REVIEW: Guan Li Catalina RTF

[gzsfrk]

UPDATE: I had my first flight! Flight Review is below the Build Review in this post.



Plane Model: Catalina RTF
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Click here to read the entire review

[gzsfrk]

Originally Posted by DAngilello

Good news.
I couldn't wait for warm weather, so I maidened the PBY off the snow.
It took full power and around ten yards, but it finally got off the ground!

Nice! Glad to hear about the successful maiden. I don't think I've read about anyone yet who has crashed theirs on first flight. Of course, if I had crashed mine on the first flight, I wouldn't exactly have been itching to come back here and describe all the gory details. (Although I would have, since I had to finish the review. )

[DaveESPI]

[/img]
DELAY in build due to CATNAPALINA !
OK, not a bad "ARTF" kit !
Mine was well made, the parts all fit with only minor fuss, and all electronics worked right out of the box. very little glitches, and the motors were good as well. I would highly reccomend sealing the electronics in some sort of splash proof cases ( small plastic snap containers perhaps or film containers as water will be possinle to get in the nose of this plane if you stuff the landing or catch the bow too hard. I had to notch a little bit out for where to route the engine wires into the wings, but it was easy with the dremel tool. I want to be able to take the top wing off, so I cut holes big enough to get the washers and screws up and out of the top of the wingmount after I glued the wing seam and plastic trim piece on top.
I'll try to maiden it in the next couple of days as we are expecting a bit of snow, and It should be able to take off nicely over some soft pack. It has Plenty of push, so the supplied motors are OK from what I can tell.
Have to tape the leading edges, and hull bottom, and the tail horizontal stab is indeed a bit fragile. Perhaps a stiff thin rod throug it will help strengthen it. Also, the connecting rods under the wing struts are fine IMHO. they work nicely and are adjustable. Overall I'd say this is indeed not a "Flyout of the box" plane, but flyable in 5 hours.

[gzsfrk]

Originally Posted by DaveESPI

DELAY in build due to CATNAPALINA !

Hah... awesome.

Originally Posted by DaveESPI

OK, not a bad "ARTF" kit !
Mine was well made, the parts all fit with only minor fuss, and all electronics worked right out of the box. very little glitches, and the motors were good as well.

Glad to hear that your build went well!

Originally Posted by DaveESPI

Interesting paint job--almost looks like shadows on water. Perfect camoflague for sneaking up on the unsuspecting carp!

[DaveESPI]

Ya, I was looking for the shimmering water effect. I decided if I really did paint it like a true night fighter plane, there would be good chances I'd lose orientation as to how Iwas flying a solid black/blue tiger striped plane, and roll it into the earth in a heavy handed over correction of the sticks.

I will add in some grey to the belly, but I wanted to leave it with just the black/ white for now and see how it looked in the air.


Sidenote: I picked up the ME-109 from this company also from Raidentech.

I was quite happy with this one and the quality was a B+ IMHO for the money, so I just need to trim this one out and get the COG measured, and I hope to fly it tomorrow

[ministeve2003]

check the cheap servos they put into it... my focke wulf had the bottom half of the servos unscrewed and one of them looked like it worked untill I moved it quickly from side to side a few times and then it showed it was stripped... I replaced all the servos with hxt900's for 3.50 each... better safe than sorry...lol
SK

[DAngilello]

I forgot to mention; I built the Guan Li PBY almost totally stock.
The only changes I made were:
Ran thin CA foam safe down the centerline to seal up the body seam.
Used 15 minute epoxy to assemble the foam pieces.
Used "Servo Arm Easy Connectors" (Ebay) on the rudder and elevator pushrods.

So, the bottom was just the bare foam, and got scrapped up flying off the snow. Not bad, but I'm glad I caught this when I did. Don't belly-land without reinforcing the bottom! Tape would work, but I plan to use Towercote. (www.towerhobbies.com) I've got a white roll somewhere...

I don't plan to fly this plane enough to justify a brushless motor / ESC / lipo upgrade. I think I'll just try an 8 cell 9.6V NiMH pack next.

FYI - The Guan Li A10 is four channel, but has a steerable nose wheel, not rudders as listed.

