Martin Harris - Moderator

Handy if you’ve got a short sighted hamster. I often wondered about turning up with a couple of large lorries and putting the statement “everything for a Pound” on the window of a well known high street store to the test! I’ve also never quite worked out how to comply with road signs before bollards/islands directing you to pass on both sides…

Absolutely - that’s why I qualified the design aspect. Manufacturers don’t always get it right - I believe at least one had to replace a number of badly designed throttle barrels some years ago where the scroll was wrong and made them horrible to try to tune in mid range.

I use that as an initial indication that the idle mixture is too rich. Unless massively rich you’ll probably get away with it but a properly designed carb will not give any obvious drop and should work reliably over its whole range if leaned correctly.

Never a truer word. An ASP 180FS that I had in a Miles Atwood Special left barely a trace of oil on the airframe - just a faint (and very scale looking) sooty mark near the exhaust outlet. The same engine, running the same fuel, in a Seagull Yak 54 left the underside like the aftermath of the Torrey Canyon (younger members might prefer to relate to the Exxon Valdez).

+1 for something like an 18 or 21W lamp - indicator or brake light filament from a failed rear/brake light one.

JD8's method is easier for a lamp (bulbs are what you plant in the garden, as our storemen at work drummed into me!) with spade connectors - you could solder to them or use a dedicated 3 wire headlight connector from a scrapyard (or Halfords!) Remember that if you use a halogen headlight lamp, it needs to be kept scrupulously clean (use meths or alcohol) and not handled by the glass or it will fail quickly. It will also get VERY hot.

Very. Tin the wires and a spot on the casing, hold the wires onto the terminal and tinned spot and apply the soldering iron.

We're lucky to be at the top of a chalk hill so our field drains pretty quickly although the downside is we sometimes find the clouds forming at ground level. Last Thursday there were actual puddles on the field and the drag through our well trimmed grass was enough for my Vampire to reach terminal velocity before flying speed was reached but by Saturday it had dried enough to reach flying speed rather more easily...although the "slight" increase in wind speed meant that the ground roll was negligible!

The concern would be voltage depression with several servos under load or stalled rather than average current draw. However, if the maker's data is to be believed, the plugs and wiring are likely to be the limiting factors.

That rate would be for the purposes of standardised testing rather than a maximum discharge rate. The voltage will drop as the discharge rate increases and that is the critical factor. The site linked shows a maximum discharge capability of 7.5A - in other terms, 3C.

Years ago, the BMFA News published a simple to use nomograph which I’ve used successfully on a number of occasions. I don’t know if anyone has an electronic copy? The published CofG should really be a range of positions within which the handling will be acceptable. Where a point is marked on a plan will be the designer’s best guess at a good starting point (or in the case of some ARTFs an arbitrary guess/error!). The position of an acceptable CofG depends on many factors - primarily the mean chord (this takes into account wing taper and sweep), the effectiveness of the tail (area and moment arm) and personal taste so there’s no “one fits all” solution although it will often be within the 25-33% range on a trainer/sport/scale type platform.

I experienced that a little after 9am. I’ll flag it to the IT team. First time for weeks though.

Whatever solution you end up with, I would recommend flying a few sorties and then measuring the remaining capacity to give an accurate idea of your maximum safe duration.

I think it depends on the age of the unit. Is it the earlier version that takes higher than 6V?

I've heard reports of poor performance from capacitor based electronic ignition running on AA cells as they have insufficient capability of delivering energy fast enough. Therefore, whatever the power draw while running, I wouldn't use AA - especially as high capacity versions have relatively high internal resistance which limits power delivery. If your unit is happy at slightly higher voltage, have you considered LiFe? P.S. I've found the following RCXEL instructions. Typical consumption appears to be 650mA so I'd aim at a minimum of 1200mAh so that you'll use less than half the claimed capacity. NOTE THE ADVICE TO USE A REGULATOR OR (MY PREFERENCE) SILICON DIODE TO DROP THE VOLTAGE IF YOU USE LiFe: 2.) Selecting a Power Source I.) 4.8 and 6v volt NiCd/NiMh Packs: The Rcexl Ignition ver 2.0 is rated 4.8 to 6v a max of 7 volts. A 4 cell 4.8v pack and 5 cell 6v pack with a minimum of 800 mAh is fine and creates a hot spark. The Rcexl ignition ver 2.0 runs most efficiently on 4 cell packs and 5 cell 6v pack . Do not use an old Pack!! If it’s not good enough for your receiver, it’s not good enough for your ignition.. If Use 4.8v pack the engines not highest rotational speed, Also use 6V pack II) 6.4 Volt Li-Fe(A123) Packs 2cell Li-Fe(A123) The Volts Max of 7.2 volts. Nominal 6.6 Volts, use a voltage regulator. Or connects one IN4007 diode to fall voltage the use. If engines not highest rotational speed, Also may directly use III.) 7.4+ Volt Li-Poly Packs.: We have found that 2cell Li-Poly Packs at peak charge can be as high as 8 +v. If you are going to use a 2 cell Li-Poly Packs, you must use a voltage regulator. Or Serially connects two IN4007 diode to fall voltage the use The Rcexl ignition runs more efficiently on about 4.8-6Volts and will draw more current at around 8+v, as well as operate at a higher temperature. You also have a higher chance of RFI interference. In brief in can satisfy under the engine highest rotational speed touse the quite low voltage as far as possible Once again, do not use an old pack to power your ignition!

It certainly looks the part. The one thing that’s bugging me is the “optional weight reduction” in the piston - how on earth did they advise machining it?

A common mistake with the OS style 2 stroke silencers is to assume that the rear nut secures the rear section. It’s a lock nut which should only be tightened AFTER the through bolt has been properly tightened. I suspect that this is the cause of lost silencer parts…certainly a common reason for leakage.

They will be recycled or reused for less demanding applications.

I'm intending doing the cycling in flight but keeping a close eye on this pack! The supplier suggested that the imbalance was acceptable but I'm not at all convinced...

Don't worry Leccy - the drift referred to was regarding an idea to "manufacture" methanol in the home kitchen. I think we can accept that while we're right to be concerned over fuel supplies, there's every likelihood that it won't be a show stopper for the foreseeable future.

As you're in Germany and David hasn't been on here recently, have a look at https://www.aerocockpit.com/ - I've bought from them and they are excellent quality. They do a variety of individual items or sets - https://www.aerocockpit.com/supermarine-spitfire-mkix--3017-5- might be of particular interest? If you're really interested in scale details https://www.aerocockpit.com/supermarine-spitfire-mkix-side-panels-kit--3017-1-5-

Loads of suppliers on Ebay

Not all threads have requests to stop discussing a particular drift. I'm sure you missed that. Please let this drop and let's get back to discussing the future of model IC engines.

Off topic post deleted

With equal respect, the drift is in continuing to discuss the blind alley of producing methanol from instructions in a cooking show. They may well have mentioned ethanol, which suitably diluted can be tolerated by the human body - you'll know it better as alcohol or booze. Continued availability of model glow fuel or its constituents is a valid point - happily these products are readily available although some searching around for suppliers of small quantities might be needed as well as a license to obtain/stock nitromethane.