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New I/C diesel project - ETA15d-x2

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Ramon Wilson19/12/2010 00:07:59
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722 forum posts
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Hi,
 
Following on from the Racers built early in the year thoughts turned to trying to
produce something similar but this time based on the ETA 15d diesel.
This was an engine - like so many others - that was much desired in my younger days but the expenditure was beyond justification at the time. A good project perhaps but a more complex crankcase than the Racers.
 
A short (planned) foray into furthering the progress on a stationary (steam) engine which began far too long ago and a longer (totally unplanned  foray into those cylinder heads mentioned elsewhere has put starting these off for some time.
 
However pleased to tell that the last fortnight has seen a considerable amount of swarf made and I thought some might like to see a couple of pics.
 
Heres the start...three blocks - two for the job and one spare - just in case.....



And today they were finished. The blocks weighed 410gms each to begin, the cases finishing at 61gms with no variation
 
One will be made as a Mk1, the second a MK2 - a similar engine but with a longer front housing and slightly different head. I have ideas for the third but not  a Mk3 at this time They are not exact replicas of the original due to the limits of machining but I think they will be close enough when they're done to look convincing.
 
Pics of all the ops are on here if anyone is interested
 
And now a big clean up is in order.
 
Regards - Ramon
Jens Eirik Skogstad19/12/2010 06:11:33
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390 forum posts
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Hey, nice work! You did the Eta 15 crash proof since there are no cast aluminium who are brittle.
Ramon Wilson28/03/2011 14:56:18
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722 forum posts
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Well after a bit of a layoff due to another project at last some further progress has been made on these engines.
 
The front housings are now finished along with the back plates on the Mk1 and 2 versions.
 
The third engine is based on the heavily modified Eta 15d developed by US Team Race exponents Herb Stockton and Don Jehlik circa late sixties. This version used the piston and liner and the crankcase from the original Eta but had a new machined front housing. The intake system was converted to a a drum valve and used the main carb body from a Cox TD 049 engine as well as the Cox venturi . This too was supported on a machined housing. As yet the intake apperture has to be machined as I'm currently awaiting an 049 engine to measure along with some very hard black plastic to make the 'carb body' from (as per the original engine).
The S&J cylinder head had extremely thin fins - just 25 thou thick with a similar gap. This scaled up to .8mm but with a depth of 8.1 mm and I felt that this may end up with 'push off' of the previously cut fin. I settled for four fins less at 1mm thick and the same gap. As it turned out the fins machined without a hitch using 'Plus Gas' as a lubricant which is very good on ally. The tool was ground by hand from the end of a throw a way FC3 cutter
 
 
In case you are wondering, the screws fitted to the original Mks 1 and 2 were unusal for the time in that stainless phillips round head screws were used. An extensive search unearthed no supply of these so they have been made from stainless 6-32 pozi drive pan head screws, the heads reduced and reshaped.
 
Hopefully there should be no distractions other than 'the garden' - here we go again- to prevent work on these until completion.
 
Finally Jens - there will be no 'crashing' as they will never fly
 
As always, hope this is of interest to someone.
 
Regards - Ramon

Edited By Ramon Wilson on 28/03/2011 14:59:23

James Burden28/03/2011 16:07:43
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93 forum posts
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Hi Ramon,
 
I must say they look great - look forward to seeing the completed engines!
 
How do you get that lovely satin finish on the crankcases - are these sandblasted?
 
James
LADmachining28/03/2011 17:22:07
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101 forum posts
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Yet more excellent work Ramon - always good to see your postings of your work in progress. Keep them coming!
Clive Hartland28/03/2011 18:52:10
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2501 forum posts
40 photos
I like what I see there Ramon, my own experience was many moons ago with Dooling 29's and McCoy 29's. All as power for control line models.
Just out of interest Ramon have you incorporated 'Desaxe' in the design?
To save frantic searching I will tell you and the readers that is an offset of the cylinder center line to one side of the crankshaft.
This facilitates a 'Throw over' of the piston and eases its pressure.
Pistons of this type need Knurling on the thrust side.
Please give some more details etc.
 
Clive
Ramon Wilson28/03/2011 22:57:02
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722 forum posts
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Hi Guy's, Thanks for the kind comments.
 
