ED Racer ‘times two’

[Rob ManleyParticipant @robmanley79788]

(hope this hasn’t already been said but..) I really think this would make a great mini series in the magazine so that our non-internet friends could see.  From how you started right through to anodizing.  Really enjoyed following it :D.  Rob. 

[TerrydParticipant @terryd72465]

Looks like your trick worked Circlip,

 

well done.

 

Terry

[CirclipParticipant @circlip]

Ramon, not a DIG at you or Terry whatsoever, just nurfed off with having to

KEEP asking for the web designers to do the job properly so that long links

will automatically fold over and not dissapear under the “Ads”.

 

  Obviously too much to ask while the “Boffins” are trying to create more and

more futile tricks to wind us up.

 

  It were a LOT longer Terry but I chickened out in case I contravened the

 “Please refrain from”

 

  Regards  Ian.  

 

 PS, The Yippee is that it’s up and running and a credit to you.

Edited By Circlip on 23/05/2010 09:31:50

[Ramon WilsonParticipant @ramonwilson3]

Hi Ian – and there I was thinking it was some kind of conspiracy

 

You are soooo right – this overlap issue really is annoying and spoils the reading of the threads – no not just this one – but for all of us when it happens.

 

If it is the long URL postings that cause it and it looks very much if it does then I would still like to hear from you or Terry (or maybe some one else in the know) just how to actually shorten it to prevent it reoccuring. I would have thought that it was exactly the kind of thing a web editor would look out for and help prevent

 

Frank sorry to ignore you, not intentional. Thanks for your kind thoughts. Speed comes from those years in a jobbing shop environment I guess – I must admit I never think about that side of things – but as you see above somewhere things could get a little slower in future.

 

Rob – thanks to you too, No I don’t think anyone has mentioned this on this thread but I have just done something similar for the Nova so I guess they won’t want anything too soon but perhaps a piece on the anodising ‘adventure’ would be in order if DC is interested that is at some stage.

 

Regards – Ramon

 

[TerrydParticipant @terryd72465]

Hi Ramon,

 

I cracked the method of producing short posts a few days ago and posted the method above, perhaps you missed it?

 

If you type a word such as ‘Here’ and then highlight it, you  then click on the ‘link’ button at the top of the post window and past or type your link and it is attached to the word.  Here is an example

 

Stuart

 

Try that, and go to Stuart Models.  I hope that this posting isn’t edited by David.  Cross fingers that I get it through the censorship. 

 

Regards

 

Terry

 

 

Edited By Terryd on 23/05/2010 23:53:35

[Ramon WilsonParticipant @ramonwilson3]

Thanks Terry that seems quite straightforward enough.

 

Do I have to fill in any of the other boxes or just the URL box?

 

 

[TerrydParticipant @terryd72465]

Hi Ramon,

 

Just the url, you could change the other preferences if you wish, but it’s not neccessary.

 

Glad to be of help,

 

Best regards

 

Terry

[Alan Worland 1Participant @alanworland1]

Hi Ramon, what a lovely bit of workmanship, a true craftsman bet they sound gorgeous!

 

Alan

[David Clark 13Participant @davidclark13]

Hi Terry

There is no censorship from me.

Occasionally there is a need to delay messages until a problem is solved.

This thread is messed up, I have managed to fix the two previous pages in this thread but can’t see where  the problem is in this one.

regards David

 

[Sub MandrelParticipant @submandrel]

Crikey Ramon!

 

For some reason I jkkept skipping over this thread, then I noticed the level of interest.

 

Those engines are phenomenal! I grovel down in the face of such achievement!

 

I have a couple of DC engine, a Spitfire and a Merlin  IIRC. I flew the Merlin f/f a few times, so i might try starting them up again. Oddly I got along much better with these old engines than more modern ABC ones (Thunder Tiger??)

 

Neil

[Ramon WilsonParticipant @ramonwilson3]

 

Cor! Steady on Neil. You should take a step back and look a fresh look at that lovely crane you have just built. – a very unusual subject and a lovely piece of model making. You should be justifiably proud. I suppose though we never see our own work as others do.

