JoeMamma

I did like ahicks did, but instead of the aluminum roofing material I used 1/8" thick by 1 1/2” wide 90 degree aluminum angle to reinforce the landing gear (both Home Depot and Lowe’s carry it).

Joe M.

microdon2

My Feedback: (47)

8 point roll - Do you mean the fix of my crash two weeks ago? That plane is a Rev 59. Haven't touched it yet - busy with other planes and some vacation. But it's right there on my to-do list.

btw - did some NICE flying this morning with my Rev 702 (my 2nd 70" Revolver, with an OS 120 4s), despite the threatening skies. This plane \ engine combo doesn't have quite the "pop" or speed of the Rev 70 \ DEL 20, but I still love it - flies great - fast and smooth with very good vertical. And very responsive at high rates And it's relatively quiet - good for flying near the Whitestone bridge (doesn't attract too much attention). Two pics attached. That's the Manhattan skyline through those trees, and the LaGuardia Airport tower to the left.

ahicks

My Feedback: (2)

Speaking for myself, you need to let those wrecks rest for a while! Depending on the size of your fleet and how mad you are at it, maybe until there's white stuff blowing around?

8.point.roll

Er, sorry about that !  For some reason I thought it was the 70'... my bad.

donddsms

My Feedback: (1)

Al,
Thanks for the landing gear info, I am actually at the point where this will be useful. I am flying my second large revolver, lost #1 on the maiden-have learned to use locktite on metal geared servo screws! I have about 30 flights on it now, and the DLE 20 is starting to run more reliably. Advice on landing from the brotherhood has diminished my bounces after touch-down, but today I noticed some cracks developing in the fiberglass landing gear. I considered replacing it with a set of aluminum gear from an old plane that is just about the right size, but lacks the swept-back feature of the stock gear. If I use this replacement gear, the cg will move forward quite a bit. Has anyone else been down this road? I have a second set of stock gear I could use, but I fear if I use it I am just delaying the inevitable.
Don

wjcalhoun

Don:
I'll chime in here. I would use the second set of stock gear for a couple of reasons. First, the (presumably heavier) aluminum gear will shift your cg in exactly the wrong direction. Fast landings are often the result of a too-forward CG, so you might try pushing the CG back 3/8" or so at a time. Mine is back from book, and she flies great.

The second reason to use the stock gear is that the sweep of the gear places the wheels closer to the CG; obviously with conventional LG, the CG MUST be behind the main LG line, but if the LG are too far forward, it makes it more difficult for the tail to come up on your take off roll, and encourages the tail to sink prematurely after your main gear touch on landing. Both of those increase the wing AOA at a time when you really don't want that to happen.

A more aft CG will slow your landings, and help to reduce the sink rate of your approach.

Bill

microdon2

My Feedback: (47)

donddsms - another option (as I'm sure others here are sick of hearing) is to use a third party gear (I use Dubro) and bolt it into a new floor w\ blindnuts just aft of the stock gear nutes. I've never had an issue with CG. This gear has never broken, even on violent crashes. And - until my last incident - its' never ripped off a plane. (though that last one was exceptionally bad timing, catching that edge of that small depression).

ahicks - I agree - it usually takes me a few weeks before I can return to a crashed plane to start the fix. Not sure if it's anger (at self), the emotional pain, or simple procrastination. Probably the last.

wjcalhoun

Don:
Mike's suggestion works as well; although the dubros are not swept, the more aft mounting that he suggests puts the wheels of the mains at about the same place relative to the longitudinal CG as the stock gear would do.

microdon2

My Feedback: (47)

donddsms - The Dubro gear is very strong, but is not as sleek at the stock gear. So I spray paint it with white fuel-proof Top Flight LustreKote, then apply three layers of trim (colors of the plan) to make it look sleeker.

ahicks

My Feedback: (2)

Nice note with a lot of info that's not often mentioned! Agree with every word. Would add only that an aft CG (to a point anyway) will also lower your stall speed!

Regarding the gear, I guess it would depend on the severity of the cracks as to whether I (personally) would replace them, but if I did, I would go with another set of the stock gear. Reason being I have that gear mount all beefed up, and would have to go with a new mount to the rear (as suggested) to use alum. gear.

Are the cracks only in the finish, or are you actually able to see the cloth w/broken strands? I ask because mine are abused terribly, but I'm currently flying on one that's broken about 1/3 of the way back! I realize I'm flying on borrowed time with that, but wanted to pass on I've found those gear are pretty sturdy. Maybe more than they look? Maybe I've just been lucky though.... -Al

JH313

Hey,

ahicks

My Feedback: (2)

I run a 6oz on a 20cc 3D profile plane I have. I'm an old man. By time that's getting close, I'm generally ready to come down anyway? Given the choice between your tanks, the 14 would be the safe choice, that should be plenty. With the 9oz you'd have t pay attention? It's your call. Hard saying how somebody else is going to fly their plane?

Regarding the prop hitting the spinner, if it's only touching not sure I'd be concerned. If it's causing the prop to twist when you draw it down, I'd look for a different prop. The APC's I run don't do that.

wjcalhoun

Hi guys:

For those of you with DLE20s in your R70, let me make a suggestion that many of you may already have taken. GET A FRANK BOWMAN RING!

Many at my field had spoken well of Mr Bowman, and the performance enhancements that a Bowman ring can bring. I did equip several DLE55s with Bowman rings with considerable improvement in performance.

Today, I finally installed a Bowman ring into my DLE20 mounted on my R70.

Baseline, the engine TODAY turned an APC 14x12 prop at 8400-8450 rpm. Sea level (actually 14 ft ASL), 90*F, needles tuned for a tan plug. I think I am about at peak for that prop.

