microdon2

My Feedback: (47)

Tail-draggers don't need a ski for the rear gear. Once you start moving the back picks up. Pls the wheel helps slow the plane down (a bit) on landing. btw - if you've never taken off or landed on snow be prepared for a treat - the fresh snow makes for a very smooth, soft landing strip. (until it starts to melt and then refreezes as a layer of ice, but it's still fun).

wjcalhoun

Hi Guys

Finished my R70 yesterday, and thought I would post the mods and pics.

Basics: DLE20, LiFe 2100 mAh battery; Futaba S9452 servos all around, except Hitec HS7985 on the rudder; Futaba 617 receiver. Miracle dual switch/fuel dot (forward switch for ignition, aft switch for receiver). [Pic 12]

Airframe: Firewall and engine box reinforced with fiberglass cloth / epoxy [Pics 1-3]. Aileron servo boxes reinforced with epoxy. Aileron hinges replaced with 6 medium Great Planes hinge points per side. 50* deflection both directions. Elevators hinged with 4 points per side. 50* flex both directions [Pic 8-9]. Rudder hinged with 4 points. Flexes to touch elevator both directions.

Control: Dual elevator servos installed onto balsa beams aft, with sheet balsa surround (to anchor covering) [Pics 4-7; pull-pull cables in guides]. All servo cables are lengthened by a solder-spice, not by plug-in extensions. Ball links on all linkages. Aileron and elevator links are 2-56 rod covered with expoxied carbon tube [Pic 17]. Rudder is pull-pull linkage with ball links [Pic 10-11]. Rudder cables routed aft through the ‘rudder’ and ‘antenna’ guide tubes.

Gear: Tail gear installed over a piece of light cherry (had it laying around the wood shop) set into a mortise in the (very soft) balsa in the tail [Pic 14-15]; Great Plains scale gear is much nicer than the stock R70 gear [Pic 18]. The main landing gear plate looked much better constructed than my previous R70. Current build has triangle stock on 4 sides, and appears to be expoxied in place, so I did not tear it out to reinforce (yet).

Electronics: Dual cockpit LEDs – port for radio, and starboard for ignition [Pic 13]. IBE/kill switch by Syssa aircraft.

Dynamics: All up weight 9#11oz. Swinging a cheap break in prop (Zinger 16x6) I measure 8400 rpm at WOT (sea level), and 12#11oz static thrust, giving me T/W > 1 !!. I’m expecting greater thrust after a gallon or two of gas, and a switch to a Xoar 17x6 prop.

Surprisingly, the CG was aft of the 5 1/2" mark and had to move the battery forward to the firewall.

Looking forward to her maiden [Pic 16,19], without pants for the time being.

wjcalhoun

A few more pics #13-19; sorry for duplicate of 17
BTW, Mike - that is my grass! No snow in Texas.

microdon2

My Feedback: (47)

wjc - very nice job on your build - your Revolver looks beautiful. Good luck on the maiden! (Too bad about the "no snow". But it's still early...)

capt1597

wjc, thanks for sharing . you have done a very nice job. i alwas find it very interesting how different people approach the same project. i am running an os 91 fx swinging a 14x8 apc prop. i reenforced the landing gear area (something i do on all my arf's). switched to the dubro fiberglass landing gear which i prefer over the two peace stock gear. i also reenforced the wing servo boxes with epoxy during the build because of the some loosness reports. stock pushrods, battery over the wing and it took two ounces of lead at the tail to balance back where i liked it. i will say that the big difference is that my dry weight is 9lbs even. the plane slow flys superbly, will hang on the prop at 80% throttle. she has never snapped at any speed when given full up elev however she snappes horribly with full down elev while inverted (i wonder why- don't know) i alwas fly on high rates and she flat spins easily and knife-edges easily as well. turns and loops are really tight when asked for. i have found that she will land quite slowly after a very long approach to allow her to slow down, man those wings are slippery. she is not ballanced as far back as a 3d plane would be but she is by no means nose heavy. i am a die-hard fuel guy and have not switched to gasoline. i like the power to weight fuel gives over gas in this size range but really it has to do with the fact that when the plane flys by the smell of the castor oil takes me back to my adolesence days flying planes behind the school a very very very long time ago and i like it. it will be fun to hear your flight report with your gaser. happy flying,capt

wjcalhoun

Capt
11 oz is a lot of weight. The gas engine, its ignition, kill switch, dual switch/fuel dot, and at least one additional servo probably make up the difference. Light is always better.
I built this one paying particular attention to the amount of flex of control surfaces. I had at least 30* on each surface on my last R70 build. It would flat spin, but not hold altitude well in the FS, so I thought I needed additional elevator authority.

