Author Topic: A New 5cc Aero Diesel Engine Project  (Read 90396 times)

Offline b.lindsey

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Re: A New 5cc Aero Diesel Engine Project
« Reply #195 on: May 29, 2013, 01:22:54 PM »
No apology needed Ramon, thanks for the added pictures too. My involvement was never from the competition side, just afternoons in the schoolyard with a few high school buddies...mostly Cox .049's which at the time could be had new for around $4.95. We did later get up in the higher displacements (.15 -.35 or so) but it took a lot more room and those wire control lines were a pain to keep unkinked.  You're right though, good times for sure and far more innocent times as well. Sadly if it were today, I doubt we would even be let on the schoolyard for fear of liability issues, etc.

Bill

Offline vcutajar

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Re: A New 5cc Aero Diesel Engine Project
« Reply #196 on: May 29, 2013, 02:40:44 PM »
Nicely done Ramon.  Sorry to hear about the problems with the other two but it seems you already got them sorted out.  Now I know why you always make three specimens. :)

 :cheers:

Vince

Offline Stuart

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Re: A New 5cc Aero Diesel Engine Project
« Reply #197 on: May 29, 2013, 04:32:57 PM »
Ramon

could you clear up a point for me in my long lost past I used to fly a near scale Spitfire C/L fitted with a Mills 75

is it true that these engines pistons were tool steel lapped to the bore at the factory ?



Stuart
My aim is for a accurate part with a good finish

Online steamer

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Re: A New 5cc Aero Diesel Engine Project
« Reply #198 on: May 29, 2013, 05:12:16 PM »
Yes - definitely happy days   
 
Apologies for the nostalgia

regards - Ramon

Not at all Ramon....thanks for sharing that!

Dave
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Damned ijjit!

Offline Ramon Wilson

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Re: A New 5cc Aero Diesel Engine Project
« Reply #199 on: May 29, 2013, 07:22:43 PM »
Careful Dave - I've been known to wax lyrical over these things for hours  ;D

Stuart as best I can say you are correct. The Mills 'heyday' was just before my own Aeromodelling initiation but I do recall adverts from back issues of the 'fifties Aeromodeller magazine that I later collected that covered the various stages of manufacture of Mills engines.

I'm pretty certain they made claim that all the liners were heat treated and ground to a high tolerance (to anyone elses ?) and the pistons too. These were then checked using a highly accurate 'fluid measuring device' to precise limits and were then individually fitted to a suitable liner. I certainly remember wondering at the time about the 'fluid measuring device' and still do - never seen one and can only assume they work on displacement.

Control line flying has always been my 'achilles heel' as far as other modelling is concerned though I do believe it has run it's course now. To compete these days means lengthy journeys from where I live and to be truthful it's difficult to justify the cost for the usual three flights or so. Plus with nowhere to practice these days - and it does take constant practice - it's best to let it go and remember the good times. Sue and I have extremely good memories of our time with the 'stunt fraternity' - members of CLAPA in the UK - and often reminisce about it - as said, very happy days indeed.

I still have four airframes left however - just in case you see ;), three ready to go though I suppose gradually deteriorating as they hang in the garage unused and one requiring painting. All the parafernalia that goes with it is in the 'old stunt chest' up the loft  ;) and I still hang on to several engines (as you do ;) ;))

This was the 'fleet' about 2005, all scratch built from plans the front three having gone, the Nobler and Oriental sold on but the Master in the foreground was lost due to a control failure (poorly soldered joint) in 2006


The silver Nobler saw many comps and came through unscathed. It made it's last flight just as the T'bird was ready to go and I remember well, despite countless flights, the dry mouth feeling on that last flight before retiring it incase anything went wrong and it would go home in bits.

They are all conventionally built from balsa,  tissue covered and painted. The lack of paint on the wings on all but one was in order to keep the weight down. The two Noblers are the smallest - wingspan - at 50.5 inches the Oriental is 52(54?) the T'Bird 55 and the Master 56.
The engines? the Oriental and silver Nobler have OS35S's, the Master an OS LA46, the second Nobler had a Ukranian built Stalker 40 (truly superb engine and made specifically for purpose) and the T'Bird the Super Tigre mentioned before. The engines in these models are required to run at a steady rich setting in level flight - universally but eroneosly called 'four stroking' breaking into a faster two stroke as the nose comes up to give power through the manouevers. (no throttle control remember) This '4-2-4' running characteristic is not something that most engines will do without modification to the timing though the Fox 35 and OS 35S would do it out of the box. Head shimming, fuel and venturi size played a big part along with a good fuel tank set up too.

