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Old Jul 18, 2012, 10:38 PM
G_T
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Joined Apr 2009
5,884 Posts
Somehow I got lucky. This fuselage that required opening the mold to replace the balloon came out as a first rather than a second. Even the weight is in range. In my experience it should finish up somewhere under 44g, closer to 43 actually, not counting screws. So it is perhaps a gram over my current standard but that's not bad considering. Except for some carbon filaments that migrated out onto the flange I haven't spotted evidence that anything went wrong. I expected the carbon filaments because I practically had the fabric swimming in epoxy for the second balloon. I knew it would force a few fibers out once pressurized. Really less came out than I expected.

It did require about twice the usual force to get the fuselage out of the mold. But it didn't break in the process. Part of the balloon is stuck in the tailboom though, so I may have to make a hook to extract it. Judging from the weight and balance, most of the balloon came out on the fill stem.

Gerald

PS - Evidence found. Minor squiggles from some displacement in some small sections of the outer fabric layer. Not bad though.

PPS - Also one small easily fillable bubble in front of the hatch recess. Also the weight should come out more towards the 43g point if not somewhat lower than that. It is quite good, one of the best yet. Sometimes it is better to be lucky than to be good!
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Old Jul 18, 2012, 10:43 PM
G_T
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Joined Apr 2009
5,884 Posts
Gary,

Yep, a nosecone can give more convenient access to equipment and greater strength/stiffness. It also may give greater weight or else it will be rather fragile in handling when not attached to the pod. But really I had two reasons to go with a hatch. First, with the current fuselage design, one cannot even get a nosecone over the pod until the opening is cut. The largest part of the pod is rather forward of the wing saddle. Second, hatch is simpler at this time. In the future, if I make another fuselage, I may go back to a nosecone. But by then I hope to be using CNC cut molds.

Gerald

PS - And yep, you might need to re-read my post.
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Old Jul 18, 2012, 11:14 PM
G_T
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Joined Apr 2009
5,884 Posts
BTW, that's a 13.9g tailboom that is neither as stiff nor as strong as what I'm shipping. The weight should be only a little higher on the shipping ones. This boom had a layup where I replaced the Kevlar with something else as a test. The hoop stiffness was noticably compromised and the bending stiffness was reduced, mostly in the vertical direction. It also doesn't have as much HM Uni at the end I'm holding as the current version. Interesting experiment, but a reject. Still, it is not too bad. It was almost good enough.

BTW, these booms will not support that much weight in the vertical direction. They weren't designed for it. At least, I don't think it will support that much weight vertically...

Gerald
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Old Jul 18, 2012, 11:24 PM
G_T
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Joined Apr 2009
5,884 Posts
Ok, let's add a little more weight.

The boom held the extra weight out to the end of the boom, but my wrist did not. I tilted, and they fell off. I wasn't strong enough. Hard to work a camera with one hand and hold the boom with the other.

Gerald
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Old Jul 18, 2012, 11:32 PM
Aurora Builder
United States, MD, Lusby
Joined Nov 2003
3,514 Posts
Gerald shipped me a fuselage yesterday and it showed up today. Thank you USPS priority "overnight" shipping!

Anyway, this fuselage is great, but I knew that before buying it. I mounted a wing on it tonight. The forward part of my Aurora Zone v2 wing sits perfectly in the saddle. The aft part not really. It would be best to cut the aft tab and properly mate it, but I elected to add a little splooge under the aft wing bolt. I doubt I am loosing much if anything. Will need a tad longer 6-32 bolt back there but that is what the hardware store is for.

Plan is to get it airborne by this weekend but no guarantees.
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Old Jul 18, 2012, 11:44 PM
G_T
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Joined Apr 2009
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I'll have to start sending fuselages with a bigger selection of bolts.

Gerald
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Old Jul 19, 2012, 07:24 AM
Aurora Builder
United States, MD, Lusby
Joined Nov 2003
3,514 Posts
Sheesh, what's next, shipping the kitchen sink? I will say the included bolts are very nice, mind sharing the source?

