AGM-86A RCBG

[burkefj]

My latest is in the works. I re-did my original alcm to have more of a full fuse and is all framed up, and glide tests were done for CG range. You can follow the progress here:

https://www.rcgroups.com/forums/showthread.php?t=1524184&highlight=agm+86a+rcbg

I've upscaled the wings for some surface area and moved them back a bit to help with CG. Full flying tail is sufficient for roll so no ailerons, which simplifies construction.

Not sure how much interest there is, they aren't round with nose-cones, and they aren't competition gliders, but they are unusual and work pretty well. My goal is to help promote RCRG's that can be quickly and easily built, have a high probabability of success and are unique.

Hope you enjoy it.

Frank

 

[hornet driver]

I like it -curious how little it weighs and what size motor are you using. Your projects always leave me thinking---can I do that with a---should look outstanding with markings:clap:

 

[burkefj]

Hi, with a 1.5ounce 2s battery for balast and an aerotech E-6RC reload it should be right at 10.5 ounces. Most of my RC BG's are right around 8-11 ounces depending on how large, how much carbon I felt I needed, and the proper CG required(a few require a half to an ounce of nose weight or a bigger battery).

It's a good motor because the burntime is long, the boost is very mild so you don't have to build them as stiff, and therefore they are lighter and the boost is higher.
It also makes them very easy to steer on the way up. Since there is no true airfoil you can boost them vertical and don't require a special launcher to do an angled launch like most stick/pod gliders would use. Just keep them going straight up and them pitch over when it burns out.

a D-5 quest motor would cut about 30 grams from the rear end, so maybe save 40 grams from the front weight required, that would cut 2 or so ounces, and get you down around 8, which wouldn't be a bad boost.

Frank

I like it -curious how little it weighs and what size motor are you using. Your projects always leave me thinking---can I do that with a---should look outstanding with markings:clap:

 

[kjohnson]

You can definitely pump out those models quickly, personally I've never been a fan of profile RC models rocket powered or otherwise.

Can't say I've ever launched an RCRG at 45 degrees either. Maybe 70-80.

kj

 

[MaxQ]

https://www.rcgroups.com/forums/showthread.php?t=1524184&highlight=agm+86a+rcbg

 

[burkefj]

Thanks, I grabbed the wrong link originally, fixed it now in the first post.

https://www.rcgroups.com/forums/showthread.php?t=1524184&highlight=agm+86a+rcbg

 

[burkefj]

KJ, I used to feel the same way about profiles, till I started flying them, the speed range, wind handling etc, I wound up flying profiles more than my full fuse planes, and now that's almost all I fly.

Everyone has their modeling preferences, I got bored with standard wing or pod/boom rcrg's, but I'm not flying them for competition or duration, I just wanted something that was different. All I meant about launch angle is that you don't need to angle these for boost which means you don't need to worry about supporting the wings or them flopping around on the rod.

There are so many rocket people and so many rc people but very few rcrg folks, I think if we can show how simple and easy it can be there would be more people trying them. Anyway, that's my hope.

Frank

You can definitely pump out those models quickly, personally I've never been a fan of profile RC models rocket powered or otherwise.

Can't say I've ever launched an RCRG at 45 degrees either. Maybe 70-80.

kj

 

[kjohnson]

There are so many rocket people and so many rc people but very few rcrg folks

You know why, right? RC folks don't like the cost per flight on rocket powered gliders, even though they'll spend hundreds on a plane (I know you make yours that can convert to EP) and rocket folks are too cheap (and proud of it ) to invest in the gear. It's a niche, and even though we show folks that it can be fun, and that it's not as expensive as people think, there will only be a few folks who will put their toes in the pool no matter how many of us tell them the water's fine.

Keep up the good work, though.

kj

 

[burkefj]

Well, I spent about an hour mounting the fuse sides and rear plate and sanding. Then spent 2 hours using some of my spare vinyl lettering, stars and bars from sig, and cutting trim monokote. I'm out of a few letters and have to do the left side, but I think it is looking pretty decent. I also cut and installed a hatch for the battery hinged at the front and kept in place by a magnet.

I'm always surprised by what a few markings, trim, or sharpie lines can do to bring out what looks like a plain shape.

Enough for tonight. Tomorrow will head down to the Evergreen museum to take another look at the spruce goose, X-15 mockup, Titan missile, etc.

A few teaser photos, the details are on my blog.

Frank

 

[burkefj]

I'll keep my hopes up. I think things have changed now. The highpower folks now don't give a second thought to spending a $50 or $75 reload for a flight, $100 motor hardware, $150 chutes and bags, electronic deployment, video cameras, tracking. Compared to a $200 spektrum xmitter that can fly 20 models, I don't think that's the biggest issue now for people. I still think people are worried the flying difficulty part, at least of those I've talked to.