Ah stop he said - you see what I mean Dave  ;)

regards - Ramon
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline dsquire

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Re: A New 5cc Aero Diesel Engine Project
« Reply #200 on: May 29, 2013, 08:30:11 PM »
Raymon

You can go on all day if you want with your trip down memory lane. I enjoy it immensely as I have enjoyed all you posts on building and lapping your engines. It reminds me of my days of R/C activity with airplanes, cars and boats in years past. They are days past that we will never live again but they will always be in our mind ready for instant recall and enjoyment.  :praise2:

Now put the pen down, throw an oily rag over the lathe, take Sue and go out and do some sailing and catch some sun and breeze.  :stickpoke:

Cheers  :cheers:

Don
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Never let it rest,
'til your good is better,
and your better best

Offline zeeprogrammer

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Re: A New 5cc Aero Diesel Engine Project
« Reply #201 on: May 29, 2013, 11:48:27 PM »
Honored to be taken along a trip of nostalgia. Much like being invited to someone's home.
I've enjoyed your posts like all the others. Keep them coming. But don't forget your other 'interests'.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Online steamer

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Re: A New 5cc Aero Diesel Engine Project
« Reply #202 on: May 30, 2013, 01:58:21 AM »
These were then checked using a highly accurate 'fluid measuring device' to precise limits and were then individually fitted to a suitable liner. I certainly remember wondering at the time about the 'fluid measuring device' and still do - never seen one and can only assume they work on displacement.




Ramon,

Try a search under "air gage".....Federal makes them amoung many others.

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Stuart

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Re: A New 5cc Aero Diesel Engine Project
« Reply #203 on: May 30, 2013, 07:59:54 AM »
Thanks Ramon for the info a bit more than I remembered



Stuart
My aim is for a accurate part with a good finish

Offline Admiral_dk

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Re: A New 5cc Aero Diesel Engine Project
« Reply #204 on: May 30, 2013, 08:42:33 AM »
Hi Ramon

Thank you very much for the video and the pictures + tales of your wonderful models. I'm sorry to hear of your problems, but it just shows that we can newer take anything for granted in our hobby - certain IC engines have mind of their own  :old:

I never had much success in my youth - several hours flicking the prop = less than 60 seconds of combined running of engine => no flying - or more correct I flew a combined 15 minutes during two years.

I kind of now knew back then, that I had fuel problems, and now I know for sure that this was the main issue along with wrong info on how to do a correct run-in of the new engine + you and a few other youtube videos has shown me that port priming is a lot more important (and require bigger amounts) than I realized back then.

Best wishes
Per

Offline Ramon Wilson

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Re: A New 5cc Aero Diesel Engine Project
« Reply #205 on: May 30, 2013, 12:29:23 PM »
Thanks for the suggestion Dave - checked it out and another example of learning something every day.

I would never have believed that the 'fluid' was air pressure. As some one well versed (or rather, was) with pressure of gases from diving days I find it quite remarkable that the fine movement involved can lead to a detectable variation in pressure. I guess I'll have to stick to my DTI and Bore gauges  ::)

Per - you were not alone - your post brings back memories when as a youngster I was with a friend who had a new DC Bantam .8cc glow engine in a KeilKraft Firefly. It was a freezing winters day and we were in the middle of a rough patch with snow on the ground trying to get this thing to start using a dry cell battery. That little 'Quickstart' spring became a major hurdle to overcome with frozen fingers not to mention constantly taking the plug out as we continually flooded it. Not sure why we gave up in the end - the engine or the cold  ::)

Zee, Don, thanks for your comments. Sue had a chuckle at my expense to your remark Don so I promised to take her out - to the model shop of course  :Lol:

Regards - Ramon
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Online steamer

