Guan Li PBY Questions

mitsudriver274 · Oct 23, 2009, 06:49 PM

I wanted to build my first seaplane pretty cheap in case I loose it in the water. My choice was between a hobbyzone super cub or the guan li pby, i opted for the cheaper plane, 52 shipped vs 64 shipped.

From others that have built this plane, what power package did you use?

Nitroplanes advertises there flying weight (brushless) at 27.5oz, I was shooting for around 30oz.

I figure for the plane to successfully row it needs at least 300w of power?

I'm looking at picking up the the motor/esc/prop combo from hobbyking, specifically the towerpro 2409-12t, anyone have any experience with that package?

I also wanted to add retractable tip floats, and strengthen the plane, any advice for my first waterplane build?

kvitekp · Oct 26, 2009, 05:53 AM

I've just built mine and had about 20 flights on it, great flying boat!

My power system is: 2 x (BP2212/10 Ultra with APC 7x5 E/EP, ESC Pentium 18A) and G-Force 2250mAh 3S. This gives it plenty of power: takes off the grass easily in less than 10 feet at AUW ~32oz. Typical flight time is 8 minutes, battery is 20% full on landing. At full throttle current is 25A each motor produces 25oz of thrust (as measured on the thrust stand).

Both the wing and the fuse are glassed using MinWax and 3/4 oz fiberglass everywhere except at the bottom of the fuse where I used 2oz fiberglass. The wing support pylon has two layers of 3/4 glass on it. This makes the wing and the fuse much stronger at the cost of less than an ounce of extra weight.

I initially flew it with two APC 7x5 E props rotating in the same direction and torque roll was very noticeable. Fortunately LHS had matching “pusher” version of the APC 7x5 E prop: this made a lot of difference, especially on full throttle take offs. I’d highly recommend to select motor based on the availability of counter rotating prop.

Balancing the plane laterally also helps, mine had to have 9 grams added to the left wing tip.

Both of my tip floats are already broken off and I don’t think I’ll have them glued back since wing and wing pylon do not look strong enough to survive those less than perfect landings when the float hits the ground first. Besides, they don’t help that much on the water, lateral balance seems to be more important, check this video: http://www.bayrc.com/boards/viewtopi...96910f66321d44

mitsudriver274 · Oct 28, 2009, 11:55 PM

What about strengthening the plane with carbon rod? Has anybody done retractable float tips on these?

kvitekp · Oct 29, 2009, 02:56 AM

Quote:

Originally Posted by mitsudriver274

What about strengthening the plane with carbon rod? Has anybody done retractable float tips on these?

Glassing makes both the fuse and the wing strong enough for the speeds this model is intended for.

Yeah, i remember seeing a forum or youtube video with retracting tip floats, not sure if i can find it now.

mitsudriver274 · Oct 30, 2009, 09:53 PM

So i've been having problems glassing the plane, I picked up 5oz cloth for the bottom and 3/4oz cloth for the rest of the plane and miniwax polycrlyic, do you first do a covering of miniwax, let the dry and apply fiberglass w/ miniwax?

First I cleaned the whole fuselage with rubbing alcohol, and then did some sanding (220 wet), after drying and cleaning the prepped area with alcohol, I applied the cloth and miniwax, but after 1 hour it was still wet and did not want to stick, so I just pulled off the fiberglass and let the miniwax dry, i've sanded it again and will try one more time with the fiberglass. Any tips on the complex shapes?

kvitekp · Oct 31, 2009, 09:19 AM

5oz cloth may be difficult to apply to the curved bottom of the boat, i used 2oz and felt like it was the maximum. you may want to consider two coats of 3/4 for the bottom instead.

My first coat is with glass and minwax, then sanding, then another coat of minwax. If you have dings or scratches on the foam you may want to use spackle (or minwax filled with baby powder) before applying the first coat.

Here's the good video and instruction on WBPU glassing process: http://www.pldaniels.com/flying/vide...0x288&pp=balsa, i prefer polycrylic (blue minwax cans), but the process is similar.

it dries out in about 6 hours but you may want to allow 24 hours before sanding. this gives you time to really work on complex shapes, just take your time.

ssatoru · Nov 04, 2009, 08:44 AM

My friend 'voodoo' did nice retract using pair of GWS retracts, placing servo in nacell. He writes this mod added total of 50g only.

