Interest

[ThreeJsDad]

For the past three years I have been building and competing with DLG's. I no longer compete but I still build. I have a great wing and if there is enough interest and someone wants to guide me I will work on a boost glider. My current wing is 1.5m

Paul

 

[powderburner]

That's a little on the high side (bad pun alert) for a BG, at least for competition in motor classes like A-B-C. Heck, if you took 1/3 or 1/4 of that, it would still be big. Not to say it couldn't be done, or that it wouldn't work---just that something that big would not boost as high. You would be counting on superior glide performance from a monster wing like that to get your duration.

However, I know that some people do build large birds with wings that size for some of the larger impluse classes. Maybe one of them will pop in here with some comments. With the right design (and a big enough motor) I'm sure there is a way to launch that thing.

 

[ThreeJsDad]

These planes typically only get hand launched to 175 in hand launch competition. This is sounding very interesting. I may have to work out some numbers for a smaller plane.

Do these planes typically have camber adjustments, and flaps?

Side-note, In the Rc sailplane world that is tiny.

Paul

PB, you got the wheels turning.....What is a good time for....say a B glider?

 

[Zack Lau]

xxx

 

[seanmca79]

https://homepage.mac.com/georgegassaway/GRP/GLIDERS/CUDA/CudaMain.htm

https://homepage.mac.com/georgegassaway/AOL/GCGassaway/rcgliders.htm

That should give you something to go on.

Do you sell DLG kits already?

 

[TheAviator]

1.5m is a tad large for a typical R/C-RG, but by no means impossible. Typical competition style R/C-RGs are just over 1m span and powered by E6's in Aerotech's little known reloadable RC case or single use Apogee E6's (much more expensive). (International S8 competition is done with this size.) Motors available for that case are the D7, E6, and E7, with the E6 being the most popular. Competition birds in the typical size class get 750 to 1000 foot boosts on an E6. Something like what you are proposing would probably still boost well on an E6 or E7, but wouldn't get the same altitude. The rule of thumb for an R/C-RG is 2:1 thrust, or at absolute MINIMUM 1.5:1. So with an E6, you want your glider to weigh 306g (3N) or less. You could get away with a little more on the E7 or D7.

As for the actual conversion, I would say that since you've had quite a bit of experience on DLG, the switch to rocket boosts would not be that difficult. The simplest way to get a rocket boost is to add a captive rocket pod above the wing and put a motor in it. The only other thing you may need to do is invert the vertical tail to keep it out of the exhaust stream. Though I've never flown a V-Tail myself, I've seen both inverted and standard v-tails come out of a rocket boost just fine.

For launching, you can use a R/C-RG tower. I used to know where to find plans of one, but for reference, here's a photo of a friend of mine flying a converted Fireworks Mini DLG out of a tower. (Photo taken by George Gassaway.) There are six carbon rails, four to hold the fuse and tail, and two to stabilize the wing tips, though these aren't necessary.

EDIT: I found the tower plans here.

 

[ThreeJsDad]

Thanks Guys, Yes I do currently have a DLG I sell. I have been building DLG's for about 4 years. I have really cut back on production to have more family time and keep my customer base to people I trust wont make me regret selling them a plane. I also do a lot of wings for folks who want to upgrade a beginner plane.

Are these planes set up with flaperons?

My 1.5 meter ships can easily come in around 320grams so I would have no problem building a smaller ship that will make weight. If it wont be launched like a DLG making weight would be no problem at all. I am almost tempted to say I would give up the boost altitude in favor of more ^2 inches of wing. My current wing is well over 300 ^2 inches.

I am thinking I may want to take my pod plug and add a motor housing and then make it a low wing. Setting up a dropped v-tail would not be difficult but it will get torn up more quickly than a traditional tail. I am leaning towards an X-tail with the horizontal on the bottom.

What MM are these motors?

I am thinking I need to do this.

Paul

 

[TheAviator]

Paul,

You can set up an RCRG pretty much any way you want. The competition birds are purpose built for the 24mm case and E6 motors. The FAI World Space Modeling Championships hold S8D for the juniors and S8E/P for the seniors. S8E/P is E-impulse radio controlled rocket glider with precision landing; 1 point for every second up to 6 minutes, then minus a point for every second over, and 100 points for hitting the landing target, with decreasing score out to 10m away, which is 0 points for landing. (The WSMC was just last week; the U.S. Junior Team took gold in S8D, and one of its members took individual Silver.) There is a 1m or better span requirement among others that elude me at the moment. Point is, most competition style high performance RCRGs are built to fit the WSMC requirements.

On the flip side however, what you can imagine, you can do. Aerotech makes two casings specifically for R/C: the RMS-RC-24/20-40, which houses the D7, E7, and E6 (20, 30, and 40 N-s respectively) Blue Thunder endburners and an E12 blackjack and the RMS-RC-32/60-100, which houses the F13, F16, F23, and G12. There are also some nice Warp 9 endburners coming out in the high power side, such as the I49.

Many of the RCRG's I have seen are simple elevator/rudder birds. I have also seen a few with a flap or spoiler. That doesn't mean, however, that you cannot set one up with flaps, spoilers, ailerons or any other mechanism you desire.

With regard to the tail, I have flown aircraft with a simple elevator/rudder but the rudder inverted, and seen both standard and inverted v-tail.

 

[ThreeJsDad]

Brian, That is great info. I will find out what I can about the rules. Under good conditions my planes can get 5 minutes or more from a launch altitude of 180'.

This is pretty exciting...

Paul

 

[TheAviator]

The rules are here. You are looking for the rules for S8, and S4 if you are interested in free-flight models too. Just one very important rule to remember for any contest, NAR or FAI: the model must ascend vertically; the wings cannot support the model during boost. Launch altitudes are typically on the order of 500-1000 feet.

If you become interested in trying out for the internats team, the tryouts are held every other year at NARAM over the weekend. My rocketry goal for this year is to become good enough at S8E/P to at least try out, if not make the team.