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Jul 09, 2018, 10:09 PM
AMA 353531
rdeis's Avatar
Question

Easiest F3-RES build for beginner group?


Hey, all. I'm considering how one might use F3-RES to introduce a group of high school students to building and soaring. I like the build and fly, the competitive aspects of this class of model, and the teamwork that the latest Model Aviation talks about happening last year in Albuquerque. Relatively low cost is a great plus, too.

Building takes a while, and I've got a Radian and some other primary trainer foamies to develop flight skills while they are building to reduce crash fears and improve model survivability.

Most of these kids have rocketry experience, a little model building experience developed through rockets and outside hobbies, and some stick time on quads.

What do you guys think? Workable idea? Which model(s) would you pick?
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Jul 10, 2018, 03:11 AM
Registered User
All the models that are specifically for F3-RES that I'm aware of are a bit on the expensive side, at least if you have to buy enough for a number of students. I recall the Sig Riser being a decent flier, and the price is fairly low. Not sure what the quality is like. I'd suggest something else if the budget is larger than I think. The 2 meter Chrysalis(the older kit, not the Chrysalis-Lite, which I'm not familiar with) has excellent building instructions,. I haven't flown one yet, though its smaller sibling flies very well. An intermediate, traditional choice would be the Gentle Lady, though I don't know about availability these days. I expect, however, that you'll find the GL and the Riser fly a lot like the Radian. The Chrysalis should have a wider speed range, though I suspect, unless you make an effort to keep it light, it might be a bit much for a legal F3-RES high start. The Spirit probably has a wider speed range too, but, IMHO, it's a mediocre pig that wobbles when you try to turn in a thermal and may be too heavy for that high start as well.

There are probably some nice, simple kits from Europe or Australia, but I'm guessing they'd end up being expensive.

If you have access to a laser cutter or an NC router, you could cut rib sets and make up your own kits. I suspect a Drifter II with a thinner, faster airfoil would be pretty nice. Maybe 8 or 9 percent thick with a little "Philips Entry". You could thin the RO-8 airfoil and use that. Get rid of the counterbalance on the rudder. Plans are on Outerzone. It ought to come out light, especially with today's radio gear. I'd suggest an RO-8 with a thinner foil, but I suspect the fuselage and tail might be a bit fiddly to build, and maybe delicate, even if you skipped the lightening holes.

Mountain Models lists a short kit for the Allegro Lite. I suspect you could build a wing using those parts, in a more conventional way, with a traditional spar. This ought to be much easier and cheaper than the normal construction, but still be adequate. Put this on a conventional wood fuselage and it might be really impressive and relatively inexpensive. But it would be considerably harder to build than the other choices I've mentioned here. That might be a big problem, and I suggest keeping things simple.

I think 100 inch models are better all-around, but they are a little more expensive and, of course, not for F3-RES. Not sure what the kit choices are these days, apart from the Riser 100, which I suspect won't be all that different from the Radian either. Skybench has some interesting kits, but at the moment they're not accepting new orders.

Keep in mind that anything you order from a "cottage industry" may take longer than you'd like to arrive. OTOH, there are some nice kits available that you wouldn't find from Sig, Tower, Horizon, etc.
Jul 10, 2018, 05:27 AM
Registered User
If it has to be F3res, then look at the Yellow Jacket. You have 5 panels to build so you can spread it across several groups. The Lite is a little easier with fewer half ribs. Bad part is cutting CF rods and tubes. Pretty easy to build since you don't have to do sheeting or webs.

I have not built an Opal but it's more traditional wood. Less CF.

Crysalis Lite is a great airplane but it's too advanced a building job for new builders.

