Mastiff lc mason engine REDO .

[Jens Eirik Skogstad]

Hi All !
An update :
I did some tests with the float
It floats quite well in water , but not with gasoline - something everyone probably knows - Although testing with gasoline does not have the weight of the check valve

View attachment 157586


I reduced the weight of the float and tested again with a weight of the check valve : all of them float quite well in gasoline

View attachment 157587
View attachment 157588

Next step : I will design a carburetor according to the test and when machining the float I will make it lighter

Due the gasoline has low density than water. Water density 1g/cm³ versus gasoline density 0,6 g/cm³ hence the float will be lower in gasoline than in water.

 

[Jens Eirik Skogstad]

Use this drawing of the float with the valve in the lower part (float needle with cone valve in lower part) to be closed by the buoyancy and cannot be opened by the fuel pressure as long as the chamber is at the correct level and stays closed without the influence of the fuel pressure. If the gasoline level is in low level, the weight of the float ensures that the valve opens so that gasoline enters the chamber and fills up before the float closes at the correct level. The gasoline level in the chamber is easy to adjust the valve by pushing in/out of the cork so you can see that it does not flow out of the spray bar in case the gasoline level is too high. The correct level of the gasoline is some millimetre below the spray bar.

It is much easier than you thought that the valve is set up on the float to shut off gasoline by buoyancy and can open with ease from the gasoline pressure.

The air in microcells of cork makes up 90% of the volume and about 50% of the weight, so its specific gravity varies between 0.19 to 0.25 g/cm³. It is therefore five times lighter than water 1 g/cm³ and does not present a problem in obtaining good buoyancy in gasoline which has a density of 0.6 g/cm³, and as it does not absorb water, it is almost impossible to sink.
Cork is chemically neutral. The structure is not only impermeable to liquids and gases, but also chemically does not react with them, ensuring its durability. Cork has resistance to liquids and gases. This characteristic is a result of the high content of suberin in Cork, 39-45% by weight. This cork has impregnation properties.

Why make it complicated that doesn't work well when it's easier to use cork as float?

 

[minh-thanh]

Why make it complicated that doesn't work well when it's easier to use cork as float?

Simple:
Because I don't like cork.

Hi All !
An update :
Continue testing the float...After some testing with the float...
I have finished designing the carburetor
Size - approx : height 37mm, length 37mm, width 27mm
If everything goes well, it will be the standard carburetor for all my engines

 

[minh-thanh]

Hi All !
An update: a bit slow
The top corner is the carburetor by design of engine
I made more than I needed, hoping none of them would be damaged during the next processing

 

[minh-thanh]

Hi All !
An update:
I just made a set to try one last time ...
There is the weight of needle (steel) for the one-way valve on the float . It it will be made of aluminum

 

[Vietti]

I built a Hermes engine with a float/needle valve carb. The plan called for the float to be made from.004" brass shim stock. Worked OK but only with a Vinton tipped needle.

 

[minh-thanh]

Hi All !
An update:
Project....carburetor in progress, ..a little change ..made on sample and tested drilling 0.5mm diameter hole -10mm deep with 2 broken drill bits

 

[minh-thanh]

Hi All !
An update:

 

[minh-thanh]

More ...
With several different thicknesses, I chose a thickness of about 0.22mm.
Note: I covered the caliper brand because I don't think it's made in Japan.

Some test videos :

 

[minh-thanh]

More ...
Everything is going according to plan
I had to make a set of magnifying glasses to work with them.

 

[minh-thanh]

Hi All !
An update:
A test
I ground a small milling bit to mill the gears - it's quite small
Just for testing, but the results are pretty good

Image enlarged by camera :

 

[minh-thanh]

Hi All !
Need advice !
I am drawing gears for crankshaft and camshaft
I am planning to change from DP to module
40 DP 70 teeth --> module 0,635 7o teeth .
What do you think ??

 

[Jens Eirik Skogstad]

Hi All !
Need advice !
I am drawing gears for crankshaft and camshaft
I am planning to change from DP to module
40 DP 70 teeth --> module 0,635 7o teeth .
What do you think ??