 

Hi Alan nice to hear from you too, sorry I haven’t been in touch – had my ‘head down’ as you can see. Yes they do ‘ring’ out a bit. I ran them both today while a friend took a bit of video – not a lot but enough to get a idea. All I have to do now is work out how to get it on here. Hows that ‘Magnum’ BTW – got it in an airframe yet

 

Initial two runs have been on a 13 x 5 wood – the CI piston in CI liner so far seeming the free-er of the two though that piston needs to be improved for better compression. Today I ran them with an 12 x 5 to get the revs up – nice and oily so not to get them over heated. The CI piston in steel liner engine probably turning about 7000ish suddenly siezed. Checking it, it was not locked solid but extremely stiff to rotate. Immediate thoughts were the Loctited shaft had failed but after it had cooled a bit the stiffness eased slightly and the piston was moving. Must be the phosi bronze big end bearing on the unhardened crankpin then. No not that either. Turned out to be a ‘pick up’ between the shaft and the ali in the bore just in front of the main ballrace. Remarkably given the stiffness this was a very narrow band – probably less than half a mil wide but it certainly brought it to a rapid stop. The other thing noticed was the now apparently very slack contra piston – not so slack as to get a compression but too slack to be able to feel its resistance with the comp screw.

 

The ‘pick up’ polished out with some 1200 wet and dry and the contra piston was ‘grown’

by heat treating – brought to a bright red heat and allowed to soak at that temp for a few mins then left to cool. Sometimes, on cast iron this will increase the diameter of contra pistons and pistons too by a small amount. This one grew just .01mm but without any distortion which allowed it to be used again. I have reclaimed several worn out diesels by this method. It doesn’t work all the time and you can’t do it twice to the same piece but if the piston or CP is worn you have nothing to lose. Obviously a piston needs to be relapped along with the bore, success depending on the amount of growth but I have seen as much as .04mm which is more than adequate. Not my idea I hasten to add  – something that great engine guru George Aldrich wrote about sometime ago.

 

Showing the pick up/heat mark in front of the main bearing area

Shows the pick up inside the bore – (first dark line is gap between case and forward face of bearing – second line is the pick up area).

 

Contra piston before heat treatment

 

Held at this temp/colour for two – three mins. Left to cool slowly. Not quenched to avoid potential distortion

Shows the .01 gain – no distortion to the OD circularity.

 

Hope this is of interest

 

Regards for now – Ramon

 

 

 

 

[John OlsenParticipant @johnolsen79199]

Hi Ramon,

 

This is all very familiar since I have had an ED Racer since about 1964. I think yours look much nicer than the real thing, much better finish.  My first engine was an AM15, which I also still have. I also have most of another one, which I need to make a crankshaft, conrod and piston for. It does still have the contrapiston. It will also need a bit of cleverness on the crankcase, since the intake stub has been busted down to the level of the spraybar holes. Don’t blame me, I didn’t do it! I think it is actually what was left after various people scavenged the parts they needed.

 

Other interesting old engines I have here are:

ED Comp Special (2cc) 

Ohlsson and Rice .29 glow engine (about 1950 vintage,  based on their previous spark engine)

OS Max 3 .15

 

and I also just recently found out that the casting that has been sitting around for years is the crankcase for a Sparey 5cc Diesel.

 

 So one day I an have to get into this sort of stuff and fix up the AM 15 and build the Sparey. I’d like to know more about the process of lapping pistons to a good fit.

 

regards

John

[Ramon WilsonParticipant @ramonwilson3]

Hullo John, Thanks for the kind comments.

I would love to be able to say that I still had my first engine – AM10 (1958) – but regretably not so.

 

When you refer to the engine with the intake shortened is that another AM15? I believe in their second or so production life they did a version which was fitted with a throttle insert for R/C work so perhaps that’s why.

 

The Comp Sec and O&R were a bit before my interest began but I remember having an OS Max 3 19 which was similar in construction, if not a bored version, to the 15. Very nicely made engines then and now.

 

Regarding lapping – nothing special is needed. There have been many articles that have covered this in depth but the basics (for me) are –

 

A short piece of threaded rod that will go inside the piston with a cross hole drilled through it that will accept the gudgeon pin (clearance fit will do). This screws into a stub of ali held in the chuck which is turned down to just a tad smaller than the piston diameter to allow the lap to move over. Turn a short (1.5mm) shoulder on this to act as a register for the inside of the piston. The rod is screwed in until the piston is tight against the shoulder.

 

My piston laps are mainly from brass, either small rectangular blocks with a hole bored though a slide fit on the piston or slices of round bar with the hole eccentric. This is then slit and cross drilled for a closing screw eg 4BA caphead. The thickness of the slice is usually about 2/3 to 3/4 the length of the piston. I haven’t found the need to put any grooves in to retain the lapping compound. Depending on the amount to come off – 1-2 thou at most – I normally begin with 320 grit then 600 and finally 1000 making sure both lap and piston are really cleaned between each change of grit size. Use plenty of lubricant – parafin with a small drop of lube oil has proved sufficient and about 300 RPM. Move the lap so that it extends over each end of the piston about 1/4 of the lap width.

