Upscale Quinstar build(s)

Staged Quinstar, anyone?

I double-dog dare you.

So this morning I removed the stacks of books and looked at my balsa laminates. Perfectly flat, yay! So I just had to start cutting a piece, just to see what I was in for. Got this far on piece one:


My initial verdict is that this will be tedious but doable. Cutting the outline is easy; cutting the various holes in the middle will be harder. The good news there is that high level of precision is really not necessary for the holes; they're there for weight reduction and cosmetics.

I then noticed that after a few minutes my wood was starting to curl. And I'm pretty sure it's curling in the opposite direction it was curled before. I'm not sure I'm going to worry about it on piece one, but I did re-wet piece #2 and place it back in the press.

I'm hoping that when I do my next round of laminating, and only laminate pieces from the same sheet, I won't have these problems. I don't think the warp will really affect anything, though, since these pieces aren't acting as "fins" in the traditional sense.

I'm not really sure if laminating the balsa sheets is accomplishing anything but causing me pain, but I'm going to keep at it for now.

Tedious to say the least if done by hand. Having a fresh x-acto(or three) would be absolutely necessary in this case I would think.

I haven't built one of these yet however, as far as the bowing of the sheets, I would think that it would be a non-issue once it's all put together, seeing as how they interlock.

Cabernut said:

Tedious to say the least if done by hand. Having a fresh x-acto(or three) would be absolutely necessary in this case I would think.

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Tedious is sort of the point here, as I'm looking for something to keep me occupied for a while. Thus far I have 3 holes cut (out of 8) in piece one. Not bad so far; it's going to take a while but that's OK. We'll see how long I keep saying that.

For now I'm using a snap-off blade (although I'll probably press the Xacto into service as well) and made my very first sanding stick to help round out the corners of the holes.

I'm beginning to wonder if this build isn't a sign of mental illness, or at least some sort of cry for help.

But it would seem that it is at least possible:


Still not thrilled with my lamination, gotta do better there.

At this rate I ought to be able to get it done this winter.

I can't believe that this all started with an offhand remark by me...

Good work fellas! op:

I should add a Thank You as well... All the documentation will help me avoid mistakes if/when I get one.

Pointy Side... er... Blunt Side... er... Smokey Side Down! :wink:

K'Tesh said:

I can't believe that this all started with an offhand remark by me...

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Yup!

Definitely my most spur-of-the-moment build...

My younger boy looks at my Quinstar G and says 'bigger'. Well, more like 'biiiggggerrr'. He's been corrupted by Tim Lehr. So he's lobbying for the full size of the laser cutter bed - 12x24"

If I ever cut another set, I think I'll add tabs to the ends of the spars and notches in the big triangle plates. It would make it far easier to glue.

That would be awesome... see how many of these you can build before I glue my first parts together.

I'm quite unhappy with my laminations BTW, probably gonna chuck what I've done and start over. From now on, I will only laminate pieces from the same sheet, to ensure symmetrical expansion and contraction.

neil_w said:

That would be awesome... see how many of these you can build before I glue my first parts together.

I'm quite unhappy with my laminations BTW, probably gonna chuck what I've done and start over. From now on, I will only laminate pieces from the same sheet, to ensure symmetrical expansion and contraction.

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One thing I've learned was that to reduce warping when using natural wood (as opposed to MDF or ply) is to glue it together so that the natural curl in the wood is in opposite directions. Imagine in an extreme case one piece creating a raised curve in the middle (like a lowercase n), you'd glue the next piece to it so that the curve is down (like a lowercase u).

Today's projects were wrapping Christmas presents and epoxying all the outer joins. Just 5 min epoxy over dried yellow glue.

Goodbye part one, we hardly knew ye.


For my next attempt, I'm cutting the two 1/16" pieces separately, and then laminating. Although this means twice as much cutting, it's so much easier to cut the 1/16" balsa (even across the grain) that I think it all went much more quickly and with less frustration. In particular, I was able to follow the curves of the inner holes much more exactly and with less effort, so I will have less sanding to do later. So now I have these:

Both of these pieces are from the same sheet of balsa, so hopefully the whole thing won't do its impression of a Pringle's chip like the last one. I will now laminate, and then cut the slots and sand everything smooth afterwards. We'll see how it goes.

And so here is part 1, mark II:

It is not perfect but it is pretty good. It picked up a slight warp after lamination but much less than the previous piece.

I think I have my process, now I just need to do this 4 more times.

Good progress on the "easy" parts. I'm going to be pretty good at cutting balsa by the end of this project.

Painted. Still experimenting with decals.

Hey, I was thinking about your two-stage Quinstar. How about tacking one of those Estes 29mm boosters to it? Your plywood version should be able to handle it....

By happy chance, the round hole in the pentagons of the Quinstar G fit the motor tube of the Quinstar OS beautifully. So it looks like it's made for staging.

BUT...

I'm not sure that An E16 would heft the stack properly, AND

I suspect that the rod whip would shake the upper Quinstar off. And I'm pretty sure that there will be substantial whip. The lug is pretty far from the center, and I think there will be a good rotation going by the end of the rod. I've toyed with the idea of 3 spiraled mini-rails, with a rail button at the tip of three fins - but it's more work than I want to put into it.

I did do a little testing with the Illustrator vector files and found that I could scale up to 54mm motor mount tubing and still fit the pieces on the 12x24" laser cutter deck

The must ludicrous build evolves: I have switched to 1/16" basswood for the main pieces. In addition to being stronger than the balsa (albeit heavier), it stays much flatter after laminating. Cutting is not bad, although it will split in some areas if I'm not careful.

