# ESO engine machining



## kadora (Oct 1, 2016)

Hello engine enthusiasts.

Winter is coming so i have more time for engines now.
I have decided to machine another ESO engine so
I would like to show you machining this engine step by step.
I am going to start with crank case casting.
This lost wax casting is crankcase and cylinder in  one body.
picture of blank casting


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## kadora (Oct 1, 2016)

Next step is easy to do but very important is to
locate casting in vice correctly because all next
machining operations will be depend on this surface.
So first pic. casting in vice , second pic. checking height of all four
corners of the top fin .
Last pic. surface milling.


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## kadora (Oct 1, 2016)

Now centering and boring the the hole for liner.


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## kadora (Oct 1, 2016)

Milling bottom part of casting


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## kadora (Oct 1, 2016)

Next three steps
1. milling surface for the front cover //front cover will accommodate
 two ball bearings for crank shaft//
2. centering hole for crank shaft
3. boring hole for crank shaft


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## kadora (Oct 1, 2016)

Now job for my mini lathe.
Very easy steps.
First two pics. show cutting 
the rim for rear cover.
Third pic. drilling hole for
timing pulley ball bearing.
Last pic. shows finished rear part.


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## Hopper (Oct 1, 2016)

Subscribed. Looks very nice indeed.


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## kadora (Oct 1, 2016)

Some additional drilling and casting is done for now. 
Next I will machine front cover - easy process .


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## kadora (Oct 2, 2016)

Yesterday I had beautiful evening listening rock songs from 70-ties 
and machining front cover.
Anyway first pic. shows blank casting .
Round stem on casting serves as a shaft for comfortable machining.
On the rest of pictures you can see how easy is to cut rim and holes for
two ball bearings.


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## Blogwitch (Oct 2, 2016)

It is nice to see someone using brazed carbide tooling.

It seems to have fallen by the wayside over the years, but if good quality ones are used correctly they can really out perform HSS and indexable tooling for very low cost.

Very nice castings BTW.

John


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## kadora (Oct 2, 2016)

And last simple operations .
Drilling holes for screws , second picture shows transferring 
holes from front cover to the crank case then cutting threads
finally checking if everything fits together .
So front cover is done next crank shaft.


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## stevehuckss396 (Oct 2, 2016)

Nice!

I'll be watching!


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## Hopper (Oct 3, 2016)

Progress is looking good. The castings seem to machine very nicely. Some nice grade of aluminium by the look.
How many CC is this model? What bore and stroke?


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## kadora (Oct 3, 2016)

Hello
Hopper you are right .I bought 70 kg of very good quality aluminium in local 
scrapyard . 
Capacity 10 cc, Bore 25 mm, Stroke 20 mm.


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## kadora (Oct 3, 2016)

This is my way of crank shaft machining.
I know two ways of crank shaft machining.
First is to machine it from solid bar //this is not job for my hobby lathe//
second is to assemble it from parts. //my way//

So on first picture are main shaft and flywheel.
Here is not need for explanation how to do these parts only diameter and thickness  of flywheel is bigger 0.5mm as needed and holes are reamed to H7.

Second pic. shows hammered bolt between flywheel and shaft.
Purpose of this bolt is to keep clockwise  and anticlockwise torque .

Third pic. drilling hole through flywheel to the center of main shaft.

Fourth pic. hammered long bolt to the flywheel. This bolt keeps front and back 
torque of the shaft.

Fifth pic. machining crank shaft to final dimensions.

Last pic. cutted thread through long bolt to keep bolt safely in place.

All joints and bolts are loctite before assembly.
Any criticism is welcome. //i am still learning//


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## Hopper (Oct 3, 2016)

Well it looks like that crank web will never move on its shaft! Should be as strong as the real thing, the way you have done it.