James, the finish is straight off the mill/lathe as machined then lightly abraded with 600 grit Wet and Dry paper used with paraffin as a lubricant. Then buffed with one of these fine comercial 'Scotchbrite' type synthetic wire wool abrasive pads before a final rubbing with a fine Garryflex abrasive block again using paraffin. These (Garryflex blocks) are a superb finishing tool for all materials particularly steel producing an extremely smooth finish without high polish. All tool marks have to be removed first though.
 
Anthony - nice to hear from you - I see elsewhere you're just as productive what are you working on at present?
 
Clive - Oh you've struck a chord here - Dooling 29 - I bought one whilst in the army in 1963 from the model shop in North Camp near Farnborough. It sat in the window on a stand of second hand engines with the price tag of a fiver!! To put it in perspective I had to ask him to hold it until payday!
Last week at the Old Warden 'Swapmeet' I held another for the first time - price tag now in three figures.
 
I guess you were involved with B team race or speed with engines like those eh? I put mine in a Mercury Thunderbird and ran it on KK Nitrex 15 which I could hardly afford in those days. Like so many engines I have owned over the years I sold it on just before departing for Bahrein - much to my eternal regret now and no that's not because of its current value.
 
I'm familiar with the desaxe arrangement but not by experience. These engines are scaled to 5cc for no other reason than a personal interest to do something a little different. Apart from the limitations of machining something from solid that was originally produced in a die they are as near the originals as possible but scaled by 1:1.26. All ali parts are from HE30, the pistons will be from meehanite and the liners on these will be from EN1a. Shafts will be as per the Racers previously built ie composites of an EN24t outer,weband crankpin with an inner from a high tensile bolt loctited in. So far this method has economised on a limited supply of EN24 and has stood up well to the rigours of static running.
 
I have found these and previous engines to be ideal projects - relatively short build times, the need to ensure good fits makes the machining interesting and finally when they burst into life well .....
 
Hope this is of interest too
 
Regards for now - Ramon
 
 
Ramon Wilson01/04/2011 12:03:13
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722 forum posts
81 photos
Don't know if this is of use to anyone but I ordered some bearings late on Wednesday night from a company called ' Simply Bearings.co.uk'. This is the first time I have used this company.
 
Dispatched yesterday - here today - postage £1.50. Now thats what I call good and reasonably priced service.
 
Usual disclaimer
 
Regards - Ramon
EtheAv8r01/04/2011 13:14:04
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111 forum posts
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Ramon
 
I am just a beginner at the very early stages of this turning & milling malarky - making as a first efforts a Hemmingways kit Centre-Height Gauge. Looking through all your pictures was a joy, thank you, and a useful part of my learning process......
 
To be able to see a part progress from a block to a finished component with detailed pictures of the steps and progress is unbeleivably useful to someone like me, who otherwise would have had no idea of how you would approach such a complex task.
 
Edmund
Windy01/04/2011 13:21:59
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768 forum posts
146 photos
Hi Ramon,
 
Great to see your IC being made.
 
About 'Simply Bearings.co.uk'.I bought bearings in 2009 from them and advice and service first class.
 
Usual disclaimer
 
Windy
 
Edited By Windy on 01/04/2011 13:24:27

Edited By Windy on 01/04/2011 13:25:52

Ramon Wilson03/04/2011 22:15:36
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722 forum posts
81 photos
Sorry for the delay in response but this is the first time I've been able to get on here for a couple of days.
 
Windy - good to see you are still 'out there' - the HT liner has really stood up well but I'm going for En1a on these engines - perhaps more on that later when I get on to them.
 
Thanks for the kind comment Gray but CNC - 'oh I wish' . Well perhaps not, my last three working years were spent with CNC and I don't think I could face re-learning - I'll stick to the Linley for now. Regarding writing - there is something in the pipeline which I am steadily working on and which is well under way but of late have fell a little behind - something I need to get back onto pronto really.
 
Edmund, your comments have made the effort all worthwhile, it is pleasing to hear that someone is getting something from the images. I have not taken so many on this engine as I did with the Racers - I do it mainly to keep a record of how I went about something as opposed to keeping notes. I can see lots look but wasn't sure if anyone actually got anything out of it so wasn't sure if it was worth doing again. I'm quite happy to take pics of ops as I go along if there is an interest out there - I just don't want to overdo the situation uneccessarily.
 