If you didn't need it to be F3res, the regular Chrysalis 2m or 1.5m from DJAerotech are more suitable and probably the most budget friendly. The DJAerotech kits will have the most detailed instructions of all of them with lots of pictures.
Jul 10, 2018, 08:00 AM
Sonoran Laser Art
I designed and manufacture the Yellow Jacket over here in AZ. It is an easy build but with that statement there are some assumptions of experience building wood models. I think they would go together and fly fine but CA is used for many joints. It's fast and if something is twisted your in trouble instantly. When your just getting started there is a curve, both in building, sanding, cutting, fit, use of various adhesives. Then comes flying, damage, and learning to repair. I'm also a Sig dealer. I have not built a 2m Riser but want to. I think you could accomplish everything your looking for, fly the same format, and get 3-4 kits for the price of one YJ. If I were in your shoes that's exactly what I would do. Then if they have hunger for a more advanced glider they will be good and ready. If you wanted to teach a nice added skill you could have them weigh various pieces of wood then record and compare. Possibly replace some pieces with lighter higher quality wood and reduce the weight. That in itself will improve the thermal capability for a little added cost and be a good lesson. Besides the F3RES kits being more modern designs and airfoils the other big thing is material quality. The Riser has good instructions, and you can look at them as a PDF on Sigs website now to see what all is entailed. Many have built these models and enjoyed them for years and I do not think you will sacrifice any fun at all. I'm pretty sure if you ordered the minimum $150 you could get free shipping too. I can assist with that if you need it. You could add some contest balsa to the order too, glue, etc. You will need to think about whether your going to use weights or pins to keep things straight and the type of building boards, sanding tools, glue, etc. Beleive me, there are a lot of guys around here willing to help. I think there was a F3RES club contest or fun fly in your town last weekend.

https://sigmfg.com/collections/sig-k.../sig-riser-kit

What a great project, I really hope you introduce these youngsters to building and flying sailplanes. The skills and enjoyment can last a lifetime.
Last edited by CloudSniffer; Jul 10, 2018 at 08:25 AM.
Jul 10, 2018, 08:23 AM
Registered User
Paul Kenney's Avatar
I would recommend the Chrysalis 1.5 pod and boom electric from DJ Areotech. It has many time saving features like interlocking tabs for the pod construction and the wing is significantly easier to build than the earlier 1.5 hand launch version. Electric launching capability will also help with smaller flying sites at schools, also the price is very reasonable.
http://www.djaerotech.com/
Jul 10, 2018, 08:37 AM
AMA 353531
rdeis's Avatar
Quote:
Originally Posted by CloudSniffer
Beleive me, there are a lot of guys around here willing to help. I think there was a F3RES club contest or fun fly in your town last weekend.

https://sigmfg.com/collections/sig-k.../sig-riser-kit

What a great project, I really hope you introduce these youngsters to building and flying sailplanes. The skills and enjoyment can last a lifetime.
There was indeed, that's my club. That event plus the article in the new MA got me thinking. I've wanted to get a project like this off the ground for some time, just haven't been able to get it together. The kids I'd like to work with are all in student-led groups, so it depends on the student leaders getting excited about it as well as getting the logistics together with the grownups.
Jul 10, 2018, 09:02 AM
Sonoran Laser Art
Quote:
Originally Posted by rdeis
There was indeed, that's my club. That event plus the article in the new MA got me thinking. I've wanted to get a project like this off the ground for some time, just haven't been able to get it together. The kids I'd like to work with are all in student-led groups, so it depends on the student leaders getting excited about it as well as getting the logistics together with the grownups.
That's cool, you have experience on hand. I'm going to say the Riser is not an easier build at all. I'm more thinking about risk. With good guidance on a few critical steps it would be a breeze. Just depends on resources and how you can go about it.
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Jul 10, 2018, 09:17 AM
Registered User
I found this thread and my first thought was the Yellow Jacket, but now I'm thinking a bit different, too.

The YJ (and several others, like the PuRES) can be built in groups: fuselage+servos, five wing panels, tails. Several kits might suffice for a large club.

My other thought was the 1.5M Chrysalis hand launch. I've built seven or eight (really!) over the years. It is inexpensive. It is frustrating to build, because it cannot be built precisely. At the same time, you absolutely know that it will fly well, anyway. But, launching on a hi-start is not a good idea. The kit includes either an X-tail or V-tail option. Use of CA is required.

