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Nigel R

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Posts posted by Nigel R

  1. Posted by Peter Beeney on 07/04/2016 09:42:11:

    However, modern engines with management systems that can take care of every conceivable running condition, all at the same time, and can then pass it on to an injector in a twinkle may be rather different.

    A few of my colleagues have worked on engine management systems, word is that acceleration enrichment is still done by these systems.

  2.  

    I’m of the school that believes one of the reasons why our model engines are relatively so powerful is simply because of the amount of fuel they are able to burn.

    We burn over twice as much fuel in a glow.

    More energy in petrol though.

    Overall I agree. There's a good reason why (some) race cars use methanol.

     

    Natural gas: 17.2
    Gasoline: 14.7
    Propane: 15.5
    Ethanol: 9
    Methanol: 6.4
    Hydrogen: 34
    Diesel: 14.6

     

    Edited By SuperNash on 06/04/2016 16:58:56

    Edited By SuperNash on 06/04/2016 16:59:24

  3. open your throttle the mix is the same but more of it is sucked in

     

    basically, yes.

    top end mix is set with the main needle, get the idle mix right with the idle needle (also affects throttling), get the idle speed right with the servo travel

    our glow carbs are a very low tech route to setting fuel air mix, but we don't really care about efficiency or emissions, just that the motor runs reliably.

    also, glow engines will run on a very wide range of air fuel mixtures, I think we get away with having very simple carbs. petrol is a bit more fussy

     

    Edited By SuperNash on 06/04/2016 16:58:42

  4. Mk2 has the small "bumpy" transfer port.

    Mk3 maybe had both bearings at various points, depending on what was available. If the supply of hybrid bearings dried up then nearest metric would be the obvious thing to go to.

  5. There's a fairly typical looking 2 stroke power graph for the (very old - mk1) Irvine 40 here:

    **LINK**

    At 12k rpm, with a silencer, it makes around 0.8bhp, compared to the peak (what the advertising would claim) of 1bhp at 17k rpm with open exhaust. So you still get a good chunk of the power at the lower revs with a silencer. At the same time, bigger props are more efficient - so more of your 0.8bhp gets turned into thrust.

    Ultimately, try a few different props, keep it around 11/12k, see what works best for a given model.

  6. Mk2 sport were definitely the Irvine product. And they were a quality motor - Irvine were a good brand in their own right, before they were used as the budget department of another manufacturer.

    When OS took over when they were all red anodised. However, if it's red and says "made in england" its pre-OS.

  7. E.D.

    trebor's Irvine will be from the '80s if it is a mk2.

    Posted by trebor on 24/03/2016 09:27:15:

    Solent Bearings in Southampton have been a great help, they have located one somewhere but there source wants nearly £50 + £8 postage disgust

    ouch!

    PS if you want to sell the jetstream carb, I will take that bit of it.

  8. Posted by Erfolg on 29/02/2016 20:15:16:

    Those who advocate elipitical wings often suggest that they are more efficient. The lift is in theory can be distributed evenly, right down to the tip. The downside is that the ideal ellipse will stall pretty much simultaneously. So the wing is often washed out, In dong so much of the theoretical benefit is compromised.

    I guess the thing that strikes me about elliptical wings is that very very few types have them (and no recent types that I can think of) - almost all full size has converged on the same solution, i.e. slightly tapered (ignoring anything flying close to speed of sound, which brings its own problems and solutions). A straight taper can be engineered to have almost identical lift distribution to an elliptical planform anyway.

    Excellent post BTW, Erfolg. As you say, for power flyers the planform almost doesn't matter. In a model we can out-power any inefficiency a particular planform will exhibit.

  9. Posted by Ian Whittaker on 29/02/2016 20:04:15:

    While the budget isn't endless

    Apple Mac

    Without trying to sound clever, I'd look at a PC.

    Phoenix (£70) plus a dx6i (£70) 1 runs fine on a £300 laptop for me and 2 plugged straight in using the phoenix widget and worked straight away.

  10. Posted by Peter Android on 22/02/2016 15:08:01:

    Was the seller selling a Camera ? or a Box ?

    Unfortunately this is how I got ripped off , As a genuine bona - fide Ebay seller , though I don't use it often , with 100% Pos feedback , a " gentleman " falsely claimed that the goods were " not as described" then filed a Paypal claim which they upheld , despite me clearly listing that viewing was welcomed prior to purchase .

    To add insult to injury , the claimant then neglected to return the supposed " not as described " item . and lied to Ebay stating they had returned said item . Paypal had already made a final decision.

    End result , I lost both the item and monies .

    So, with very few exceptions , I will only accept paypal GIFT on any most items - posted to protect myself.

    Be aware , there are some very cute - cookies out there who deliberately and criminally manipulate the whole paypal system to their advantage.

    I am happy to say , that most fellow bmfa members realise this , and I have no issues with bmfa members purchasing from me - via paypal gift and have done so in the past few days. and in the past.

    Cheers. P

    In this case it sounds like selling the box was part of the camera sale. If a seller has taken pictures of it, then I'd expect the things in the pictures to arrive in the condition in the pictures. Just playing devils advocate if you sell (for instance) a mint condition boxed dinky toy its worth something, wheras with a knackered box its worth lots less...

    I sympathise with your position though, the whole Ebay/Paypal scheme is open to some abuse.

    I'm surprised that Paypal didn't want postal proof from your "gentleman" that he had posted and returned the item to you and that you had signed and received it.

  11. Ubergeekian

    I think the Ebay route advised above will net you the most cash. It's quite an effort for a lot of engines (I also have a lot - around 60 - to list in the near future) but you'll get the best exposure and value. The advice about touching nothing is good, too, the "brand new in box" should mean just that for highest value.

    Post pictures of the unidentified engines, I'm sure there will be responses from the knowledgeable collectors on this forum.

    Posted by Robin Colbourne on 21/02/2016 11:56:58:

    I recently bought a camera from Ebay which was shown in its original box. On receipt, I found the seller had wrapped the whole camera box with brown 2" parcel tape, and that was despite being packed under a layer of bubble wrap. After a lot of effort, I managed to peel all the tape off with minimal damage, but the box is still sticky. Grrrr!!!

    I must admit I would be filing a claim for "not as described" and ask for a partial refund, if the seller had damaged the box. Ebay will generally go with the purchaser if something like this is raised.

  12. Hi Jon

     

    Seems that whatever else you do w.r.t. new sizes and multi layouts, the current fashion of the market is demanding petrol. Of course you know this very well already; you're already working on what my best suggestion is (a 30cc-ish single).

    Maybe an optional carb adaptor elbow would work as a fix for those needing a relocated carb.

    Also a vote for a laser-approved (if not produced) fuel pump/reg setup.

     

    Nige

    Edited By SuperNash on 05/01/2016 18:04:05

  13. Thanks sam, interesting story behind the redshift. The redshift system seems to be quite a complete system more complete than the ys regulator if it included a metering widget hooked up to the exhaust. Great shame the designer was lost.

    Weston are currently showing the ed carb on their website so its currently my first choice if I can get one. Failing that one of the uk irvine 40/46/53 sized jetstream will fit and they're a sweet carb.

    Nige
  14. thanks slim (and all)

    yeah I think its as I suspected - as you say a limitation of the tx.

    as for the model & setup, (sadly) simulator only for now, so the lack of flaps & gear isn't a real world problem, until I get back to flying real world hardware again that is, at which point time for a new tx

    having said that the facilities on even these cheap radio are massive compared to 25 years back

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