Whatever happened to my GWS Sport?

[Dave Robelen]

Hi All,
I had been staring at the old faithful GWS Sport hanging from my shop ceiling, and daydreaming of a little more scale-like version. After flipping through a bunch of back issues, I came across a free flight Peanut scale model by Walt Mooney called the Aeronca Defender. A few measurements later, it turned out that enlrging the Peanut plan by 300% would fit my old wing design just nice.
The result is what you see here. 39" wingspan, 6.5 oz weight, GWS IPS A drive, and a bunch of plastic covered sheet balsa. Controls are a pair of GWS Pico servos, R4P receiver, and an IC-50 ESC. Battery a 120 mah X 7 cell Sanyo ni-cd.
Before a purist hops up and points out the non-scale colors, I like a colorful model, and it looks neat against the sky. Besides, they don't make the light films in flat OD. Picture below.
Regards, Dave

[Dave Robelen]

Another angle,

[Dave Robelen]

And one more,
Cheers, Dave

[468/f]

Dave,

That is a great looking plane!! I want one too!! Plans? Where can I get a set?

I bet it is fun to fly!

Take Care,

Roger

[Dave Robelen]

Hi Roger,
I am currently working on a package for AirAge now. Although I do not know which way they will publish it, they will have the plans fairly soon.
It really is a neat plane to fly. Silhoueted against a sunset cruising along, or shooting touch and go's, either way it is fun to watch. Although it is reasonably aerobatic, and will loop, roll, spin, and such, the real pleasure is that it is relaxing. Thanks for the nice words.
Regards, Dave

[Sr71fan]

Dave,

Absolutely BEAUTIFUL, as usual! :)

Gary

[bmutlugil]

Hello Dave,

Once again a very good looking (and most probably good performing) model..

Colors make me think it is Microlyte covered, is this correct? Is this model docile enough to be used for training?

Best regards,

Bulent

[GHMBO]

Dave
A very nice AirKnocker. I have a few hours in its successor.
Jim

[Dave Robelen]

Hello Bulent,
Thank you for the kind words. The covering is actually Solite, a light film made in England and distributed by Skyhooks and Rigging, (among others). It is a lower temperature film, and is probably about twice the weight of Microlite. Of course, it is more durable also.
As far as the flight characteristics, yes, it is amply docile for training. With the CG in a slightly forward position, and limited elevator travel, the model will not stall, but simply undulate in pitch while the stick is held back. When I moved the CG further back, and increased the elevator throw, I found that it will do a lovely spin or snap roll. As long as the rudder is kept centered, the stall is still quite docile.
I would compare the flight to the GWS foam Cub, with the exception that the Defender is considerably more efficient. It will gain altitude in a moderate thermal with the power off, and cruise level with substantial reserve.
Take care, Dave

[flyinhigh]

I have a question,with all your beautiful planes that you produce and desighn why dont you just publish your own plans for them?Would that be a conflict of interest for airage?I would much rather hand you the money for your plans then them . :D
You do a terrific job with that SoLite too ,I love it!!!

Happy building
MIKE

[Dave Robelen]

Hi Mike,
That is a very good question. the only way most any publisher will agree to use a design article is if they get the rights to the plans as well. By publishing the articles, I get the opportunity to show more detail, and draw attention to new subjects. There are people who sell only the plans, such as Nick Ziroli, but his projects are very large models, and each plan sells for a goodly chunk.
I hope that helps, Dave

[flyinhigh]

Hello Dave
Thanks for shining light on it,I never really thought about it that way.Well thanks for sharing your projects with us Dave and just because I dont chime in on every one dont think I dont like em,This one is definitly on the build list its small and cute.Will it be on Microflight?
MIKE

[Dave Robelen]

Hello Mike,
I don't get to pick the specific magazine, that is the editors job. Either RCMF or Backyard Flyer depending on their priorities.
Regards, Dave

[CalmAir]

Hi Dave,

It looks great! The wing and tail section look identical to the GW Sport. Am I correct in assuming that?

It also looks as though you are using the dowel and magnet scheme to attach the wing on this one.

I am planning on purchasing the GW Sport plans after I finish the C180, and now you unleash this one. Mmmm, decisions, decisions. They both would be very good candidates for LiPolys. I have had excellent results with the IPS using lithium ions as long as the AUW is less than 8 ounces. The LiPolys are lighter yet.

I have been studying the GW plans in BYF and only have one question, which probably will be answered when the full size plans arrive, but I will ask it now. The 1/16" ribs used on the horizontal stabilizer are sanded to an airfoil shape. I understand that these taper out toward the ends, but how tall are the ribs at the root of the stabilizer? Did you just start out with a rectangular shape and sand them after the stab is complete? Looking at the Aeronica they do not seem very tall.