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## kadora (Oct 4, 2016)

Today only simple part - con rod pin.
I use for the con rod pin Linear bearing shaft //or guide?//
because it has ultra hard surface and is grinded to high precision diameter.
Disadvantage of this linear shaft is impossibility to drill a hole through 
shaft so the only way how to fasten pin to the flywheel is welding.
1. pic. cut pin //with angle grinder//
2. pic. pin glued to the flywheel.
3. pic. aluminium sleeve - to sink heat from the pin during welding process.
//Sleeve should be more massive but i do not have suitable AL piece right now.//
Tomorrow welding.


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## kadora (Oct 5, 2016)

Hello
Crank is done.
1. pic. welded pin //pin is not overheated//
2. pic. checking if pin is in line with main shaft.
3. pic. crank assembly - see spacer between ball bearings.
My conclusion is that this way of crank shaft machining 
is not so precise as machining it from bar but there
is possibility to use very hard materials for main shaft and
con rod pin without quenching .


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## kadora (Oct 6, 2016)

Today housing for teeth pulley shaft ball bearing .
1. pic. ball bearing in the housing.
2. pic. housing pressed to the casting.


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## kadora (Oct 9, 2016)

So time to machine rear cover.
This part holds only one ball bearing so 
machining is easy.
1. pic. blank casting
2. pic. cutting rim and drilling hole for ball bearing housing.
3. pic. ball bearing assembled in housing then pressed into casting.
4. pic. copy holes from cover to the crank case + cutting threads
5. pic. liner before pushing  into cylinder.
I use factory made liner //ASP  RC engine spare part//
because this liner has hard chrome plating on inner side.
This hard plating I am not able to do at home


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## kadora (Oct 10, 2016)

Sorry I do not know English word for this part so
I will call it Carrier.
This item is transferring torque from crank shaft 
to the teeth belt pulley.
Carrier consist of 3mm thick steel ring with two grooves  //1. pic.//
One groove is for con rod pin , second is only for balance purpose.
2. pic. already TIG welded shaft /again I have used linear bearing shaft/.
3. pic. assembled carrier and crank in crank case.


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## Hopper (Oct 10, 2016)

Next time you need a heat sink on a welded crank pin like that, try pushing the pin into a large potato. It will absorb an amazing amount of heat. That's the way the professionals do it! It works very well for soldering copper pipe etc too.


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## DiegoVV (Oct 10, 2016)

I´ve been following your project progress and it looks good. 

Aanyway I can see you are milling the parts using a drill chuck....not a good idea. Drill chucks only accepts axial loads, not radial as the ones involved during milling. Apart from the lack of precission, it´s quite easy ending up with the chuck jumping suddenly off its arbor...scary for me.

Also you are milling with a dovetail cutter. Again apart from the lack of precission, dovetail cutters are designed to cut dovetails, not for facing. The flutes are very thin on their tips so you can easily break the cutter if you take a deep pass. Also the quality of the surface will not be the best.

Only my two cents.


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## kadora (Oct 11, 2016)

Potato cooling is perfect idea I will try it .

Diego VV thank you for your advices.
I am self educated machinist and I really 
appreciate every recommendation.

Thank you guys.

Sending pictures from con rod machining.
To machine con rod is common job but everyone do it
in slightly different way.
I machine con rod in fixture //1. pic.//
I move con rod with hand from one endpoint to the second endpoint.
After each round I push con rod 0.2 mm to the milling bit until I reach required diameter. 
I know not very safe.


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## Hopper (Oct 12, 2016)

I love your jig for machining the round end on the con rod. Rotary table? We don't need no steenking rotary table!


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## kadora (Oct 13, 2016)

Machining bushings need not to be explained.
1. pic. bushings pressed in con rod
2. pic piston
Again I used factory made piston because piston´s
aluminium is unbelievable hard probably piston is
forged.
Piston pin is cut from linear bearing rod.


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## Hopper (Oct 14, 2016)

Nice work. Where did  you buy the factory made piston?


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## kadora (Oct 14, 2016)

Hello Hooper
Search for HOBBYKING then GLOW ENGINE PARTS on the left side column.

