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View Full Version : POGO (Convair XFY-1 from Hobby Lobby)


CorsairJock
12-22-2005, 02:36 PM
Just recieved my Convair XFY-1 "Pogo" kit from Hobby Lobby.

Before I go any further, here is a link for info on the full scale version:
http://www.nasm.si.edu/research/aero/aircraft/convair_pogo.htm

There is a review of this kit here:

http://www.rcgroups.com/links/index.php?id=4920

My 1st impressions:

Kit package is about 1/2" thick, this is probably the norm for the new generation of foamies. Hobby Lobby packed it very well, in a larger box.

Contents are 2 sheets of 6mm Depron, with parts die crunched. Just when I thought all new kits were laser cut, along comes this one. Die crunching might have been OK with thinner Depron, but not so well with 6mm.

NO carbon rods and/ or spars. Included rods are steel.

Nice motor mount plates, appear to be made from fiberglass.

That's about it for now, hope to start construction (and maybe even complete) over the holidays.

If you have (or want) one of these, PLEASE posts your thoughts/ techniques/ power choices/ likes/ dislikes/ etc. here.

Picture below is from the E-Zone review.

CorsairJock
12-23-2005, 03:29 PM
Major problem uncovered today: as I was removing parts from Depron sheets, I suddenly realized that 1 side of 1 of the sheets (2 sheets per kit) was incorrectly printed 180 degrees off. That is to say: while 1 side was A-OK, the opposite side has the graphcs totally out of alignment with die cuts, as if the sheet was accidently rotated 180 degrees before that side was printed.
Hobby Lobby has been notified, I await their reply. Based upon past experiences, I expect no problems.

UPDATE: New one arrived very quickly, in time for me to get some major work done over the Christmas weekend! I just now glued the wings together using Gorrilla Glue, must wait for it to cure before proceeding.

NOTE 1: Instructions call for foam friendly CA, but I like using Gorrilla glue for it's gap filling properties.

NOTE 2: HOBBY LOBBY is GREAT! I'm so happy with their quick response that I intend to place another order with them this weekend, maybe for another AXI motor.

stuk_at_work
02-06-2006, 08:36 PM
My Pogo arrived from H-L about a week ago. After seeing several of my fellow club members attempt to land one vertically in the gym at the HS where we have our meetings, I decided to build a "blue foam" version first and practice my landings with before glueing the foam in the kit! BTW, as mentioned in the RC-groups review, take-off from vertical was pretty straight forward, even in the gym by all those who flew (not me).

I've got everything done now except the rudders. I am not happy with the way the instructions have you tie the two pushrods together off the same servo arm. The geometries can never be right that way. I think the author of the RC-Groups review used a separate servo for each rudder half (connected to a Y cable) to solve the problem, but I'm already starting off with about a 3/4 oz weight penalty (blue foam parts weight 1 oz more, fiberglass? in kit weighs 1/4 oz more than my plywood substitute), so I'm trying to avoid doing that. I was thinking of tying the two rudders together & connect the servo to only one half. I'll probably cut a prototype tonight (advantage of blue foam!), but was wondering if anyone else came up with an elegant solution to this problem before I started experimenting?

flypaper 2
02-07-2006, 04:55 AM
Built a scratchbuilt Pogo a couple of yrs ago and the two rudders were on a Y pushrod but one side of the Y was soldered to the first one so I only had one wire connected to the servo. Hope that makes sense.

CorsairJock
02-07-2006, 02:01 PM
I agree, the instructions really suck for this kit. In fact, in one review that I read, that builder mistakenly assembled the fueslage sides BEFORE assembling the wings. I don't think he ever realized it.

And that motor mount/ landing gear setup is pretty heavy. I considered leaving it off, but decided I might be needing the option to use it (rather than land vertical). I did dremel off some of the fiberglass, removing a few grams, and I will leave off the top 'landing gear' wires.

As for the bottom rudder: I have added another servo for it, and intend to couple it (computer radio) to ailerons (for better roll) AND rudder (for knife edge). I am using those inexpensive ($10) 5 gram (4.3 gram advertised) Blue Arrow servos from Hobby Lobby, so very little weight is added with the additional servo.

stuk_at_work
02-07-2006, 04:06 PM
I "completed" the Blue Foam Pogo last night (still need to decorate it a bit). Came in at 9.7 oz, w/o the battery.

For the rudder, I ended up using one pushrod, shaped like a big "V' to connect both rudder halves. The pinched end of the "V" goes into the servo arm, and there is a L shaped bend at each of the other ends that connect to the control horns on the rudders. Right now, only spring tension is keeping the pushrod in the rudder control horns, but I'll either bend "the rest" of the z bend in, or go out and buy some of those DuBro Micro EZ links (#849) to secure them in place.

