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Member postings for Gordon Whitehead 1

Here is a list of all the postings Gordon Whitehead 1 has made in our forums. Click on a thread name to jump to the thread.

Thread: Laser Engines - Technical questions
25/05/2018 15:47:40

This Spit, due in August, might fill the bill for your 180 Timothy:

Thread: Glasair III, race number #42
22/05/2018 21:24:01

Hi Timo

I'm so pleased that I've found your thread, which I didn't see last year. Your construction shots are most instructive and inspirational, whilst the flying shots present the model superbly and the video definitely puts the icing on the cake. I can't believe that there are so few comments from other modellers.

I note that you built the ailerons and flaps integral with the wing structure before separating them for hinging, the slotted flap hinging being most impressive.

Your illustrated build has provided me with much food for thought regarding my own next scratch-built project which like yours will be a model of a side-by-side twin seater, will be about the same size with a huge cockpit canopy, and will benefit from being built as lightly as possible.

A very big thanks for sharing your skills with us all.

Kind regards


Thread: Powered by Laser, a gallery thread
22/05/2018 20:28:29

Update on my 155-powered 11lb 65in Krier Great Lakes. Had about 10 flights to date. Started with 3 flights on a 16x8 APC, then one flight each on two 17x7 Turnigy wood props, the scimitar-shaped one giving the better performance with a quite high vertical. Fuel was standard Propower 10. Then I fitted a 17x8 APC and diluted the fuel half-and-half with methanol to end up with a 9% oil and 5% nitro mix, as suggested by Jon in the Laser Tech Questions thread.

What happened next .......

Unlimited vertical, which was as surprising as it was pleasing.

Then while trimming out the rudder-aileron interaction in knife-edge I selected the snap roll flight mode to see if the model still tracked true. Full top rudder had the model arcing up and over in a knife-edge loop, which was another surprising result. Less oil residue too, which was a major aim of the fuel switch. As it recovered to level knife-edge with very little loss in height I really did think that I couldn't believe what I'd just seen.

krier gt lakes 002.jpg

Right now I should probably fit a dummy radial to act as a baffle and force cooling air though the fins, to compensate for the lower oil discharge carrying away less heat.


Thread: Propdrive 5060 380kv
04/05/2018 23:09:42

Hi Linda

There's a huge difference between the 380kv of the Propdrive motor and the 450kv of the Rimfire. On the same GP recommended 17x8 prop, to get the same shaft rpm (and hence the same pitch speed you'll need for the equivalent aerobatic performance) from the 560-380 as the Rimfire 120, you can't avoid increasing cell count beyond 6S. Otherwise, if staying with 6S, increasing prop pitch and diameter is the only option.

Whilst kv figures can be unreliable, they're the only spec we have to go on, and should be close enough for decent estimations to be made. Assuming that the 380 and 450 are approximately true, then the 380 has only 84% of the pitch speed on 6S and the same prop. So you'll need to increase the pitch from GP's recommended 8in to 9.5 theoretical, and 10in in practice. So your 18x10 looks like being a good choice at present. If you're worried about excessive current draw, simply trim the prop tips in 1/8in steps (ie reducing overall prop dia by 1/4in each snip) until you achieve the current you want, remembering to re-balance after each trim. Whilst current draw will drop, the rpm and hence pitch speed won't change all that much.

I know it's a bit late, but the nearest equivalent motor to the Rimfire I found in the HK range which should handle the power you want is the Turnigy Aerodrive SK3-5055-430kv and even that is somewhat low on kv, but still a lot closer than the Propdrive's 380.

Hope this helps, and good luck with your maiden.


Thread: Laser Engines - Technical questions
23/04/2018 22:18:20

Yup! Laser LP25 rolls off the tongue easily. As Lasers are uniquely British, there's nowt wrong with using "P for petrol" in the name.

Thanks for the video Jon. The 155 sounds very healthy and I've ring-fenced the dosh ready for my first Laser 25cc petrol when you achieve production.

Glad to note that glow production is restarting BTW.

23/04/2018 16:53:03

We had a flier through the letterbox today from our local lawnmower agent to say they've started stocking both alkylate juices yes

Have you any video of the 155GA to show us Jon?