[gzsfrk]

Holy moly!

The 3S LiPos I ordered came in today, and after charging one of them, I decided to try it in my Catalina as easytiger had described. Holy moly! What a difference a few more volts makes. I didn't even have it at half throttle and it was producing more thrust than the 8.4v NiMH. When I briefly had it at full throttle, stuff went flying everywhere off the table I had it sitting on and it was all I could do to keep the thing from moving forward.

Can't wait to try flying the thing with the LiPos, although I still need to find a good LVC solution for a brushed ESC.

Now I'm thinking I might have to find a really light little 7.4v LiPo for my Yellow Bee. That thing would turn into a bullet!

[ministeve2003]

let us know how much better it flys with the lipo... I converted my focke wulf to brushless before flying it... I cut back to a 8x6 prop to slow it down...lol now with a 2250 pack it flys forever...
SK

[easytiger]

Originally Posted by gzsfrk

Holy moly!

The 3S LiPos I ordered came in today, and after charging one of them, I decided to try it in my Catalina as easytiger had described. Holy moly! What a difference a few more volts makes. I didn't even have it at half throttle and it was producing more thrust than the 8.4v NiMH. When I briefly had it at full throttle, stuff went flying everywhere off the table I had it sitting on and it was all I could do to keep the thing from moving forward.

Can't wait to try flying the thing with the LiPos, although I still need to find a good LVC solution for a brushed ESC.

Now I'm thinking I might have to find a really light little 7.4v LiPo for my Yellow Bee. That thing would turn into a bullet!

Tojaso!

In flight, the difference is quite dramatic. Like, climb out at a 45 degree angle with the lipo batt.

Same transformation to the A-10, though the A-10 is certainly more sprightly than the Catalina on NIMH power. With the Lipo, it's just great.

I have the P-47 put together, it's as cute as a button. I will try her first tomorrow with NIMH power, then do the lipo upgrade. Just want to see her fly first on the stock gear.

I also have the ME109.

The servos, several of mine did not have the case screws screwed down all the way, like yours. And one of them had a broken gear right from the start. Oh, well. I put that one on the rudder of the P-47 and unplugged it for the moment...I am not using landing gear. I also used some of the excess clear material from the decal sheet for skid protection on the fuselage.

I would NOT call all the electronics junk, not by a long shot. The servos in the Catalina and A-10 have been fine so far...out of 10 servos, only one has been bad...

[wilky]

Originally Posted by easytiger

I put that one on the rudder of the P-47 and unplugged it for the moment...I am not using landing gear.

Tiger, Just a thought. when a servo is unpowered they are fairly easy to move. are you not concerned that the rudder may get bumped or move in flight causing the plane to start to turn? If the servos shot, why not run some CA down into it to lock in in place if your just using it to hold the rudder still.

[easytiger]

It's a thought, but I'm not really worried. The forces on that tiny rudder are not much. As soon as I have a chance, I will change the servo out, though, so I don't want to glue it...

[DaveESPI]

WHat did you guys do to set the COG out of the box ?

Can it fly just as it comes out of the box with no mods ? it seems a tad nose heavy, but maybe thats all depends on where you hold it from.

I was going to fly it lastnight off the snow, but it was a tad too windy and dark for my pleasure in the parking lot so I opted for another smaller 30.00 plane that was a blast to fly from TRU

I ordered the winter camo ME-109 from raidentech. I assume it is the same Manufactuer ?

hopefully there is a thread about it around somewhere also.

[easytiger]

Originally Posted by DaveESPI

WHat did you guys do to set the COG out of the box ?

Can it fly just as it comes out of the box with no mods ? it seems a tad nose heavy, but maybe thats all depends on where you hold it from.

I was going to fly it lastnight off the snow, but it was a tad too windy and dark for my pleasure in the parking lot so I opted for another smaller 30.00 plane that was a blast to fly from TRU

I ordered the winter camo ME-109 from raidentech. I assume it is the same Manufactuer ?

hopefully there is a thread about it around somewhere also.

CG is set from the factory, and it's non-critical, anyway. It's a floater.