How it works.

Guanli RC PBY Catalina retractable floats (0 min 11 sec)

Flights

PBY-5 by Voodoo (1 min 56 sec)

Satoru

Oct 23, 2009, 06:49 PM	#1
mitsudriver274 Registered User Join Date: Jul 2009 Posts: 20	Guan Li PBY Questions I wanted to build my first seaplane pretty cheap in case I loose it in the water. My choice was between a hobbyzone super cub or the guan li pby, i opted for the cheaper plane, 52 shipped vs 64 shipped. From others that have built this plane, what power package did you use? Nitroplanes advertises there flying weight (brushless) at 27.5oz, I was shooting for around 30oz. I figure for the plane to successfully row it needs at least 300w of power? I'm looking at picking up the the motor/esc/prop combo from hobbyking, specifically the towerpro 2409-12t, anyone have any experience with that package? I also wanted to add retractable tip floats, and strengthen the plane, any advice for my first waterplane build?

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Oct 26, 2009, 05:53 AM	#2
kvitekp Registered User Join Date: Sep 2007 Location: Santa Clara, CA Posts: 81	I've just built mine and had about 20 flights on it, great flying boat! My power system is: 2 x (BP2212/10 Ultra with APC 7x5 E/EP, ESC Pentium 18A) and G-Force 2250mAh 3S. This gives it plenty of power: takes off the grass easily in less than 10 feet at AUW ~32oz. Typical flight time is 8 minutes, battery is 20% full on landing. At full throttle current is 25A each motor produces 25oz of thrust (as measured on the thrust stand). Both the wing and the fuse are glassed using MinWax and 3/4 oz fiberglass everywhere except at the bottom of the fuse where I used 2oz fiberglass. The wing support pylon has two layers of 3/4 glass on it. This makes the wing and the fuse much stronger at the cost of less than an ounce of extra weight. I initially flew it with two APC 7x5 E props rotating in the same direction and torque roll was very noticeable. Fortunately LHS had matching “pusher” version of the APC 7x5 E prop: this made a lot of difference, especially on full throttle take offs. I’d highly recommend to select motor based on the availability of counter rotating prop. Balancing the plane laterally also helps, mine had to have 9 grams added to the left wing tip. Both of my tip floats are already broken off and I don’t think I’ll have them glued back since wing and wing pylon do not look strong enough to survive those less than perfect landings when the float hits the ground first. Besides, they don’t help that much on the water, lateral balance seems to be more important, check this video: http://www.bayrc.com/boards/viewtopi...96910f66321d44

Oct 28, 2009, 11:55 PM	#3
mitsudriver274 Registered User Join Date: Jul 2009 Posts: 20	What about strengthening the plane with carbon rod? Has anybody done retractable float tips on these?

Oct 30, 2009, 09:53 PM	#5
mitsudriver274 Registered User Join Date: Jul 2009 Posts: 20	So i've been having problems glassing the plane, I picked up 5oz cloth for the bottom and 3/4oz cloth for the rest of the plane and miniwax polycrlyic, do you first do a covering of miniwax, let the dry and apply fiberglass w/ miniwax? First I cleaned the whole fuselage with rubbing alcohol, and then did some sanding (220 wet), after drying and cleaning the prepped area with alcohol, I applied the cloth and miniwax, but after 1 hour it was still wet and did not want to stick, so I just pulled off the fiberglass and let the miniwax dry, i've sanded it again and will try one more time with the fiberglass. Any tips on the complex shapes?

Oct 31, 2009, 09:19 AM	#6
kvitekp Registered User Join Date: Sep 2007 Location: Santa Clara, CA Posts: 81	5oz cloth may be difficult to apply to the curved bottom of the boat, i used 2oz and felt like it was the maximum. you may want to consider two coats of 3/4 for the bottom instead. My first coat is with glass and minwax, then sanding, then another coat of minwax. If you have dings or scratches on the foam you may want to use spackle (or minwax filled with baby powder) before applying the first coat. Here's the good video and instruction on WBPU glassing process: http://www.pldaniels.com/flying/vide...0x288&pp=balsa, i prefer polycrylic (blue minwax cans), but the process is similar. it dries out in about 6 hours but you may want to allow 24 hours before sanding. this gives you time to really work on complex shapes, just take your time.