I have two words for you my friend (not counting this lengthy sentence). Big 'chute.Making the pods as strong as possible has been a major focus of the build. Still no guarantee they'll survive the first landing.
I have two words for you my friend (not counting this lengthy sentence). Big 'chute.Making the pods as strong as possible has been a major focus of the build. Still no guarantee they'll survive the first landing.
Ya, big 'chute + JLCR. Or at least, bigger chute than usual for me. I usually opt for smaller parachutes on models that I think are likely to be pretty much landing-proof. Not this one!I have two words for you my friend (not counting this lengthy sentence). Big 'chute.
The one thing I might have done differently would be to harden the ends with a thin or thinned epoxy rather than CA. But if you think what you've got is overkill, and I don't disagree, then epoxy would be even overer kill.My priority with the pods was to make them as strong as possible...
Finally, I CAed just the rear of the tail cone, which is going to be the part that bears the landing impact, and then CWFed the whole thing. And the pod is finished:
View attachment 407552
LIPS!Some Rocky Horror would be cool though.
I briefly thought of a JLCR, but then thought you wouldn't want the weight, and might not have enough altitude to support two deployment events. So I was just thinking about going "a size up" from whatever you'd normally use for a rocket of this size/weight.Ya, big 'chute + JLCR. Or at least, bigger chute than usual for me.
Yes. But I *have* been curious to experiment with thinned epoxy as an alternative to CA for hardening nose cones. Wouldn't commit it to critical part until I had worked out the process.OK, caught up now.
The one thing I might have done differently would be to harden the ends with a thin or thinned epoxy rather than CA. But if you think what you've got is overkill, and I don't disagree, then epoxy would be even overer kill.
If I confirm that the JLCR would work OK in a BT60 (it is made to) then I would probably try to use it for E flight, which should be over 1000'. For Ds or below it's probably not appropriate.I briefly thought of a JLCR, but then thought you wouldn't want the weight, and might not have enough altitude to support two deployment events. So I was just thinking about going "a size up" from whatever you'd normally use for a rocket of this size/weight.
Yes. But I *have* been curious to experiment with thinned epoxy as an alternative to CA for hardening nose cones. Wouldn't commit it to critical part until I had worked out the process.
Finishing resins, warmed epoxy, and thinned epoxy are all options here. Thinning epoxy weakens it somewhat but for hard-coating balsa that shouldn't really be an issue.This may not work for what you want to do, but I have used a gentle application of heat from a heat gun to warm and thin epoxy. It starts to get quite thin and flows easily which makes it easy to coat a surface and penetrate to some depth. I've done it with BSI epoxy, which seems to be safe when heated, but I've heard that some epoxies can release noxious fumes when heated (not good). Also, the finishing resins (like Z-poxy or BSI 20 minute) is quite a bit thinner than the average epoxy. (standard TRF notice: wear gloves with epoxy)
Yes. However, they'll be plain old TTW, no additional reinforcement in the BT around the fin slots. That should be good enough here.Will the fins be through wall?
Good heavens, are you trying to pierce armor with that thing?I ask because on my Hammerhead Shark all the fins and canards are papered and they are all through the body tube wall. Some are just through the body/coupler and flush with the I.D., and at the rear they are all the way through to the motor mount. It also has a full length internal coupler tube.
Yeah, I haven't used it yet so I don't have a feel for it. Dunno if I'd be inclined to use it on a low-ish flight (say, 500'-600'), although maybe there's really no good reason not to.Howzit Neal! Just FYI a JLCR can be set to activate from as low as 100' alt.(IIRC).
The lowest I would go is 200' cuz you need as much as 50' for the chute to fully deploy.
Wouldn't be concerned too much about the weight: 0.6 oz. and it's forward of the CG.
Combine it with a big chute and you have the best of both worlds: Minimal wind drift and a soft landing.
Not really.Is there room between your motor mount and the body tube for "holes" into which you could stick um, sticks, that could be easily replaced if they break?
