Estes Quinstar or How I Learned To Keep Swearing and Fix the Balsa

[katinthebox]

I'm going to start this out by saying I have an incidental tremor, and sure, that sometimes complicates things... but I swear this kit has the flimsiest balsa I've ever handled... Some of the carnage is depicted here...
I can't wait to finish this. It looks so cool, but *damn* the quality of the material... 4 sheets seemed to be made from wishes and dreams, the fifth was more what you'd expect, but the grain was so deep, it was just destined to snap at some point.
Anyhow, that said, I have a piece of advice- Ignore the instructions, glue your two smaller pentagons together, and then glue them into the center of the main body pieces before applying glue fillets to the rest of the build. I used the end of a mechanical pencil to tap it into place against the surface I had it resting on... It's the only way to have a stable center, which this whole build depends upon, and the only way I can imagine the piece would fit in there to begin with... Also, don't look at any piece of this too hard before picking it up. It can break based on the power of suggestion alone, I swear...
Estes- Unless each and every one of the cutouts in the main body portions is 100% necessary for spin, please, for the love of rocketry, shrink the cutouts or else use better balsa stock!

 

[aviserated]

Aren't Estes rockets packaged in China? Estes balsa quality varies from too soft and warped, to firm and strait. You can use what's leftover as a template and go buy better hand select balsa then cutout to your liking.

 

[katinthebox]

Frankly, I can't say where I'd be sourcing my balsa from to start with, but if I get my hands on some decent balsa and there's some downtime on the laser cutter at work, maybe that's a possibility, but this balsa is the subbest of subpar, and I've been building nothing but estes for the past several months.

 

[aviserated]

Hobby Lobby, Ace hardware, Michaels, etc.

 

[neil_w]

That's too bad, it's a great kit. The balsa in mine was fine. I filleted the bejeezus out of it (everywhere wood touched wood), left out the 18mm mount and fly it on D12-0s. Lots of fun. I built an upscale too.

 

[katinthebox]

In the process of the bejeezus filletting, myself. I can't help but think the paint job will benefit from it.
I'm about to put the last few bits (the trapezoids) in either later tonight or tomorrow before work... So far, so good. My repairs seem sound and the damage seems well distributed enough that I think there's no evident singular failure point...

 

[neil_w]

The whole thing is very solid when finished, since everything is braced against everything else.

 

[katinthebox]

The whole thing is very solid when finished, since everything is braced against everything else.

Exactly... it's just getting it to that point causes failure... which is why my engineer brain both applauds and wants to reduce the cutout sizes, or else edit the instructions to recommend only very light sanding and any CWF application taking place prior to removing any parts from the balsa sheets.

 

[katinthebox]

Hobby Lobby, Ace hardware, Michaels, etc.

Maybe I could have worded that better...
I understand where to buy things, what I don't know is the quality of the raw material I'm walking in to buy, and, considering going the raw material route is going to involve the additional time sinks of a) finding or making my own DXFs b) cutting balsa to fit the engraver tray at work c) recalibrating the engraver for cutting balsa as opposed to engraving plastic d) waiting for the damn thing to run... maybe I can cut it down to 3 runs based on the size of our engraver e) recalibrating the engraver to engrave plastic as opposed to cutting balsa....
Where I work, we have suppliers and manufacturers we order from. If they don't make it themselves, they supply it. This is an especially key distinction when it comes to raw materials. Sure, the metal shop down the road has a killer price on flatbar CRS, but is it good?
Fastenal gives us a solid hardware stock, but they don't make any of what they sell us.
Last I checked, there wasn't a mill attached to any hobby shop near me. Assessing whatever stock is on hand and potentially waiting until they restock to go back and try to find something decent is adding another errand to the list... Frankly at this point, I'm coming out way ahead on overall efficiency of my own time and also learning how to fix something if I just roll with what came in my kit.

 

[neil_w]

If you really have a flimsy batch of balsa, you could always paper it. That would add a huge amount of strength at the cost of some weight (which really wouldn't affect the Quinstar so much I don't think).

Of course, the task of papering around all the nooks and crannies in the five main structural pieces would be quite... entertaining (I would relish the challenge, but I'm a papering fanatic).

 

[katinthebox]

If you really have a flimsy batch of balsa, you could always paper it. That would add a huge amount of strength at the cost of some weight (which really wouldn't affect the Quinstar so much I don't think).

Of course, the task of papering around all the nooks and crannies in the five main structural pieces would be quite... entertaining (I would relish the challenge, but I'm a papering fanatic).

How challenging is this as opposed to, say... putting a new screen protector on a phone?
I ask because of the incidental tremor I mentioned... There's some things that are just never gonna pan out for me, and finicky application of a flimsy object is right up there with eating soup at a work lunch. My hand's gonna twitch at an inopportune moment, and either the paper won't sit right, there'll be an irreparable airbubble, or else, a few minutes later, an errant cat hair will manifest itself in the most evident place imaginable.

 

[neil_w]

If you've never papered before, those pieces are probably not the best place to start. But the tremor wouldn't be an impediment, I don't think.

Also, if it's already glued together, papering would be even more difficult.

