# Felgiebel 16,6



## F-DS (Nov 28, 2019)

Ahoj
Po dlouhém plánování jsem začal stavět dvoudobý benzinový motor Felgiebel. Připravoval jsem se na stavbu motoru dva roky a poté, co jsem dostal plány, zkušenosti s konstrukcí dalších motorů a pístní kroužky, mohl jsem začít svůj nápad naplňovat. Svou konstrukci jsem zahájil vytvořením válce.

Motor má neobvyklý objem válce 16,6 ccm, protože použití prstenů pro větší vrtání. Kroužky o průměru 26 mm jsou pro mě nedostupné, protože jsem použil možnosti prsteny o průměru 28 mm.
DS


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## F-DS (Nov 28, 2019)

Turning of cylinder and rib contours.


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## F-DS (Nov 28, 2019)

Production of canals and crimped cylinder.


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## F-DS (Nov 28, 2019)

Future carburetor.


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## kadora (Nov 29, 2019)

ahoj z akeho materialu si robil kruzky?
what material did you use for piston rings production?


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## F-DS (Nov 29, 2019)

kadora said:


> ahoj z akeho materialu si robil kruzky?
> what material did you use for piston rings production?



Kroužky jsem koupil od české firmy "Piston Rings Komarov s.r.o". Právě kroužky jsem začal shánět  jako úplně první a od rozměru kroužků, které jsem sehnal jsem upravil obsah válce.
I bought the rings from the Czech company "Piston Rings Komarov s.r.o". Just the rings I started looking for the very first and from the size of the rings that I got I modified the contents of the cylinder.


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## F-DS (Nov 29, 2019)

Releasing slot.


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## F-DS (Nov 29, 2019)

Carburetor throat. Unfortunately, the carburettor tube ripped in my first attempt. I made a thorn to widen my throat.


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## kadora (Nov 30, 2019)

Such things happens.


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## F-DS (Dec 1, 2019)

I fit the transfer channel to the cylinder.  Now I'll try to make a new carburetor.


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## aka9950202 (Dec 2, 2019)

Very  neat work. I am envious. 

Cheers, 

Andrew in Melbourne


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## F-DS (Dec 2, 2019)

aka9950202 said:


> Very  neat work. I am envious.
> 
> Cheers,
> 
> Andrew in Melbourne



Thank you.


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## F-DS (Dec 3, 2019)

Extension of carburetor throat-attempt number two.
The throat had to be repeatedly heated by the burner to light red and then tap the thorn with small knocks.


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## F-DS (Dec 9, 2019)

Preparing for soldering.
 I made a fixture to attach the carburetor to the cylinder. It holds the transfer channel itself as it is pressed. I insured him with a wire anyway. After a long deliberation, I made an unplanned exhaust flange.
Before soldering, I coated the soldered places with a mixture of borax and alcohol.

I can provide my own sketch on the flange.


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## F-DS (Dec 9, 2019)

Cylinder just after soldering. He's not cleared of borax yet. I soldered with silver, soldering itself lasted about 30 minutes and there was no need to heat the cylinder red.


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## F-DS (Dec 9, 2019)

After rough cleaning of borax.


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## John Antliff (Dec 10, 2019)

A tricky brazing job and well executed.  Did everything end up in the desired positions?


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## F-DS (Dec 10, 2019)

John Antliff said:


> A tricky brazing job and well executed.  Did everything end up in the desired positions?



No, thanks to the necessary preparation, nothing moved. I was surprised how everything went according to plan.
Perhaps only the exhaust flange wanted to secure against sliding down.


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## F-DS (Dec 10, 2019)

Anyone have any idea how to gently clean up borax? Steel brush, chemically .....?


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## rweber (Dec 10, 2019)

I never used Borax, but the flux I used from Felder was quite well removable with a 15% sulfuric acid. Heated up to about 30-40°C. Take care,  use gloves and glasses!


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## F-DS (Dec 11, 2019)

rweber said:


> I never used Borax, but the flux I used from Felder was quite well removable with a 15% sulfuric acid. Heated up to about 30-40°C. Take care,  use gloves and glasses!




In addition to using a steel brush, I thought of dissolving borax. For example, I would cook the cylinder in an old pot for an hour so that the water was just before boiling. This would allow the borax to loosen. I'm afraid to use acid so that the cylinder does not start to rust after use.


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## werowance (Dec 11, 2019)

i use dremel with little wire brush sometimes,  and sometimes i use dremel wtih what looks like scotchbrite pad on the end.  both work well for me


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## F-DS (Dec 11, 2019)

werowance said:


> i use dremel with little wire brush sometimes,  and sometimes i use dremel wtih what looks like scotchbrite pad on the end.  both work well for me



This is quite similar to my clamping of a special steel brush in a drill. Probably clean the cylinder with a steel brush. Maybe it won't even scratch because it's made of very good material, like a carburetor and a flange. Only the transfer channel is of ordinary mild steel.


