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Author Topic: Gordon Whitehead 23.5" Nieuport 11 Bébé for E.D. Baby diesel  (Read 3303 times)
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Jack Plane
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« Reply #150 on: June 23, 2022, 03:19:03 AM »

Chris - Fascinating stuff, thank you for sharing your knowledge... so October 1959  Smiley  And quite a significant manufacturing business really, churning out so many thousands of engines of each size every year... not your common-or-garden cottage industry then!

Joe - thanks for that.  I too messed around with rubber, CO2, the odd small Cox and even a diesel or two as a young teenager in the 1970s... and in all my endeavours I frankly had so little real understanding, except what I read in Aeromodeller.  It didn't help growing up in a densely populated part of inner London with no clubs or adult enthusiasts I knew of,  and no mates who were into the hobby, except a Spanish guy who lived down the street (he later left to go to university at Michigan and became a banker in South America) and a kid at school who did some control-line diesel in the playground because his dad had taught him (but when his parents got divorced he became a punk-rocker and royal pain in the butt).

Mark - thanks for that too.  You actually raise an interesting point for me.  While many of us seek to replicate full-size aircraft in miniature, paying close attention to as much absolute accuracy as possible within the limitations of scale, weight and flying performance (i.e. the Open Scale entrants here in the UK in both indoor and outdoor FF), my own approach is slightly different:

I'm in the camp who like to see scale models as impressions of the real thing rather than almost perfectly accurate masterpieces... which is really liberating!  It doesn't mean being sloppy with making or casual with basic scale outline and proportions and other obvious model elements, but once these are in place I then have a choice as to how much flavour to give the finished article.  Enough usually to highlight the essence of the full-size original, rather than worry about the nth degree of realism or accuracy.

Which is why I find, for example, coloured tissue Peanut Scale models so charming and evocative... and I hope I've managed with this bigger, heavier, oilier diesel Nieuport a similar sort of thing.
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ffkiwi
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« Reply #151 on: June 23, 2022, 06:36:15 AM »

Jon-you may find these interesting then:  http://www.modelenginenews.org/cardfile/ed_story.html     (this from the late Ron Chernich's website)

 https://www.adriansmodelaeroengines.com/catalog/main.php?cat_id=81

A reasonably comprehensive history of ED...at least the model engine side of the house....

  ChrisM
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Jack Plane
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« Reply #152 on: June 23, 2022, 06:14:07 PM »

At last a decent trimming session, with footage!  Grin

Port Meadow, Oxford today.  Late morning drizzle quickly passed, then stayed dry if a bit muggy, not too hot thankfully, and with light easterly winds.

https://photos.app.goo.gl/g611kPo6rn5ncC647

Club member Andy filmed the first three videos:  with the 7x3 prop on the normal way round, it was consistently tricky to find the compression sweet-spot which delivered enough power to climb out properly and not sink to earth, but not so much that it shot skywards too quickly and as the fuel-level dropped a bit the engine leaned and ran even faster... hence the manic looping on the third video!  The compression screw thread is perhaps too coarse for an old engine - the difference between too much and too little initial power is a mere 1/32nd of a turn!

The remaining five videos were self-filmed.  Of these the first one shows the effect of too much compression (a wild patrol), the second shows that of too little (model just sinks to the ground on launching).  Then, prior to the last three videos, I removed the prop and mounted it backwards - and what a difference this made to reducing the excessive thrust!  The narrow compression range remained a problem, but at least the mad thrust was knobbled.

The basic pattern is left under power and right on the glide normally (but strangely not always so).  The model actually needs still more right-thrust than the 4.5° it already has, and perhaps a tad more of down than the 7° built in.  In the absence of having any shims at the meadow for increasing the down-thrust I bent in a hint of down-elevator - which partly explains why the glide is so steep; the other reason simply being a small heavy model with lots of drag!

I think the Dart is still too powerful a motor (which is why I was hoping to get the ED Baby running inverted!), however I will increase side- and down-thrust on the workbench before the next outing.

Also I don't know what effect changing to a coarser pitch or bigger prop (7x4 or 8x4) might have? ...would it widen the current narrow usable compression range? ...give a slower prop speed maybe? ...but higher top speed? ... and better or worse torque effects?

