TyFlies
Strong User
Nice work, and nice plane!
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Midwest Slope Challenge (WOW) ODR One Design Racer
- Thread starter JJ Colorado
- Start date
JJ Colorado
Very Strong User
Now that I have another ODR plane ready I'll probably fly my Cobra a lot more. The ODR style planes are great all arounders that can fly in light winds, yet tear up the sky when adding 6 or 8 oz of ballast. The Cobra is a bit shorter than the Voodoo Child and has a gooped EPP fuselage so it can handle rocky LZs and slopes better.
I have experimented a bit with the VC. The Cobra has a swept back LE, straight TE. VC the opposite, straight LE. So far no noticeable flying difference, but I haven't A/B'd them on a good day. Of course the CG is different but neither is set right on the ragged edge of a rearward CG like my Thermal Duration gliders.
I decided to bottom hinge and top drive the flaperons on the VC. Not as pretty when sitting on the ground, but that made it easier to setup flaps for landing. No flaps setup on the Cobra, but I thought adding them to the VC would make tight LZs a bit easier on landing. They work, but to keep servo resolution precise I only have about 40 degrees of flaps. That seems to slow the glider a little for landing, but I'd need to set them to about 70 degrees to have it get really slow for landing, and since these gliders are primarily for racing I'm not willing to compromise centering or precision for slower landing speeds. Still nice to give the flaps a 40 degree blip right before touchdown just in case there is a rock hidden in the landing area. The WOW ODR rules prohibit programmed mixing so the flaps are actuated manually on the throttle stick.
Hill Hobbit
Very Strong User
So snap flap isn’t legal then?
JJ Colorado
Very Strong User
Correct, for the ODR races at Wings Over Wilson in KS, you can't have programmed flap mixing. You can manually use flaps but no snap flap.
A key part of this is to keep things simple. And I doubt that snap flaps would be benficial.
A key part of this is to keep things simple. And I doubt that snap flaps would be benficial.
JJ Colorado
Very Strong User
For those who might have an interest in a ODR kit, the Canuck is cranking out some Pink Mess ODR glider kits. You can get just a fuse, wing cores, tails to make a ODR spec racing glider.
Further info on RCGroups at:
www.rcgroups.com
Several folks have ordered components to gear up for the races at the Wings Over Wilson event.
Further info on RCGroups at:
Pink Mess ODR 60" Racer - RC Groups
New Product Pink Mess ODR 60" Racer Slope Soaring
TyFlies
Strong User
Curious what you guys think about making the ailerons bottom hinged rather than top hinged. (opposite of how it is in the bare wing photo, and opposite of my current plane). Seems like bottom hinged might be slightly more efficient since bottom airflow would be smoother. Any thoughts would be appreciated.
I know it’s 90% about the flying ability rather than the plane, but JJ flies really smooth and I need all the advantage I can get. : )
Still have some more sanding to do.
I’m making two new ODR’s one will be the brother to this Bad Voodoo Pro which is getting a bit beat up, and another will be a “Pink Mess” ODR from Canuck.
I know it’s 90% about the flying ability rather than the plane, but JJ flies really smooth and I need all the advantage I can get. : )
Still have some more sanding to do.
I’m making two new ODR’s one will be the brother to this Bad Voodoo Pro which is getting a bit beat up, and another will be a “Pink Mess” ODR from Canuck.
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Doc J
Very Strong User
Haoyang Wang
Very Strong User
Hinge at the bottom gives you more down travel, hinge at the top for more up travel.
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JJ Colorado
Very Strong User
For a ODR slope racer you don't need a lot of aileron (flaperon) throw. Since I wanted to have the option to slow my Voodoo Child down for landing I have used a bottom hinge to enable significant flap actuation. A top mounted control horn has less chance of getting snagged on landing (unless you land inverted) and allows for easy linkage inspection prior to flight, or adjustments when trimming.
The only advantage I see for a top hinge system is that it looks cleaner when the plane is laying on the ground (horn and linkage below the wing).
The only advantage I see for a top hinge system is that it looks cleaner when the plane is laying on the ground (horn and linkage below the wing).
JJ Colorado
Very Strong User
So the Canuck (Andrew) made a bunch of ODR kits in varying level of completeness to assure a good stock of airplanes at WOW, the Midwest Slope Challenge which is next week in Wilson Kansas. Here is my version of his kit which I call a Blue Mess. Also a pic of it's sister the Voodoo Child which is a derivative of the Bad Voodoo ODR kit. The Mess weighs in at 26 oz which is just above the low weight limit. I've built in a ballast mount and stick based on some F5J ballast setups. Will need that for racing.
Some detail. The main difference between ODR planes is the fuselage. My Cobra has a shaped and gooped EPP fuse which is durable but probably a little draggy as well as a little shorter than max allowable length. Both the Voodoo and Mess designs have very sleek glass fuselages that are the max length as per the ODR rules (36 inches). The thin, smooth cross section along with a longer tail moment should be beneficial. The ODR spec requires a 7" root chord, and a 5" tip chord with straight taper only. The Cobra has a staight TE. The Voodoo has a straight LE. My Blue Mess has 1" of LE and TE taper. Doubt the type of taper has any perceptible effect on performance, but it may influence stall or snap behavior in a tight turn. Hope someone is watching and oberving that because I plan to focus on flying and racing.
