ESO engine machining

[kadora]

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

 

[kadora]

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.

 

[kadora]

Now centering and boring the the hole for liner.

 

[kadora]

Milling bottom part of casting

 

[kadora]

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

 

[kadora]

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.

 

[Hopper]

Subscribed. Looks very nice indeed.

 

[kadora]

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

 

[kadora]

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.

 

[Blogwitch]

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

 

[kadora]

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.

 

[stevehuckss396]

Nice!

I'll be watching!

 

[Hopper]

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?

 

[kadora]

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.

 

[kadora]

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//

 

[Hopper]

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.

 

[kadora]

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.

 

[kadora]

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 .

 

[kadora]

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

 

[kadora]

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