But I can certainly understand your point about $ per flight for the RC folks, they can get batteries that will last a couple of years for the cost of a reload or two

Frank

You know why, right? RC folks don't like the cost per flight on rocket powered gliders, even though they'll spend hundreds on a plane (I know you make yours that can convert to EP) and rocket folks are too cheap (and proud of it ) to invest in the gear. It's a niche, and even though we show folks that it can be fun, and that it's not as expensive as people think, there will only be a few folks who will put their toes in the pool no matter how many of us tell them the water's fine.

Keep up the good work, though.

kj

 

[kjohnson]

I'll keep my hopes up. I think things have changed now. The highpower folks now don't give a second thought to spending a $50 or $75 reload for a flight, $100 motor hardware, $150 chutes and bags, electronic deployment, video cameras, tracking. Compared to a $200 spektrum xmitter that can fly 20 models, I don't think that's the biggest issue now for people.
Frank

HPR folks wouldn't blow their nose with an E6 dude.
kj

 

[mikec]

I still think people are worried the flying difficulty part, at least of those I've talked to.

I fly HPR and RC and I've been interested in getting into RCRGs but there are very few kits out there, and what there are (Delta Star, for example) need to be flown under power. I'd rather be hands-off during ascent and then in control for the glide phase. If somebody made a variable-geometry glider of some kind that seems like what I would want.

 

[burkefj]

Well, I'm an hpr guy and to me cool flying models are good to me whatever size they are.

Maybe I'm the exception, but most of the hpr guys I know don't just build big either.

HPR folks wouldn't blow their nose with an E6 dude.
kj

 

[burkefj]

Mike, all I usually do on boost is slight pitch adjustment and a bit of roll at times to counter any wind, not really doing a lot, unless I specifically want to do aerobatics. Boost is pretty gradual so you don't need to be as quick on the sticks as say on a higher thrust motor. Are you just worried about reaction time under power?

Frank

I fly HPR and RC and I've been interested in getting into RCRGs but there are very few kits out there, and what there are (Delta Star, for example) need to be flown under power. I'd rather be hands-off during ascent and then in control for the glide phase. If somebody made a variable-geometry glider of some kind that seems like what I would want.

 

[mikec]

Are you just worried about reaction time under power?

I watch guys with Phoenixes doing rolls on ascent, and I feel that if I could do that, I ought to be trying. RC helicopters make me feel inadequate enough as it is so I'd be satisfied with something that would simply be incapable of aerobatics.

 

[burkefj]

Well at least the ones I fly are pretty docile if you leave the sticks alone, these are way way easier than flying helis, I know

Frank

I watch guys with Phoenixes doing rolls on ascent, and I feel that if I could do that, I ought to be trying. RC helicopters make me feel inadequate enough as it is so I'd be satisfied with something that would simply be incapable of aerobatics.

 

[burkefj]

Three nice test flights today. For once I had to remove nose weight and move the battery back 3 inches. It's still conservative as I have more post boost up trim than I probably need with a more rearward CG but it flies very nice this way.

Enjoy the flight! Plans will be posted on my blog tonight.

Frank

https://www.youtube.com/watch?v=-K4atP9G9lo

 

[CF-105]

Foam airframes & cheap, reliable electric motors have been a game-changer. At least it was for me! Just wrapped up my first summer of r/c flying, and plan to do some indoor flying over the winter.

RCBG's are part of my future plans, mainly scale rocket-propelled aircraft.

Another source for ideas: before supersonic wind tunnels were available, aircraft designers would stick a scale model of the aircraft on a missile booster (ie. Nike) and fly it to get the data they needed. I've seen photos of a prototype B-58 model that was flown from Wallops.

 

[Robudda723]

would the dollar tree foamboard be strong enough for this? I do hpr and some lpr and mpr with my son as well as fly rc planes and helis. Been looking to do some rc boost gliders myself.

I also see that they do some competitions with duration and spot landings with rc boos gliders, but have not seen any kits or plans for those. Would love to have some local competition at my club for something like this.

Thanks,
Rob

 

[burkefj]

You can use the dollar tree foam board, but normally folks remove the cardboard covering to save weight. I have not used this material. Depron is pretty forgiving, and pretty stiff and light and not brittle, and easy to work. I get it from rcfoam.com and in quantity it only runs about $6.50 a sheet, normally my planes need only one sheet, and my local hobby shop stocks it by the sheet for $10 so I haven't bothered to try anything else as it wasn't a major expense. Some guys are upscaling profiles using home depot 1/2" insulation type of foam as well.

I'm sure others can chime in for competition based rc rg's. There are some guys making custom kits.

Frank

would the dollar tree foamboard be strong enough for this? I do hpr and some lpr and mpr with my son as well as fly rc planes and helis. Been looking to do some rc boost gliders myself.

