Here is a list of all the postings Martin McIntosh has made in our forums. Click on a thread name to jump to the thread.
|Thread: Servo fitting|
|Dare I say buy a bigger car if you wish to continue modelling! My 120" Lanc and 100" one piece glider wing fit easily into a common or garden Vectra! Shame though, no room left for the wife and kids. MM.|
|Thread: Are there many Depron Builders?|
|Check out R/C Model Flyer, about a year ago, for my Depron Cozy. ( sorry David). MM.|
|Thread: The neighbours are complaining|
|Interesting about the pushers. I have a couple of Rutan foamies, which of course are pushers, and the noise is considerably greater than wnen the same motors are used in tractor type models. Regarding pipes, if you Techno weld an ali aerosol can of suitable size to the rear of a standard, old fashioned none disc tuned pipe, then fit say a 6mm ali tube or just `pepperpot` the end with 1.5mm holes, you will end up with an amazingly quiet set up. Been using this for years. MM.|
|Personal preference probably. I like the motor to respond to small movements at the low end to allow small blips to control the rate of descent when landing. MM.|
|Thread: Four Stroke query|
|YS engines specifically tell you not to use after run oil because if it is petroleum based it will destroy the silicone seals within the motor, also not to run out the remaining fuel, simply store the model with the cylinder head facing downwards (which I always do, of course???), But what I always do is to ensure that the fuel line to the carb is completely drained so that it does not become clogged with thick oil. I have not as yet had any such corrosion problems with any of my four strokes as far as I know, but plenty with OS two strokes. May be that the hotter running four strokers burn off more of the corrosive substances Don`t know. MM.|
|Bravedan, the trottle arm is also rotary. Assuming equal lengths, if the servo moves through 30 deg. then so must the throttle. Agreed that with a lot of movement each end of the travel will become exponential, but scarcely measurable for our purposes.MM.|
|Thread: CA's - shelf life...|
|My expreience is that, unopened it will last a long time but I use it for almost everything so it does not hang around for long. The exception is the foam friendly type which solidifies in the bottle very soon after being opened. After use, place the nozzles in a jar with about a 1/4" of acetone and fitted with a metal cap. By the morning they will be as good as new (not my idea - read it in RCME). Martin Mc.|
|Thread: BDU servos|
|Warning. I was daft enough to buy 2x BDU 5010`s and 4x BDU 7010`s. They were advertised as digi but are not. The 5010 is basically a reasonable unit with good centring and were fitted to my new Nihuis 63" Spit. Just before the 5th flight the rudder servo failed. This was due to the servo wires being squashed together by the tight fitting case bottom. Solution was - no not chuck it - reposition the wiring, secure with Evil stick and relieve the case bottom with a Dremel burr. The 7010`s however are much worse. An aileron servo failed before the 4th flight because the internal wiring had fractured due to the fact that the servo amplifier just floats around in the case with no support whatsoever. Also the 7010 servo arms supplied do not fit. DON`T BUY ANY!|
|OK point taken, must just be stuck in the mud after 45ish years of linear throttles. MM.|
|Thread: Tony Nijhuis 63" Spit|
|Reflown the Spit today with the tail set to zero with respect to the wing section centre line using a laser. Very slight up trim as expected. Now flies like a dream. MM.|
|The current BMFA guide does not specify a minimum spinner radius- don`t ask me why. Martin Mc., BMFA examiner.|
|Thread: The neighbours are complaining|
|Don`t try that with a four stroke- my Spiteful caught fire because a 4T exaust is much hotter than a 2T! Prop blade tips make a huge difference. If you have rounded tips such as the shape of a typical wingtip (not talking about APC shape-more the Super nylon), then squaring the tips as if you had done it with sandpaper on the edge of a spinning prop can save you 3dBa which is half the previous noise level. Try it. Martin Mc.|
|Thread: futaba interference|
|Glitches usually go the same way for a given set up, ie., right/down. I recently had a similar problem when, nomatter what sort of Rx I fitted, the model (ic) would glitch badly, despite the receivers being flown OK in other models. The servos were replaced one at a time. Mistake. Two coreless servos were each causing the problem. When replaced as a pair the glitching disappeared. If your model is electric, could it be that you are trying to operate too many, or too high a current drain servos from your ESC? Try fitting a UBEC (try ebay) which will allow you to operate four or more servos from a 3-cell Lipo pack. These are typically 3A rated. It worked for me. Martin Mc.|