23/04/2018 08:57:13

It sounds as if a Laser 155 gas (155FG?) would be a winner Jon. Despite the fall-off in ARTF availability, there are still a lot of 20-30cc kits around that it would suit. I'm obviously biased, but having just sold all my bigger engines and the Jungie to downsize a bit to easier managed models, that capacity makes more sense to me than the 180 gas. And if club members would go for purring FS instead of howling DLE (I can dream), that would be a universal benefit.

Tygon is a bit stiff for use as a clunk line in small tanks. I seem to think that you don't like felt filter clunks, but one of those would stop air entering the system.


23/04/2018 07:38:54
Posted by Jon - Laser Engines on 19/04/2018 20:48:16:

I have been able to fit my 155 petrol prototype into my pulse 125 and intend to get it in the air soon. Testing it on the ground it was peaking at 8800 on a 16x8 using aspen fuel. I was surprised by that but I will take it

That sounds like a pretty good figure Jon. Are the idle and throttling as impressive? Have you maidened the Pulse yet? Inquiring minds need to know :}


Thread: Powered by Laser, a gallery thread
23/04/2018 07:29:17
Posted by Chris Walby on 14/04/2018 21:26:36:

Seagull Dual Ace with twin Laser 70's,

Major result for me, comes in just under weight and no added lead ballast (RX batteries are behind the canopy).

Taxi tests complete, minor work on throttle linkage and then it will be maiden time!


Heck! I've just googled the kit and if yours has come in at under the stated 11lb auw you'll surely have a rocket ship there, Chris, it's so sleek. The spec quotes a pair of .46's!


22/04/2018 22:51:39

I'll definitely attend the Ashbourne event Geoff. I read your u/c thread, and immediately surfed Ebay for springs suitable for u/c's; there seemed to be an abundance, so thanks for that tip!


22/04/2018 16:25:19

Thanks for the kind comments guys. There's no doubt that a dummy radial as on the Stearman and Jungmeister with a slot to direct air through the 155's cylinder fins would greatly improve the looks, as well as providing the ideal cooling for the engine. In practice I've not had a problem with overheating in radial cowl installations like this so didn't worry much about it. There's a fair sized annular gap between the rear edge of the cowl and the fuz proper, which appears to be extracting hot air satisfactorily for now. One thing I did was incorporate a dummy air scoop to direct cool air to the carb

carb scoop.jpg

Made from litho plate the lower wall extends inside the rear cowling and up between the carb and silencer to help to isolate the carb intake from the hot air whizzing round the silencer. The scoop did end up smaller than I expected, especially when the carb needle ended up passing through the middle of it, but it might make a difference.

An excellent idea I pinched from the Great Planes bipe kits was the carry handle which fastens onto the centre-section struts and incorporates storage for the interplane struts and the inter-aileron link wires.

krier gt lakes 007.jpg

That's a lovely photo of your Jungmeister, Steve. Propwise I have a couple of 17x7's and a 17x8 waiting for trial next time out. The 17x7's are Turnigy wood. Dirt cheap, quite a thin aerofoil section, well finished and balanced, I don't know whether to expect great things at the price but worth a punt. One has a conventional blade shape, the other is scimitar-shaped so that's even more of an experiment. The 17x8 is an APC.

Regrettably it rained this morning Tom so spoilt the festival somewhat until the sun came out around midday. We went yesterday afternoon in blazing sunshine and had a proper ice cream from the card shop on the corner of Welles Street - I've never liked that Mr Whippy gloop sold at fairs etc.



21/04/2018 22:33:35

At last! Our field had become dry enough to drive on, and the grass runway firm enough to fly from, even though the grass was still 3in long. It's been quite a wait from last November when I finished the 65in span 11lb Krier Great Lakes until today when I finally maidened her. I'd checked the Laser 155 out on the bench on its APC 16x8 but it had never run in the model until today. So final throttle setting up was done this morning at the field.

No problem!

Once I'd adjusted the throttle servo travel to provide a nice idle, and set up a 2-position switch to fully close the throttle and stop the engine if required, there was nothing else to do but fly her, egged on with enthusiastic help, support and encouragement from clubmate Martyn K of these forums, the only other flier there despite the ideal flying conditions.

So off she went, the 155 running well and sounding utterly gorgeous. I'd set the control surface throws on the scaled-up bipe to the same angular movements as my original Enya .46FS - powered 47in span version which I'd designed built and published in RC Modeler and RCMW in 1989; it's a good job that I had noted these movements on the plan for future builders.