I guess the saying is true: Great minds think alike!Get two or three Chop Sticks. Dowels would also work. Hey, maybe even PENCILS, with the rubber erasers at the bottom. Glue them on the back next to the fins so they stick out the back maybe three or four inches past the motor.
I do quite a bit before I start the build thread.
And only just barely!Neil has only recently come to the position that it's acceptable to have more than one active build thread at a time
If you know you're launching (well, landing) on a soft field, you could use a small 'chute to deliberately come in hot and be sure to stick it.(in fact, if you launch on grass or plowed earth, you might even literally "stick" the landing.)
Good heavens, are you trying to pierce armor with that thing?
This may not work for what you want to do, but I have used a gentle application of heat from a heat gun to warm and thin epoxy. It starts to get quite thin and flows easily which makes it easy to coat a surface and penetrate to some depth.
Also, the finishing resins (like Z-poxy or BSI 20 minute) is quite a bit thinner than the average epoxy.
I use WEST System epoxies and it is fairly common to use a heat gun on a low setting to thin the epoxy so it penetrates deeper and let the air bubbles rise to the surface.This may not work for what you want to do, but I have used a gentle application of heat from a heat gun to warm and thin epoxy. It starts to get quite thin and flows easily which makes it easy to coat a surface and penetrate to some depth. I've done it with BSI epoxy, which seems to be safe when heated, but I've heard that some epoxies can release noxious fumes when heated (not good). Also, the finishing resins (like Z-poxy or BSI 20 minute) is quite a bit thinner than the average epoxy. (standard TRF notice: wear gloves with epoxy)
Oh, one of my favorite things. One part that serves TWO purposes.MAIN FIN ASSEMBLY, PART 2
There needs to be a way to attach the rings (cue Marvin voice) to the fins. The angled (salami cut?) rings make it even trickier. I am helped, though, by the fact that the rings are small and should not be absorbing any significant impact.
Each ring will be slit at the "inside" (closest to the airframe) and slid over the fin. Small pieces of 1/16" balsa are affixed to each side of the fin to give the ring edges something to glue to.
Each piece is cut at an angle to it'll be (mostly) hidden inside the ring.
View attachment 407880
Then the pieces are glued inside that handy outline printed onto the fin templates used for papering the fins:
View attachment 407881
Before the glue is set I check and adjust alignment by sighting down the edge:
View attachment 407882
Note the edges of the balsa pieces that will glue to the ring are beveled slightly.
Getting there!
I leave it to others to answer, since I have no idea.Would that be called a gusset?
Other than strength, any advantages to papering basswood over balsa?Fore and aft fins, also 3/32" basswood papered with white glue and copy paper (for consistency):
View attachment 408320
I might very well go to glue-papered basswood in the future when I need strength and can handle the weight. Quite nice to work with.
New business idea: I do nothing but paper fins for people. I swear I could do it all day long. Soooooo satisfying. Don't ask me why. (I miss the dancing marshmallow man)
A side effect of strength: easy to handle. I'm not likely to put fingernail marks in it accidentally, and I can sand quite vigorously without having to worry so much about oversanding. Especially helpful when sanding off excess paper.Other than strength, any advantages to papering basswood over balsa?
with the exception that papering also in most cases takes care of the filling of the grain. I agree, though, laminated balsa is the bomb for providing strong balsa, especially when you have compound curves, points, or other, what do you call them, "fiddly bits". I use 1/16" balsa 3 ply for my rotor stops on my helis and air brake rockets, they have to be strong in both horizontal and axial planes for their intended use. This technique would be good for rockets that have pods at the ends of fins, you can cut the center piece span a couple of mm short, outer pieces normal, makes a natural "groove" for the pod to settle into. I use the groove as a slot to hold the pull band extensions in place during launch.When you need better strength but are more weight sensitive, remember that laying up your own balsa plywood is basically the same process as glued papering.
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