I have the ME109 also(yes, same manufacturer), it's nice, but it will snap, given not much provocation. Small tail surfaces. The P-47, though, is just great...

[easytiger]

Yes, it can fly right out of the box with NO mods.
By the way, ditch the spinners...they cost power, they are there as a safety feature so nobody gets poked by the prop shafts...

[gzsfrk]

I'm going to hold off on flying the Catalina with the 11.1v lipo for the time being. My Watts Up meter came in and I've done some testing.

With a fully charged 7 cell (8.4v) NiMH battery, the Catalina pulls about 11A at full throttle sustained with servo action. However, with the 3S (11.1v) LiPo plugged in, that leaps up to over 25A with just the engines at full throttle. I really doubt that the cheap-o ESC is rated at 25A, so I'm thinking I'll install an ESC for which I know the specs before flying with the lipo.

Also, the BEC is way underpowered to handle the downconversion from 11.1v to the 5.5v needed by the servos and Rx. In my tests, with no throttle, I operated all the servos constantly for several seconds. Over the course of about 10 seconds, all 4 of the servos will gradually weaken and then eventually one of them will seize up (buzzing noise), rendering all controls inoperable until you disconnect then reconnect the battery. There is no such issue when using an 8.4v NiMH (presumably because the BEC in the ESC has less work to do to downconvert the voltage). That's just too big a risk, even if I was careful not to overwork the controls while flying.

I think I'm going to either order a SmartBEC, or maybe try and find a good brushed 30A ESC with an LVC cutoff switch you can set for either NiMH or LiPo. Anyone have any suggestions?

[easytiger]

Actually, the ESC IS rated 25a, says so right there in the instructions.

The BEC, I cannot imagine a scenario where you would be running all four servos continuously for ten seconds with this Dumbo, unless you were trying to hover it.

And full throttle is a rare scenario, too.

But, hey, it does indeed fly on 8.4v, so do that, if that's what you like, but it's a lot more fun on 11v, the possibility of a crash due to overwhelming the BEC is a rather "corner" scenario.
I'm going to glass the bottom of mine for longevity, when I have the chance...the foam does not hold up well to snow or grass, much less anything rougher...

[gzsfrk]

Originally Posted by easytiger

Actually, the ESC IS rated 25a, says so right there in the instructions.

Thanks for pointing that out. I don't know what happened to my instructions sheet, nor did I even realize the ESC specs were printed on it.

Originally Posted by easytiger

The BEC, I cannot imagine a scenario where you would be running all four servos continuously for ten seconds with this Dumbo, unless you were trying to hover it.

Flying lipos without a lipo LVC, running 4 servos off a BEC that can barely sustain them--you DO love to live in the Danger Zone, don't you?

Originally Posted by easytiger

I'm going to glass the bottom of mine for longevity, when I have the chance...the foam does not hold up well to snow or grass, much less anything rougher...

When you do that, be sure to post some pics and write up a short flight review of it post-mod if you get the chance. I'm curious as to how that would look and fly. As for me, I've belly landed mine on 7 different flights (2 more today, thanks to the lovely weather), and the bottom is still in pristine condition with only the packing tape coating that I have on it.

[FlyingMonkey]

Originally Posted by wilky

Tiger, Just a thought. when a servo is unpowered they are fairly easy to move. are you not concerned that the rudder may get bumped or move in flight causing the plane to start to turn? If the servos shot, why not run some CA down into it to lock in in place if your just using it to hold the rudder still.

It's foam, isn't it?


Just shove a toothpick though the rudder into the vert stab, you can always pull it out later.

[easytiger]

Originally Posted by gzsfrk

Thanks for pointing that out. I don't know what happened to my instructions sheet, nor did I even realize the ESC specs were printed on it.



Flying lipos without a lipo LVC, running 4 servos off a BEC that can barely sustain them--you DO love to live in the Danger Zone, don't you?



When you do that, be sure to post some pics and write up a short flight review of it post-mod if you get the chance. I'm curious as to how that would look and fly. As for me, I've belly landed mine on 7 different flights (2 more today, thanks to the lovely weather), and the bottom is still in pristine condition with only the packing tape coating that I have on it.

