area and tumble recovery boosters can be challenging to track. Bare balsa and tubing can be hard to find on the ground. I found that out when I flew my Flutter-Bye on a B6-4, it's not a multistage, but it comes down in pieces, never did find the lower segment, even though I had to be within 100 feet of it in my search.

Also would consider an A8-5 in sustainer for first flight, especially if there is any wind at all. Multistagers tend to weathercock easily, sustainer can easily go "cruise missile" laterally on you. At best makes for a long walk, at worst a long fruitless walk.

Hope you get two straight vertical trails!

 

[smstachwick]

Looks great! Hope you get some paint on it before it flies. With an A8-0 in the booster, it should stage fairly low, but I don't know about the height of the grass or bushes in your launch area and tumble recovery boosters can be challenging to track. Bare balsa and tubing can be hard to find on the ground. I found that out when I flew my Flutter-Bye on a B6-4, it's not a multistage, but it comes down in pieces, never did find the lower segment, even though I had to be within 100 feet of it in my search.

Also would consider an A8-5 in sustainer for first flight, especially if there is any wind at all. Multistagers tend to weathercock easily, sustainer can easily go "cruise missile" laterally on you. At best makes for a long walk, at worst a long fruitless walk.

Hope you get two straight vertical trails!

Thank you!

DART is fortunate enough to have a site on Mission Bay’s Fiesta Island that’s just a big dirt lot. No grass anywhere except on the berms that mark the edge of the range. Beyond that is the perimeter road and the beaches, dog park, etc. I also usually fly two-stage with my girlfriend acting as my “booster buddy”. Video recordings sometimes catch a booster’s landing spot too.

Typically we’ll have ~4mph winds or less when flight ops start around 8AM. Altogether, that might be doable.

 

[bjphoenix]

For some reason that I don't remember, I built a copy of the Estes Astron Apogee II many years ago. It has never been launched and I'm not sure if I'm brave enough to launch it but someday I probably will. When that kit was developed Estes didn't have C motors, I don't know what the original advertised altitude capability was with B motors.

 

[smstachwick]

For some reason that I don't remember, I built a copy of the Estes Astron Apogee II many years ago. It has never been launched and I'm not sure if I'm brave enough to launch it but someday I probably will. When that kit was developed Estes didn't have C motors, I don't know what the original advertised altitude capability was with B motors.

They probably have the catalog for the relevant year on the website. Their archives go to the early 60s.

 

[smstachwick]

So…I’m considering signing this thing up for night flights at LDRS, assuming it survives until then. Does the stock white polypropylene nose allow through enough light from a blinky for safe flight? Or am I going to have to get creative with the Christmas lights to make a nose out of something more transparent?