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## F-DS (Dec 15, 2019)

I used a brass brush to roughly clean the cylinder from borax, then boiled the cylinder for a while in the water, dissolving the remaining borax and cleaning it manually with a toothbrush.







After the borax was cleaned, I grinded the overflowed silver with the help of a straight grinder "parkside" and home made abrasive handles of P240, P500 and P800 to create a smooth transition.

I also focused on the cut of the cylinder. Since I have the opportunity, I borrowed reamers (from a diameter of 25.5 to 27.5 mm) and I passed through the cylinder. The reamers have a tolerance of H8 and in reality the cylinder now has an average deviation of 0 to + 0.1mm. For the cut I bought a honing head, which I increase the drilling to 27, 8 mm.






With the honing head, I also bought a NGK CM-6 candle. to make the cylinder head.


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## F-DS (Dec 22, 2019)

Grinding with honing head. The deviation on the inside diameter of the cylinder is 0.02 mm. (0.000787401575 inches)
Interestingly, the honing head reduced the internal diameter of the cylinder.


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## F-DS (Dec 22, 2019)

Production of cylinder head.


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## F-DS (Dec 22, 2019)

Finished but not yet stuck head.


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## F-DS (Jan 4, 2020)

The Christmas holidays are over and we can continue to build Felgiebel. I had a 3D model of the crankcase printed out and now I will be making molds.


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## F-DS (Jan 19, 2020)

Now I put the crankcase aside and I'm currently working on the crankshaft.
Previously, I made a propeller carrier and a puller for the carrier. The gripper has an internal taper hole with a 1:50 pitch.


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## F-DS (Feb 5, 2020)

Do you harden crankshafts into similar engines?


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## F-DS (Feb 20, 2020)

Half-produced crankshaft.


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## Mechanicboy (Feb 20, 2020)

F-DS said:


> Do you harden crankshafts into similar engines?



No necessary to harden the crankshaft if you are using the high tensile steel. 

If hardening the crankshaft, there is the risk to bend the crankshaft and the surfaces need grinding with tool post grinder or gringing machine for shaft due the diameter is increased after hardening.


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## F-DS (Feb 21, 2020)

Thank you, that after hardening will change the dimensions of the body I did not know. At least I have one heavy job lightened.


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## Matthias (Feb 21, 2020)

Dobrý den, jaký materiál jste použili pro válec a klikový hřídel.  Plánuji postavit 4cc Kratmo.  Plán zahrnuje materiály, které již nejsou k dispozici.  S pozdravem Matthias


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## F-DS (Feb 21, 2020)

Válec i klikový hřídel jsem dělal z oceli Poldi T6W. Měl by to být materiál podobný ČSN 19 083. Lze použít Poldi C45, ČSN 12 051.


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## Matthias (Feb 21, 2020)

Díky, musím zjistit, jestli v Německu existuje.  Jaký druh zapalování chcete použít?  Postavte si elektronickou nebo zapalovací cívku sami?  
Zdravím Matthias


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## F-DS (Feb 21, 2020)

Plánuji, že si zapalovací cívku vyrobím sám, podle návodu v knize "spalovací motorky pro letadélka." Když se nepovede, tak jí koupím.

Ich plane, die Zündspule selbst gemäß den Anweisungen im Buch "Benzinmotoren für Flugmodele" herzustellen. Wenn es fehlschlägt, werde ich es kaufen.


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## Matthias (Feb 21, 2020)

Slyšel jsem, že v České republice by měla být společnost, která prodává zapalovací cívky.  Společnost jsem bohužel zatím nenalezl.  Hodně štěstí a hodně štěstí.


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## F-DS (Feb 21, 2020)

O žádné takové firmě, která by pocházela z ČR jsem nikdy neslyšel, ale je to možné.
Ich habe noch nie von einem bestimmten Unternehmen aus der Tschechischen Republik gehört, aber es ist möglich.


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## Mechanicboy (Feb 21, 2020)

Privet/Привет! F-DS and Matthias, not hard to read yours Czech language since i can russian since i am married with ukrainian wife.   

You wrote about the ignition for model engine, here is the link where you can order the ignition set: https://www.bigplanes.nl/contents/en-uk/d120.html


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## Cogsy (Feb 21, 2020)

Guys - please post in English, even if it's just run through Google translate. Thanks.


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## Mechanicboy (Feb 22, 2020)

F-DS and Matthias, for model engines with contactbreaker, you can order the coil from this website:

https://minimagneto.co.uk/Products.php

http://www.model-engine-ignition.com/home/coils


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## F-DS (Feb 28, 2020)

Production of gypsum mold for casting of engine crankcase. If the casting is not according to my wishes, I will also make a mold from sand.
I used an ordinary cutting spray as a separator.