If you choose your prototype carefully making these small engines is not really all that difficult and there are many designs now that do not require the use of castings. The part count is small as is the elapsed time to build but attention does need to be paid to fits and squareness/alignment. My chosen ones so far are purely down to personal preference and have made for some interesting set ups to achieve the crankcases but outside of this all the other parts are quite straightforward. If you have any doubts of this just compare them to the magnificent examples of multi cylinder engines built in the past by the likes of Barry Hares and I'm sure you will agree by those standards these are small beer. However, as said before when it finally bursts into life the reward is out of all proportion to what's been made.
 
I have just made a new fixture for turning crankpins on single pin shafts. I had previously used one made at work for a very small job there but this has proved a bit marginal so something larger was required. It's based on a piece of cast angle offcut I had which had a reasonable surface finish. You can see whats been done - nothing complicated just a need to ensure squareness in both planes. The vee grooves were gashed with an FC3 cutter and the angles put on with a 45 degree multi flute countersink. The face plate was refaced and a check with a ground 12mm bar showed an 03mm run out about 70mm from the end of the fixture. The angle made for any easier approach but it could easily be fabricated.
It is very easy to set true and as such is pretty universal for all throws within it's scope. If the shaft is a little long it can always be packed out on a parallel. Oh, and in case you are wondering - that one bolt is okay - providing the live centre is in situ Here's the first end done.
Hope this of further interest
Regards - Ramon

 
Ramon Wilson15/04/2011 23:01:14
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722 forum posts
81 photos

Just a short add on to the last pic. The crankshafts are now finished...
 
The inner parts were turned from some particularly tough 8mm cap head bolts and Loctited (638 High Strength Retainer) into the main parts - there is a small head, half a mil up on diameter let into a counterbore about 1.5 mm deep at the web end. This is to add certainty to not pulling the shaft through when tightening the props. They are not pinned in anyway and so far previous shafts made this way have stood up well to the forces involved. The inners are made slightly up on finished diameter - in this case 6.5mm for 1/4" front shafts and 1/4" for 6mm to allow enough for finish turning between centres. BTW The pic of the main journals at the end of the last post shows an eagerness to get on but a wrong approach - the crankpins should really be turned after the main journal is finished to ensure the best prospect of axial alignment. As it turned out this one was okay but the other two were done in the correct order! The threads were screwcut and chased - it was far too tough material to spoil dies on!
The assembled front end is for the Mk1 and was finished today. It was assembled to check the alignment of the bearing housings but will now have to be stripped down ready for bead blasting in the next week or so.
'
I've been promised a 'break' for the weekend - something about the garden she said but hopefully next week or so will see a start on the liners and pistons.
Hope this is still of interest
Regards for now - Ramon
LADmachining15/04/2011 23:25:58
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101 forum posts
10 photos
Definitely of interest - keep the updates coming!
 
Your updates will hopefully inspire me to get back out to the workshop.
 
I have lots of smaller 'works-in-progress', but my main project in particular is taking up all of my time - she is about 7 months old now and growing rapidly!
Ramon Wilson17/04/2011 09:50:52
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722 forum posts
81 photos
Hi Anthony, What better distraction from the workshop can you have - time to 'play' will come eventually though, never fear.
 
Despite my distraction in matters domestic I did manage to get the other two shafts asembled yesterday and the alignment checked. This is the stage so far then...
 
Has any body any ideas about small scale nickel plating. I need to plate these particular spray bar parts if possible but do not want to go to any great expense as unlike the anodising I think this will be something rarely carried out in the future.
I haven't looked into it in any detail as yet - just wondering if anyone can point me in the right direction to achieve this finish with the simplest of out lay
Regards for now - Ramon
jomac17/04/2011 10:40:04
113 forum posts

Ramon Hi, just search the web, there a few sites out there, you use Chromic acid and Sulphuric/acetic acid in conjunction with a battery charger for silver or black chrome. all in a small plastic container, I read somewhere that you could rechrome cylinders, virtualy by the road side,???.