Well the first flight took me back 30 years. A bit of up trim and, a bit of right on the first circuit, and the plane felt so comfortable and dialled in that with the engine running so well it would have been remiss of me not to try a few aeros. Three 10-minute flights packed with loops, slow rolls, vertical rolls, stall turns, 8-point hesitation rolls, vertical 8, octagonal loop, flick rolls, spins, avalanches and on it went. The new 155 inspired complete confidence as it purred through that lot with all the appropriate throttle variations between idle and full chat without a hiccup. Looking back and thinking about it, I hadn't even flown any model since last November, so the 'Lakes played its part very well, too; it's a natural for performing airshow style aerobatics.


Thanks Jon. Your 155 is an absolutely superb engine.


krier gt lakes 001a.jpg

Thread: Cap Cam
17/04/2018 15:27:07

Hi Steve, thanks for your comments. The pic on the wrist-mounted one looks as if it has been cut out of a picture postcard. It might work acceptably if you were to use a lamp as the alignment check object but otherwise not very versatile as you need to do the check at the field really. You've got your camera well-positioned in all the shots so you're well set up. Those youtube vids you see shot with a hat cam where the plane keeps disappearing above or below the screen are not worth watching to the end and I wonder why the guys even bother to post them.

Kind regards


Thread: Laser Engines - Technical questions
16/04/2018 22:55:38

Regarding matching rpm on twins, years ago when I flew a couple of small OS .15-size twins a lot, I'd tune both engines for max rpm, chuck the plane up, and the airflow through the props then made them run at just about the same revs at full chat. Revs would be in the 12k range. Dunno if 4-strokes would be so accommodating though.


Thread: Cap Cam
16/04/2018 22:40:25

Thanks Steve. I found your cctv tester on Amazon, but just a bit pricey for this occasional job. There is this item which might be worth blowing the 26 quid on if it worked.

It is supposed to be a CCTV tester. Acknowledging that you only get what you pay for, if it actually worked as a CCTV tester, Is it likely it would decode the analog signal and produce the pic of where one is looking like yours does?

Kind regards


16/04/2018 12:58:54

An excellent idea Steve. I've never heard of a spot monitor before so googled it. Is yours some sort of wrist-mounted monitor screen? Which one is yours, how's it linked to the camera, and where can we get one like it? Is it possible to link the camera output to a mobile phone and save having to buy a spot monitor?

I'm looking forward to your outdoor footage.

Kind regards


Thread: Your Transmitter History
07/04/2018 13:39:12

I forgot to include my World Engines Digit Midget micro propo bought specifically for Club 20 racing. At the simultaneous hand launch of my first ever race, the launcher next to me managed to throw his plane at mine, removing half of the fuz top deck and the fin. Luckily the (expensive) radio gear survived untouched.


07/04/2018 11:07:02

Aeromodeller single channel valve Tx. Ground based, tank whip 8ft aerial, microswitch button switch on flylead

Terrytone (I think that was the kit, I built it in a plastic sandwich box as I couldn't source an Oxo tin ) transistor Tx with push button.

Radio Modeller single channel transistor Tx - home made case bent up from scrapyard bought aluminium sheet.

Open Tx?? Pah!!!!!! Who needs that when you can loop and roll your Mini Robot with just one-button controlling an Elmic Conquest escapement? wink

RCME Unijunction Pulse Proportional Tx for Galloping Ghost.

Futaba Digimax 4

RCME Propo Tx

Futaba 5-chan M-series

Fleet 6-chan

JR Unlimited 8 Multifunction Tx for 7 years or so

JR PCM-10 for 10 years or so

JR PCM-10X for another 10 years

Spektrum DX-8 for about a year

Spektrum DX-18 first generation since it came out





Edited By Gordon Whitehead 1 on 07/04/2018 11:07:53

Edited By Gordon Whitehead 1 on 07/04/2018 11:08:21

Thread: Martyn's Dalotel
04/04/2018 09:36:29

It'll be the ejection seat button. Hence the encircling ring of exclamation marks.


Thread: WMWF Ullswater March 2018
31/03/2018 18:53:32

I love the photos guys, and although I couldn't ident any model as chainsaw powered, I thought you all might like to read this reader's letter from the Cumberland and Westmorland Herald, which I've copied from a local Cumbrian model club's emergency newsletter issued for info to that club's members (of which I'm one even though I live many miles away).

Cumberland & Westmorland Herald

I'm not passing judgement or making suggestions, but I sure hope that no harm comes to your future flying activites at this beautiful venue.


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