Lap the piston until it will just enter the bore cleaning the piston carefully before trying each time. I then use a tee bar handle drilled this time for a good fit on the gudgeon pin and now holding the liner in one hand and using a back and forth and wringing action slowly lap the piston to the bore using a very small amount of 1000 grit.

This can prove quite tight to begin with but will suddenly ‘give’. At this stage remove the piston and thoroughly clean both the liner and piston before re-assembly with a drop of light oil.

A quick method of cleaning is to use gun cleaner cellulose thinner. Put some in a sealeable container drop the piston or liner or lap in – one at a time that  is.  Seal and give a quick swirl  to remove virtually all the residue. A second container  makes a really squeaky clean job of it.

 

Hope that helps you, like all things it’s a matter of trying and having a go. If you’ve not done it before try ‘lapping’ a test peice first to see how effective the process is before you tackle a  piston – it’s a bit of a gut wrencher when you realise you are under

 

Regards – Ramon

[John OlsenParticipant @johnolsen79199]

Hi Ramon,

No, the second AM15 crankcase was actually broken in that area. My thoughts on cleaning it up as a boy was that I would fit it with an RC style carburettor, and some of my first attempts on my Dads ML7 were making such things. Lack of radio control gear, or any money to buy it with, tended to render such thoughts moot. But that would be the sort of thing to do. Any slight restriction of the intake area would not be a big deal at this point in time.

The Ohlsson and Rice and the ED comp special are both older than me, or close to it. The Ohlsson and Rice would be about 1950 vintage, they had just started making the glowplug version, by leaving off the contract breaker. I think the Comp special is 1949, if I am interpreting the serial number correctly. I picked up the Ohlsson and Rice as an old second hand engine, and built a 1939 design of model aircraft for it…a Powerhouse, which I beleive is still a well known model. Seven feet wingspan. I still have the model, although it currently lacks covering. So that would have been built around 1964 or 65. Still have the lathe too. The last of the scars on my wrist from when the AM15 nearly got away seem to have faded over the last few years.

Now back in those days, as a teenage boy, I was able to go to the chemists and buy ether and even amyl nitrate no problems. My Dad went with me the first time so they knew what it was for, but after that I could just walk in and buy ether by the pint. I bet it would be harder to get that sort of stuff now.

So how did you manage to end up with the three bosses for the cylinder mounting screws the opposite way around on the two engines? I guess it does not matter, so long as you put the liner in to match. Going by my engine, the correct one has one boss to the rear and two either side to the front. Mine has the cylinder fins anodised red.

regards
John

[RICHARD GREEN 2Participant @richardgreen2]

Hello Ramon,  have you any idea what grade the aluminium was that  you used for the crankcase ?

 

                                                         Richard.

[Ramon WilsonParticipant @ramonwilson3]

My apologies for the delay in responding Richard.

 

I had totally missed your post and, having just returned from a holiday, was checking up on ‘what’s been happening’

 

The grade used was HE30 – I believe this now has a new specification reference – I purchased it from my previous works where it’s still referred to as such.

 

Hope that helps –

 

and apologies to you too John for likewise – don’t know what happened there brain fag I guess.

 

Powerhouse – was that a Sal Taibi design? I seem to have a recollection of that ‘in here’ somewhere. That would have been a big model for ’64/65. Much later than that, in the late eigthies/nineties I guess I half built a Jasco Flamingo of similar size for one of those first OS 60 four strokes but R/C was never my cup of tea and ended up selling the airframe and engine on before tackling those enormous wings.

 

I wondered who would spot the ‘deliberate’ mistake on the Racers – you are correct of course. When I began to mill around the exhaust area on the first case I milled through where the rear boss would have been. Rather than scrap it the bosses were transposed so they are not a true pair.  but then they are not meant to be exact replicas hence the change of colour. If – if, I can manage to get the crankcase out of solid I’m hoping the next design will be more representative of the original – more on that later

 

Regards for now – Ramon

[John OlsenParticipant @johnolsen79199]

Hi Ramon,

 

I think you might be right about Sal Taibi, sounds familiar. It was in Model Airplane News about 1939, I no longer have access to those issues.  It was big, but mine was much lighter than the original since there were no batteries for the ignition etc…it weighed about 3 pounds ready to go, and the .29 gave it a nice steady climb. It would get to about 150 to 200 feet on a tankful of gas, then take a couple of minutes to glide down. (Guessing the heigh by comparison to glider towline height.) Except for the time it caught a thermal and went for a half hour flight, landing in the Waingawa river. Oh well, no harm done.