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## Matthias (Feb 28, 2020)

Be careful about pouring aluminum into Gibs.  Gypsum must be completely dry, otherwise steam bubbles will form.  It may be that aluminum splashes on you.


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## F-DS (Feb 28, 2020)

Yes, I know. I have already cast into the plaster mold. Let the plaster dry for at least 2 weeks under the fireplace.


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## F-DS (Mar 14, 2020)

I have a roughly finished connecting rod.

Bearing ready for pressing.


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## F-DS (Mar 14, 2020)

Grinding the connecting rod width to the final dimension of 6.5mm


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## F-DS (Mar 14, 2020)

Finished connecting rod.


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## F-DS (Mar 30, 2020)

I cast the crankcase of my Felgiebel engine. During casting, I had a small accident, when the metal was poured into the mold, the mold broke and most of the aluminum leaked out of the mold. I then glued the mold (using a regular glue stick, because it contains little water) and I cast it again, which was successfully cast. In fact, the casting is better than it looks in the photos. The last picture shows the first cast scrap, which is porous and full of bubbles. These bubbles were caused by the evaporation of trace water.

When using gypsum molds, there are always problems with moisture, which I have been dealing with for a long time, but they are difficult to manufacture and do not allow me to reach such a surface as gypsum molds. I have repeatedly tried to conclude that the gypsum mold must first be "burned" by pouring molten aluminum into the mold before casting the usable casting itself, which will cause immediate release of steam during the first casting and thus spoil the potential casting. Only after this "firing" can liquid metal be poured into the mold without fear of the occurrence of additional steam, which otherwise causes cavities inside the casting, rough surface and porosity. The mold used now was dried for several weeks under the stove for a few weeks, then fired in an oven at 200 ° C for 1 hour, and finally just before casting I heated it for about 80 ° C with a hot air gun in a special "preheating box". This measure did not help either. In the form you can see made inscriptions, which unfortunately did not cast. (E only)


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## Dragons_fire (Mar 31, 2020)

I'm learning lost PLA casting in plaster and I've found that adding just a few percent of Portland cement and a few percent of sand really helps with the strength of the mold. The cement really slows down how quickly the mold dries though. I let it cure for a week, then put it in front of a space heater for a day and that blows warm air over it and helps remove moisture. Then goes into an old pottery kiln and heats to 110°C for 4 hours, then up to about 180°C for 2 hours, then up to 350°C for another 4 hours.  I let it cool in the kiln overnight, then the next day it's ready for casting. It makes an almost exact copy of the surface finish on the 3d part, and there is no noticable voids in the cast part.

I also find it's a lot safer to surround the mold with sand (bottom and sides) before pouring the aluminum. It seems to hold any cracks in the mold together, but will also prevent any spilled aluminum from running all over the place.


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## F-DS (Mar 31, 2020)

to: Dragons_fire

Does the drying of the mold you described help make the first cast usable? The tip surrounding the mold with sand is good, it increases safety and slows down cooling, which helps to better shape the internal structure of the casting.


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## Dragons_fire (Mar 31, 2020)

I'm doing lost PLA, so the 3d printed part is actually burned right out of the plaster mold.  These molds are only useable one time, and they are broken apart to reveal the part inside.  Attached is a pic of some handles I made. They are about 3/8" (10mm) thick. There has been some grinding and some machining done to them before this pic, to remove the sprues and clean them up a bit. If you look close, you can see how it picked up the layers from the 3d printed part right in the aluminum.


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## F-DS (Apr 24, 2020)

Since I am not satisfied with the surface of the crankcase casting, as there is time (due to the presence of the flu) and because I wanted to have the engine name "FELGIEBEL" on the casting, I decided to cast the crankcase once more, this time in sand mold. I started to adapt the model for this method of casting, I made letters from the putty. The process of making letters can be seen from the photos.


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## F-DS (May 6, 2020)

I glued the letters to the crankcase model, which I then painted with a thicker layer of synthetic varnish.


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## TonyM (May 7, 2020)

I'm looking forward to see the final casting. Where are you in CZ. I am in the north near Novy Bor


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## F-DS (May 7, 2020)

I live in the Olomouc region, Přerov district. Nový Bor is 320 km from us.


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## Rudirk (May 7, 2020)

This is one of my first casting. I made a easy wood model and buried sand for casting. The next part was much better. I made a lot of 0,5 mm air holes in sand.


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## F-DS (May 7, 2020)

How did you achieve cavity formation in the casting? Two-part casting form?


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## Rudirk (May 8, 2020)

Yes, I made two wood parts .


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## F-DS (May 16, 2020)

Sand preparation. As a binder, I used ordinary clay, as sharply sieved construction silica sand. I started with a binder / sharpening ratio of 215/1000, with a gradual end to 1/3. The mixture is full of clay, but it forms a smooth surface. I'll see if a higher proportion of clay does not matter during casting.