Some detail. The main difference between ODR planes is the fuselage. My Cobra has a shaped and gooped EPP fuse which is durable but probably a little draggy as well as a little shorter than max allowable length. Both the Voodoo and Mess designs have very sleek glass fuselages that are the max length as per the ODR rules (36 inches). The thin, smooth cross section along with a longer tail moment should be beneficial. The ODR spec requires a 7" root chord, and a 5" tip chord with straight taper only. The Cobra has a staight TE. The Voodoo has a straight LE. My Blue Mess has 1" of LE and TE taper. Doubt the type of taper has any perceptible effect on performance, but it may influence stall or snap behavior in a tight turn. Hope someone is watching and oberving that because I plan to focus on flying and racing.
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Red
Very Strong User
Yes we are. Talked about the scratch build this morning actually, time to get started on a fuse plug.
JJ Colorado
Very Strong User
If you need a fuse Eric or the Canuck can probably get you one, or a few in a reasonable time. Took Canuck a lonnng time to make the plug and mold for his pink mess fuse. The wing cores are pretty simple to have made. Standard balsa sheet core layup.
I think Larry might even be able to crank out a Cobra kit for that matter. The EPP fuse (expecially when gooped) is indestructable, but I cant imagine either of my glass fuse's breaking either. They are pretty stoutly built.
That is in part why I also like the ODR slope racers. They are a good size at 60" wingspan, and with a base 9 - 10 oz / sq ft they are fun to fly planes in modest winds. Add 5-9 oz of ballast and the get moving pretty quick. Not as fast as a Magnus 60, but respectably quick, and (minus the ballast) low stress. And they are fixable.
I think Larry might even be able to crank out a Cobra kit for that matter. The EPP fuse (expecially when gooped) is indestructable, but I cant imagine either of my glass fuse's breaking either. They are pretty stoutly built.
That is in part why I also like the ODR slope racers. They are a good size at 60" wingspan, and with a base 9 - 10 oz / sq ft they are fun to fly planes in modest winds. Add 5-9 oz of ballast and the get moving pretty quick. Not as fast as a Magnus 60, but respectably quick, and (minus the ballast) low stress. And they are fixable.
JJ Colorado
Very Strong User
WOW ODR races are over and the Mess gliders, Pink, Blue, whatever flew Very well and Fast. I finished first in two of my four races, but unfortunately had a mid air with my Blue mess just as I was crossing the finish line. Uggh. My Voodoo child finished my final race but a record of 1st, 2nd, 1st, and 3rd wasn't enough to get on the podium. That 2nd was due to Ty getting in front on the start of that race and keeping me 50 ft in his wake the whole time. There was a fly off and in the end Ty took 3rd place overall, with me calling for him. Great racing and a lot of fun. My Mess will get cleaned up to race again.
In the mean time, here is a link to a video of the first round.
In the mean time, here is a link to a video of the first round.
JJ Colorado
Very Strong User
BTW, the cores and dihedral for both of my ODR gliders are the same. The only difference is the wing taper. The Voodoo has a straight LE while the Mess has equal taper front and rear. The spec is a 7 inch root chord and 5 inch at the tips. My Cobra has a straight TE, with all the sweep in the LE but I didn't bring it to WOW.
From doing some test flights the straight LE seemed to turn slightly harder, but was not as stable tracking. I liked the even taper better as it didn't need as much correction while going from one turn to the other. YMMV. The winds were a bit gusty so this could all be perception but after a few test flights I knew the Mess was my primary plane. In fact I scored another set of cores from the Cannuck as I may build a new wing for my Voodoo with the same equal LE and TE taper as my Mess. It is not much of a difference but when racing you want the glider to fly as thoughtlessly as possible.
One other observation, and this could be a confounding factor for what I just described. I made the vertical stab on the Voodoo a bit over sized as I hate waggle when coming out of turns. Neither plane had any waggle, but the larger vertical stab made the Voodoo crab into the wind more than the Mess, so the Voodoo is getting a tail cut before the next race.
From doing some test flights the straight LE seemed to turn slightly harder, but was not as stable tracking. I liked the even taper better as it didn't need as much correction while going from one turn to the other. YMMV. The winds were a bit gusty so this could all be perception but after a few test flights I knew the Mess was my primary plane. In fact I scored another set of cores from the Cannuck as I may build a new wing for my Voodoo with the same equal LE and TE taper as my Mess. It is not much of a difference but when racing you want the glider to fly as thoughtlessly as possible.
One other observation, and this could be a confounding factor for what I just described. I made the vertical stab on the Voodoo a bit over sized as I hate waggle when coming out of turns. Neither plane had any waggle, but the larger vertical stab made the Voodoo crab into the wind more than the Mess, so the Voodoo is getting a tail cut before the next race.
Doc J
Very Strong User
There is no doubt that bottom hinged wing control surfaces work better. Tested and proven.
The airflow over the underneath of the wing is always smoother than the upper surface, and its best to try to keep it that way.
Doc.
Doc J
Very Strong User
Woo...looks like fun. Some advice from a long-time (ago) pylon racer:
Fly your fastest line and dont worry about avoiding anyone. It will either happen or not, and its almost impossible to judge any avoidance manoeuvre. Remember every control input slows the plane down.
Lovely to see MOM again and long may it continue!
Now...lets get the ISR race going again.
Doc.
