Martin Harris - Moderator

Surprising how it mounts up. Hope all goes well when she takes to the air. When do you plan to maiden her?

If mine survives the CofG experiment it will have flown in my care for over 21 years with no real handling problems in the air. There’s a lot of wing so hopefully it will carry the extra weight of your engine. There’s an outside chance of a wing drop with your higher wing loading so you might consider setting a little up aileron at neutral to provide some washout effect for first flights. I did once manage to induce a spin off a turn at low level over trees in turbulence - a handily placed large blackthorn bush added some more weathering but saved the model from serious damage. P.S. Are you sure about the weight? With your forward engine location and CofG in the plan position, I’m wondering where another couple of pounds has crept in?

My old girl pictured in 2006 with a temporary engine - an old OPS60 that I bought for a never completed Mick Reeves 1/6 scale (80") Hurricane before I stopped model flying in favour of full size gliding. Imagine expecting a 60 2 stroke to power an 80" warbird these days - but in 1977 it was a monster engine! It was wearing both the Mick Reeves concealed "silencer" and an add on Pitts style in order to get below 82dB. It just seemed the "right thing" to use the never flown OPS in a Hurricane while I was waiting for some bearings to arrive for the now venerable SC90FS that powered it before and after to this day. The weathering was originally faked but is now even more authentic! I've taken another 4 oz out of the Hurricane’s nose, reduced the elevator movement a little and managed to squeeze in some 1/2” larger wheels while I was at it. Hopefully taxying will be a bit better - and the stability won’t be too much affected…at least with a full tank! I did try 3" wheels but they were too close to the leading edge for the depth of the wheels. Did you use very thin ones Payneib?

In this case, we’re looking at a solution for the ground handling difficulties which seem to plague some models - and the Hurricane in particular. There’s no magic about a CofG position marked on a plan - we rarely know whether the designer has marked it there as a result of practical testing, calculation or even guesswork! Then we also don’t know whether it’s been chosen by personal preference or with safety in mind. In fact, if the plan shows a CofG range rather than a single point, I’d have more confidence in the designer’s aerodynamics competence. In this case, I’m carefully conducting a test of combining more rearward positions with reducing elevator movement based on Jon Harper’s experience with similar warbird models. This may not correspond with full size movements but perhaps scale effects e.g. Reynolds Number, start to become significant on control effectiveness with models of 1/6 or smaller scale? I have also provided a “taxi” switch (non latching) which gives a higher rate for taxying and initial stages of the take-off run. This carries over from pre-experiment times.

Flight tested today. 4 oz. of lead removed from over the engine. CofG 1/2” back from plan position - elevator reduced to plan specified (3/8” up and down) amount. No apparent reduction in stability (it’s some time since I last flew the model) but still eager to nose over. Grass freshly cut but quite damp and draggy for the little 2” wheels. Inverted flight required definite push so I’ll be removing more lead.

A club near ours lost its longstanding flying field on what was apparently the whim of the farmer's wife. It seems that she'd contracted Lyme's disease and as a consequence, suffered long term mood swings.

Returning to the subject... As mentioned earlier, I bought mine at a swapmeet in early 2003 (looking quite elderly even then) and I've just remembered that on the included plan, it shows torque rod operated strip ailerons. I see yours has, like mine, scale position inset ailerons and split flaps. Were these detailed as an option in the build notes or were later plans/kits modified? Anyway, I've removed some lead to bring the CofG back about half an inch from the plan position and reduced the elevator movement. The grass has been cut today so, fingers crossed, I'll start putting Jon's advice to the test tomorrow... P.S. I see the Pegasus website illustrations show strip ailerons...

How strange for Paul - using a fuel with no castor! I can't say that I've noticed any sign of overheating but my version (91) sits in the front of a very vintage (re-engined several times) circa 1982 Stearman, nicely exposed to the breeze between the dummy cylinders. I hesitate to say this but I promised the old boy who "gave" me (I managed to persuade him to take some money) the model when he was downsizing, that I would use the several gallons of Duraglo 10% (6% castor/9% synthetic) that came with it which was "the one and only" fuel recommended by the distributor before Westons (oddly, one that they distributed) and have largely honoured the pledge. The old boy used to bore (and often exasperate) club members by constantly harping on about this recommendation. Strangely, once Westons took over the engines, their fuel became the only suitable one! Could he have had a point? The idle seems quite normal and I don't recall 58s having problems - perhaps they redesigned the carburettors at some time? There shouldn't be too much problem arranging good cooling in the Pup, Lindsay, as long as you don't fall into the trap of thinking the wide open spaces of a rotary's cowl will provide it. Rather counterintuitively, what actually happens is that hot air pools in the cowling around the engine and any airflow takes an easier route. A dummy engine or suitable blanking plate to encourage air to flow over the cylinder and head, coupled with a suitable exit should do the job. It looks like BEB was mounting it inverted so a good exit should be easy to arrange.

Well, as Andy Symons liked your email Leccy, perhaps my advice wasn’t too good and suggesting pre-arming the kart racers with knowledge of the ANO might well be a step too far. What I would still suggest is talking with the kart club to impress on them how seriously the club takes the matter and confirm that members have been instructed not to fly while the race meeting is taking place. Perhaps give them contact details for the committee in case anyone should turn up to fly - member or other. Surely working with them is better than reacting to a disastrous situation.

Whether or not deliberate overflight is barred, the consequences of an inadvertent transgression seem so serious in this case - the club has been told that any overflight will result in the loss of the field - that surely, any logical conclusion is that flying cannot take place on those days. The danger here is that the sensible members will be in their workshops on these days and not at the field to regulate any reckless activity by rogue members. I would suggest contacting the karting club and making it clear that should anyone attempt to fly during their meetings, it is directly contrary to club rules, the members involved will be dismissed from the club and you will support action against them for any contravention of the ANO. The karting club could easily take photos to identify any transgressors.

I'm not aware that the 58 runs any hotter than a conventional poppet valve engine. Has this been your experience Manish? The SPs certainly required careful thought as the finning was aligned at 90 degrees to the airflow.

Sadly missed - I never met him but had quite a few conversations by PM as well as interacting with him on various forum threads and felt like I knew him. Lindsay, I think you’re confusing the 58CD with the “walnut whip” RCV 60 - 120 SP engines, which drove their propellers from the rotating cylinder at half engine speed. The 58 and 91 versions had a conventional layout (although with a horizontally split crankcase) driving the propeller from the crankshaft but the cylinder rotated internally to provide the sleeve valves.

Not on a Laser - the valve gears and cam followers prevent access to the crankshaft and piston so it’s much easier to remove the head to measure bore/stroke if it can’t be identified by other means.

Are you getting fuel leakage at rest/while filling or are you diagnosing this from air bubbles in the fuel feed? If the latter, then it may be fuel frothing due to vibration. ARTFs often have quite rigid mountings to their tanks. Packing the space around the tank with scraps of foam rubber can reduce this effect dramatically. I’ve also seen advice to add a few drops of “ArmorAll” - a car vinyl cleaning product but haven’t ever tried it - and a quick squint at the Halfords site suggests they’ve diversified the range from the original product, so take this advice carefully.

I can’t say it’s ever been a problem on any of mine. I wonder if you’ve got a hidden split or other fault? One thing to watch out for is the screw loosening, particularly after a period of storage so it’s as well to make it a regular maintenance check.