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## F-DS (May 16, 2020)

Mold drying


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## F-DS (May 23, 2020)

I cast the crankcase of my engine. I heated the mold with a hot air gun before casting, the casting was better than I expected, I am satisfied with this casting. I photographed both castings, for comparison. 
During the casting, I had a small accident, I made a product to increase the hydrostatic pressure in the mold to improve its run-in, but the aluminum spilled instead of the exhaust hole out of the side.


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## Rudirk (May 24, 2020)

Hallo, the part looks really better. I think you could use it for machining your engine.


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## William May (May 24, 2020)

Truly, all that matters is what is left after machining, and it looks like you have a good surface finish on all the areas that WON"T be machined, so you are good to go. Looks like an excellent casting!
To avoid "side-flow" where the metal comes out the split line of the mold, I usually cut a small step around all the edges of the lower mold, then ram the upper mold. The result is what I call a "seal-mold" where the metal is better contained. 
This is a common problem, and depending on the casting, may not even matter. If your mold is all on one half of the mold box, and if that half is the lower one, then even if  you do get some side-flow, the mold still filled, and the casting will be OK. 
You did a nice job on the lettering, also!


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## William May (May 24, 2020)

I just looked at the equipment  you are using to cast! (I hadn't looked at the small pics before). You didn't just do a GOOD job, you did a MAGNIFICENT job. Turning out good castings with good equipment is expected. But turning out good castings with a backyard makeshift foundry furnace like yours is an awesome accomplishment.  And you even used lettering! I am VERY impressed! I would say that when you get better equipment, you will have no trouble turning out excellent castings! 
Maybe you should do a section in here, about casting on a very minimum equipment and cost level. That might start a LOT of new people making castings!


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## F-DS (May 24, 2020)

Thank you for the compliment, I'm still amazed at how the casting went. The casting section sounds like an interesting idea. Since the casting has no defects, I will use it on my engine.


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## F-DS (May 29, 2020)

When it doesn't work 
I started turning the crankcase, after an hour of machining, when I was parting the rear cover, my casting cracked. The quarry shows how the casting is porous and inhomogeneous, the shape of the casting is not everything, I have to go back to the "drawing board" and come up with another solution for the casting.


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## F-DS (May 29, 2020)

I made a piston, the clearance of the piston rings is 0.07 mm.


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## Peter Twissell (May 29, 2020)

Shame about the casting cracking after all your excellent work in mould making and pouring.
What was the material used for the casting?


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## William May (May 29, 2020)

F-DS said:


> When it doesn't work
> I started turning the crankcase, after an hour of machining, when I was parting the rear cover, my casting cracked. The quarry shows how the casting is porous and inhomogeneous, the shape of the casting is not everything, I have to go back to the "drawing board" and come up with another solution for the casting.
> 
> View attachment 116674


Sorry to hear about that! If you send me your address in a PM, I will send you a couple of "Degassing Discs" for aluminum, no charge.. I applaud your efforts at casting, with minimal equipment, and I am sure your posts on here are a real eye-opener to many who have thought about doing some small castings, but have been hesitant.  With the amount you cast, that will last you for 10 castings, easily. I have a box full, and I only use a part of one disc for a full #8 crucible of aluminum. It is a proprietary disc that looks like a laundry soap tablet. You drop it in, AFTER you have removed the aluminum pot from the fire for pouring, and then submerge it in the aluminum with a stainless steel poker or cone. (I use a cone, with holes in it. You press it under the surface of the molten aluminum, and it starts to bubble and release gases.) These remove the oxygen from the molten aluminum, slag our the impurities, and you can then skim them off and do your pour.  it is only a 30 second operation, the last before you pour the molds. You will be amazed at how much crap suddenly  appears on the top of the metal. Then you use a tool with a ledge on it to skim the aluminum, and you are left with a nice, shiny pot of metal. Then you pour, and you get a lot better castings, even with the minimal equipment you work with.  THE ONLY THING IS THAT THE GAS GENERATED AS IT BUBBLES IS POISONOUS! YOU DO NOT WANT TO BREATHE IT, SO STAY UPWIND OF THE METAL POT WHILE DE-GASSING.


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## ixb1 (May 29, 2020)

Ahoj F-DS
Did you saw this Felgiebel build thread?Just for inspiration.




__





						Building the Felgiebel
					

Dear all,  after finish the Mono (http://www.homemodelenginemachinist.com/showthread.php?t=27456) I was looking forward to find a new project. When beeing at an exhibition I meet a guy that was showing an Felgiebel engine. It's supposed to be one of the first model engines available in Germany...




					www.homemodelenginemachinist.com


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## Mechanicboy (May 30, 2020)

Molding mistakes made by yourself: Never interrupt while pouring floating aluminum into the mold in the meantime.

When you stop pouring floating aluminum, the first part of the aluminum cools before pouring the floating aluminum again until the mold is completely filled. The reason is that the cooled aluminum will never be bonded with floating aluminum.