I also see that they do some competitions with duration and spot landings with rc boos gliders, but have not seen any kits or plans for those. Would love to have some local competition at my club for something like this.

Thanks,
Rob

 

[AstronMike]

would the dollar tree foamboard be strong enough for this?

Thanks,
Rob

Well, if you go to the old rocketryforumarchive, or whatever it is called, you'd find GOBS of decent sized gliders made of this stuff posted there. Same goes for YORF, although I do free flight stuff instead of RC.

Just so you know, the so called 'Dollar Tree Foamboard' is really Adams Readiboard and NOT a 'true' foamboard. By this I mean the 'stuff' sold at Walmart and office supply places is REAL foamboard, and is heavier and stronger than Readiboard - but a LOT more $$$ for strength and weight you likely do not really need.

Depron....well, between myself and Frank, I'd say *that* stuff is well hashed out!!

 

[AstronMike]

You can use the dollar tree foam board, but normally folks remove the cardboard covering to save weight. I have not used this material. Depron is pretty forgiving, and pretty stiff and light and not brittle, and easy to work. I get it from rcfoam.com and in quantity it only runs about $6.50 a sheet, normally my planes need only one sheet, and my local hobby shop stocks it by the sheet for $10 so I haven't bothered to try anything else as it wasn't a major expense. Some guys are upscaling profiles using home depot 1/2" insulation type of foam as well.

Frank

Ive never had to remove the outer coating on Readiboard, as it is paper based and makes for easy gluing. Also, that 'coating' is very light and not worth much trouble to get rid of. Shoot, if you're THAT off the deep end on saving weight, then just go to Depron in the first place.

The Readiboard is perfect for gliders (I'm talking mainly nonstandard designs here) using midpower motors down to like D12/E9. Look up my Bomarc LV on YORF, and the 'clunkier' F/G jobs on the old archived forum.

For anything using Estes BP motors only, Depron cannot be beaten. Yeah, its not gonna win any awards for strength, but it does not need to. I tend to 'edge tape' it with chrome tape where needed to add that little extra rigidity for boost. Please look up Marauder LV posts on this Forum for the best example. I tend to use the 3mm Depron most for such gliders.

Also, I have a rocket (yes, a rocket) made from 1mm Depron for the 'body tubing' and 3mm for the fins and C rings. Using a minimum of reinforcing, it is 5.5" diameter and 85" tall - pretty much like a LOC Magnum in size - but at only 8 ounces. It's not that flimsy either and is awaiting a calmer launch day.

Once you get heavily into Depron, balsa looks like ancient stuff.

 

[burkefj]

Mike, that's interesting, i was just thinking of rolling my own of depron to make a very lightweight pershing 1A that could work with small motors without tons of nose weight for CG.

Frank

Ive never had to remove the outer coating on

Also, I have a rocket (yes, a rocket) made from 1mm Depron for the 'body tubing' and 3mm for the fins and C rings. Using a minimum of reinforcing, it is 5.5" diameter and 85" tall - pretty much like a LOC Magnum in size - but at only 8 ounces. It's not that flimsy either and is awaiting a calmer launch day.

Once you get heavily into Depron, balsa looks like ancient stuff.

 

[luke strawwalker]

Since yall brought it up, John Pursley has been working with Depron tubing for his huge LPR Saturn rockets... He was rolling some Depron tubes and heat setting them in his home oven a couple years ago when some of the club guys and I had a get-together over at his house. He's been making lots of tubes out of 1/32 lite-ply but the Depron is even lighter, and plenty strong. He's been working on and off on the project for awhile and according to some things he posted on our "old rocketeers #724" yahoo group, he's going to be posting more about the build on his "accur8.com" website.

Neat stuff! OL JR

 

[AstronMike]

Mike, that's interesting, i was just thinking of rolling my own of depron to make a very lightweight pershing 1A that could work with small motors without tons of nose weight for CG.

Frank

The main reason I like the 1mm stuff for this is that it comes 'precurved', since it is originally made and stored on HUGE rolls. Making any Depron rolled tube under about 5" diameter is tougher, since the stuff is rigid enough to resist being kept into a circle. Mine needed the extra few C rings to 'blow' it out to keep form.

Smaller tubing would have to be heat set, as Luke mentioned as well. I'm not that crazy, yet, and I've actually used plain ole paper (one or two ply) for ultalight tubing up to BT80 sized.

Finishing, well, Depron is pretty 'grainy', and if you go to any expense of trying to fill/finish such a large model you throw out some/most of your weight savings.

Something like a 6" to 8" Pershing would be cool, and if you have LOC 7.5" tubing for a mandrel you are pretty darn set.

You know, I wonder if that 'aeroshell' stuff Estes had for the SR-X and Cosmos Mariner was actually premolded Depron all along.....probably is.

If John Pursley comes up with even cooler ways of 'Depronizing' stuff I'd want to hear about it.