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Nigel R

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Everything posted by Nigel R

  1. Super nylon are fairly decent props. I prefer them to apc. I wouldn't go out and get a new apc prop yet, use what you have.
  2. Hello all I've inadvertently ended up with some Robart units (the 1/8" OD tubing, air up/spring down) and some 4mm OD tubing control clobber. The 4mm stuff looks like the black horse clobber (but is some old Eurokit stuff). I guess I simply need some way to convert between the two tubing sizes - does such a widget exist? Clearly the easy option is to buy the Robart control gear bundle, but this seems an expensive answer...
  3. Covering. Have to force myself to start. Whatever method I'm using. I'm fine with woodwork and kit install.
  4. ED, Eneloops are gold standard, as RX batteries are a single point of failure, I spend out on the best here. Of course, options exist to have multiple packs with failover type setups, but the best option is almost always a simple setup with reliable parts. Plus, Eneloops seem to have good shelf life. Anywhere stocking ripmax clobber will carry eneloop packs: http://www.ripmax.com/Item.aspx?ItemID=O-4EN2000AASF&Category=090-010 I expect someone will be along to say how good LiFe or LiPo packs are soon... 😈
  5. Also worth adding; at idle - with the engine running at a vacuum in the intake, there is comparatively little air/fuel charge to be compressed, with a low amount of compression comes a low amount of heating of the intake charge at full throttle - the engine is running wide open, a much larger air/fuel charge enters the motor, thus more compression occurs, and with more compression comes a larger increase of charge temperature the hotter mixture contributes to the advance of ignition "Diesel engines or compression ignition" Technically, glow engines are compression ignition - aided and abetted by the catalyst in the glow plug of course.
  6. I'd only somewhat agree Martin - I've several engines that I've tweaked and tweaked to get "perfect" transition and they've wound up in a slightly different needle setting to the "perfect" idle. It's a balance, as ever. I'd add that carbs with an old or busted O ring are never going to be right, so there's that, too.
  7. Just checked the stats on this, its listed as 61" and 9lbs finished weight. I'd go for a 120 glow four stroke. Plenty on Ebay as a second hand.
  8. As noted above, glow motors often lose RPM at low speed without the driver. If the idle is reliable without it... well, who cares? Worry about nailing the full throttle tuning, and getting idle + transition reliability, everything else is not that important. Just thinking aloud about factors affecting the ignition timing on our glow motors, there are a lot - heat of engine, heat of plug element, element wear, element composition, fuel/air mixture, how well the carb atomises the fuel... adding or removing a glow driver to the mix changes that balance by adding heat to the glow element + advancing the ignition point. Worth noting that automotive diesel engines - which also rely on compression ignition - use direct injection at terrific pressure and can time the injection squirts to affect ignition timing. We have none of that control!
  9. What vapex cells are they? They do "standard" and low discharge types (marked as "instant" i think). Your results look about expected for standard type. Although the variance is quite large. Low discharge are better for our purposes, in my opinion. Those should show 80pc of the rate capacity when cycling at 2C.
  10. Used to? Still do on some of my needles...
  11. Model Technics Laser 5 - is 5% nitro 15% synthetic
  12. Another on fleabay, new SC silencer that will fit. https://www.ebay.co.uk/itm/203005035517
  13. Enya are good motors, but less common, and I think spares may be an issue. Os and saito are far more common. You pays your money etc.
  14. I concur about brand choice, for second hand. End of season, run the engine dry off possible. That's the only after run precautions I ever take. Jons advice is all spot on.
  15. Or use less throttle stick?
  16. I'm just saying what I see Simon; I agree entirely with what you say. Everyone wanted ARTF, so we had ARTF, now ARTF is too expensive for a lot of people and the volume goes down. ARTF were very cheap, artificially I suspect (because various global/political factors which have now changed), and now they are not cheap, and shifting in lower volumes. I agree, a similar problem, but market forces are what they are. Balsa and glow? Perhaps, liteply and petrol. Times change. None of us can predict the future. It will not be so bleak as all that. Just... different. Maybe in 10 years, turbines will cost 1/2 what they do now... 10 years ago, a foamie jet with a tiny turbine was still sci-fi.