When pouring aluminum into the mold, keep pouring until the aluminum starts to solidify or there will only be gas blisters and shrunken aluminum that will not cover in all places in the mold.

Keep the mold as dry as possible without developing steam during molding. I am using cast sand mixed by 80% sand which has 0.5-0.6 mm grain size mixed with 20% clay.


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## TimTaylor (May 30, 2020)

Did you use a cover flux? It will reduce the dross and minimize hydrogen absorption from the atmosphere.


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## Mechanicboy (May 30, 2020)

TimTaylor said:


> Did you use a cover flux? It will reduce the dross and minimize hydrogen absorption from the atmosphere.



I never used flux in aluminium, remove slag and degassing the aluminium before pouring only. The aluminium came from old engine parts. Se at my products of cast aluminium and own made model engines.


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## TimTaylor (May 30, 2020)

Mechanicboy said:


> I never used flux in aluminium, remove slag and degassing the aluminium before pouring only. The aluminium came from old engine parts. Se at my products of cast aluminium and own made model engines.


Very nice work!

The reason I asked is that from the picture, it looks like the OP's casting failed due to a porosity issue. Usually this is caused by absorption of hydrogen gas from the atmosphere that is released as bubbles as the aluminum cools. Lengthy exposure time to the atmosphere and excessive superheat of the molten metal are major contributing factors. A cover flux, which is basically a salt compound, will minimize absorption. A drossing flux will separate usable aluminum (as much as 80%) from the dross. Degassing can be done chemically or mechanically. Most chemical degassing agents are chlorine or fluorine based, and as William May said earlier, the fumes generated are quite hazardous. A much safer alternative that works pretty well is sodium carbonate. It's pretty cheap in granular form and non hazardous. You simply put about a table spoon in a piece of aluminum foil and roll it into a tight packet, then use a clean steel rod to push it to the bottom of the crucible of molten aluminum and hold it there until the bubbling stops and the foil is melted. Scrape the dross & pour...

I learned metal casting in a foundry class years ago in high school, and we were taught to use fluxes, so that's what I have always done. We poured aluminum on a daily basis and brass or bronze about once a week. Once every couple of months we'd set up the cupola furnace and do a cast iron pour.....


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## Mechanicboy (May 30, 2020)

Tim Taylor, I'ts new for me to use sodium carbonate as flux. Thanks you for information.


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## F-DS (Jun 4, 2020)

The problem with casting was not the interruption of aluminum casting that would cause its incoherence, but the fact that I added 1/3 of the aluminum from the car pistons to the batch. The pistons contain a high% of silicon, which was supposed to guarantee the strength of the crankcase, but apparently its presence caused just a rough structure and fragility. I believe that the pistons are cast under different conditions than what I achieve in the home environment and therefore the material does not behave as it should.


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## F-DS (Jun 4, 2020)

Today I cast another crankcase casting, this time I used a different 3-part mold, of which the first two parts are screwed together, so that the aluminum could not separate them from each other and spilled sideways. 3 parts of the mold form a chimney into which the metal is poured. I used the same one last time. I wiped all the joints of the mold for the circuit breaker with water glass mixed with sand, so that the aluminum could not flow out of the mold other than through the vent hole. I had a good feeling from the mold, it had a perfect shape and it was already quite level, the problem was again moisture, which caused me to continue to cast the crankcase. (more on photo)

Now I will focus on further machining of the crankshaft, casting has been enough so far.


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## F-DS (Jun 4, 2020)

Note that the inlet and vent channels are quite well cast, probably also due to the poorly chosen material from which the mold is made. It already contains too much clay. 

I used two types of molding compounds for the production of the mold, a compound with a rougher structure was used for the part with the channels, which does not create a smooth surface, but dries well and does not retain moisture in it.


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## F-DS (Jun 4, 2020)




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## F-DS (Jun 4, 2020)




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## Mechanicboy (Jun 5, 2020)

Too much moisture in the mold. Let it dry in some days before cast if you do not have drying oven for mold. It is not necessary to have high silicone in aluminum from piston, aluminum from cylinder head or water pump is good enough for casting.


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## aka9950202 (Jun 6, 2020)

I have cast aluminum using a gas fired furnace and with a charcoal / bricket furnace.  The charcoal was a failure as i could not control the temperature.  The castings seemed to have a grainy structure and cavities which were large enough to put a pencil into.

My first gas furnace was a square of firebricks and the heat source 2 mapp gas torches. It allowed better control with perfect results.  

Cheers, 

Andrew in Melbourne


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## F-DS (Jun 9, 2020)

I did the (perhaps last) casting of the crankcase today. The shape of the casting looks fine, there is only one defect on the casting, namely a cavity in the space on the crankshaft. The cavity is about 3 cm deep and 1.5 cm wide. Fortunately, the cavity doesn't matter, it was probably caused by a bad vent channel, which was filled with aluminum too soon and the air from the bearing space no longer had how to escape from the mold. I subjected the risers cut from the casting to mechanical tests in the form of bending and malleability. The alloy looks like it's already fine, it's definitely not brittle and it's not very soft either. I am satisfied with this casting.