I picked up one of those 400XT motors Hobby Lobby was selling for $20 (I think they still are), and did a "tethered" hover off my workbench. All I can say is "grin-grin-grin". Unfortunately, the winds are still blowing at 15-20 mph, so a real test is going to have to wait a few days.

CorsairJock
02-07-2006, 04:38 PM
I have a few 400 XTs also, and am considering installing one on my Pogo. Could you give more details on your's (all up weight WITH battery, what prop, what battery pack, and does it appear that hovering is easily accomplished with your setup)?

stuk_at_work
02-07-2006, 07:29 PM
All up weight should be just shy of 13oz (9.7 oz + 2.97 oz of 1320 Thunder Power Lipo). I could probably shave another 1/4 oz off by replacing the JR R700 Rx I Currently have hooked up with something lighter, and I'm sure there are lighter ESC's than the Thunderbird-18 I'm using (which, by the way works great with this motor) and would bring the weight down more. Keep in mind that the "raw" bluefoam parts weighed a full ounce heavier than the Depron parts than came in the kit. Just to be complete, I am using Hitech HS-55 (3) on all flight surfaces.

I'm running a 10x4.7 APC Slowflyer prop. I seem to remember that it pulled about 120 watts, but I only ran it this high briefly, as it was drawing over the recommended 10 amps of current at the time.

The "hover test" I did on my workbench was with a much heaver 1500 maH Kokam battery (3.5 oz?) and the Pogo "lifted off" at about 3/4 throttle, if that.

CorsairJock
02-08-2006, 06:24 PM
On the 400XT: I think there are a lot of people who are pushing them to the brink of melt-down. From my own tests, I think 10 amps is the absolute most you would want to draw with one of these, and then only for a few seconds, as they quickly start to warm up at that current draw. I have found that they draw about 7 ~ 8 amps with 10 x 4 and 2 cell (Li-Po), the same draw with 8 x 6 on 3 cells. Thus, I have decided to limit myself to 8" props when using 3 cells, and I will be using a Castle Creations Thunderbird 9 ESC. Hopefully, this will provide adequate thrust for the type of flying this aircraft is designed for (vertical take-offs and landings).

What will help in my case, is all up weight is projected to be a just a few grams over 10 oz with my 950 mAH, 12 C rated 3 cell Li-Po packs.

I should have the answers tomorrow (Thursday, Feb 9).

flypaper 2
02-08-2006, 09:50 PM
One thing you'll find is, on vertical takoff you'll want to jump it off the ground fairly quickly, then back off on the throttle. Too slow and it will fall over just at lift off. I had to reprogram the CC ESC to FAST START as slow start wasn't fast enough. Once you get up to level flight it flies quite well a bit above half throttle.

CorsairJock
02-09-2006, 05:11 AM
Yikes! I suppose that means it wouldn't be wise for me to try it out in my living room, just to get it to hover a little?

flypaper 2
02-09-2006, 12:05 PM
I'd test fly it outside first so you can see what it's parameters are first. It does wobble around like a drunk in hover so you need to be quick on the sticks. Mind you, this was the characteristics of a scratchbiult so don't know if they'd be the same. Control throws and all that.:p

CorsairJock
02-09-2006, 03:23 PM
But it's so COOOOOLD out there.
OK, I threw caution into the wind and tried it out in my living room today.

First off tho, I should mention that my AUL is 286 grams, or 10.09 oz. Reasons it is so light:
I ommitted the upper 'landing gear' wires.
I used Blue Arrow 5 ch.Rx & servos. The servos (4 used) are about 4.7 grams each, are rated at 10 oz/ in totque, and routinely sell at Hobby Lobby for about $10 each.
Motor (400XT ) is light: about 50 grams with backplate.
ESC: ThunderBird 9
Battery: 3 cell 950 mAH, 12C rated Li-Po.

The test: to see if it will 'lift off' using APC 8 x 3.8 Slo-Flyer prop.

Results: YES, but had to use about 80% throttle, leaving not much reserve. The reserve will be needed when I decide to attempt vertical landings, so I'll probably switch to a slightly bigger prop.

I only lifted off about an inch, as I don't want to fly it in my living room. It did tip over several times before I got the hang of it: just feed in a generous amount of up elevator and right rudder(s). I have a feeling that the reason these inputs are needed is because the bottom/ left side is heavier than the top/ right, mainly because the battery is mounted on bottom/ left. I am speaking in terms of motor/ thrust centerline, while standing up. Once I got the hang of it, I did it several more times, each time gradually increasing throttle, then immediatly backing off if it became airborne.

Now all I need is a calm, and much warmer day, so I can try it in my front yard.

stuk_at_work
02-09-2006, 11:03 PM
I would switch to a larger prop to get a little more power out of the config.

