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Author Topic: W. Peter Holland's "Size 9" single float seaplane for RET electric R/C  (Read 559 times)
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Sundancer
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« on: August 06, 2016, 11:18:10 AM »

I've just finished my version of this quirky little model from the mid 1960's, as the first photo shows it has passed it's floatation test and has also been taxied around the swimming pool at low throttle, steering remarkably easily without any form of water rudder.  First flights will be over land and should happen soon.  AUW is 11.8 ounces/330 grams, finish is tissue over doculam with lots of nitrate dope to water proof and the float has an additional skin of doculam over the tissue for extra waterproofing and protection when flying over grass'

Power is a 90 watt 28 mm outrunner which fits neatly into the radial cowling which is cut from a small size Danone yoghurt drink bottle, APC-E 6" x 4" prop, 12 amp ESC, two 4 gram servos driving the ruddervators with Tx mixing from a DX6 and a 6 channel Orange Rx.  Battery is a Dualsky 550 2S.  The colour scheme is inspired by my countries of birth and residence - British union flag on the bottom of the float and French Tricolour on the top.hensive

With a 12 oz/sq foot wing loading I am slightly apprehensive about the first flight, which will be hand launch over grass, and cannot decide yet whether to launch it underarm holding the fuselage behind the wing or overarm gripping the back of the float, I'll just have to go with what feels right!
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W. Peter Holland's "Size 9" single float seaplane for RET electric R/C
W. Peter Holland's "Size 9" single float seaplane for RET electric R/C
W. Peter Holland's "Size 9" single float seaplane for RET electric R/C
W. Peter Holland's "Size 9" single float seaplane for RET electric R/C
W. Peter Holland's "Size 9" single float seaplane for RET electric R/C
W. Peter Holland's "Size 9" single float seaplane for RET electric R/C
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Konrad
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« Reply #1 on: August 06, 2016, 11:53:29 AM »

Now that is an odd looking biplane Roll Eyes
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Cut it twice and it's still too short!
Sundancer
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« Reply #2 on: August 06, 2016, 12:26:42 PM »

Actually Konrad I am fairly sure that the float will contribute some lift as well as drag, looking at the cross-section and the angle, so technically it COULD be viewed as a biplane - or rather more correctly, a sesquiplane with a VERY low aspect ratio lower wing!  Some of the other comments have been: "It is an aeroplane with it's own built-in display stand" and "A modeller's delight - a model you can play with in the bath!"

I started off the build thinking it was going to be ugly but it has "grown" on me to the extent that I now think it has a strange elegance with the graceful swept "V" tail, and especially with the addition of the radial cowl and transparent cabin.  The whole thing just has a "balanced" look about it, especially when you see it on the water.  Peter Holland designs were always a little off beat, but as an very competent artist he did have a good eye for lines.
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Hepcat
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« Reply #3 on: August 06, 2016, 08:39:00 PM »

Sundance,
You have made a nice job of that, one wonders how it could look so attractive but it does.  If the float is at a reasonable angle to the wing, and I think Peter Holland would have taken care of that I don't think it will have much effect.  The only thing that gives me the collywobbles is that it has one of those peculiar 'V' shaped rear ends which is neither fish nor fowl.  The 'V' has very narrow little strips hinged to its back end which are probably called 'ruddervaters', and I would have thought were ruddy useless if she tries to go belly up.  However as I know nothing of seaplanes, radio or electricity you would probably be wise to ignore my attempt at humour but I do, seriously, look forward to a flying report.
John

PS An underarm launch would finish with her near the ground and also possibly hit your hand on the tail.  I think that it is a two person job if you are going to get the model away safely and under control quickly enough. J
« Last Edit: August 06, 2016, 08:59:01 PM by Hepcat » Logged
Sundancer
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« Reply #4 on: August 07, 2016, 04:07:24 AM »

Hi John

Well, I did do the first "flight" this morning.  The overarm launch was fine and the power is about right, but it was horribly tail heavy, despite the CG being as per plan and also had a violent left turn.  By remaining calm and using my superior flying skill (if you believe that you believe in fairies!!) I got it back safely on the ground after two or three nerve wracking minutes.  A very careful check reveals no warps or mis-alignments, so in addition to pulling the CG forward I will add some right thrust.  Despite your misgivings the small ruddervators (I like "V" tails and have lots of them) provided plenty of control authority (fortunately), but it was very dutch-rolly; some of this will be down to being tail heavy, but I think it needs a bit more vertical tail area and will add an underfin.  So it has spent some time clear of the ground although I wouldn't dignify it with the term "flying"; however, if it was all easy it wouldn't be any fun and I am sure I can sort it.

Best wishes

George
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DavidJP
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« Reply #5 on: August 07, 2016, 05:46:55 AM »

Well done George - I remember Pete Holland as an architect but none of his buildings.  As a youngster I admired his designs and built the Miranda - it flew jolly well and would take off from wet grass at Epsom Downs using the downhill slope.  I look forward to more news.

I do vaguely recollect that when we tried an RoW from a very large puddle it was reluctant to unstick and the effort failed because of lack of "runway".  The boffins said it was the late plate type float although there was a bit of a step?  Maybe the scalloped undersides are required?   
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Konrad
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« Reply #6 on: August 07, 2016, 12:04:20 PM »

The "Y" tail is definitely in keeping with the esthetics of the design. Do think on making it oversize even though it will be adding tail weight. The oversize is to try to gain effectivity in the dirty air from the float pylon. I'd start the sub fin from the leading edge of the dorsal extensions all the way aft. Please be aware that too large a fin area (total) will result in spiral instability (loose heading in a climb).
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Sundancer
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« Reply #7 on: August 07, 2016, 12:59:21 PM »

Yes, I am going with extra fin area along with further forward CG and some right thrust.  I'd rather have spiral instability than the horrible dutch roll!
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Sundancer
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« Reply #8 on: September 22, 2016, 05:34:17 AM »

Well, the CG, side thrust and extra fin area worked a treat and the model is now a delight to fly as seen in the photos below.  It is still tricky to hand launch, but I am getting used to that.  The odd appearance in the air is something I now find quite attractive, in some attitudes it looks like something from "Star Trek"!
Attached files Thumbnail(s):
Re: W. Peter Holland's "Size 9" single float seaplane for RET electric R/C
Re: W. Peter Holland's "Size 9" single float seaplane for RET electric R/C
Re: W. Peter Holland's "Size 9" single float seaplane for RET electric R/C
Re: W. Peter Holland's "Size 9" single float seaplane for RET electric R/C
Re: W. Peter Holland's "Size 9" single float seaplane for RET electric R/C
Re: W. Peter Holland's "Size 9" single float seaplane for RET electric R/C
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DavidJP
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« Reply #9 on: September 22, 2016, 07:08:16 AM »

Yes.... Mr Holland would be pleased with that!!  Good effort.
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