|You are all talking rubbish! If you want (why?) expo on throttle just experiment with moving the servo or throttle arm off centre. Martin Mc.|
|Thread: Tony Nijhuis 63" Spit|
|Thanks Tony, will remove and reset the tail again. CofG does not seem to be any problem. I have run it into the long grass and it does not tip over. Would at a guess be OK with it even more rearward. The RAF 30 tail section (modified) has proven to be OK on a Spiteful (not a recommended subject to model). Martin Mc.|
|Graham, it comes in 125ml tins which will do several Spits and a Lancaster to boot! Even Humbrol enamel which is an expensive alternative, would only require 1-2 tinlets of each colour, because it covers better. I use this for roundels etc., applying to plain paper circles which are then glued together with PVA and centred with a pin. Just apply to the model and smooth down with a cool iron. PVA acts as a contact adhesive if applied to each surface, but it takes a little practice. Martin|
|Graham, I used Spectra (previously Spectrum I believe) on top of primol coated silver Solarfilm (which, incidentally, is much easier to apply than the solid colours) , the first coat of each colour being applied slightly thinned with Spectrum thinner, then a full strength coat of each, applying the lighter colours first then, when complete, making the contours with 4mm wide strips of masking tape. I applied the second coat as soon as the first was dry (about one hour) then removed the masking when dried to a matt finish so that the masking tape adhesive did not get time to set hard. Any rivet or panel lines you wish to add should be done prior to painting. By that I mean raised (rivets) or indented (panel lines) . When completely dry you may add pencil/ink lines then roundels/ transfers. The whole model should then be Tuffcoated using a 3/4-1" very soft brush. I normally mix gloss and matt 50/50 but it seems that the latest batch of Tuffcoat matt is not so matt as it used to be so you may wish to use neat matt. Must take this up with Ripmax. Do not rely on the Spectra alone to be fuel proof especially if you use any nitro at all in your fuel. Coat the canopy with gloss Tuffcoat. Martin.|
|Gary, what an interesting and informative club website you have - more should follow suit. your Spit build so far looks great so the best of luck. MM.|
Hi Graham, don`t worry about the weight, mine is now 7lbs 10oz inc. the 9oz noseweight and the two heavy metal geared digi servos behind the cg. If you are using a single retract servo near the wing L.E. as suggested you should not require so much lead, but I think that some will be needed. The model is not heavily wing loaded. My retract equipped smaller version with a similar set up weighs 3lbs 9oz as against the original quoted 2lbs 8oz and is very reluctant to spin let alone stall. No problems there with the 63 either. The cg is exactly the same percentage of the wing chord in each case. Tried the laser level today - confirms that the tail is still one deg. too negative despite a previous change of 1.25 deg. The plan appears to be correct; apologies to Tony. Must be something to do with the centre line distorting when pulling the rear fus together around the curves. Strange that it did not happen with the smaller one though. Being basically an aerobatic flier, I am always normally careful to get the decalage correct.
Do not use excessive control surface throws on this model as they are all fairly sensitive. If you can, try around 40-50% expo on aileron and elevator.
Don`t know what motor you intend to use but as a guide the YS is a bit of an overkill. MM.
|Help needed by Tony Nijhuis maybe? Finished the 63" Spit. Solarfilm/Spectra finish, YS63S, built-up tail and fin as is my usual with this type of design, retracts using two metal gear digi servos with servo slows to give scale speeds, loads of detail, BUT! It flies like a pig! I need lots of down trim, power on or off. The C of G is on the rearmost limit with 9oz lead up front - blame the retract servos rear of the cg for that (see later). I checked the wing and tail incidences and decided that my tail could be out a little, so removed and reset it to the plan. Result? less down trim but still does not want to fly level. Tried downthrust but no better. I have been flying the smaller version since Christmas and it is faultless, also having two retract servos behind the cg, OS26S and no noseweight. One of my favourite models. Is there a problem with the plan? Cannot detect any differences between the two re incidence. My tail now actually LOOKS at a positive incidence to the fus centre line. Got access to a laser incidence checker tomorrow so I shall see if that reveals the culprit. Anyone else flown one yet? PS. Gary, solarfilm, when painted, hardly wrinkles at all in the sun. Martin.|
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