While I did not fly my Pogo today, I did brave the wind and cold to test fly my Klein-Aviatek (sp?) Mustang. What does this have to do with a Pogo, you ask? Originally the mustang had a geared speed 400 on it, but recently I upgraded it to an XT-400 brushless motor with a 10x3.8 prop. This is the exact config. I switched to on my Pogo last night.

This mustang, rtf, is over 16 oz, and I need the 100+ watts for it to fly "fun". I was concerned last night when I ran my tests with the Pogo and the 10x3.8 prop, it got hot pretty quick at 10 amps, and that was not even at full throttle! With the 10-15 mph winds today, I needed the full throttle stick quite a bit, and even after 5 minutes of flying (the wind was getting to my eyes), the motor was still cool to the touch. I know testing in 28 degree weather with a 10-15 mph wing is skewing the test results a bit, but I'm encouraged that some of the concern I had with the "dead-air" test on my workbench may not be as big an issue as I first thought.

I will still wait for milder weather (40F?) to test fly the Pogo, but it's tough waiting with it sitting finished on the workbench!

stuk_at_work
02-16-2006, 04:13 AM
Weather finally broke in this part of NJ. I had some of my electrics down at the field today, and tomorrow I plan on bringing the "blue foam Pogo" out for it's maiden flight, assuming the winds really do hold to the 5-10 mph like we had today!

qban_flyer
02-16-2006, 05:17 AM
Good looking Pogo shots, both in flight as well as at rest. :)

The one in front of the fireplace is absolutely awesome! :)

After reading all the posts here about instructions and the like, I am kinda glad I did not order me one when they were on sale, though. :o

CorsairJock
03-06-2006, 12:54 AM
Flew mine for the 1st time today. I stayed with 8 x 3.8 prop, and it took off (vertical, from ground) with no problem, leveled off and had some fun. Flies like most other 3Ds: fast rolls, tight loops, turns on a dime, and has unlimited vertical. All this with a $20 brushless motor.

Now for the landing: very difficult to do vertical landing (well, for me at least). In fact, I was not able to accomplish it. I could come in low 'n slow, pull up and apply power to hover, but it was difficult (not possible) for me to maintain straight up attitude while descending. Many times, it ended up tipping over and landing motor 1st (good thing it's a $20 motor), but with no damage. I attempted 4 landings with same results.

It's still cold here in Michigan, so I'll try again another day, but this one has me thinking about installing a better landing gear so I can plan on normal landings.
OR, maybe think about installing a gyro (for landings only).

stuk_at_work
03-06-2006, 09:39 PM
Finally flew mine today! Ditto to what CorsairJock said. A few things to add. When taking off, you cannot be tentative. Full throttle and get ready to push the stick forward!

I found mine to be verrrry sensitive to the controls. I will double check my throws and expo settings tonight. I never took the radio off of low rates! Except for takeoff, most flying was done at 1/3 throttle or less. Loops were effortless at about 1/2 throttle. At full throttle, this plane is a bullet! Vertical is unlimited. Remember too, that I'm flying the "blue foam" version, which is 2-3 ounces heavier that what most are reporting.

Orientation is tough. After about 10 minutes of flying, although there was still plenty of power left in the 1320 pack I was using, I had to bring her in, I was starting to lose "which way was up". The wind (5-10 with higher gusts) didn't help, although I was surprised at how well the plane did do in the wind! Next flight, I have a red & green blinking L.E.D. set ... I think I may put them on the wings to see if this helps with visibility.

flypaper 2
03-06-2006, 10:01 PM
Had the same problem with orientation. Painting the canopy black helped a lot against the aluminum coloured fuse. The only way I could land mine on its tail was, on dead calm days,come up from downwind with the bottom rudder about 6 in. off the ground. Bring the nose up quickly to a couple if ft. and half throttle and it will sit on its tail. When you try to come in from higher up, it's in its own turbulence and bobs around to much. When it comes in low with abrupt nose up, it hasn't had a chance to make any turbulence so it's much smoother. Give er, a try.:D

stuk_at_work
03-08-2006, 07:16 PM
Flew the blue foam Pogo again today. Winds were still up there, and after (2) aborted vertical takeoffs, I opted for a hand launch. This plane is actually pretty stable when horizontal!

Although the flashing L.E.D.s looked real cool when I had the plane sitting on my desk in the office, they could not be seen in the bright sunlight at the field. I'll keep them on though, and try again on an overcast day when the contrast isn't as good.

I found the problem with my control "sensitivity". When I went to adjust my low rates before my flight today, I found that both my high and low rates were set at 100%, no expo! So much for my initial preflight check. Well, at least my elevons weren't reversed!