I installed the Bowman ring (a 10 min job, literally; pull the cylinder, take off the old ring, clean the groove, install the new ring, oil the cylinder and piston, reinstall the cylinder), and restarted with the same prop, needle settings, etc, and got 8700 rpm. My DLE20 has about 4.5 gallons of gas (Pennzoil 1:32) through it, so it was almost 'broken in'. Frank's ring gave me another 250 rpm on a pretty well broken in engine that had great performance. I have had similar increases with a DLE55 (8 gallons, 200 rpm), and a DLE55RA (on my R90, a 350 rpm increase). Also noticeable was the improvement in compression when I pulled the prop through TDC. It is harder to flip through TDC, and the prop rebounds very quickly after TDC. With the new ring, the engine acted as if it was a bit lean on the low end, stalling with rapid throttle advancement. Richening the width of the screwdriver slot (low end) solved that problem. Maybe someone with small engine expertise could explain that to me.

I do not own stock with Mr Bowman, and have no financial interest in his business. His rings DO improve the performance of DLE engines, which apparently from the factory use a very hard cast iron in the production of their rings, and they pay little attention to the ring gap. My ring gap was large enough to see easily with the naked eye - at least 30 thousands, perhaps 35. Frank Bowman's ring gap is very small. I did not measure it, but it was probably less than 10 thousandts by eye. This in itself may account for the improvement in compression. In addition to his engine acumen, Frank Bowman is a real gentleman. If you do not have a Bowman ring in your DLE20, I would recommend it! Installing is NOT a big deal and significantly improves the performance of the DLE20 (as well as the DLE55 and 55RA).


Best
Bill

Rodney C

My Feedback: (1)

Bill, I echo your suggestion and comments about Bowman piston rings. Another good suggestion, which I've done on all three of my new DLE20's is replacing the stock CM6 spark plug with an NGK CM6 plug. This resulted in a marked improvement in the performance of my DLE20's. Rodney C.

microdon2

My Feedback: (47)

Agreed on the value of the Bowman rings. And they're very reasonable - around $13 each. btw - Mr Bowman has rings for basically any and all makes and models of RC plane engines (pretty sure he has a list posted). Pretty impressive. And, as WJC mentioned, they're surprisingly easy to change (I thought it would be a major operation). With the rings Frank Bowman also supplies notes on how to eliminate suction loss on DLE engines due to poorly seating reed valve assemblies, which can significantly improve your low-idle and ease of starting.

donddsms

My Feedback: (1)

Thanks Bill and everyone else for the advice regarding my landing gear. I decided to fiddle with the CG once more, and moved it to the inside of the wing tube, as close to the center as I could get. Boy, what a difference that made! I can flare on landings, and just float to the pavement. The first take-off was a bit hairy, I wasn't expecting the plane to jump into the air. I no longer need half the runway on my take off roll. The plane is much more responsive in flight. So I am going to keep the stock gear and try to make them last as long as possible.
Don

afjetmech

Anyone have a link for the Bowman rings?

microdon2

My Feedback: (47)

He may not have a web site - I may have seen his ring list on printed docs. Here's an RCU thread with his email and other comments about him.

http://www.rcuniverse.com/forum/m_11...m.htm#11451507

One thing I just learned from reading this is that - if you send him specs for a ring he hasn't already made he'll make them for you for free, just so that he now has that model in stock. Pretty good deal.

wjcalhoun

Email is pretty quick [email protected] He can give you prices and other details.


He does not take credit cards; you can use paypal (which I do not), or send him a check. I had my rings a week after the check left my house.

As Mike said, I believe that he will make rings for uncommon engines; you can ship the piston / cylinder to him, and he will custom fit a ring.


Don - glad to hear of your success; CG plays a big role in the flying characteristics of every plane, but I think the R70 is especially sensitive to CG changes - it is 'tunable' based on how one likes to fly.

Rodney - I thought that everyone replaced the stock DLE plug with a genuine CM6 from NGK, but there are enough new folks on that it is probably a good idea to reiterate that advice. There might also be reason to reiterate the importance of proper gapping. Gap should be minimum 0.018" (thickness of #11 Xacto blade), but many gap them wider, 0.024- 0.028". The ignition has plenty of pop to create a spark across the larger gap.



Bill

lopflyers

My Feedback: (12)

OK guys, my R70 met her demise, I was on final for landing and she touched down really smooth. Well the rudder and the tailwheel didn't cooperate too much and she went left into the grass and a ditch.

The LG came off ( for the 4th time) and the engine box was shattered.

I took the engine out and all the electronics and plan to put all in a new Zlin.

Can I stay in the Revolver brotherhood even without a Revolver?

Im planning to get the 90 soon

ahicks

My Feedback: (2)

Sorry to hear of your plane's demise! [X(]

Have to wonder if it might not just be a question of time before you have another? We sometimes wander, but we always come home?

I'm one of those that runs the wider gap (.024-.025) on the CM-6 plugs. It's done because it seems to allow the engine to run cleaner in mid range, makes it less fussy regarding it's needle settings. Or, it's happier running rich. Either way you want to think of it. No clue why. It just works. -Al

wjcalhoun

Lop
Sorry to hear of her injuries.

You might send the plane to microdon2 - he has fixed what looked like a box of sticks and made her fly again!

microdon2

My Feedback: (47)

wjc - funny, I was thinking the same thing.

Lopflyers - sorry to hear about your crash. you sure you dont' want to order some parts from TH and put her back together? (fuse, cowl should do it - right?)

If not, keep all parts. When you DO order a replacement Rev 70 those wings might come in handy.

lopflyers

My Feedback: (12)

For sure im keeping the wings.

microdon2

My Feedback: (47)

That's my target, too. An impressive airplane.