However, I consider it a possibility that once you have all the pieces glued together, it will all be stronger than you expect and it'll be fine. Not having actually touched the balsa myself, I can't know for sure, but it definitely gets stronger with each new attachment. So maybe just finish building the thing and give it a whirl (in the case of the Quinstar that's a literal whirl).

If, after complete assembly, it still seems weak, you could glue on some choice reinforcements with spare bits of balsa. But I can tell you for sure that mine has absolutely no flex in any direction, and that only became true when it was finished.

If it still falls apart on its first flight or something, you could try contacting Estes and see if they'll replace it. I had one kit (Odd'l Cyclone) that came with sub-par balsa, and it shredded on the first flight. They replaced it for me, and my second one has been a trooper, with many flights on it.

 

[BABAR]

If you really have a flimsy batch of balsa, you could always paper it. That would add a huge amount of strength at the cost of some weight (which really wouldn't affect the Quinstar so much I don't think).

Of course, the task of papering around all the nooks and crannies in the five main structural pieces would be quite... entertaining (I would relish the challenge, but I'm a papering fanatic).

regarding the extra weight, you upped the motor mount to a 24 D, which should easily manage the extra mass. Until QJets start making some booster motors or Estes releases a C5-0, going 24 mm makes the most sense.

regarding papering, number of ways to skin that cat.

1. Adhesive paper

Scan the cut out fins, with a ruler to make sure an inch is an inch.
Print on adhesive paper, one true and one mirror imaged.
Use a knife to cut the outlines and the holes and apply.

2. glue

could probably do exactly the same thing.

alternatively, still do both original and mirror.

on the first side, cut out the outer outline, for the geometric windows, cut from CENTER of each window to CORNER. Apply to appropriate side with glue, push each segment through to WRAP AROUND the sides.

on the second side, cut out both the outer OUTLINES AND THE HOLES. Apply this side and will mostly cover the “edges” of the pass throughs from the first side.

 

[dr wogz]

Yeah, I found mine to be a little disappointing too. Don't get me wrong, way cool kit, love the engineering that went into it & how it all comes together. But the balsa is flimsy in some places, regardless of fillet & corners & such.

kat: Instead of cutting out of balsa, cut it out of 1/16" ply.. and up the motor mount to 24mm!!

Mine has had a few flights, but the underside 'ribs' tend to get knocked & quickly break.. And that to me is the weak point: thin sections perpendicular to the grain (easy snap!)

papering (or glassing) one side of the balsa would help keep the 'cross grain' sections intact.. 3M 77 and tracing paper even.. Even just some strips of paper to strengthen these sections..

 

[katinthebox]

Yeah, I found mine to be a little disappointing too. Don't get me wrong, way cool kit, love the engineering that went into it & how it all comes together. But the balsa is flimsy in some places, regardless of fillet & corners & such.

kat: Instead of cutting out of balsa, cut it out of 1/16" ply.. and up the motor mount to 24mm!!

Mine has had a few flights, but the underside 'ribs' tend to get knocked & quickly break.. And that to me is the weak point: thin sections perpendicular to the grain (easy snap!)

papering (or glassing) one side of the balsa would help keep the 'cross grain' sections intact.. 3M 77 and tracing paper even.. Even just some strips of paper to strengthen these sections..

If only I had the tools to do that! I could ask my father in law if I could use his workshop, but I've been assured that would really just wind up being me asking him to do it for me, which is sweet and all, but also a little y'know?

 

[katinthebox]

I came up with a really great trick for the bejeesus fillets this morning!

I was looking at the knockouts still sitting on my table when I realized the smaller trapezoid and teardrop shapes have the perfect radius for getting a nice smooth surface where I can't easily get my fingers.
The circles (not pictured as I'm pretty sure we all know what a circle looks like) also worked great on the widest angles. I had a couple fins (arms?) that wound up with slight overhangs where they shouldn't have, so I used the edge of an old gift card to get an even, flat surface between the two balsa pieces.
Can't wait to get it painted this weekend!

 

[SecondRow]

I really like this model. I’ve built two of them. They make for a very satisfying boost and recovery. Like Neilw, I make the motor mount removable so I can fly it on 24mm D12-0s. I can put it back in if I want to fly on 18mm, but that option never materializes.

My latest one is beat to hell. I think it’s time for a new one.

 

[katinthebox]

I really like this model. I’ve built two of them. They make for a very satisfying boost and recovery. Like Neilw, I make the motor mount removable so I can fly it on 24mm D12-0s. I can put it back in if I want to fly on 18mm, but that option never materializes.

My latest one is beat to hell. I think it’s time for a new one.

How high's it go on a D12-0? I'm a little underwhelmed by the altitude advertised on the card, but I'm sure lateral drift can be pretty significant on the way down.

 

[neil_w]

It doesn't go that high on a D12... but definitely higher than a C6. Hey, it's a saucer. I find the D12 flights to be quite satisfying and fun. Usually lands within 20 ft of the pad, no drift on this thing at all.

 

[SecondRow]

There won’t be any lateral drift. This is a real draggy rocket. It will spin on the way up and spin on the way down. If you’re looking for altitude, this is not the rocket for that.

 

[katinthebox]

There won’t be any lateral drift. This is a real draggy rocket. It will spin on the way up and spin on the way down. If you’re looking for altitude, this is not the rocket for that.

Interesting, I was thinking it might "snowflake" in a slight breeze.