View attachment 160158

No possible with module 0.7 , but with module 0.6 can you use. The problem the gears is not in right distance between these two shaft. Better to keep DP 40 gears since you already made the shaft holes in exact distance. Instead cutting gear wheel you can buy ready made gears who are cheaper than to buy gear cutter.

 

[minh-thanh]

No possible with module 0.7 , but with module 0.6 can you use. The problem the gears is not in right distance between these two shaft. Better to keep DP 40 gears since you already made the shaft holes in exact distance. Instead cutting gear wheel you can buy ready made gears who are cheaper than to buy gear cutter.

I already know that,
I know standard module 0.3....0.6, 0.7....
I want to know if using "non-standard" module like 0.635 is ok?!

 

[L98fiero]

I already know that,
I know standard module 0.3....0.6, 0.7....
I want to know if using "non-standard" module like 0.635 is ok?!

Everything is ok if you are making the mating gears, some combinations of DP/module and pressure angle will work better than others but if you make the mating gears it should all be good, within reason.

 

[timo_gross]

Hi All !
Need advice !
I am drawing gears for crankshaft and camshaft
I am planning to change from DP to module
40 DP 70 teeth --> module 0,635 7o teeth .
What do you think ??

View attachment 160158

I think it is fisible with module 0.7 cutters. The center to center distance for the DP40 (module 0.635) gears is 33.34 mm if you make a module 0.7 pair with 32 and 64 teeth, you end up with 33.6 mm center to center disance.

My guess is that you can squeeze out the 0.6-0.34=0.26 mm center distance, using profile shift. Blanks a litte undersized same cutting depth.

The alternative would be helical gears. Adjusting the helix angle to get desired center to center distance. In that case it would result in a pair of 31 and 62 teeth with module 0.7 and a helix angle of 12.5°. Provided I did not miscalculate, this will result in center to center distance of 33.34 mm.

No possible with module 0.7 , but with module 0.6 can you use. The problem the gears is not in right distance between these two shaft. Better to keep DP 40 gears since you already made the shaft holes in exact distance. Instead cutting gear wheel you can buy ready made gears who are cheaper than to buy gear cutter.

I do not think that is entirely true. (see above)

However with module 0.6 it is very close without fussing around using a 37/74 pair results in 33.3 c-c-distance. (I doubt that this will create a problem for a diy project)

I already know that,
I know standard module 0.3....0.6, 0.7....
I want to know if using "non-standard" module like 0.635 is ok?!

Non standard module cutters work same as standard ones, as L98fiero explained. (Module 0.635 is conversion from 40DP, so some people would even consider this standard as well)
Down side of "non standard" is that there are no cheap cutters that can be bought. And it cannot be combined with commercial gears. (In that context "non standard" means not DP and not metric module, or some very weird pressure angle.)

Greetings Timo

 

[minh-thanh]

@L98fiero , @timo_gross !
Your comments make me more confident, thanks !

I think it is fisible with module 0.7 cutters. The center to center distance for the DP40 (module 0.635) gears is 33.34 mm if you make a module 0.7 pair with 32 and 64 teeth, you end up with 33.6 mm center to center disance.

My guess is that you can squeeze out the 0.6-0.34=0.26 mm center distance, using profile shift. Blanks a litte undersized same cutting depth.

The alternative would be helical gears. Adjusting the helix angle to get desired center to center distance. In that case it would result in a pair of 31 and 62 teeth with module 0.7 and a helix angle of 12.5°. Provided I did not miscalculate, this will result in center to center distance of 33.34 mm.



Non standard module cutters work same as standard ones, as L98fiero explained. (Module 0.635 is conversion from 40DP, so some people would even consider this standard as well)
Down side of "non standard" is that there are no cheap cutters that can be bought. And it cannot be combined with commercial gears. (In that context "non standard" means not DP and not metric module, or some very weird pressure angle.)

Greetings Timo

Thanks you !

 

[minh-thanh]

Hi All
Gears 35-70 DP40 or 35-70 module 0.635 or module 0.6 or 0.7 I don't know but it's pretty smooth

 

[minh-thanh]

Hi All
My next game: Gears 32DP - - helical gear

 

[minh-thanh]

Hi All !
I just cut the gear - helical gear 45, it looks pretty good.