David Davis 2

Masher, MFA appears to have produced three Yamamotos: the Mark 1 and Mark 2 which were built up kits with a foam veneer wing, these were all the rage in the Eighties, and the New Yamamoto which had a fibre glass fuselage and which looked something like a Cessna to my eyes. I think that the difference between the Mark 1 and Mark 2 was largely structural but the New Yamamoto was a different model altogether and probably had a larger wingspan to make up for the extra weight of the fuselage. The Outerzone plan: https://outerzone.co.uk/plan_details.asp?ID=8956 indicates that the Mark 2 had a 56" wingspan. The New Yamamoto was too fast for me as a beginner. I believe that the Marks 1 and 2 were better trainers but I've never flown either so can't speak from personal experience. I got rid of my New Yamamoto and built a Telemaster 66 powered by a Merco 35 which flew much more slowly. I took my A Certificate on that model and eventually wore out the engine! I wonder why MFA chose to use the same name, or almost the same name, for two very different models. It's even more confusing than Keil Kraft's Junior 60 and Super 60! And why call it the Yamamoto? Wasn't he a Japanese admiral?

I used to have one powered by a Merco 61 when I was leaning to fly. It flew far too quickly for a trainer as far as I was concerned so I got rid of it.

Richard, when you get round to making the Tempests could I order decal set PRD which I believe was the Tempest flown by a pilot called Frank Wheeler. This is not the same man who lived at the bottom of my street, his name was Leslie Wheeler but I have no way of finding out which squadron he flew with or how his aircraft were marked so PRD will do. Put me down for a dolly kit too.

This is not really a technical question either but there is a bloke over on the Laser Engines Facebook page who is under the impression that the V twins are no longer available owing to the popularity of the flat twin. His post is quoted below. " ... I was told by Laser that there’s no interest in making them as the flat twins are in demand. Heck I have had no luck in bya few pieces I want for a 200V that came into my possession." Is this true?

They drive on the wrong side of the road in Germany too but they mostly fly Mode 2.

I live in France mate, the weather's better and the houses and wine are cheaper! Most Frenchmen, 85% I've heard, are Mode 1.

I am the only Mode 2 pilot in my club. When training Mode 1 beginners I bind my transmitter to my trainees' models and then bind both transmitters to one another then test that they operate as they should before flight. Make sure that all the control surfaces don't move when you hand over control.

I've put my name down for a Tempest because Mr Wheeler, a man who used to live at the end of our street, used to fly one. Graham, I'm in the same position as you and Nigel! I've a Warbirds Replica Hurricane still in its box, ditto a Stampe Monitor, a Supra Fly, and a Super Kaos Junior. Then there's that Flying Flea that my late best friend started twenty-one years ago, the Bristol Blenheim that I took over eight years ago, a part-built BE2e and a DSM Aerostar which I am renovating. I also plan to build a 1/4 scale Fokker Triplane and I need to repair the club's Seagull Boomerang and my Baron! On top of all that I am finishing off a Galaxy Models Mystic. At seventy-five I have no serious health issues... perhaps if I didn't like a drink so much...😄

I have one powered by a Laser 80. You need a big car to transport this model because the wing is one piece.

I agree.

Quite so Toto. I always buy APC props having been convinced of their superiority by the cognoscenti but I also have several Master Airscrew paddles which I use on larger models. I have never done a side by side comparison of the two makes but if a Master Airscrew will allow one of my models to take off, to fly about and to perform a few aerobatics, I'm happy. At your stage of the learning curve you are are not looking for optimum performance so continue using your Master Airscrews as you suggest.

Ok Toto, about 100 watts per pound assuming the model weighs 5.5lbs. It's a little more than I would advise but it will certainly get it up there in short order. Certainly better than staggering about on 32 watts per lb which is what the previous set up seems to have produced. I'm surprised it flew at al with so little power! You will be on the buddy box until you gain sufficient experience and confidence, just remember the throttle moves both ways so you can always throttle back if the model is flying too quickly for you. Best of luck for the weekend and let us know how you get on.

Anyone know of a cowl which would fit a DSM Aerostar 62?

Props are available in many sizes. I believe that competition aerobatic pilots back in the Eighties and Nineties flew with propellers with more pitch than the diameter but that was in the days of i/c engines. The biggest pitch available on a 12" propeller which I have been able to find after a brief search has a 12" pitch. https://stevewebb.co.uk/index.php?pid=ELP12012E&area=PROPS. Please be aware that by using a propeller with such a coarse pitch the acceleration of your model on take off will be adversely affected. I hope you have a long runway at your club! If you've got 1.5" clearance between the 12" propeller tip and the ground, you could fit a 13" diameter propeller and still have an inch clearance and you could always fit a bigger set of wheels as well. Just a thought.

Yes length always precedes pitch so a 12 x 10 prop is twelve inches long from tip to tip and moves the aircraft forward a theoretical ten inches with each revolution.

So, ignoring for the moment the differing points of view offered here, the facts are as follows. Your existing power train produced 192.5 watts at full power on a 4S LiPo. Given that your model weighs between 2.6 and 2.8kgs that is about 6lbs in Imperial measurements. Divide 192.5 by 6 and the result is 32.083, so your existing set-up is producing 32 watts per lbs. This is significantly less than my advised 80 watts per lb or Peter Jenkins 100 watts per lb, in fact I'm surprised it flew at all on so little power when 50 watts per lb is generally recommended for slow-flying vintage models! If my calculations are incorrect, doubtless I will be advised by those for whom mathematics is a more comfortable subject! Given that my Telemaster 40s which were larger trainers and the same weight as your Domino flew on 4S, there's no reason why your model should not fly on a 4S LiPo, you just need a larger prop to get the the power you require. You've ordered some 12 x 10s which will make a difference. I will be interested to see the results.

One of the few things I miss about England, that and real ale and meat pies in pubs!

Well I've left it square anyway. It was easier to cover!

Jazz 20 here: https://www.sarikhobbies.com/product/rc1771-jazz-twenty/. It has a 47" wingspan.

Mini Jazz by Malcolm Corbin. I have seen them fly well on an OS 10 and 15.

My next build will be David Hurrell's 1/4 scale Fokker Triplane. I have always admired this aircraft since I saw a red Walter Musciano control-liner, powered by an AM 35, fly round and round the school playground when I was about twelve years old. I will start it once I've finished a couple of other models and repaired the club's trainer.

I do my own maiden flights these days. Being the only Mode 2 flyer in my club I have to!

I was thinking of making the centre section ribs out of balsa and retaining the wing with a peg and bolt system. I'll also take Ace's advice about making the tip ribs from balsa.

Thank you for your advice gentlemen, capped wing ribs it is. A club colleague has given me a large sheet of 6mm depron which is more than enough to make up the wing ribs. I'll keep you posted.

I am planning to build a new wing for my Baron, a three-channel French trainer, in order to compete in la Coupe Des Barons next year. Though I have considerable stocks of balsa I noticed that there is some depron in our club's workshop which I am sure they would let me have for a small financial consideration. Rather than use the Baron's multi-spar wing construction I propose to use the classic three spar arrangement a la Super 60 with a D section leading edge and the wing ribs made from depron. As it will be my first time using depron I have the following questions. What thickness depron should I use for the ribs given that the model has a 62" span wing and 9.5" chord? (155 cms and 24 cms respectively.) Is it ok to cover the wing in Oracover or similar bearing in mind that the centre section, wing tips, leading and trailing edges will be balsa? If not should I cap the wing ribs in balsa? Which glue would you recommend? Picture of a Baron below for those unfamiliar with the design.