Idea for R/C boost glider (NP)

Yes, Ive seen this stuff years ago, and even flown some larger gliders with it, but I feel it is too heavy compared to foamboards, which Ive used up to a full J without shredding.

Completely round? Ive done a lot of round saucer gliders, the largest of course being that J one back in 96 that used half inch foamboard. It was like

52" diameter, and weighed 14lbs on the pad, as it needed a long nose pod to get the boost CG that far up. Worked damn well too, never got to try it on a K.....

How bigs this gonna be, and whats it really gonna look like? You mentioned RC, which Ive not really done (but a buttload of large FF ones) so it has to be a decent sized glider, and for it to be a PG as well, must be something of a G+ rocket.

As far as getting something up, PG'ing it is almost a sure bet but uses a lot of rocket power for still not much glider.

Probably consider making a FF version first and constructing this out of standard foamboard from Walmart, unless you can find some 1/8" stuff, then use

*that*.

For some reason, it seems that the black colored one is stronger and lighter than the rest. Walmart should have this, it is stiffer it seems, and its the one with the black inside as well. Also, darn easier to glue to, which Coroplast isnt unless you are using epoxy.

A big point of making a large glider out of these materials is warpage. There is NO such thing as a straight flat piece of board! However, this is actually in your favor, since you make the most warped sides act as dihedral.

Even if you find a flattish piece, let it sit alone for a day and see if it doenst curl a tad. If you live in a humid area, MUCH so in a short time. Having a strong central spar glued along its entire roll axis helps to alleviate future warpage fore and aft.

Pretty much anything will end up working to some extent, if you hash out your plans with a FF version and then add known good Rc gear later.

AstronMike

Whats this foam board your talking about.

Im hoping lift-off weight will be less than 4lb's and thinking the wingspan will be 18" - 24" completely round.

Actually for coroplast I use goop, its strong yet flexible.

Thats a good idea.

awesome stuff but VERY heavy

AKA "foamcore board". It's made of a thin sheet of styrofoam laminated on both sides with slick paper. Very light and rigid.

You can get smallish sheets of it at office supply stores, usually in 3/32" thickness. Art supply stores the standard 3/32" plus some have thicker stuff, such as 1/2". There's a similar material called Gatorboard which is sturdier but also more costly and harder to find.

I'd really like to make it from fiberglassed styrofoam, but I cant seem to find plans for one that is suitable.

Its a sandwich type, with a foamy core, usually 3/16" thick, between two cap sheets of stiffened paper. Walmart has this near school supplies in 20x30 sheets, get the black ones of course. Larger ones are available at your office supply stores like Staples.

Craft shops can want like $5+ for a sheet, so pay two bucks at Walmart instead, unless you find some 1/8" stuff there.

1/2" stuff I only got thru the trash at work eons ago (Im a janitor, not a rocket scientist) but that got me some nearly free HPR gliders way back in the day.

Good size range, even if you decide to make a FF version.

Did you know you dont actually need an elevator or elevons on a saucer? If you have the glide CG about 28% aft of leading edge, it usually glides itself. Still, having the CG a bit forward of that and then using some elevator makes it more glide stable in winds.

Dont forget the boost CG as well. The boost CG must be at or higher than the LE of the disc. Not a problem if you use like a 6ft rocket.

Also, a good way to make a FF version is to do a 'saucer on a stick' with like an 18" disc glued to about a 30" dowel, with dihedral bent right into the midsection of the disc (basically bend the thing in half some) and add a hook and nose wt to the tip of the stick till you achieve a decent glide. Since its FF, bend up the tail edge very slightly, just noticeable, and toss away till it glides, then shoot this off said long rocket. Or do two of em at once since these dont weigh much.

AstronMike

I think youre referring to 3/16", Ray, as Id be all over some 3/32 if I ever seen it. Unless its stocked with the Model Aircraft Parts 8^).

Speaking of this, I got hold of 4 large sections of this, and intended to make a K or L version of my old Astron Excelsior glider that went up to Js. Darn strong stuff, and reasonably light, but storing them in the Florida humidity ruined them a few years. If I ever get back into HPR, and L2 stuff, Id go this route. 'Bout as likely as Jerry goin' straight tho 8^)

AstronMike

Sounds like it to me.

The stuff rules. Haven't used it with rocketry yet but it works great for parkflyers. What you do is soak it in the tub to remove the paper and then use a heat gun to form a airfoil. You'd be amazed what shapes can be formed with a heat gun.

This is the basis for my 100 buck RCRG glider concept. Might make it a winter project if I ever finish my home theater.

Ted 'the backfilling has completed' Novak TRA#5512 IEAS#75

There are two guys up here that are already doing just that, and they work quite well. The models are deltas, with triangular cross-section folded fuselages and a simple 24mm pod up front on a short pylon. Perhaps 18-20" span or so, with tape hinged elevons and two-channel elevon control. Micro gear, I think Hitec HS-55 servos, ~100ma battery pack and micro receiver. They fly them single stage on D12-s and also chad stage them. They pop the motors out at apogee a la Estes Falcon, Space Invader etc. You can also rig the pod to vent ejection gases and NOT pop the motor to comply with safety code, or rig a pylon to drop. I've seen them fly several times and they fly well, and are not quite the bricks you would expect. In fact I think they boost higher than Strato- or Astro-Blasters on a D, but then again most models do..

Mike D.

Well, not exactly as per your plan as you are referring to piggy-backing, but I meant they are using Coroplast and having success with their models.

Your idea to piggyback shold work quite well. Just keep the velocity down, as I don't think Coroplast flying surfaces are going to want to fly at 387 mph on the way up..

Mike D.

Ive done FF versions of this, but a bit larger and also using a small canard for pitch stability since they arent RC.

At George Gassaways request, I have these now along with the FM radio.

Ok, where do you get these at? All I have now is a 270mah, too large for Ds, and I had a 50 but cant remember where I got the darn thing.

Just like the ones Ive described above, the old Estes E15 was perfect in this.

MIne kept the casing and ejected the forward section of tubing and NC, as I needed the larger CG shift. Glided better than youd think.

AstronMike

Try:

also Balsa Maching has 110 packs that have the same weight and size as the

50mAh packs

Ok, where do you get these at? All I have now is a 270mah, too large for Ds, and I had a 50 but cant remember where I got the darn thing.

I am betting it less "nimh" tech that is the problem so much as it is low quality control. demand is too low as of yet for those itty bitty packs.

Lion is getting far more afforeable and "easier" to charge etc..

Chris Taylor

Any thoughts on litho poly?

Should be more than adequate for RCRG.

Ted Novak TRA#5512 IEAS#75

Chris Taylor Jr wrote:

Any thoughts on litho poly?

As an R/C flier who uses LiPoly's as well as rocket geek I totally agree with this. Use LiPoly's when you are experienced with care and feeding of NiCads, when you really need LiPoly's for the application versus thinking they are cool, and are willing to pop for a good quality charger to handle them and able to use appropriate care. For something like this project, it's like putting a Ferrari engine into a pickup truck IMHO (that's the only analogy I could think of). Just go small NiCads. Small NiCads are readily available from all sorts of vendors. You simply don't see them packaged with R/C sets as they are used for fringe applications. Packaged radio sets are supplied with commonly used configurations only, with the exception of those catering to park flyers which, however, carry larger battery packs since they are used for motor juice as well as the radio system. So for example you'll easily find an affordable GWS or other flight pack (or complete radio outfit) for park fliers, but the receiver battary will be 270 mAh or larger.