PS good looking motor and machining, ( I might have to paint mine to cover up the machine marks !!!)

John Holloway

PPS have not started up the Bolaero18 yet, to busy chopping down trees.

V8Eng17/04/2011 18:42:17
1336 forum posts
28 photos
Hi Ramon.

GLR distributors advertise nickel plating kits in ME.
 
http://www.modelmakingsupplies.co.uk
 
 
Ramon Wilson17/04/2011 22:02:53
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722 forum posts
81 photos
Hi John,
Good to hear the Bollaero is finished if not yet run. Do you visit the Barton Model Flying Club website? There are a lot of Aus contributers on there and they may be able to help regarding fuel supply difficulties.
 
Thanks for the suggestions and the link too, Edmund. The items I would like to do are very small and not worth the outlay for a plating kit given the amount of likely need to do similar in the future, however, having looked at various sites and suppliers I think that this topic may benefit from a separate thread. Thanks for the input though.
 
Regards - Ramon
Ramon Wilson21/04/2011 21:35:17
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722 forum posts
81 photos
Hi there,
I don't know if this is of use to anyone .....
 
I made the prop drivers for the three engines today and tried something new.
 
Previously I have always put the face knurl on first with the stock firmly held in the chuck to resist the forces involved. The problem with this is that the internal taper to match the collet has to be cut after and this does need to be concentric. Doing it this way means turning the blank in the chuck or, as I tried recently, boring the taper in reverse from the front to ensure said concentricity. Of course there is no way the size of the taper can then be checked to the collet. In all this is a small part which needs to be made accurately but one which presents problems.
 
Today I reversed the procedure. Setting the topslide over first -10 degrees in this case - I began by making the split collets from brass. These were all cut by running the lathe in reverse and using a boring bar to turn the taper. The reason behind this was that this way the topslide does not have to be moved to cut the internal taper on the drivers
 
 
 
Using the three jaw chuck all three drivers were then cut and shaped from their back face including the tapers, The tapers could then cut using the topslide until the collets entered to the correct depth. The drivers were finished all over except their front face at this one chucking.
 
The brass was then returned - don't be tempted to use ally for this stage as it will probably pick up and lock onto the taper - and another taper turned and the end drilled and tapped (2BA in this case). First off the drivers were pushed onto the taper using the tailstock centre and the front faces brought to length using a parting tool as far in as the centre would allow. They then had to be transferred to soft jaws to gently remove the remaining lip and reduce the centre area. This way kept the minimum to come off for the three jaw and any slight discrepancy in concentricity here at this stage did not matter.
 
The tapered bar was then reset and a truing cut taken then it was into the unknown!
 
I really wasn't sure if this set up would take the pressure of the knurling operation but there was no problem at all. I took the opportunity to make a simple mod to the existing push knurling tool which was previously used on the Nova and Racers. The only straight knurl I had then was too fine so this was first time with the new coarser ones bought at Ally Pally. The picture is self explanatory - I saw this idea on the Barton Contol Line website and it works really well. The knurl can be swiftly removed and cleaned and quickly returned. In fact this was done not only between parts but during the actual knurling. I have no coolant system so it was out with a squeezy bottle and a stop halfway to clean the knurl and the part of swarf. Bringing the knurl gently into contact with the previous knurling presented no problem with alignment - each part was knurled twice in effect.
 

 

Heres what they finished up like...
 

 
The knurl is not captive on the dowel, it's movement is restricted by the thick washer holding the driver though in actual fact there appeared to be no lateral movement.
 
All in all a successful change of approach - I hope someone finds that useful.
 
Regards - Ramon
 
 

 
 
 
 
 
 

Edited By Ramon Wilson on 21/04/2011 21:45:51

Ramon Wilson03/05/2011 23:50:31
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722 forum posts
81 photos
Following the recent query by 'Jomac' and a PM on how I would go about a small I/C engine cylinder I have this morning begun machining the liners for the Etas.
 
For those who may have an interest this is how I went about it - keep in mind however that this is not offered as the way to do just how I approached it and the reasons behind it. A little background then.......
 