Since the C180 was a gift I must finish it first, but I have an itch to scratch and the GW Sport caught my eye as soon as the magazine came out. I really enjoy the IPS powered aircraft that you can tool around with and daydream a little. Guess I am getting old. When I need a speed fix I have one to give me that, but it's hard to beat a realistic looking slowflyer while the sun is setting. Thanks for designing a few of those rascals around the IPS!

Regards,
Dale

[Dave Robelen]

Hello Dale,
You have a sharp eye. The wing on the Defender is held on with dowels at the front, but I used plastic screws at the TE. I guess I just could not trust magnets with this. The wing on the Defender is identical with the GWS Sport with the following exceptions. The center has two dihedral breaks, and the tip shape is slighly different.
The stab ribs in the Sport are sanded to shape from rectangles to a flat bottom section. The tail on the Defender is completely 3/32" sheet balsa. The hinge line was so near the center of the stab, it would have been a mess trying to make a framed stab that narrow. Flat seems to fly fine, I can't tell any difference at any rate.
Regards, Dave

[CalmAir]

Hi Dave,

Ahhhh, my eye did not catch the dual dihedral break, although it is apparent in the photos. The photos also show a good view of the wingtip.

Thanks for the info. Ordered my GW Sport plans today so I won't have to wait for them when the timing is right to start building.

Dale

[flyinhigh]

Dave
What makes this plane so lite?I see an almost 40" wingspan and it only weighs 6.5ounces?is this right?Im interested to know how you got it so lite...If you used contest balsa would AAA balsa work?Im not to sure on what AAA balsa really is,as far as weight class.
Thanks
MIKE

[Dave Robelen]

Hello Mike,
What makes it so Light? Well, I built it from wood that mostly weighed about 7 pounds/ cu. ft, although some was heavier like bulkheads and wing spars. The Solite flim covering helps keep the weight down, and my equipment is the little R4P GWS receiver, along with the IC--50 ESC and two small servos. My battery is fairly light, a Sanyo 7 X 120 mah ni-cd. Finally, using a pair of light wheels helps as well.
I hope that helped some, Dave

[Chris]

Oh my god, that plane is HUGE!!! ;)

Another beautiful plane, Dave. My back-log of planes to build just got one longer. I've been wanting to put some of my old "big" components to use, and this looks perfect. Thanks for sharing.

[American Flyer]

I haven't forgotten the GW Sport. I am finishing mine up. The plane builds nice. I still have to cover it. Are those fake ailerons on that version of the sport ? From the top they look real, from the bottom not so real. Could the GW Sport be converted to a good aileron trainer ?
Is the sport a faster flyer than the Tiger Moth or then Pico Stick ?

[Dave Robelen]

Hi American Flyer,
Those "ailerons" are lines drawn with a Sharpie. You have a keen eye. Th GW Sport does generally fly faster than a Litestick, mainly due to the cleaner wing. It wil fly almost as slow, but the top speed is better. Either model would work fine with ailerons if the wing were built without dihedral, or just enough to avoid a "droopy" look. Full span ailerons about 12% of the width of the wing would do very nicely. An easy upgrade in the power department is to fit a GWS IPS "E" drive that has been set up with the EDF motor. This package, combined with the 9-7 prop is good for a 30% increase in thrust with very little increase in battery drain.
Regards, Dave

[CalmAir]

I have not forgotten the Sport either. Received my plans and hope to start on it in March.

Dave are you referring to using a IPS E gearbox (10.7:1) with the EDF motor installed? With 9x7 prop?

Dale

[Dave Robelen]

Hello Dale,
That is the combo I was reffering to. The EDF motor is low in torque, but really winds up when it has a high gear ratio. In the "E" drive with the 9-7, the thrust on 7 cells is 30% greater than a standard A drive with the same prop and battery. This thrust advantage is maintained all the way to 25 mph (the fastest speed I tested). The current is quite reasonable at 2.4A full throttle static on the seven cells. I love it! Most of the top pylon racers in the indoor event are using this motor with various props and gears. The static thrust running on a prop is just about double what the Fan unit produces at the same number of cells and a much higher current.
Regards, Dave

[CalmAir]

Thanks for that tidbit Dave. It makes sense and yes that is almost an amp less than it draws in the EDF, if my memory is working right. That will be something to mess with in the future, but for now, the EDF stays on Bones!

[Dave Robelen]

Hello Dale & all,
Attached is a chart from a scan showing the performance of three different 180 motor setups driving a 9-6 APC Slow Fly prop. Th middle line is a carbon brush armature and brushes with the case that has the stronger magnets. If you don't mind swapping parts around, this is a nice option.
Regards, Dave

[American Flyer]

I am just about finished. I got it covered. The weather has been too lousy to fly. I have a couple of finishing touches left. With the reynolds wrap covering it came in at 5.9 oz with the battery. I will probably recover with solite at some point. All I need now is a calm day.

[American Flyer]

Bear with me here. I want to try and post this picture a second time. The quality of the last picture was poor and
I am new at this.