Cylinder head 
Just for illustration 1. pic. shows rubber form and head wax pattern.
2. pic. cutting bottom part of head to have smooth surface.
3. pic. cutting two diameters one for liner second for combustion 
chamber + checking if liner is tight .
4. pic. bottom side finished.
5. pic. milling top head surface . Bottom and top surface must be
 parallel  because next machining process will be depend on accuracy of
these surfaces.


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## kadora (Oct 15, 2016)

Now drilling holes for valve sleeves and valve pushers.
1. pic.  machining holes for sleeves .
2. pic. milling space for sleeves rims .
3. pic. finished drilling .
4. pic. milling space for cam shaft .
5. pic. machining holes for valve pushers /lifters/.
6. pic. drilling probably the most complicated hole for glow plug.
Into this hole I cut M8x0.75 thread . Later I will insert 
glow plug adapter there . Glow plugs have very short thread
and it is always risky to fasten plug in aluminium
so for this reason I usually do plug adapter from steel .


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## Hopper (Oct 15, 2016)

Nice work. What material will you make the valve seat inserts from?


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## kadora (Oct 16, 2016)

This engine has valve guide and valve seat in one body.
This item is produced from brass.1. pic.
The same material for lifter´s guides. 2. pic.
Sorry for picture quality i am not able to take 
good pictures from shiny things.


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## Hopper (Oct 16, 2016)

Interesting. I am quite fascinated by the difference in metallurgy between full sized IC engines and what can be used in model IC engines. It sure makes things a lot simpler not to have to use hardened valve seats and so forth. I guess short running times and working under no-load conditions helps the model engines get away with softer metals etc.


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## kadora (Oct 17, 2016)

1. pic. shows lifter guides assembly.
2. pic. valve sleeve  assembly.
3. + 4. pic. assembled parts.
5. pic. drilling intake and exhaust holes through casting and through 
one wall of valve sleeve.


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## eborengineer (Oct 18, 2016)

Kadora
A very interesting looking engine.  Can you say where the drawings can be found.  I assume from your comments that you cast the parts yourself and no castings are available. If possible could you post a cross section drawing.  Thanks 
Mike


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## kadora (Oct 18, 2016)

Mike I have CAD cross section but I am not able to convert
CAD drawing to the JPEG pic. so I can not publish drawing here.
If you want CAD cross section drawing i can send it to you via E-mail.
Yes castings are made in my house but i have some small quality problems
in casting process yet  so i have to solve them  first.

OK today only drilling holes for head screws.


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## kadora (Oct 19, 2016)

I would like to show you different way of valves machining.
I know old machinists will gave loud laugh when they see 
my next pictures but i have two engines fully running with
these valves. /this is not my idea to use screws as base for valves
my French friend has many such engines/.
Anyway find on market screws which have the same diameter
of stem. /use micrometer/
1. pic. there is basic screw , cutting disc //screws are made from very hard material possible to cut only by this Dremel disc// and already cut valve.
On valve stem is sleeve needed for machining clip circle groove .
2. pic. grinding clip circle groove. /squeeze sleeve tight in chuck/
3. pic. finished valves.
4. pic. another advantage - screw head has Philips cross so to grind
valves to the valve seats is easy job.


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## Blogwitch (Oct 20, 2016)

Very unique way of doing it.

Now you say you used countersunk wood screws. 
I always thought that they used an 82 degree angle for the head while standard metric countersink bolts (bolts have a plain shank between head and thread and an engineering screw is threaded all the way up to head) use 90 degrees. I may be wrong, but if it is correct, how do you compensate for it?

John


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## kadora (Oct 20, 2016)

Hello John
I do not claim that countersunk wood screw is perfect solution
but my intention is to show beginners easier way of first engine 
machining. I am not able to measure screw head angle .
Is big difference between 90 and 82 degrees?

Winding springs is simple job .
I wind spring wire on fixture as you see on 1. pic. /brass item/ and 
already wind coils.
2. pic. shows way of wire winding.
3. pic. coil stretched out.
4. pic. grinded ends of spring.
According spring wire vendor - finished /formed/ spring need to be
heat for 30 min in 300 degrees of celsius so I going to heat up oven.