  17. Depends. How big is your model? How many servos? What kind of servos? What is the engine - single cylinder 2 stroke? Seven cylinder radial?
  18. I can't see there being much money in small engines. Without money there will be no commercial offerings. There is money where there is mass market, and some where there is expensive fancy sunday bests. The expensive fancy sunday bests are no longer mid-to-large size glow, instead that seems to be big petrols, going up to massive motorbike sized petrol radials for 1/3 scale warbirds, then there are turbines, etc. The mass market in small engines? Might be something with RC cars I guess. Everyone wanted electric. Now we have electric. Electric power makes props turn round but is quite dull. Electric does not have the mechanical beauty of a finely engineered IC. That's ok if you don't really care about the motor as a toy in and of itself; if you simply want to plug in a battery and fly. Not everyone wants a swiss watch, but, anyone who wants to mess about with small engines is the minority and the minority does not get a diverse selection of manufacturers vying for our cash. I also don't see very many on here rushing out buying new small or mid size glow motors (with the exception of some Laser aficionados, although that has now ended, not sure what you guys are going to splash out on now. OS? Saito? Move up to a big Valach? 20cc and up is still dominated by petrol, so that's an indication of what people want, in that size. The 2 strokes are easy enough to operate and probably cost a lot less than electric, following recent price rises on electric clobber. Seems to be a future there.
  19. Not worth messing with it, I would agree with the above posters suggesting getting rid and replacing
  20. Make some hatches in the wing from thin ply, fix some wood blocks to the hatch, mount servo to the blocks. Or some pre-rolled: https://www.elitemodelsonline.co.uk/More/Radio-Equipment/Radio-Accessories/Servo-Mounts/40994-/Micro-Wing-Servo-Mount-2pcs?fo_c=3984&fo_k=582ee6f617e198858da484827152f322&fo_s=gsuruk&srsltid=AfmBOopx3hG4j84BGbo3vgVmwtsCecIvy_U7Z-MjinW5ZodtKAdJm3Adx6E Lots of ways to skin the cat. Or, just fit the upright and let the servo arm stick out into the breeze, this is usually the quickest way.
  21. Not every aviation company is in that place.
  22. I should say, despite what you might think given previous postings, I do find the whole field of manned multirotors interesting. I simply don't think that going off half baked, with people inside these things, over places with people living in them, is the right answer. It isn't 1903, we're not the Wright brothers, this isn't precisely a new field of knowledge we're exploring and discovering, and we do know how to do safety critical engineering.
  23. Because replication and redundancy comes with its own issues, it's not necessarily easy, and in life-or-death scenarios such as this, a glib sales pitch means squat. If there are two spare rotors going up, now you have a problem regarding re-routing power around between the other rotors? You've added complexity to the control systems now. Are the rotors truly redundant? As in, any and all mission scenario is possible with one or two not working or not present? Or "redundant", as in, not really redundant, but you can limp down to the ground without fatal impact? Whatever the answers - taking three copies of multiple systems up into the air is cargo you don't want to be carrying, that's reduced range or time. End of day, I wouldn't say it's extra safety in the slightest - far from it, they're doing this in order to meet basic safety needs of the cert basis. Why repeat a system three times otherwise? Customer pays extra for extra copies. As an aside, and this is a total straw man argument - the kind of language you are seeing from these kind of places is exactly the same as was seen from that ill fated Titantic tourist submarine. At its core, it was a sales pitch of "it's brilliant, because <waves hands like Paul Daniels> technology". They also thought taking multiple copies of mission critical systems onboard was "extra safety", too. And don't even mention the technology (or total lack of) in the hull of that death trap.
  24. Not going to go into much depth but I will say that including the redundant copies of various bits of hardware makes me extremely suspicious of the quality of the parts being duplicated in this manner. Another way of putting it is, they are so certain these critical parts will fail, they are fitting extra ones to take over when it happens. This doesn't feel like a project that is inspiring confidence in its basis for certification.
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