Sounds as though yours is set up very nicely.

Thanks

CARS II

My Feedback: (7)

Wjc

Very nice build!
Thank you for the pictures and details of the mods. Capt is right she is very slippery, I turned on the Flaperon program because of that and it does make a lot of diferience when they are down on landing, with the Ailerons down as Flaps use 0% on the Elevator to start with.

I was able to put two goods flights on mine last weekend, she flys like on rails and is very smooth on low rates, ahhhh what the the heck!! this is just one beautiful flying machine there, I said it and I'm sticking to it

Enjoy, you will have many happy flights with her [&:]

microdon2

My Feedback: (47)

CarsII -

"ahhhh what the the heck!! this is just one beautiful flying machine there, I said it and I'm sticking to it" - A pretty bold statement... given we're in a "Larger Revolver" thread! Ha. I'm with you.

wjcalhoun

Cars II, Mike, and Capt
Thanks for the compliments.

Maidened her yesterday. 73*F, 7mph SSE winds (basically down the crosswind runway). Two flights of about 15 min each. Used about 9 oz of gasoline for each flight.

GC at 5 7/8" aft of the leading edge at the fuse (3/8" aft of recommended).
4 clicks of up elevator, and 1 click of R aileron had her hands off S&L.

The inverted 45* upline test had her curling very slightly to the horizon - confirming that the CG is about where I want it.

Loops, rolls, a couple of hammerheads, a few spins, inverted, immelmans, knife edge L & R (she couples to the canopy both directions), split-S, 1/2 cubans, and reverse 1/2 cubans was about it. She really moves at WOT. I do not really want to wring it out for a while until I get more gasoline through the engine.

Vertical performance appears to be unlimited. She drifted left consistently on the vertical upline, so may need to decrease R thrust. Glide slope at high idle (2400rpm) is very very shallow; takes less than 1/5 throttle to hold S&L. As noted before, a very clean and slippery airframe.

Landing was completely uneventful. My low idle is about 1850-1900 rpm, so she settles beautifully, touches down cleanly, and does not bounce.

I had mentioned in my earlier posts that the ARF build in the box seemed better than my first R70. The gear plate was better installed, and the monokote was essentially perfect - no wrinkles.

It really is a nice aircraft. Gotta give credit to the design team, to the ARF construction factory which seems to be doing a better job, and to GP for having brought her to market.

Now, if we could just get the 50cc Revolver in the mix!

landeck

My Feedback: (1)

I am at the opposite end of the power spectrum with a Magnum 91 FS and it still flies as nice as can be. It will fly all of the non 3-D maneuvers with ease. It is just a great flying plane however you power it.

Bruce

microdon2

My Feedback: (47)

wjc -

HOW COOL would an 82" Revolver with a DLE 55 be??? HELLO - GREAT PLAINS ....

Sbach342Guy

I've been running a .60 2s in mine for two years. It's only been in the last month or so that I wished I had more power. I had considered an upgrade but have decided to keep the R70 as is. My Edge 540 and my MXS have unlimited vertical so I'll use them for more spirited flying. The R70 is a blast to fly the way I have it powered. It's just for a different type of flying.

Luchnia

My Feedback: (21)

Totally +1

Sbach342Guy

Anyone have the April 2011 issue of Model Aviation magazine? There is a review of the Revolver 70 w/an O.S. .61 engine. They used a pretty big prop and I can't remember which one and my magazine seems to have disappeared. I think the reviewer used a 14x5.5?

prr6100

you sure its April 2011?

Sbach342Guy

Yep, I can see the table of contents on the AMA website for that issue of Model Aviation. I just can't get into the article.

microdon2

My Feedback: (47)

If someone can find that article can you post the link here? Would love to read it.

prr6100

APC 14 X 5N, your right April 2011, O.S. .61 FX

captinjohn

I have a Supertiger .70 that will turn a 14x6 prop like crazy. I put a Frank Bownan piston ring in it. She is a runner for sure! Capt,n

Sbach342Guy

Thanks for looking up the prop info from that article. Wish it was available in electronic form to all AMA members. I think you have to pay extra for access to the electronic version of the magazine.

prr6100

if you really want a copy of the article, I will try to scan it and send it to you

Sbach342Guy

Microdon2 expressed interest in reading the article.

microdon2

My Feedback: (47)

prr6100 - I'd love to read it - just sent you a PM. Thanks.

Mike

prr6100

on the way, i hope

CARS II

My Feedback: (7)

prr6100

If you don't mind I like to read it too, please.

Send you a PM.

Tks.