1" Bore x 1" Stroke Vertical I.C.

[Bearcar1]

  This ones gonna be fun as Hell and am looking forward to witnessing your progress Brian. Thanks for sharing.


Bearcar1
Jim

[Brian Rupnow]

I sent out a request for pricing this morning for material to make the two crank case pieces and the base from aluminum, enough brass to make the gas tank support, the rocker arm tower and the gearcase, and a piece of grey cast iron to make the cylinder from. I have scraps of material laying around here to make almost all of the remaining pieces. I have a section of heavy wall pipe sufficient to make the flywheel from, with a machined aluminum center.

[Brian Rupnow]

The aluminum bar for the crankcase and base was the easy part.---$30.

[Brian Rupnow]

Hah!!!--Sometimes a nights sleep helps out your thinking process!!! I can attach the gear case with two #10 shcs. I wanted to do that yesterday, but  I was thinking that the bolts would break through the side of the crankcase in the thin area behind the ball bearing. This morning I see that that is not so, there will be lots of "meat" for the screw threads which hold the gear cover up against the side of the crankcase.

[Brian Rupnow]

The two crank-case halves will be right and left hand on a lot of the major features, but there will be a number of features which apply only to one side or the other. The first thing to do before I start cutting and carving is to drill and ream each half for a 3/16" diameter locating dowel. These holes will have virtually zero clearance between them and the dowels so that I don't end up with two crank-cases that don't match up in some of the critical areas. The dowel holes are put into the crank-case halves in areas where they don't interfere with anything else.

[Brian Rupnow]

I picked up my aluminum for the crank case and base today after lunch, and spent a quiet afternoon detailing. When right and left hand parts are simple, you can get away with one drawing, specifying "One as shown and one opposite hand". When they get fairly complicated there is much less chance of something getting machined wrong if two drawings are made, one of the right hand part and one of the left hand part.

[Admiral_dk]

3D Model looks good Brian 

I will advise that you make two small 'dents' close to the pins, to help you take it apart again. All the smart designs I've seen has something like this and it's a real bonus.

[diego.lopez1]

Nice desing !!

What ignition system do you use?, where do you buy it?

Best regards.

Enviado desde mi Mi A2 Lite mediante Tapatalk

[Brian Rupnow]

Diego--I use 1976 Chrysler car ignition points and condenser and a generic 12 volt coil, powered by a 12 volt battery.

[Brian Rupnow]

This morning the 3" x 1" aluminum bar was cut to 2 pieces the correct overall length and then both pieces were drilled thru and reamed for 3/16"  alignment rods loctited into the holes to keep the plates perfectly aligned. The two holes for the shafts passing thru were both drilled and reamed to the shaft size (They will be opened up for clearance at a later stage of machining). The five counterbored holes were first drilled completely thru with the correct tap size for #10 thread, then opened up as #10 clearance holes 1" deep thru the first plate, then counterbored. Next step will be to tap the five holes for #10 thread and profile the outer edge of the two plates (while still pinned together).

[Brian Rupnow]

So---the "easy" part is done. The sides have all been profiled and the holes drilled, tapped and counterbored. I have some more profiling to do on each side of the crankcase, and then the exciting part starts---machining the inside cavities. The reason that I drilled and reamed the shaft holes "on size" is to aid me when setting up in the four jaw chuck to machine the cavities. I just think it will be easier to indicate off a shaft stuck in the reamed hole than trying to pick up center from the reamed holes.

[Craig DeShong]

Brian is making chips again.

Looks like another fun project.  I’ll be watching... and watch that ice, it can be treacherous... a fall on the ice lead to a knee replacement for my sister a few years ago.

[Brian Rupnow]

Using my time honored tradition of "make it up as I go along"---In order to turn that boss on the side of the crank-case, it's a trick. What I really have to do is machine all the material away except the boss. To do that, I have to be able to hold the crankcase in my rotary table. I need something to "grab onto" with the 3 jaw chuck which is permanently mounted to the rotary table. I can mill 90% of the material away by just mounting the crankcase in my swivel based vice. However, the corners need to be milled away, and for that I need the rotary table. So---I've loctited a piece of 3/8" shaft into the 3/8" bore in the crankcase, letting it stick out about 1" on each side. That will let me do the radius on both sides on the big end. Then I will press that shaft out and loctite a 5/16" shaft into the other end to allow me to radius the other end.  Not a really good method for production, but should work fine on a "one off".

[Brian Rupnow]

Today I determined that if I swapped positions of the carburetor and the exhaust, that would keep my gas line away from the flywheel and give me room to mount a small, belt driven fan between the flywheel and exhaust. Similar to an earlier vertical i.c. that I designed and built a few years ago, the belt would be an o-ring driven by the flywheel. I haven't shown it here, but may have time tomorrow to do some more on the design.

[Brian Rupnow]

Here we are at boss machining stage-1. All of the material that can be removed has been removed using conventional "in the vice" machining. Now it's time to step over to the rotary table and round the corners on the large end boss on both sides.