When the cylinders for the Racers were made I asked on here if anyone had any experience of hardening small liners without distortion as no grinding facilities were at hand. Two main recommendations came out of this - one to use cast iron the other a tough, high tensile steel neither heat treated,. You may recall I tried both in combination with cast iron pistons and both were successful though it has to be said - on these two examples - the high tensile liner has worn better and provides the better seal.
 
Since making those liners I have spent quite a lot of time reading and talking to others on this issue. Also, over the years I have copied a lot of articles mainly to do with control line aerobatics and all stored in folders. Delving through one specifically on engines I found, tucked away within, an article by George Aldrich on piston and liner set ups.
 
For those who have never heard the name, George Aldrich, an American modeller is fondly remembered not only as the originator of the classic 'Nobler' aerobatic model - still competitive today - but more so was highly respected for his prowess and knowledge on two stroke engines specifically in the speed and aerobatic disciplines. Indeed for several years before he passed away he earnt his living setting up and tuning model engines for modellers world wide.
 
His article made interesting reading. Entitled 'CIS set ups' the CIS referred to Cast Iron in Steel and specifically leaded steel liners left in the soft state (ie not case hardened).
Because of this article and other factors that came to light including one world championship home produced team race motor using a simlar combination I decided to follow suit and use En1a freecutting mildsteel. (I had previously used this on the Nova but that was because of the ease of machining those thin fins and well before I found this article. The piston liner fit on that is as good as you could wish for in a diesel - good compression and no blow by)
 
As suggested to Jomar the 17.9 bores were done first in the 32mm dia blanks drilling then roughing to 17.5. A light skim was taken over the id then they were replaced to be finish bored. By keeping the wall thickness to the maximum any distortion created by jaw pressure is kept to a minimum, infact on those final cuts the jaws were nipped just sufficient to grip enough to to the job. The boring bar for the final cuts was as large as the clearance would allow
 
 
Once the bores were finished the outsides were roughed and then all were mounted on an expanding mandrel for finish turning
 

 
Last thing was to make the initial cuts for the transfer ports. Next op is to pierce through at a 25 degree angle which should make for an interesting set up given the limited height available under the spindle
 

So far so good - four of 'em? - well, just in case theres a boo boo
 
Hope this is of use to someone
 
Regards - Ramon
 
 




Ramon Wilson06/05/2011 21:56:21
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722 forum posts
81 photos
Hi again, well just as thought, with the dividing head set up at 35degress (not 25 as previously said) the distance between cutter and point of entry was a negative 50mm.
 
After some discussion with the 'General' a Soba 4" tilting rotary table was sourced from Chronos. I have to say how impressed I am with their service. Ordered at 9.30 on Wednesday morning it arrived at by courier at 4pm on Thursday - post free too. Now that is good.
 
However, with the bit between the teeth I thought it was finally time to make a boss that would bolt under the cross slide drilling attachment to locate into the Myford cross slide
as per the topslide. This would allow angular positioning. Then a means to move the spindle in a controlled manner as opposed to the lever feed fitted was cobbled together using a Myford topslide leadscrew and nut. Passed my way by the maintenance fitter at work some twenty odd years ago 'Ray's' gift finally found a use
 
With that done the temptation to try it was too much and just before the RT arrived the first liner had it's ports in.
Here's some pics of the set up which worked well.
 
The leadscrew drive worked well but please note the complex 'return drive backlash eliminating compensating mechanism'
 
Rotary motion was applied by having the lathe in low speed in back gear. This kept the spindle steady enough while plunging through but allowed rotation by turning the clutch pulley by hand.

 

Fingers were somewhat sore after filing all sixteen slots but pieces of silicone fuel tube on the square and 3 square files helped ease the pressure considerably. The two Barreft files were reduced on the off hand grinder to suit the widths involved.
 
I'm well pleased with the little Soba rotary table. For the cost it's very well made though there are areas were the odd improvement will not go amiss to refine it a little but it turns smoothly enough and all seating surfaces are accurately ground with a good surface finish. To coin an old army phrase though I guess I did 'anticipate the word of command' a bit as the set up on the lathe proved ideal but it will make a useful addition to the mill and will certainly get set up ready to use in the future. Just don't mention it to the General though
 
Regards for now - Ramon

 




 
 
 

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