ESO engine machining

[kadora]

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.

 

[Hopper]

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.

 

[DiegoVV]

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.

 

[kadora]

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.

 

[Hopper]

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

 

[kadora]

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.

 

[Hopper]

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

 

[kadora]

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.

 

[kadora]

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 .

 

[Hopper]

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

 

[kadora]

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.

 

[Hopper]

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.

 

[kadora]

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.

 

[eborengineer]

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

 

[kadora]

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.

 

[kadora]

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.

 

[Blogwitch]

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

 

[kadora]

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.

 

[Blogwitch]

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

 

[kadora]

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