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Re: A New 5cc Aero Diesel Engine Project
« Reply #206 on: May 30, 2013, 12:37:45 PM »
Actually the technology has been around since at least the late 40's...though it's gotten much better.   Some of the very best ultraprecision machine tool spindles float on compressed air ( groove compensated aerostatic spindles).
Just another fairly useless piece of information stuck in my head.... ::)
The DTI works just fine....
Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Maryak

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Re: A New 5cc Aero Diesel Engine Project
« Reply #207 on: May 30, 2013, 12:53:15 PM »
To try and overcome the problems inherent in oil operated hydraulic governors, I was lucky enough to be at Maidenhead when the RN was playing about with a fluidic governor, having no moving parts and being supplied with low pressure air as the operating medium. Mind you it was quite a large lump of metal and I think this was the principal reason for abandoning the idea.

Inside looked like something that a bored colony of worms would concoct.

Oh! and before I get tooooo far off track.................beautiful aircraft Ramon. :praise2: :praise2: :praise2: :praise2: :praise2:

Best Regards
Bob
Если вы у Тетушки были яйца, она была бы Дядюшкой

Offline NickG

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Re: A New 5cc Aero Diesel Engine Project
« Reply #208 on: May 31, 2013, 08:42:55 PM »
Ramon,

Really nice work there, can't remember whether I've said before but the first thing I ever tried making was a 0.8cc sparey compression ignition engine - needless to say I didn't get very far - not a good choice for a beginner! Strangely one of the elderly gents in our club did something similar - he's now made all sorts of great models and I think recently went back and re-made the sparey with his new found 50 years of experience and talent! He's also recently completed a 15cc V-Twin - L W Chenery which like yours looks like a work of art but he hasn't started it yet - keeps saying he hasn't got around to it yet but think he's a bit nervous of trying! He has just started having a go at the V8 aero engine by Eric Whittle too which is looking good.

With the compression ignition engines, do you wind the screw in to push the contra piston down giving a high compression to start with and then wind it out to lower it as the engine heats up?

Offline Ramon Wilson

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Re: A New 5cc Aero Diesel Engine Project
« Reply #209 on: May 31, 2013, 11:02:24 PM »
Hi Nick , theres been one or two who said they've had a go since I've been posting - so I'm sure you have. Whilst many have successfully made small capacity engines as a first go personally I think it's expecting too much especially with a diesel as those piston/liner tolerances are so tight the smaller you get. I've rebored .8cc but not made an engine of that size yet.  5cc is (for me) such a nice handleble size - parts not so big as to warrant a big outlay and not too small for workholding purposes. The 2.5 currently being worked on seems very small by comparison.

With regard to compression - the actual compression is really dependant on the load - for optimum revs it will vary depending on propellor diameter/pitch. They can also be ran with the compression backed off to lower the revs - engines used for sport and scale free flight models traditionally run them in this fashion.

Once well run in some engines do require a slight increase in compression to start, others not - it is quite difficult to describe as it's very much a feel thing. The smaller they get the more difficult it can be - some engines like to be very wet, almost flooded in fact, to start while others will get going on a couple of finger chokes

On a good performing engine the compression is rarely touched bar a tweak or so - rather with well established settings the needle is opened a turn more and the engine flicked and allowed to warm in bursts - it will start and run for a few seconds - and this is continued each burst running a bit longer then finally the engine will break into intermittent, burping, firing before settling down as the needle is gradually turned in to it's normal setting. The compression may need to be slightly adjusted depending on conditions - ambient temperature for instance. The Rivers 3.5 Silver Arrow I once had virtually never required the compression adjusting over several years of flying - a lovely motor to use.

Watching the video possibly appears to give a contradictory view - but this is first running and finding where the settings are. It's easy to flood an engine when you don't know it's characteristics and the the comp then does need backing off - that's the good thing about hand starting - you can rapidly feel that situation develop. Once running if the engine goes' hard' and begins to die it's over compressed - quickly backing off will ease things but if the engine has got hot it will usually come to a stop in a very laboured manor.

If anyone in the UK would like to see small diesel engines being operated to their very top degree then a visit to the control line team race circles at the Model Aircraft Championships at Barkston Heath near Grantham and held over the August Bank Holiday is a must - an ideal time and place to stock up on diesel fuel too ;)

Hope that helps a little Nick
Regards - Ramon
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

 

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