My modified build of "Chucks Single"

[cfellows]

MB, looks great! The cam and gears should work perfectly. Looks like you are in the home stretch.

Chuck

 

[Metal Butcher]

MB, looks great! The cam and gears should work perfectly. Looks like you are in the home stretch.

Chuck

Good morning Chuck.
Still a long way to go. I have some free time over the next two days due to bad weather. Maybe I can make some progress on the cam follower.
Small problem tho. I need to get off my lazy ... mode that's also brought on by bad weather and a few other excuses I use! ;D
Oh, by the way, does the cam shape look like it will work? I made it removable in case its wrong.
-MB

 

[cfellows]

Yes, the cam shape looks perfect.

Chuck

 

[Metal Butcher]

Today I made the cam follower and it's roller. The follower was machined out of standard 360 brass. It would have been good to have used a ball bearing for the roller but I decided that a hard 660 bronze roller would suffice. It can be easily be replaced with a ball bearing if the bronze one proves to be inadequate. I made the roller shaft out of very hard to machine steel. This should hold up well to the friction of the bronze roller. The design of the follower was based around dimensions for a standard 1/4" x 1/2" x 3/16'' wide ball bearing for quick and easy replacement. I drilled and tapped the front of the follower 4-40. The rod between the follower and the valve stem will likely be a brass 3/16" rod with a protruding 4-40 stud.
Not sure what to do about the v-stem end, it looks like an adjustable cap screw was used by previous builders.

I did not use any ball bearings on this build. This may prove to be a mistake that could have been overcome by building the motor as a 2-stroke.

-MB

 

[RobWilson]

Looking mighty fine MB intresting engine build ;D
Rob

 

[Maryak]

MB,

Great progress. :bow: :bow:

Best Regards
Bob

 

[cfellows]

Looks great, MB. I would suggest that you put extra thread on the follower end of the push rod so you can adjust the length of the push rod (and valve clearance) by screwing it in or out. You could use a lock nut to lock it where you want it. Then you can simply drill a shallow hole in the valve end to accept the valve stem. Also, you might consider a 1/8" push rod. 3/16" might be a bit heavy looking.

Chuck

 

[Metal Butcher]

1) Wow did I get an extreme example of a sun burn from 3 full days of motorcycle riding. Today's rain gave me the opportunity to take a break from the sun, finish up this build, and post the final results and pictures.

I used a brass 3/16" push rod attached to the cam follower with a 4-40 stud. On it’s front end a 4-40 cap screw and nut allow for adjustments. It is also a perfect fit for the end of the valve stem. The 3/4" long .020" exhaust valve spring was too stiff and required 20 psi to run the motor. I switched it to a ½’’ long .020" spring and it ran on 5 psi. Still not satisfied I tried a 3/4" long .016’’ spring and it ran on 2 psi! A motor that runs on low pressure is my goal and to me indicates a successful build. After a 15 minute break-in period it now runs well on 1psi every time.

2) The photo below shows the 6 bolt pattern I used on the valve and cylinder head. I like the look of cap screws on small areas like bearing blocks and cylinder heads. I also like button head screws on larger areas like supporting structures and bases. Purists will disagree with my choice but after all it is my build. I made the intake as a separate piece using 3/16" model pipe tapped 10-40.

3) The size of the exhaust pipe and it’s flange were kept to minimum since it is held on by two small 0-80 cap screws. The front of the bearing block that holds the cam gear was rounded to suit.

4) I used 660 bearing bronze for the crank bearings and cam roller. I was concerned that with out ball bearings, the use of plain bearings would cause too much friction. This could have prevented the crank from cycling 4 strokes for a return to the firing position.
I was wrong! The engine will easily cycle 6 to 8 strokes after cutting off a 1 to 2 psi supply pressure.

5) The birds-eye shot below shows the spacers I added between the fly wheels and bearing blocks to bulk up the look of the crank shaft. It seemed that the large 3" flywheels made the crank shaft look somewhat undersized.

6) This last photo shows a different angle of the gears and cam arrangement.

My thanks go out to both Chuck (cfellows) for providing the drawings and the additional build information I needed, and also to Gail (GailInNM) for generously donating the correct gears to make my build possible. I would also like to thank the rest of the members on this forum for their support and encouragement.
:bow: :bow:

-MB

 

[GailInNM]

Great build MB !! :bow: :bow: :bow:
Gail in NM,USA

 

[RobWilson]

GREAT WORK MB FINE LOOKING ENGINE
ROB :bow:

 

[Maryak]

MB,

Beautiful Engine. :bow: :bow:

Best Regards
Bob

 

[bearcar1]

MB, nicely executed and a very neat and clean engine. BRAVO! ;D It sounds like you have it dialed in well to run down to 1PSI, quite an accomplishment indeed. :bow:


BC1

 

[putputman]

Beautiful job MB. You really did a nice job on the finishing touches with the paint, brass, & metal cylinder. The combination really sets it off.

 

[cfellows]

Another MB Masterpiece! Beautiful execution.

Now, if only we could see and hear it running...

Chuck

 

[Metal Butcher]

Another MB Masterpiece! Beautiful execution.

Now, if only we could see and hear it running...

Chuck

Chuck, you will have to take my word for it.

It runs great.

Really great!

-MB

 

[bearcar1]

Running? :big: Who said anything about running? Geesh, a tough crowd here tonight, they want it to run as well as look nice!!!! Rof}

BC1

 

[Metal Butcher]

Below are two pictures taken consecutively. The first one shows the blurred spinning flywheels, and the second shows the pressure gauge. Running on one pound of air. No camera tricks involved, or trickery of any type! Not exactly video, just use you imagination with the sound.

Oh, and It sounds great!

 

[Metal Butcher]

This is my first video ever, it was posted with the help of a friend. It's not the best quality but you can see and hear the engine running. The motor was placed on a 2X2 square foot piece of cardboard which I placed over the cluter on my work bench. This caused quite a bit of bounce that can be seen. At the very end of the video, while trying to rotate the motor, I blocked the exhaust port which stalled the motor, oops! Throughout the entire video the motor is running 2 PSI of compressed air.

-MB

[ame]http://www.youtube.com/watch?v=DkBhHVbtKtU[/ame]

 

[bearcar1]

Ooops! Whadda' ya' mean OOPS! Rof} Rof} Rof} Rof} Veeerrrry Nice running engine ;D

BC1

 

[Paolo]

Whaooooooooo nice sound!!!! :big: :big: :big: My compliments!!
Cheers Paolo