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## Blogwitch (Oct 20, 2016)

I wasn't criticising you K, I was just curious.

I actually bought a set of 82 degree single edge countersinks many moons ago by mistake, and actually have used them many times since when screwing metal plate to wooden bases using countersunk wood screws. I suppose they could be used to make the angles in the head if you did use hardened wood screws as valves.

John


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## kadora (Oct 21, 2016)

Excuse me John if I was rude you know English is not my mother language.
 I am open to critisism take my apology.


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## Blogwitch (Oct 21, 2016)

I understand completely K, think nothing more of it.

Just carry on with what you are doing, you are doing great.

John


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## kadora (Oct 21, 2016)

Thank you John.

Valve retainers is simple job not worth to describe.
Picture shows everything.


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## Hopper (Oct 21, 2016)

Brilliant in its simplicity - just like the ESO itself. 
I like the countersunk screw idea.Those things are as tough as, er, nails as the saying goes. Actually, much tougher though. Probably a great material for valves. And I like the way you use the Phillips slots to grind the valves in. I have noticed some model IC builders simply machine the seats in one setting and then the valve guides in another, then press the guides into the head  and expect everthing to line up and seal, something we would never do in a full sized engine. Love your simple low-tech solution.


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## kadora (Oct 22, 2016)

Valve lifters again easy job.
On first picture you can see small holes in the middle of the lifters.
These holes have two purposes.
First is to release pressure in valve spring cavity when lifter is 
pressed down by cam shaft lobe.
Small amount of oil is always leaking between valve sleeve and
valve stem into spring cavity . Pressure created by lifter escapes through this
small hole together with drops of leaking oil and lubricate 
cam shaft lobe.
On my first eso engine I checked if it works and it works perfect.
Lifters are machined from drill rod.


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## kadora (Oct 23, 2016)

Gun metal bushings for cam shaft.


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## eborengineer (Oct 23, 2016)

Kadora - I too liked the novel use of screws as embryo valves.  I would have predicted that the material was strong enough but would have questioned the surface finish and possibly the roundness.  Have you had to hone the stems in any way?
Mike


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## kadora (Oct 24, 2016)

Mike 
You are right . Majority of screws on market have rough surface "stem"
but i have found screws with surprisingly nice  surface and roudness of stem
good enough for valves.


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## kadora (Oct 24, 2016)

Before drilling holes for screws which fasten head to the cylinder
is needed the alignment of teeth pulley shafts.
So I applied low temp. melting epoxy between cylinder and head ,
pushed rods through bearings in the crank case and in the head.
Then I put rods on a glass sheet and by vice weight both rods.
By this way is easy to get both shafts perfectly parallel .
Picture says more.


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## kadora (Oct 25, 2016)

Epoxy is dry so I can copy head holes to the cylinder 1. pic.
Black tape protects spring cavities away from drilling chips.
2. pic. Making threads M3 depth 15 mm.
Next will be cam shaft machining - terrible boring job


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## Hopper (Oct 26, 2016)

Camshaft machining, maybe  boring to you but I'm interested to see which technique you use. A cam grinder is on my list of "to do" jobs.


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## kadora (Oct 26, 2016)

Today just shaft with blank lobes.
1. pic. teeth pulley and shaft.
2. pic. checking if is everything OK before
lobes milling. Material drill rod Dia 10 mm.


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## kadora (Oct 30, 2016)

For milling lobes i have built simple fixture.
Fixture contains stationary unit with attached protractor
and rotational unit with attached arrow 1. pic.
On 2. pic. is backside of fixture .On the top of orange cylinder 
/stationary unit/ you can see screw X by which is possible to fix 
rotational unit to the stationary unit.
3. pic.  blank cam shaft is secured to the rotational unit
by small screw /see allen key above arrow/.
4. pic. fixture fasten in vice and thick allen key to secure
rotational unit to the stationary unit /screw X/and arrow set in 0 degree position.
So cam shaft is ready for milling lobes.