[CalmAir]

Hi American Flyer,

Looks like she is ready to go! I was considering the Reynolds on mine, but I think I will go with the So Lite. Who knows, have to build it first. Your weight came in very nice, ought to fly great.

What are the diameter of your wheels and which battery are you going with?

Let us know how the maiden flight goes.

Regards,
Dale

[American Flyer]

The wheels are 1 1/4 inch I got at a LHS. I am going to use a 7 cell 120 Nimh batteries I got from Cloud 9. I also have the 150ma version. The packs weighs about 1 oz each.
I have used these in my tiger moth and in the pico stick. They are much lighter then the gws 150 nicads. Flights in the moth are at about 7-9 minutes. The moth is a little more nimble as well.
After, I get the GW Sport flying I will experiment with some of the different packs I have. With the weight, I saved on the covering I may be able to get away with larger packs.

[Dave Robelen]

Hi,
I meant to mention, that model looks mighty sharp with the RW. You brought it in at a very impressive weight also. I would expect it to fly longer than the LS because the motor draws lss current in flight with the lower drag. Take care of i and enjoy.
Regards, Dave

[all_fly_all_day]

Mr Robelen, have you considered making a little spinner for your prop on your new plane there? Or dont you think that would look good. Just a thought.

Brandon

[all_fly_all_day]

by the way, that is an awesome plane:eek: :cool: :)

[Dave Robelen]

Hello Brandon,
Thanks for the compliment. I did not do a spinner because the full scale aircraft did not have one. I agee, it might add o the apperance of a model.
Regards, Dave

[CalmAir]

American Flyer,

I am curious as to what method you used to shrink the Reynolds?

Dale

[Dave Robelen]

Hello Dale,
I will jump in here. What woks best is a radiant heat source that dies not blow hot air at the material It shriks at a pretty low temp, and if you use say, a heat gun, it will billow away whlit it is soft. I have successfully used a 500W floodflight, our oven (door open), leave it in the car trunk on a sunny day, etc. Gey creative, lot's of heat sources will shrink RW.
Regards, Dave

[CalmAir]

Thanks Dave,

I tried several methods when building the bones and they all worked fine. I did not try the dashboard trick yet. My son used a hair dryer on a sig cub rubber power. I like to see what others are doing because folks come up with things I would never think of. This forum has such a wealth of information that just makes the hobby more enjoyable than ever.

Dale

[American Flyer]

No real trick I got the RW as wrinkle free as I could and left it on a sunny window sill. It tightened up real good.

[American Flyer]

I finaly got a chance to maiden this plane. The first time I went out I had a calm evening. While making adjustments I broke off a control horn and put it back in the car.
Two things I did note first. I had mounted the servos to far to the rear of the plane and the model came out tail heavy. I could get it to balance with the battery pushed all the way forward with the rest of the gear. The second thing was that to change the battery, I would have to remove the wing each time. This was a bit of a pain.
I decided to solve both problems by putting a hole in the bottom of the model and gluing a battery mount from the bottom of the engine mount to the bottom rear cowl former. The battery packs fit perfect in this location and the model balanced better with the added weight. The wing did not have to be removed.
The first flight was about a week later. For the first flight I handtossed the model. It rose right out of my hand and was almost in trim. It flew faster than the pico stick and the tiger moth and just as good. I got about 7 minutes of flying time on the nimh 150 batteries. I could have been more conservative on the throttle.
I tried my 280 nimh the plane did not fly as good due to the extra weight but still did great. I got about 12 minutes on these batteries.
I was impressed on how well it floated with no power. It was fun to put it up at an altitude and cut the engine. I also put it into the ground two times (not on purpose) It survived.
I did some ROG's. They were straight and it rose well. (It was cool). I have built all kinds of models before but, there is nothing cooler than building a model that actually flies.
I would recommend this plan to anyone as a first time builder. I think my old pico stick has seen its last flight.

[CalmAir]

Thanks for the flight report American Flyer, I was wondering if you had time to fly her yet. Congradulations on the good flights. It is a very good feeling to fly one that you build up from scratch.

I will be starting on mine by the end of this week. Did you mount the servo's according to the plan, or did you mount them in a different spot.

You mentioned that the performance was down with the larger pack. Would you let me know what the weight was with the second pack? I am also curious about the fuselage. Did you cover it or paint it?

Dale

[American Flyer]

The servo area on the plan is marked with the words "servo area". I put the servos butted up against the support. If you backed them up about an inch it should balance. The servos would be right under the words "servo area" on the plan. This was my error if I followed the plan it would have been ok.

The weight with the heavier battery was 6.9 oz. It still flew great but there was a noticable difference. 15% additional weight. I have noticed this difference in other planes between the two batterys. In my TM, I get nice round loops with the lighter battery. With the heavier battery they are egg shaped.

The fuselage was painted. Just enough to make it white. Go light on the paint I was surprised how much weight it added. According to my notes, the paint on the fuselage added 3grams.