If anything, I would evaluate including a stab mounting option. Either fixed or v-mount. I think most would pay $25 more for a good mount. I'm not sure if traian is still making mounts, but his fit will.
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Old Jul 19, 2012, 08:11 AM
Father of Fr3aK, DLG Pilot
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USA, OH, Worthington
Joined May 2002
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Mounts are my least favorite part to make, period. Miserable. The amount of time it takes to make a good, light, sturdy mount is absurd. That's why I'm starting to integrate the pylon into the fuse mold, which is no small task either.
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Old Jul 19, 2012, 09:31 AM
Launchpad McQuack
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Netherlands, Moordrecht
Joined Sep 2004
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Quote:
Originally Posted by tom43004 View Post
Out of curiosity, what is XXLite fuse weight typically?
From the Dutch forum:



The above was a prototype. Add 3 grams for production versions.
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Old Jul 19, 2012, 10:05 AM
Aurora Builder
United States, MD, Lusby
Joined Nov 2003
3,514 Posts
Quote:
Originally Posted by tom43004 View Post
Mounts are my least favorite part to make, period. Miserable. The amount of time it takes to make a good, light, sturdy mount is absurd. That's why I'm starting to integrate the pylon into the fuse mold, which is no small task either.
Mounts are my favorite part to make! There is no cutting foam, no tricky materials to cut, nothing fancy. Takes me 30 minutes to make a 1g stab mount!
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Old Jul 19, 2012, 10:05 AM
Aurora Builder
United States, MD, Lusby
Joined Nov 2003
3,514 Posts
Quote:
Originally Posted by Prop-er View Post
From the Dutch forum:



The above was a prototype. Add 3 grams for production versions.
Which fuselage? Dimensions would be good to know, not just weight. Have you launched it to 180'+? Has Gavin thrown it?
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Old Jul 19, 2012, 10:35 AM
G_T
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Joined Apr 2009
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I'm guessing the weight doesn't include the canopy, and if it is an XXLite fuselage, the shortness is worth a couple grams or thereabouts.

As I said before - light is easy. Light and stiff and durable is not. If that one is good enough, kudos!

-----

My source for the screws I'm currently shipping is Fastenal. There are some relatively local ones so I can just stop in and pick them up. The only annoyance is they close at 5 and are not open on weekends. I have three lengths available one being shorter than what I've been shipping. It would work for some wings, but I figure people might get tempted to use it when it doesn't engage enough threads and then strip a bolt out. I'd rather ship one a bit long and let the user shorten it. I may rethink that though.

I'm going to research anodized aluminum bolts and titanium bolts to see what I can find, when I get the chance. That could kock a couple grams out of the finished plane weight. This likely won't be an option on this first batch of fuselages as I'll be done before I have alternative screws. I do like the steel screws that I ship, but steel is not exactly light. It should be rock solid though. I expect I could at least replace the rear bolt with an aluminum one. I don't know if I trust the front one to aluminum. I'll have to find some ratings and think on it.

I should be prepping for fuselage#12 tonight and will lay it up tomorrow or Saturday.

I also need to get my fabric order together or there will be too long a gap between batches. I think I'm going to be out of fabric in a couple of weeks.

-----

Tail mounts - Yes, I should do something about that sometime. I don't have the time right now though. It is pretty easy to make a 1g (or lighter) tail mount.

Spring-V - I've published that one.

Phil Barnes used to make his own rather nicely aerodynamic mounts. He took a balsa stick and sanded an airfoil, so it looked like a propeller blade. Then he bagged a layer of carbon on the outside. He would cut sections off this stick with a bandsaw. Wrap sandpaper on the boom, sand to fit, and glue on. Level the top, drill oversized holes for the stab screws, and pot the threads. Done. Actually, some lightweight helicopter propeller blades can probably be used directly. The cost would not be bad when you consider how many mounts you get.

The advantage of both these methods is that they produce a stick of stock material from which one cuts the individual pieces, and one only needs a little vacuum system to make. The disadvantage is the cutting makes dust and I can't do that in my place. Bloody carpets...

Gerald
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Old Jul 19, 2012, 10:56 AM
Father of Fr3aK, DLG Pilot
tom43004's Avatar
USA, OH, Worthington
Joined May 2002
6,769 Posts
I have used the same methods in the past... but it's still 20-30 minutes of time for a 1g part. I guess "production snob" mode has kicked in. For that amount of time I want to see a substantial part of the airframe, or a work of art if it's a small part.

I make mine currently in batches of 6 in a mold with scrap carbon and a special filler material. I don't use foam anymore. I probably spend an hour making a "six pack" but it still feels like time wasted in my life.

Maybe I need more therapy
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Old Jul 19, 2012, 10:59 AM
G_T
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Quote:
Originally Posted by tom43004 View Post
... Maybe I need more therapy
AKA flying???

Gerald
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Old Jul 19, 2012, 11:03 AM
a.k.a Frank Campbell
Long Beach, CA, USA
Joined Jan 2007
752 Posts
IIRC my XXlite fuse was 34 grams, the wings were 100 grams and it built out to 215 grams.
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