This has turned into a fairly wide-ranging exploration of how to work with hobby woods, and I'm OK with that. Currently working on my second main piece; hope to get one cut every week or two, so this thing should be ready sometime in the spring.

Hey now!



Just a dry fit, but a huge relief to see that it will go together. I was particularly pleased to see that my pentagonal top pieces fit well.

Still have *lots* of sanding cleanup to do on all the parts, but the cutting is done. It's amazing how much better piece #5 is than the ones I did earlier; I really improved my technique a lot as I went along.

Total weight of wood parts is 133g.

Looking good. I'll have to weigh mine, and see what the plywood comes in at.

I see you didn't put in the slots and tabs for the wedge shaped 'shelves'. With the plywood, it took a good bit of force to get the pieces in place to lock-in. Just glue will be less BFI, more finicky to keep aligned during drying.

Have you test fit the motor mount tube?

Charles_McG said:

Looking good. I'll have to weigh mine, and see what the plywood comes in at.

I see you didn't put in the slots and tabs for the wedge shaped 'shelves'. With the plywood, it took a good bit of force to get the pieces in place to lock-in. Just glue will be less BFI, more finicky to keep aligned during drying.

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Indeed, I didn't think I could pull it off with my hand-cut pieces. I'll just glue, and possibly put in some additional bits of wood in the seams underneath for additional strength (all my horizontal pieces, e.g. the shelves, the triangles, and the pentagons, are balsa BTW). I don't think I'll have trouble keeping them aligned; with TBII and a double-glue joint it can tack up pretty quickly.

Have you test fit the motor mount tube?

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In order to do that I would have to possess the motor mount tube. Although actually the outer tube is just a BT60, so I ought to scare up a piece and give it a try.

I've identified what parts I need, although I'm a little unclear on what to use for an engine block (recall that this is intended primarily for 29mm BP motors, so I want a block in there, and I'll use an Estes retainer at the back). BMS has 5052H rings, which I suppose would work as a block if I stacked a few.

That would violate Wildman Tim's Second Law. (No Engine Blocks!)

If you are using the screw on motor retainer, a few wraps of masking tape cut to about 3/16" wide works dandy.

Charles_McG said:

That would violate Wildman Tim's Second Law. (No Engine Blocks!)

If you are using the screw on motor retainer, a few wraps of masking tape cut to about 3/16" wide works dandy.

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Yes, but in this case the pentagonal "cap" on the top will ultimately block the use of any excessively long motor anyway, so I'd prefer to just block it in the tube a mere few millimeters further back. Tape wrapping the ends of the BP motors is fine but in this case it's a needless extra step. I think I'll probably just try those 5052H rings and see what happens.

I've built mine for a 38mm CTI 1-grain. I have a 38mm printed version of the Estes retainer. I can adapt down to 29mm and 24mm - but the adapters all depend on an aft thrust ring, rather than a motor block. I'm just getting used to putting on tape thrust rings, even on my 13mm Bs.

I should be able to fly E-G, given enough thrust.

Do saucers still need the 3:1 min thrust to weight?

Charles_McG said:

I've built mine for a 38mm CTI 1-grain. I have a 38mm printed version of the Estes retainer. I can adapt down to 29mm and 24mm - but the adapters all depend on an aft thrust ring, rather than a motor block. I'm just getting used to putting on tape thrust rings, even on my 13mm Bs.

I should be able to fly E-G, given enough thrust.

Do saucers still need the 3:1 min thrust to weight?

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Would you mind sharing some details about the printed 38 mm retainer? I've been wondering if something like that was possible and I'm just starting to dabble in 3D printing.

neil_w said:

Yes, but in this case the pentagonal "cap" on the top will ultimately block the use of any excessively long motor anyway, so I'd prefer to just block it in the tube a mere few millimeters further back. Tape wrapping the ends of the BP motors is fine but in this case it's a needless extra step. I think I'll probably just try those 5052H rings and see what happens.

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I also just checked and the length of a 29mm BP motor is just about 4.5". Coincidentally, the height of the upscale Quinstar body pieces is... 4.5". So it seems like a perfect match.

Charles, how long of a body tube/motor mount did you put in there? If much longer than 4.5" you would have a fair amount hanging out the back.

Ok, my OS Quinstar is 19g. The Quinstar G is 288g before motor mount.

The motor tube is about 5". The files I got from Thingiverse are taller than the Estes retainers, and this one is upscaled.

Charles_McG said:

Have you test fit the motor mount tube?

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This seemed like a Smart Thing To Do, so I just tried it. The tube is a BT60:

The good news is that it fits snugly. The bad news is that it is *very* snug. I think it is deforming a bit to fit the available space. That means I'm going to have to try it again with some centering rings in there to insure it holds shape. If there's a problem... well, it'll sure be an interesting exercise trying to figure out which combination of slots to open up a bit to make it fit more comfortably.

On a brighter note, I've finished sanding all the parts, so it's actually ready to assemble.

I think I can now safely put "can correctly assemble a Quinstar without referring to the instructions" on my resumé.

If I'm understanding correctly, the BT-60 is just friction fit in there for now? If that is so, pull it out. Then grab a large dowel (1-2" Dia.), and wrap sand paper around it. Find the vertical center of each pentagonal panel, where the BT makes contact with them, and sand on that line. It should only take a little bit on each panel to relieve any stress.