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## F-DS (Jun 9, 2020)

Casting with risers.


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## F-DS (Jun 10, 2020)

This is what the last casting looks like after cutting the risers and light grinding. It can be seen that the casting has an excellent surface and shape geometry. There will be no need to mill the mounting feet and the crankcase will be easy to polish.


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## F-DS (Jun 10, 2020)

I photographed all my previous castings backwards and then I wrote to them (in Czech) why I was forced to cast another specimen. Maybe it will help someone save work with similar research.


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## F-DS (Jun 10, 2020)

Again, I photographed the model for comparison.


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## F-DS (Jun 10, 2020)

I already have the crankshaft ready.


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## F-DS (Jun 14, 2020)

I started machining the crankcase. I pressed a bronze sleeve into the case, ground the crankshaft into a plain bearing and custom-made the propeller carrier on the crankshaft so that the crankshaft had an axial clearance of 0.5 mm. For the first time, I put a propeller on the shaft. In the photographs after machining the inner space of the crankcase, it can be seen that the casting is really high precision casting, the thickness of the crankcase wall is the same everywhere (within a small tolerance).


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## aka9950202 (Jun 15, 2020)

Nice work.  Great to see someone making their own casting.

Cheers, 

Andrew in Melbourne


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## Rudirk (Jun 15, 2020)

It looks perfekt. 

Rudi aus der Eifel


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## F-DS (Jun 15, 2020)

Thank you Rudirk and aka 9950202.


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## F-DS (Jun 21, 2020)

I finished the crankcase, made the rear lid of the crankcase, I made a protrusion on the lid, through which the lid can be screwed to the crankcase upwards. In this way, the lid and crankcase form a stronger unit. 
I ran a motorized crankshaft in the crankcase. 
I made paper seals.


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## F-DS (Jun 21, 2020)

I pressed the piston pin into the piston, pressed the safety brass lenses. I cleaned the individual parts in gasoline and kerosene and then assembled the engine.

The engine rotates quite lightly without installing the spark plug, it does not bite. After fitting the spark plug, the engine has excellent compression in the combustion chamber. I put an aluminum seal 0.5 mm high under the cylinder head. The pre-compression in the crankcase also seems excellent to me. The engine is only oiled with kerosene, the compression is not increased by the added oil.


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## Mechanicboy (Jun 21, 2020)

Hi, never use the E clip to lock the connecting rod on place. The consequence is that the connecting rod can force the E clip to rotate so that the E clip can be throwed out from the crank pin due to centrifugal forces and cause greater damage to the engine. Let behind the back cover / piston to hold the connecting rod in place on the crank pin.


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## F-DS (Jun 22, 2020)

I was hesitant to use a paper clip, so I kept the original solution in reserve, drilling a hole with an M3 thread through the pin and leaving a gap between the pin face and the lid so that I could put a suitable washer secured with a screw in the pin axis. So I'll put the clip away. Otherwise, the groove for the staple is made in such a way that the staple does not rotate spontaneously in it and is still sprung, so I thought that this fixed mounting of the staple could prevent its rotational movement.

Would the engine be able to operate without any protection of the lower connecting rod eye?

Other engines do this as usual, but there is a gap between the connecting rod and the crankcase cover over 2 mm, so the connecting rod cannot "lean" on the cover.


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## F-DS (Jun 24, 2020)

Can this clamp be used? I can't imagine her spontaneously slipping, it runs almost around the whole pin.


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## Mechanicboy (Jun 25, 2020)

No problem, but i prefer the back cover are holding the conrod at place on crank pin.


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## F-DS (Jul 29, 2020)

I replaced the clamp on the lower eye of the connecting rod with another, which better encloses the pin. I had to grind the second clip 0.15mm to fit it smoothly into the groove of the pin.


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## F-DS (Jul 29, 2020)

I used a needle and a nozzle from the MVVS 2.5 engine for the carburetor, as both components have quite the same parameters and as they were available. We will see if the cross-section of the nozzle nozzle hole will suffice for the engine, historically a petrol engine with a capacity of less than 17 cc could have similar consumption as a modern glow engine with a capacity of 2.5 cc.

 I made two square washers with a semicircular recess for the nozzle nozzle.


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## F-DS (Jul 29, 2020)

I made the circuit breaker according to the original plans, it is just built upside down, as well as the exhaust and overflow channel of the engine. The main body is soldered with silver. The contact on the spring is made of silver, the second contact is an ordinary M3 screw without any modification, in time I will probably either use brass or cover the existing screw with silver. The screw tightening the breaker sleeve is temporary.