This Dumbo could not even wheeze up the onramp to the Highway To The Danger Zone. It's one of those planes that you can put down the TX to light your cigar while flying. I don't really feel any risk from the BEC at all.

Glassing, well, it's just a little neater than tape. There are many online tutorials and such about that...I use West Systems, my favorite.

Yes...a toothpick will work, good idea, on the rudder. I've already replaced the servo, though...

[gzsfrk]

Originally Posted by easytiger

Actually, the ESC IS rated 25a, says so right there in the instructions.

Just an FYI. I found my Catalina instruction/spec sheet over the weekend, and the graphic shows that mine supposedly has a 40A ESC? Now THAT seems odd. But if true, then my worries about overloading the ESC are certainly unnecessary. (BEC concerns are still worth considering, though.)

I ought to try and simply build a resistor (or series of resistors) setup, hook them up, and try running it up to 20A, 25A, and then 30A and hand check the temp on the ESC. What's generally the hottest, temperature wise, that an ESC should be able to safely run before you risk damaging it?

[easytiger]

You are right...the ESCs in the twins(A10 and Catalina) are indeed 40a, the ones in the singles are 25a...

I would not worry about toasting them...

[gzsfrk]

Well, I took the Cat out for a spin today with the 3S 2250mah LiPo, and I have to say, I have mixed feelings. While it initially was crazy with power (I -did- manage to do the loop this time ), it seemed to drop off kind of fast. Got the battery back in, checked it, and it was still over 11v, so I'm thinking I may well have been overloading the ESC to some extent (not via amperage, possibly, but maybe it just wasn't designed to handle 11.1v input).

After flying with the 3S, I downgraded back down to the 8.4v NiMHs for two flights for comparison. While the drop in power was noticeable, it wasn't so bad that I couldn't stand to fly it after experiencing the power increase that the LiPo provided. Maybe I should just go ahead and take the plunge to upgrade the thing to dual brushless and be done with it.

I think I may also be having some CG issues. I balanced the plane according to the spec sheet, which shows that the CG should be about 1" from the leading edge of the main wing. I thought that was strange, since the general rule of thumb I read is 1/3 the distance from the leading edge of the main wing to the trailing edge.

Is that how yours is balanced, easyt? If not, where do you have your CG set?

[FlyingMonkey]

Brushed motors do not like 3S lipos.

They could be on their way out already..

Time for a couple towerpro brushless motors

[easytiger]

Originally Posted by FlyingMonkey

Brushed motors do not like 3S lipos.

They could be on their way out already..

Time for a couple towerpro brushless motors

You can't assume that, as you don't really know how the motors are wound...

At any rate, I have at least five flights on mine, and the motors are still holding up on 3s. I don't do a lot of flying at full power...the plane just does not need it.
There is enough power with the NIMH pack to fly fine. More than enough with the 3s lipo pack!
CG...you know, I just don't remember. I built it stock, then put it on my fingertips just to make sure it was not tailheavy, I was not particularly precise about it. With the lipo pack, the CG probably moved back a little. It's not really critical on this aircraft, and it DOES sound like it is set far forward, if I started from scratch, I'd do 1/3 back from the LE and not be even slightly worried about it being tailheavy...in other words, you can try to move it back, I would not expect it to bite you. But since the thing is floaty and nice where the CG is set from the factory, you can just as well leave it alone....

[cr2k]

I was wondering about a LiPo. I will try a 3s. Mine had leaks in the bottom from poor joining. used Ca and covered with strapping tape. Had to replace the wing servos as they froze up somehow. Did a loop on the Ni Mh batteries but the "struts" came loose. Strut Clevis' pins are to short to go through ply eyes. Going to cut off pin and drill through and use removable clips. I taped on the wing cover and left it so it could be taken off and apart for transport.
Great Flying plane for what it is. I hit a thermal today and it went up up up!

I am surprised that it taxis and water turns as well as it does with that minimal rudder, but dipping a tip float helps it pivot around.

Fun plane for the price. I see more and more long term RC pilots going to these "toy" planes for the fun of it.