Still... I'm pleased as punch to have got this far with the Nieuport, have learnt so much in the process, had a ton of fun so far!
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Jack Plane
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« Reply #153 on: June 23, 2022, 06:44:34 PM »

Jon-you may find these interesting then:  http://www.modelenginenews.org/cardfile/ed_story.html     (this from the late Ron Chernich's website)

 https://www.adriansmodelaeroengines.com/catalog/main.php?cat_id=81

A reasonably comprehensive history of ED...at least the model engine side of the house....

  ChrisM

Thanks for these links Chris - interesting reading!
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« Reply #154 on: June 24, 2022, 04:03:47 AM »


That's looking really good now under power, last flight was looking nice . No doubt with the downthrust and the elevator back at its glide settings it's going to be a great flyer

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Also I don't know what effect changing to a coarser pitch or bigger prop (7x4 or 8x4) might have? ...would it widen the current narrow usable compression range? ...give a slower prop speed maybe? ...but higher top speed? ... and better or worse torque effects?

A coarser pitch will increase the torque and tighten the turn under power further, larger diameter will slow the engine down and soften the power.

It may well be worth trying an 8x4 as it will slow the engine down a bit making it more tractable and as it running slower the increase in pitch may not increase the torque very much ...that's my thought anyway
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Jack Plane
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« Reply #155 on: June 24, 2022, 05:14:50 AM »

Cheers Chris

Will increase both down- and right-thrust a tad, and try an 8x4 (both options, prop on normal and backwards).

In the interests of keeping what remains of the digits on my right hand, I resorted to using needle-nose pliers to more safely adjust the compression!  But don't like the sharp metal hovering in the vicinity of the aluminium head, so will make up a suitable hardwood driver instead.

Windier weather seems to be now setting in for a while (and my VMC KK Eaglet kit should arrive today... for the Vintage under-25" span postal comp!) but will report back on the Nieuport's progress as and when.
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« Reply #156 on: June 24, 2022, 05:15:41 AM »

"...... had a ton of fun so far!" and that is what it is all about.
Ron
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Gary Dickens
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« Reply #157 on: June 24, 2022, 06:23:35 AM »

Maybe replace the compression screw with a 6BA? 8BA? cap screw and use a long allen key to adjust compression.
I'll look forward to seeing the Eaglet come together, one of my favourites...
Gary
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« Reply #158 on: June 24, 2022, 06:32:53 AM »

Another way is to make a compression adjuster from a piece of tube that will slide over the comp screw with a slot cut in it to engage with the comp screw lever.

Attached files Thumbnail(s):
Re: Gordon Whitehead 23.5" Nieuport 11 Bébé for E.D. Baby diesel
Re: Gordon Whitehead 23.5" Nieuport 11 Bébé for E.D. Baby diesel
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Jack Plane
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« Reply #159 on: June 24, 2022, 03:54:52 PM »

Thx Chris and Gary - good suggestions.

In the meantime found I had an 8x3 prop which I fitted to the Dart and tested:  same pitch as the 7x3 so shouldn't be any faster through the air, but very usefully the increased flywheel effect meant that the engine can now be decompressed through a greater range without cutting out!  So once I've hacked a bit more down and side thrusts in to the mount - and normal summer weather resumes - I'll give this a go.

I also took delivery today of a replacement bubble-tank for the ED Baby and tested it with that:  upright it's as sweet as before, inverted the same pig as before, sidewinder doable (starts and runs) but not as happy as upright.  Thus, with this particular engine at least, I've proved it's not a question of fuel tank level, more one of orientation.

So one option (just for the hell of it - and Gary's idea when I chatted to him) is to maybe one day re-hack the whole engine-bay of the Nieuport to mount the ED Baby upright...  then see how differently it performs with the original intended engine!  Grin

Jon
Attached files Thumbnail(s):
Re: Gordon Whitehead 23.5" Nieuport 11 Bébé for E.D. Baby diesel
Re: Gordon Whitehead 23.5" Nieuport 11 Bébé for E.D. Baby diesel
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