When all the excess metal is cut away this will be a Vivell .09 diesel.

Randy I guess the term scratch built is taking on a new meaning. Do you have a milling machine
besides the lathe unimat?? I for one and am sure the rest of us would like to know what you are
using. Were ou a tool and die maker in your last life..Keep us posted as this procedes

Randy looking at this I can only identify the crankcase, crankshaft. I assume the black cylinders
are the liner and cylinder why do you not explain this to the non machinists among us

Dan,

I'll post some shots of the shop and explain, but to answer the question, yes I have a little Mini Mill and Mini lathe from Harbor Freight.

As far as the bits in the picture go, they are as L to R follows:

Top row
Alum block: Fixture for case machining
Fuel tank casting, alum
main bearing housing, alum
crankshaft stock, 1018 steel
cylinder stock, 1018 steel

Bottom Row
head and rotor stock, 6061-T6 alum
tank top casting, alum
piston stock, cast iron
case casting, alum
main bearing stock, bearing bronze

Must be fun, building your own engine

Well,

First I'll answer the questions. Dan, as a matter of fact I was a machinist for a number of years before I moving into design engineering. However don't thing that you need to be a professional machinist to do this sort of work. There are good sourses for learning machining and equipment and tooling are now inexpensive enough to have without feeling guilty unless you can't stand Chinese products.

Dual, I have a ball builting and restoring engines. There is nothing like it when it first fires and runs. The first flight of a new model is exciting but in a different way. Engines are only assemlies of parts until they run.



Here are a few starting shots. In this series you see the case machining fixture being made. The cylindrical part is to allow chucking in the lathe to do the boring and threading work. In addition to thatcylinder there will be another bolte to the bottom to allow machining of the top features of the case. As I get into the case machining it will become obvious. The thread I will be cutting is a 32 pitch left hand thread. The construction of this engine is unusual because the crank amd main bearing thread into the front of the case rather than the crank being inserted fron the rear and a seperate cover being used to seal the case.

This engine will have a bore of .51" and a stroke of .5". Slightly over squared and a high performance engine for its era. It will have a rear rotary valve as well. Porting is what is called the original "Schnurle" like the Cox engines.

1st pic, fixture block laid out
2 & 3rd shots, fixture in machinging
4th shot, case setting in partially finished fixrture to check clearances.

Here are some shots of my shop.

First 2 are the Mini mill
3rd, general shop
4th Mini lathe

Lotsa nice toys!

George

Well, tonight was very productive until I made the last cuts in the case.

I'll have to post again to show the problem. In these shots you'll see the case in the lathe in its fixture. The case is machined out and threaded. Sorry about the threading shots, the batteries were too low.

This series of shots shows the top of the case being machined with the fixture repositioned. I've also included a shot of the treading tool but its pretty bad.
Tha last shot shows the bummer, a casting void right in the cyilinder base gasket face! What a drag!

Randy watching the progress with great interest but I have to admit I am lost on the shot
of the threading (4th one) is that some sort of an adjustable jaw chuck that the cylinder
is in in the gear train does it drive from top or bottom. I am not a machinist but have hung a round a few shops never saw that set up martin

Also they void is a bummer can you get a round it??

Dan,

The "chuck" you ask about is the fixture you see being built in the second installment. It is designed to hold the case in axis of crank CL and cylinder CL in the lathe. Boring on a lather is much much easier then on a mill, so I make every effort to do as much on the lathe possible saving the mill setups for screw holes and port work.

The forth shot is the gearbox of the lathe. It is not a "quick change" box so you have to set up the gear ratios to cut the screw pitch you want. in this case 32 TPI LH which is where the main bearing housing will thread into the case. The gear at the top on the spindle drives the train, the one at the end on the bottom drives the lead screw that actually drives the saddle of the lathe.

The caster is going to replace the casting. I have JB welded it and recut the faces but thats not really the way to do it. I'll use this case to fit everything and when the new case comes I'll machine it up fresh. Maybe I can get some good shots of the thread cutting process then.

thanks for education on the threading process --almost all done with the case and a casting void
a least you get a new one but more work/will watch the progress thanks martin

Maybe time to go to Harbor Freight (a mile from my house) then practice practice practice
maybe some steam castings

One of the guys i know is a top notch machinist think I can talk him into "lessons"

Today's progress, main bearing housing. The pictures show turning the bearing from bronze, tuning the housing casting, the parts pressed together and the case and housing assembled into something that resembles a crankcase.

Second page of main bearing housing.

All the latest progress while waiting for the new case. I've completed the crankshaft blank which still needs the crankpin turned. This will be done in another fixture I have yet to make. The cylinder was a comedy of errors but I finally paid attention on the third try and won. And a shot of the base assembly that actually looks something like and engine.

Looks good Randy, what went wrong with the cylinders #'s 1 and 2??

That JB weld repair looks good, too good to throw out the case, now you will have to build a 2nd one to use it up Roger replaced the casting I presume for free? He is a good guy.. SOmetimes a casting can have an internal flaw and not much you can do about it untill you start cutting.... been there done that!

AJC

this is expression of true art form in metal

Hi Andrew,

Roger has already replaced the casting, but I'm thinking along the lines of using the repaired case and building the glow version with the other. In my profession I get to see allot of casting oopses, getting a new head or block ready for production can be a tremendous challenge.

Cylinders, I shouldn't have posted that shot. The right end of the piece has the groove below the bottom fin cut too deep, the other end was nervana until I realized I'd made it .045 too short, which by the way just happens to be the thickness of the cuttoff blade, bet you know this one, I think everyone ever cutting fins has done that.

Dan,

I never thought of it as art, but it is one of the ways I express myself to be sure. I get great enjoyment from building models, engines and motorcycles.

I think "hobby" metalworking IS an art. I know I do many things free hand, and it is allmost akin to carving in wood. When you get into CNC, and following plans 100% (which I rarely do) it isnt as much art as a mechanical process.

I know it is a form of expression, to me anyway.

I know I am a lot more impressed when I see someone make something on basic equipment like Randy and I have, rather than see someone do everything CNC. And casting is another way to express your creative side Randy when you get set up for that, you are going to LOVE it... DOnt wait too long!!

I think metal working CAN be art, but not necessarily. When I take a piece of flat sheet metal and form it into a fendor or gas tank with not much more then a hammer and a shot bag definately. The art is in the person thongh, not the piece, CNC produces some beautiful parts, every one perfectly like the last, near flawless, but no human touch at all. Cold parts, no "signature". At the same time I've know excellent machinists that would scoff at the thought of their work being art, it was their job. For people like Andrew and I it done purely for the love of it. Money is only an issiue when its short, making it is not the purpose. I guess when you look at it like that, it certainly is art, but I never sat down and looked for inspiration for my next project.

A little progress today.