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## kadora (Oct 31, 2016)

Milling lobes starts in 0 degree position.
1.pic. here is milling depth of lobe in my case 2 mm.
Then secure height of milling bit for rest of work.
2.pic. milling lobe in CCW direction , turning lobe in 2 degrees increments
till 120 degrees is reached.
3.pic. return lobe to 0 degree position and  mill lobe in CW direction
till - 120 degrees.First lobe done.
4.pic.  return lobe to the 0 degree and attach second arrow points to 0 degree.
Then release screw what secures camshaft pull camshaft out
to see second lobe./DO NOT MOVE ROTATIONAL UNIT/
5.pic. turn camshaft till second arrow points to 100 degrees CW and secure it in this position.
6.pic. milling second lobe in the same way as described above.
Lobes timing angle is variable for CW and CCW running engines.


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## kadora (Nov 1, 2016)

To finish camshaft the washer needs to be "riveted"
on the end of camshaft.1. pic.
2.pic. steel ball rivets end of shaft under press.


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## kadora (Nov 2, 2016)

Teeth belt tensioner.
First cutting thread M3 for tensioner shaft 1. pic.
Here is important to consider what direction engine will turn.
In my case CCW. /if CW pulley must run on opposite side of belt/
2.pic. tensioner pulley has gun metal bushing.
3.pic. assembled pulley.
By changing diameter of pulley is possible to adjust the tension of teeth 
belt./engine has to be assembled for this tension setting/


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## Hopper (Nov 3, 2016)

Looking good!


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## kadora (Nov 3, 2016)

Thank you Hopper.
1.pic. shows small teeth pulley on the carrier shaft
This is only for illustration how it goes together.
2.pic. carrier,belt and small pulley assembled in crank case.
3.pic. head gasket cut out from 0.4mm thick hard paper.
/office file/
Everything ready for final engine assembly 4.pic.
I had time for machining carburator adapter and exhaust 
port so i attached these parts on cylinder head.
Sorry for watch /my second addiction/i did not notice it
when i took picture.
Now I need head cover hopefully i will have time to cast this part during weekend.


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## Hopper (Nov 3, 2016)

Great little device for machining the camshaft with. Much cheaper than a rotary table too!


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## kadora (Nov 6, 2016)

1.pic. blank head cover .
2.pic. drilling 2.5 mm holes for cover screws.
3.pic. milling decorative fins.
4.pic. milling angled rim for better approach to the glow plug.
5.pic. head cover glued to the cyl.head to be able to copy cover holes to the cylinder head. //I like this epoxy because of its low melting temperature//.
Epoxy label says 30 min. drying but I prefer 2 hours cure time.


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## Hopper (Nov 6, 2016)

Clever idea gluing the two pieces together before drilling the holes through both for perfect match. I'll file that one away for future use. Thanks for the tip!


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## kadora (Nov 8, 2016)

Today only one picture.
Here is nearly complete engine including engine holders.
Next step /not needed/ is to blast surface of engine with glass pellets .
Glass pellets leave much shiner aluminium surface than sand blasting
and covers small imperfections and scratches. 
Intake and exhaust ports have to be blocked.


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## Hopper (Nov 8, 2016)

Looking very nice. What is the lubrication system? Just splash lube from what is in the crankcase? Any oil in the fuel?


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## kadora (Nov 9, 2016)

Lubrication is oil mixed with fuel + small amount of oil in crankcase
for maiden run.


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## kadora (Nov 22, 2016)

Finished engine.
For maiden run I always use factory made carburator ,
brand new 4 stroke glow plug and propeller to cool fresh engine.
Helpful is to paint one tip of propeller in TDC  to know in which position the piston is.
Exhaust end pipe is made from transistor radio telescopic antena.
ESO logo is made from small plastic letters glued with instant glue
to the base and painted .

Thank you for your interest .


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## Hopper (Nov 22, 2016)

Very nice indeed!


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## mirek111 (Dec 25, 2016)

Teprve dnes jsem se dopracoval na tuhle stránku.Ú&#382;asná práce!


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