Tiny Racer-X, racer-T, Racer-V

[Joe Kollmann]

HI all,

We've been testing a series of small "one design" racers with a view toward a casual pylon series at our local club.
Based on the tiny trainer fuselage, and using an "A" pack on three s, It's gaining some traction and I thought it was time to put a note here on the FT site in case anyone out there was wanting to try one. Here is the link to the RCGroups Fly-A-Ways club thread on the planes.

https://www.rcgroups.com/forums/sho...mann-2Buck-Racer-X-Racer-T-and-Racer-V-Series

PDF plans in a couple of layouts are on that site and here as well.

Though I've designed and flown a few dozen RC airframes over the years and a few full scale experimentals, this was my first try at a DTFB design. It's fun, but has it's limitations, and the very obvious advantage of being cheap, cheap, cheap. It's a welcome diversion from my normal activities as a designer on various defense, aerospace, industrial and medical related products and projects.

The little racer is just a TT with a significant wing clip, different planform and some fairings, with a variety of empennage possibilities. It flies just right and is extremely wind-resistant. One of the impediments to getting people to participate in Pylon or combat is the cost of the loss of an airframe. So, I thought this would be a natural. Early interest is very encouraging and we should have a half-dozen or so in the air at the same time within a week or so.

Developmentally, A couple of us just began subtracting and adding area , parts and trying various planforms from flight to flight at the field. Then I came home and drew out the ones with the best result and built the next version. All three empennage configs have been built and flown now and they all fly great, with minimal differences between them in handling and/or speed capabilities. I started with an elliptical wing looking for best L/D but quickly realized that the shape doesn't lend itself very well to DTFB construction. A DH88/103 style triangle might work too,
but the basic Sea fury'ish clipped elipse planform with a little reflex gave the best empirical result. Looks pretty sweet too! View attachment racer-X sheet 2 packed.PDF View attachment racer-X sheet 1 packed.PDF View attachment racer-X sheet 1.PDF View attachment racer-X sheet 2.PDF

 

[rockyboy]

Man, this is an AWESOME project! I've been tossing around thoughts to get some of the 'old fogies' in my local RC club into DIY foamy combat and racing, and this looks like an excellent approach! Thank you so much for posting plans!

Oh yeah, Welcome to the Forums!!

 

[Joe Kollmann]

Thanks!

Thank You for the welcome RB,

I think this is ideal for a "low impact " intro to pylon. As you point out, many of us "Temporally challenged" Silverbacks are short of time and others don't want to risk their typical 200hr intensive build to the rigors and viciousness of flying low and fast with other goofy old fogeys (of which I am a card-carrying member).

Cheers and hope you try one. They are super-easy to build, fly and launch and can really take a beating.

-Joe

 

[Hai-Lee]

I applaud your effort and you ingenuity developing yet another TT offshoot.

Last year I had a similar need but as our club is in a built up area racers were frowned upon so we went for dogfighting instead.

The variety of electrics and setups make the dogfighting really interesting. Some highly maneuverable and responsive and others really fast with incredible acceleration. Most are still flying even with a few midairs!

Pity our workloads are so great because a canard racer would be an interesting sight considering the ability to do very tight banked turns.

Please continue to post any developments.

Have fun!

 

[Joe Kollmann]

Canard is an interesting prospect...The only ones (canard racers) I can think of were the "Amsoil" F-1 racer and the various VAri-EZ's that did pretty well in The "CAFE" series. Given the sensitivity of the forward airfoil design where accuracy and minor reflex are critical to performance, It might be hard to do in DTFB. It would only cost $2 to try though.

I think it would be a challenge to get a canard to perform in level flight as well as a conventional tail. I do intend on trying a "pitcheron" version because the build would be strong and simple and the control wires/horns could be deleted. Also, it would be a two servo airframe, hence lighter, and could survive a more radical clipping with the same loading and a cleaner airfoil. I just need to design a 50 cent way to pivot the wings.

I'm looking forward to some ribbon/combat with these too. They are so small that, even when you are trying, It's very hard to get two of them to touch each other.

We had two in a club event yesterday and in a limbo contest I struck the vertical steel pole Three Times! The third time finally dislodged the wing and damaged the turtledeck but it will fly again. These are tough little planes.

Here is a pic comparing the size and configuration to a Tiny trainer

 

[SlingShot]

Most excellent young man! I highly approve. Laid back simplified racing.

I think to understand the appeal of this, you just have to remember how much fun you have racing around in little go-karts that aren't necessarily very fast.

 

[Hai-Lee]

Funnily enough both rockyboy and I have built and flown a TT based canard. It was easy to build, (especially if you had a lot of TT parts laying around), and 2 versions were built.

My favourite was the fixed foreplane variant which was minimalist with only 2 servos setup with flaperons. Sadly the canard I built was really designed as a minimalist trainer for those who have lots of FB but do not have the ability to purchase lots of motors and propellers.

In order to make control more manageable for the beginner the fuselage was lengthened to slow pitch response and increase stability in gusty conditions. If you wish to see the concept read: http://forum.flitetest.com/showthread.php?29171-Tiny-Trainer-based-Canard-anyone

My version had a great turn of speed, (on a 100W motor), and had a real sharp banked turn because with all of the weight at the rear effectively when the elevator was given max up, the wings went into negative lift whilst the foreplane experienced increased angle of attack and really pulled the nose around like a parachute. It was scary the first few times I tried it. Nothing I had flown up to that point could out turn it but it did cause a substantial loss of airspeed.

Sadly I gave my TT canard away to make room for other projects and I plan to build a new version in the future perhaps a little more refined.

Great racers and I may download and build sometime in the future.

Have fun!

 

[Joe Kollmann]

FOUR IN THE AIR AT ONCE

Well...we've got a few of these built now. Seven, I think. In ten laps no single plane can lap another and the wings are between 100% and 50% of the design in the plans for the tiny racer. WIth less wing it predictably gets harder to fly but isn't significantly (if at all) faster. I believe the T-tail is the most stable and controllable and has lasted the longest. We've had three to five up and mock racing in winds up to 15KT with no problem. Here are a few pics