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## Peter Twissell (Jul 29, 2020)

That clip will definitely rotate in the groove and unless your engine is only going to run at low rpm, the risk of it coming away is high.
How far can the conrod move backwards before it contacts the inside of the piston?
It is normal in model 2 strokes for the backplate to limit conrod movement. Heavily used engines which I have stripped show very little wear in that area, so there is clearly not much force there.
Perhaps make a new cover or attach a disc to your existing cover.


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## F-DS (Aug 14, 2020)

I started the production of the last component of my engine - high voltage coils. I wound the primary winding manually, I made a simple electric winder with a counter for the secondary winding. I have already wound 2 layers of secondary winding of 500 turns and it works as expected. The primary winding has a diameter of 0.5 mm (a total of 130 turns), the secondary 0.1 mm (30 x 500 turns). I insulate the winding layers with "Modelspan" paper.


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## F-DS (Aug 23, 2020)

I finished the high-voltage reel, the photos show paper insulation, temporarily secured with a fishing line.


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## F-DS (Sep 13, 2020)

The coil is complete, the ignition is operational and two attempts have been made to start the engine. For the first time, the engine experienced only isolated inflammations, the engine was unable to run due to an ignition failure. I made the second attempt with the "Henry" ignition. I managed to keep the engine running for 7s, that's a success. Now I have to look for a few mistakes and the engine will be one step further to the moment when it will run reliably. First of all, I have to increase the ignition current (2 alkaline monocells are not enough), then I have to increase the axial clearance of the crankshaft to 0.5-0.7 mm, instead of the current 0.3 mm. Finally, it is necessary to focus on better switching of the circuit breaker, as it is the source of the biggest problems.


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## KenC (Oct 4, 2020)

Maybe I skipped over something, but I did not see anything about how you made your piston rings, which is quite a technical thing to do correctly. Or perhaps you built your engine to use some commercially available rings. 
Ken


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## F-DS (Oct 5, 2020)

Hello, I bought the rings, I write about it in my 5th post.


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## KenC (Oct 6, 2020)

Thanks, my mistake. I guess that aged 80 I am allowed a few! 
Buying rings was very wise, though I have always made my own following the Trimble method.
Ken


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## F-DS (Oct 6, 2020)

What method of production do you mean by "the Trimble method"? Cutting a ring from a pipe?


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## KenC (Oct 8, 2020)

George Trimble is/was a model engineer who wrote an article in one of the magazines, possibly "Strictly I C" about designing and making piston rings. It is fairly well known by experienced model engine builders. Too difficult by far to summarise so if really interested maybe a Google search might find a reference to it. Apologies but I no longer have a copy.
Ken


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## F-DS (Oct 8, 2020)

Thank you for the explanation.


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## F-DS (Oct 8, 2020)

When I saw during the tests how the engine can kick after being swallowed with fuel, I began to wonder what would happen if the bolts holding the cylinder to the crankcase loosened during operation or a similar "kick", or rather tore out of the crankcase, because it holds only about 5mm in aluminum and the threads are not perfect. So I decided to partially disassemble the engine again and screw it firmly into the crankcase and glue the stitches to which the cylinder will be attached. This will better adapt the engine to future disassembly. Also, thanks to this modification, I may forgive myself for the future laborious repair of torn threads.


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## F-DS (Oct 13, 2020)

Newly made connecting rods with threads (stiffs), with which I attach the cylinder to the crankcase. I also already have brass high nuts ready. All I have to do is glue the grafts to the screws and I can fold the engine.

In the end, I had to make stints and nuts in 6 pieces, because I always didn't succeed in 2.


The last picture shows the grafts with the screws originally used.


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## F-DS (Oct 17, 2020)

And here it is, today I started my Felgiebel for the first time.


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## F-DS (Oct 17, 2020)

It was around 8 ° C, Natural 95 fuel and M2T oil in a ratio of 1: 4. I finally used an electronic ignition, with an interrupter. I plan to release the high voltage coil in the future. I started the engine about 15 times today, each time for about 30 seconds, then it warmed up and started to tighten. Maybe he'll let it go by running in, but even so, I fulfilled my dream of making a functional internal combustion engine at the age of 17. Maybe I was unnecessarily complicated, but I got to the end and that's the main thing.


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## rweber (Oct 17, 2020)

You rellay used a mixture 1:4? I guess you mean 4% Oil

And if it gets tight when it warms up: Check piston-zylinder clearance!


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## rweber (Oct 17, 2020)

I forgot: Congratulations for your running engine!


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## F-DS (Oct 17, 2020)

Indeed, the ratio of oil and gasoline is 1: 4, for the original, the run-in was 1: 3. Thank you for your congratulations.


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## F-DS (Oct 17, 2020)

I know that the piston is too tight, I was already afraid of tightening during production. But I prefer tighter and then grinding than looser and making a new one.


