40% Extra 300 Construction by-the-numbers
09-14-2006, 11:35 PM
#26
RE: 40% Extra 300 Construction by-the-numbers
A disclaimer. I've been flying the standard Extra 300 prototype quite a bit over the last month or so, and it flies extremely well in the stock dihedral configuration and two blade 30x14. Its a great flying plane even without the dihedral taken out. The ability of the plane to start and stop a snap consistently and precisely has not changed, but the three aileron servos per wing have primarily made snaps more crisp. The wing panels are nearly the same weight-only about 4 oz lighter than my existing Extra 300. (I used a hole saw on the root rib and hollowed out the tips, and sanded the wing surfaces quite a bit).
This new configuration weight provides necessary performance with a three blade which is primarily driven by the Don Lowe Masters sound rules, as well as my desire to not interfere with local flying clubs' noise footprint.
Due to the pipes being so long, and the CF gear and other lightening techniques, I did discover during initial CG checks that the plane appeared to have CG further back than the existing Extra (I wanted to set this plane up as identical as possible). My fears went away when I painted the cowl. The paint put several ounces up front which put the CG right in range. Batteries are in front of the tube about where the fuel tank sits. The spinner does not have a lightened backplate, its 9.2 oz total. About twice the weight of the ZN spinner I was intending to use. I believe the plane slows down so well because of the Greve's pipes- they seem to allow the engine to come down to a low idle quickly. Less of a flywheel effect. I did notice that accelerating the throttle quickly- it took about .25 seconds longer to get to a higher mid throttle power rate. Having said all of this, the engine still is relatively new so I bet its a little rich on the low end.
The PAK kit arrangement went together very well. Since the wings, back deck, elevators and rudder/fin were pre-sheeted and sanded, and cowling and wheel pants primed as they were, I definitely would not otherwise have the time to put together the kit in the time it took otherwise. I basically put it together in 2 1/2 months (April and then August/mid-September). I'm very happy with the way it turned out and hope you find this building thread helpful if you choose to purchase and build a PAK kit from JTEK Radiowave.
Thanks,
Don
This new configuration weight provides necessary performance with a three blade which is primarily driven by the Don Lowe Masters sound rules, as well as my desire to not interfere with local flying clubs' noise footprint.
Due to the pipes being so long, and the CF gear and other lightening techniques, I did discover during initial CG checks that the plane appeared to have CG further back than the existing Extra (I wanted to set this plane up as identical as possible). My fears went away when I painted the cowl. The paint put several ounces up front which put the CG right in range. Batteries are in front of the tube about where the fuel tank sits. The spinner does not have a lightened backplate, its 9.2 oz total. About twice the weight of the ZN spinner I was intending to use. I believe the plane slows down so well because of the Greve's pipes- they seem to allow the engine to come down to a low idle quickly. Less of a flywheel effect. I did notice that accelerating the throttle quickly- it took about .25 seconds longer to get to a higher mid throttle power rate. Having said all of this, the engine still is relatively new so I bet its a little rich on the low end.
The PAK kit arrangement went together very well. Since the wings, back deck, elevators and rudder/fin were pre-sheeted and sanded, and cowling and wheel pants primed as they were, I definitely would not otherwise have the time to put together the kit in the time it took otherwise. I basically put it together in 2 1/2 months (April and then August/mid-September). I'm very happy with the way it turned out and hope you find this building thread helpful if you choose to purchase and build a PAK kit from JTEK Radiowave.
Thanks,
Don
11-17-2006, 10:53 AM
#27
RE: 40% Extra 300 Construction by-the-numbers
Don,
How have the planes been flying? Are you going away from the Comp ARF stuf? I've built a few Colombo Anderson kits and it looks like construction is very similar. I only have enough room for 35% stuf so I'm stuck in the 100cc range for planes. Do you know how well the smaller JTEK planes compare? Thanks
Steve
How have the planes been flying? Are you going away from the Comp ARF stuf? I've built a few Colombo Anderson kits and it looks like construction is very similar. I only have enough room for 35% stuf so I'm stuck in the 100cc range for planes. Do you know how well the smaller JTEK planes compare? Thanks
Steve
11-24-2006, 09:30 PM
#28
RE: 40% Extra 300 Construction by-the-numbers
Several have asked similar questions regarding the 35% Radiowave planes. I've flown the 35% Extra 330 and it really tracks well. I believe you can post on another thread and Al should be able to give you some details.
Yes, the reason I'm flying the Radiowave Extra 300 is because I like it the best of all the planes I've flown. I have one Comp ARF/ Fiberclassics Extra 330 and its for sale. Lots of nastalgic memories and its light as can be, but feel more competitive with the 300. I have no plans to sell my Radiowave.
Thanks,
Don
Yes, the reason I'm flying the Radiowave Extra 300 is because I like it the best of all the planes I've flown. I have one Comp ARF/ Fiberclassics Extra 330 and its for sale. Lots of nastalgic memories and its light as can be, but feel more competitive with the 300. I have no plans to sell my Radiowave.
Thanks,
Don
12-13-2006, 04:00 PM
#30
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RE: 40% Extra 300 Construction by-the-numbers
I just wanted to say what a great thread this is and that I am new to giant planes as well as building them. I hope to get into some pattern flying this spring . Thanks for all of your input and nice pics. See you at the field.....
07-25-2008, 09:02 PM
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RE: 40% Extra 300 Construction by-the-numbers
Hi Don! Dose the stock 300 have any coupling in 3D knife edge. I know you took the dihedral out and had 5-6% mix.
01-16-2009, 11:30 PM
#38
RE: 40% Extra 300 Construction by-the-numbers
The plane is very honest in 3D. Rolling harriers are the strongest, knife edge high alpha is fine. I don't feel anything detracting during 3D. The plane flies well. Now, I fly the CG forward (same location as sequence flying), just more throw on high rate ailerons, elevator, and rudder.
Don
Don
04-11-2009, 08:47 AM
#40
RE: 40% Extra 300 Construction by-the-numbers
And I am pleased to say this was the airplane that was featured in a very professional instructional video....
Here is a how-to video on RC Aerobatics.
www.rcaerobaticvideo.com
Here is a how-to video on RC Aerobatics.
www.rcaerobaticvideo.com