 

I used to carry it under my arm riding a bicycle down to the airstrip. Must have looked quite classic.

 

regards

John

[David Clark 13Participant @davidclark13]

Missing dimension

The dimension from the rear of the crankcase to the centre line of the cylinder is 15mm.

This has been measured off the original drawing using TurboCAD.

regards David

 

 

[Ramon WilsonParticipant @ramonwilson3]

Hi David,

My apologies again to any one following this for this omission – I did spot it in the magazine but have been away on holiday last week with the computer well out of reach.

 

I will re-check all the other drawings for any thing else that may be amiss – the original drawing has now been amended.

 

For those interested I was able to give one of the Racers a really good run at the Forncett ‘do’ yesterday. Running on a 10 x 6 Master wood airscrew the revs ‘sounded’ significantly up on previous runs using a 12 x 5 and it ran most consistently despite the ambient heat. Unfortunately the battery had failed in the tacho taken along so no actual figures as yet but as many remarked – it did ‘sound’ good

 

Regards – Ramon

[Clive HartlandParticipant @clivehartland94829]

The Powerhouse was indeed an excellent design, The wing span on mine was about 36″ and was powered by a 3.5 deisel.

It would climb in three half loops and flip at each one and then glide in big circles.

The O & R engines I seem to remember were cast in Magnesium and were extremely light. The rear crankcase on mine was damaged and I could not repair it, No idea where it is now but I did lose a packing crate between Hong Kong and the UK.

Another plane was the Banshee which also flew like its name. It had a poor glide pattern though.

 

Clive

[Terry FordParticipant @terryford]

Hi Ramon,

 

I’ve only just joined this site, but I have been blocked as my post could be commercial.

 

So this is why I am a bit late looking at your most brilliant engineering skills. I’ve been in engineering most of my life, but your skills are enviable.

 

My brother bought me an Ed 246 racer, in the 60s, lovely engine, I can still smell it. In fact I still have a white mark across my middle finger nail, where the Prop caught me up, ah memories!

 

I remember building a wing shaped control line balsa and dope plane, and with all of my mates sitting round the ring while I revved up the engine, but having no skill with the control line and thinking ‘up a bit’ sent it straight over my head and nose dived behind me. With the plane all smashed, and the engine slightly seized, I went home and they stayed where they were. I pulled a panel from our Lap larch fence, cut the engine square, fit the engine and went back to my ring of mates. We flew the plank around with only centrifugal force as control, till the fuel ran out. Happy days.

 

Cheers, Terry,F

[David Clark 13Participant @davidclark13]

Hi There

You have not been blocked.

Your commercial post has been deleted.

regards David

 

[Terry FordParticipant @terryford]

Sorry David,

 

Bad choice of words.

 

Cheers, Terry.

[Ramon WilsonParticipant @ramonwilson3]

Hi Terry, thank you for your kind words.

 

First let me welcome you to the Forum – despite your inauspicious start I’m sure you will enjoy what you see and read. There are some very extremely helpful people on here.

 

It’s pleasing to hear that the thread has brought back memories of your early days of control line – my first flight – with a own design model, had exactly the same flight path

 

It was own design because needs must – I must have been a glutton for punishment – my first C/L model, a KeilKraft Ranger and a Xmas present to go with my first engine, never even made the outdoors – I did not have access to a soldering iron so bent the control wire into the bellcrank and glued a piece of balsa over the top to prevent it coming out – not successful would you believe The first thing I actually got to fly was made of hardwood with ply wings. I made it in woodwork class and it flew like a brick but it did fly and didn’t break and would you believe, it was a biplane to boot too. Ah, happy days is right.

 

Enjoy your time on here

 

Regards – Ramon

[Sub MandrelParticipant @submandrel]

M brother and I used to fill the nose of airfix kts with plastacene, tie several feet of fishing line to a hole in the end of one wing and whirl tem around our heads

 

I’d forgotten all about that!

 

I’m tempted to put an rtp motor in a small balsa job, stick a 12V gel battery in a rucksack, put the plane on two long wires and see what happens!

 

Neil

[Author]

Posts