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## ixb1 (Oct 17, 2020)

Pěkná práce!


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## bobden72 (Oct 18, 2020)

Looking good, congratulations on your first I / C engine.


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## johwen (Oct 18, 2020)

Great Effort F-DS engine beat sound healthy also Now make a second using your skills accomplished from this engine. just don't stop. Cheers John.


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## F-DS (Oct 18, 2020)

Thank you for your praise. Now I will deal with the modification of the engine accessories to the original historical. Brass tank, original ignition, engine bed ...


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## Mechanicboy (Oct 20, 2020)

Congratulations!  Are you using 2 stroke motor oil in gasoline/petrol?  The recommented oil is 1 part single grade SAE 60 or 70 motor oil mixed in 3 parts gasoline/petrol for running in the engine and keep good compression in long time. 1/4 mix is a bit too little oil in gasoline/petrol. 

Counts of octane in the old design of the engine is no problem since the modern gasoline is high of octane than the octane in gasoline in old days was low, about 60-70 octane.  Selection of octane is determined by ratio of compression also high compression gas engine need high octane to prevent knocking by misfire caused by self ignition.


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## F-DS (Oct 20, 2020)

1 part oil and 3 parts gasoline is a 1/4 ratio. 25% oil, 75% gasoline.


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## F-DS (Oct 20, 2020)

Today I ran again, this time earlier, which caused higher engine speeds. It should slow down the warm-up of the engine, which would prolong its operation, as a result, the engine can run at idle and high speeds for the same length of time, it heats up similarly. After a few starts, which lasted about half a minute each time and each time the engine ran at higher speeds, I looked through the exhaust at the piston and the rings in their condition. Just like that. And on the top ring I saw a small black line that was slanted along the length of the ring. I wondered how such a groove probably formed when the piston made only a rectilinear movement and the only thing that occurred to me was that the ring broke. So I interrupted the next start and thoroughly disassembled the engine. Apart from the fact that the engine is in excellent condition and that almost all components do not show signs of wear, I also found that the ring is really scratched, I do not know how such a groove was created, anyway I just mistaken the engine in gasoline and reassembled. When cleaning, I appreciated the polished piston, which went extremely well with a brush and gasoline. After removing the rear cover, it was clear that the connecting ring of the connecting rod did not move, so there is probably no danger of its spontaneous removal. (I mount it through the gap towards the crankshaft axis) 

After disassembling the head, it is clear that the piston and cylinder are very lubricated.


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## KenC (Nov 9, 2020)

Well you got there in the end. As with a number of things in life, the first time is the best. You have shown how perseverance can overcome adversity.
Ken


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## F-DS (Nov 9, 2020)

Yes, although I really wanted to, I was still not sure if I could build an internal combustion engine in amateur conditions and with a minimum of experience. And surprisingly, I managed to make it.


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## F-DS (Dec 6, 2020)

Felgiebel already runs with homemade ignition.


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## F-DS (Dec 6, 2020)

The high voltage coil gave the engine the correct authentic expression, compared to CDI ignition, the engine heats up less. The needle and lead settings remained similar.


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## dsage (Dec 7, 2020)

Nice work. That runs really well. Congratulations. What circuit are you using to drive the coil?


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## F-DS (Dec 7, 2020)

If you mean a source by this circuit, then the coil is driven by 4 NiMh monocells with a total voltage of 6V. The coil is 3-4V according to the instructions, but it hasn't burned yet, so that's probably not a problem.


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## dsage (Dec 7, 2020)

I was meaning what is the electronics. Is it a circuit you built yourself or a purchased one.


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## F-DS (Dec 8, 2020)

In addition to batteries, the ignition consists only of an interrupter and a high-voltage coil, both of which I made. In short-purchased are only piston rings, spark plug and of course the ignition supply.

If I bought parts of the ignition, I wouldn't be able to call my ignition "home-made".


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## F-DS (Feb 3, 2021)

Production of engine bed. It is fired from 3mm thick iron sheet.


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## Peter Twissell (Feb 3, 2021)

I assume by 'fired' you mean laser cut?


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## F-DS (Feb 3, 2021)

Of course, I didn't use the word correctly.


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## Peter Twissell (Feb 3, 2021)

No problem, I think we all understand that many on this group are not native English speakers.


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## F-DS (Mar 5, 2021)

Work on the motor holder continues. I'm not an experienced welder, but it still doesn't look bad.


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## F-DS (Oct 17, 2021)

Anniversary of Felgiebel

Today is exactly the year when I first started my first engine.



I could now start to complete the project, mainly on the tanks and the engine bed.


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## aka9950202 (Oct 18, 2021)

F-DS said:


> Anniversary of Felgiebel
> 
> Today is exactly the year when I first started my first engine.
> 
> ...



Congratulations.  Keep it up and you will go far.

Cheers, 

Andrew  in Melbourne


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