Another model I built several of is from the Charles River Soaring Society, in Boston. I forget the name. It is a sheeted, foam core wing that with a single balsa spar inserted can be hi-started. Arrow shafts are used for the tail boom, and the pod can be any balsa box. Foam cores were roughly $35 a ship-set. The model made it easy to experiment with polyhedral, X-tail versus V-tail and wing incidence.

Too bad the Top Sky, Chinese-built DLG is no longer available.

If the instructor is an experienced builder, three Yellow Jackets spread among 10-15 people might be a doable project. Threading the ribs on the spars will certainly teach patience.

Good luck!

Yours, Greg
Jul 10, 2018, 09:35 AM
Sonoran Laser Art
Quote:
Originally Posted by glidermang
I found this thread and my first thought was the Yellow Jacket, but now I'm thinking a bit different, too.

The YJ (and several others, like the PuRES) can be built in groups: fuselage+servos, five wing panels, tails. Several kits might suffice for a large club.

My other thought was the 1.5M Chrysalis hand launch. I've built seven or eight (really!) over the years. It is inexpensive. It is frustrating to build, because it cannot be built precisely. At the same time, you absolutely know that it will fly well, anyway. But, launching on a hi-start is not a good idea. The kit includes either an X-tail or V-tail option. Use of CA is required.

Another model I built several of is from the Charles River Soaring Society, in Boston. I forget the name. It is a sheeted, foam core wing that with a single balsa spar inserted can be hi-started. Arrow shafts are used for the tail boom, and the pod can be any balsa box. Foam cores were roughly $35 a ship-set. The model made it easy to experiment with polyhedral, X-tail versus V-tail and wing incidence.

Too bad the Top Sky, Chinese-built DLG is no longer available.

If the instructor is an experienced builder, three Yellow Jackets spread among 10-15 people might be a doable project. Threading the ribs on the spars will certainly teach patience.

Good luck!

Yours, Greg
A small tapered reamer (General) makes fitting the ribs a breeze with a marked stop and steady hand. Then cheap bar clamps from Harbor Frt to secure the LE and hold the pod together. I like rubber coated excercise weights for this build not pins so you just need a flat surface. MDF works good. Which ever way you go I think it's cool your thinking about F3RES and bungee launching. This type of activity is what made RC Soaring great back in the day. There's just something about the plane shooting up on a bungee.

With 3-4 person teams in F3RES they could even share a build and THE PLANE in a contest.
Last edited by CloudSniffer; Jul 10, 2018 at 09:43 AM.
Jul 10, 2018, 11:38 AM
Registered User
Paul Kenney's Avatar
Quote:
My other thought was the 1.5M Chrysalis hand launch. I've built seven or eight (really!) over the years. It is inexpensive. It is frustrating to build, because it cannot be built precisely. At the same time, you absolutely know that it will fly well, anyway. But, launching on a hi-start is not a good idea. The kit includes either an X-tail or V-tail option. Use of CA is required.
My thoughts on the 1.5 handlaunch are similar, but the pod and boom version has updated the design and makes it much easier to build with precision. Of course it is not a pure sailplane, but electric has its advantages for beginers.

I have been able to launch my 1.5 handlaunch with a modified hi-start that does not have as much pull strength but still achieves very nice launches using a vertical orientation.
Chrysalis 1.5 m Hi-Start (1 min 57 sec)


Sidenote: I have really enjoyed following your builds of the Pures and Slite by the way, I regret that I passed up on the Slite when I had the chance to get one. I was next in line but could not purchase at the time.
Jul 10, 2018, 05:41 PM
supreme being of leisure
ZAGNUT's Avatar
the riser 2M is a lot of work but it is also forgiving in the way it builds. screw something up and it's no big deal to fix it. it's also forgiving in flight and on the wallet. way back in the day this is the kind of kit lots of teens started out with and often without any help from an experienced modeler.

another option would be to pick something nice and simple from outerzone like the olympic 650. maybe get the ribs laser cut and then you're pretty much at the same level as the riser but without the hassle of cap stripping the wing...probably a lot cheaper as well.
Jul 10, 2018, 06:15 PM
AMA 353531
rdeis's Avatar
Quote:
Originally Posted by CloudSniffer
...This type of activity is what made RC Soaring great back in the day. There's just something about the plane shooting up on a bungee.

With 3-4 person teams in F3RES they could even share a build and THE PLANE in a contest.
Exactly. I started with a 2m trainer back in the day just like everyone else, and even though the club was helpful and Dad was great, and all that other stuff, I felt like a second class citizen that couldn't really compete and could rarely get good flights until I progressed to a "competitive airframe". When I finally was able to get my Pantera, I still had another couple of months of building time before I could get it going.

The modern airplanes are so much easier to build, and more capable, and as a member of a team there's more motivation to develp your skills- and the product when its all done will be a "competitive airframe" right off the bat!

(That puts extra burden on sim time and training time because nobody wants to be the guy that broke up the team's nice bird, but that seems like a neat side effect that improves their chances of flying successfully)
Jul 10, 2018, 10:26 PM
Sagitta Fanboy
The RESolution v2 is both on the inexpensive side for an F3-RES, and a very simple build.

It's also less weight sensitive than the newer designs (builds up anywhere from 550-650g) and flies very well.
Jul 11, 2018, 12:46 AM
Registered User
glidermang:
I think you're referring to the Terminator, which can be found on the Charles River Radio Controllers web site. (not Soaring Society, we have slimers, electric pilots, even people who mess around with the dreaded quad copters). Anyway, here's a link to the Terminator:
http://www.charlesriverrc.org/articl...minatorhlg.htm
It's important that you get a stiff enough arrow shaft, or it will pitch down every time you launch hard. I only flew one for a few minutes, but the pitch down was really annoying. Are arrow shafts really that much cheaper than tapered booms?
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The little Chrysalis ought to hi start just fine, if you use the right size of rubber. Perhaps 1/4 inch FAI Tan Sport, meant for rubber powered models. New, out of the box, you can stretch it something like 7 times its length before it breaks, but I don't know how it does after being in the sun, rubbing on the ground, etc., or how much it should be derated for repeatability.
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Two meter, traditional floaters are fine, but I suspect they won't seem much different from a Radian. I think a better airfoil is called for.
Jul 11, 2018, 06:19 AM
Registered User
Quote:
Originally Posted by lincoln
All the models that are specifically for F3-RES that I'm aware of are a bit on the expensive side, at least if you have to buy enough for a number of students. I recall the Sig Riser being a decent flier, and the price is fairly low. Not sure what the quality is like. I'd suggest something else if the budget is larger than I think.
Quote:
Originally Posted by ZAGNUT
the riser 2M is a lot of work but it is also forgiving in the way it builds. screw something up and it's no big deal to fix it. it's also forgiving in flight and on the wallet. way back in the day this is the kind of kit lots of teens started out with and often without any help from an experienced modeler.
I noted the comments about the 2M Riser.

From a build standpoint, it should be do-able for your students. I built one when I was 16 or 17 years old (a long time ago, haha), and it was no problem.

With the stock dihedral, it doesn't turn well. If you build one, add more to improve handling.

The plane will be heavy if built stock. I don't have the mass information handy, but others have weighed theirs and my understanding is the wing is comparable to other designs, but the fuselage is a tank. My recollection of my Riser was that is was (overall) rather heavy. My guess is the fuse is built to survive beginner's use, and is thus overbuilt. FWIW this may be a consideration for some of the other designs suggested, if a kid dorks a landing you might have some significant damage (and repairs).

Hope you're able to select a design and get the kids interested. Maybe have some club members come to school and show off their birds? Have a hand launch demo at the athletic field?

Regards-
Dave


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