A new engine for fall---

[Rosco-P]

You could mill most of the corners away while it's still clamped down on the mill. It will still be an interrupted cut but not nearly as severe.

Interrupted cuts aren't a problem for HSS tool bits.

[brian Rupnow]

Hmmmmmmm---The best laid plans of mice and men----I reamed the holes in my web plates with my 0.4985" reamer. I then went to press the 5.0005 drill rod into place. It was su7pposed to be a .002" interference fit. It didn't exactly fall through, but it sure as heck didn't press. So much for my "all press fitted" crankshaft. That will now be amended to "My silver soldered crankshaft!!!"

[brian Rupnow]

Just as I was all set up to start silver soldering, my wife called about some emergency connected with the new house. Seems that 3 year old grandson had managed to lock and close a bunch of doors that there were apparently no keys to unlock!!!--After dashing across town and applying my dormant burglary skills (which mostly involved beating on the locksets with my 3 pound hammer till the guts all fell out of the locksets) I got to thinking-----I really didn't want to solder the crankshaft. I wanted it all pressed together. Then I got to thinking, I have a lot of 5/8" cold rolled shaft ends about 10" long that some kind soul from Toronto or Orangeville brought me a couple of years ago. The simplest thing in the world would be to turn new crankshaft ends (They are only about 3" long) and bump up the end diameter to whatever size will be a hard press fit in the holes I reamed in the webs. I THINK I know why the reamed holes are larger than they were supposed to be.---Hindsight being 20/20, I think I was running the reamer too fast and that made it cut oversize. I know that the drill rod I have just re-measured is exactly 0.500, not the .5005 that I was expecting it to be, and it is a somewhat loose sliding fit in the reamed holes. This leads me to believe that if I make up a new crankshaft end that is 0.500 diameter for all of its length except the last 3/8" which I hold at .503" diameter, I should ultimately end up with what I wanted---all press fitted together. The follower end will be turned to 3/8" over its full length, again, except for the last 5/16" where I will hold the 0.503" diameter. This is holding things to closer tolerances than I am used to working to, but it will give me what I wanted.

[brian Rupnow]

It has been a rather upside down afternoon for me, and in all the excitement I forgot to post a couple of "in process" shots of the crankshaft webs. The shot where the two bars are clamped on the milling machine bed show the shaft holes being drilled and reamed, and the holes drilled which will give the 1/4" radius in the inside corners. The second shot shows where the excess material has been milled away, and both parts are almost completely separated from the parent stock. The next step, if I ever get there, is to press the webs onto the crankshaft ends, set them up in the lathe, and turn the outer diameter of the plates to the finished dimension.

[brian Rupnow]

IT WORKED!!!!! 0.503" was just the ticket. It was all I could do with my big nasty old mechanics vice to bring the shaft all the way thru the web, and then with a hollow socket backing the web up, about 3/8" more. Then I set it up in the lathe, cut the stub end off that was sticking thru, and finish machined the outer diameter of the web. Tomorrow will do the same to the follower half of the crankshaft.

[brian Rupnow]

So--Ladies and Gentlemen--Here we have it!! My very first, two piece pressed together crankshaft. One picture shows the two pieces separated with the needle bearing for the big end of the con rod laying between them. The second picture shows the two piece crankshaft assembled with the needle roller bearing setting in its place. Each end of the crankshaft is supported by two bearings or bushings. The force from the con rod is totally transmitted through the 3/8" thick web plate to the large side of the crankshaft. The"free" end of the con rod journal engages with a slip fit hole in the other web and drives the smaller diameter side of the crankshaft, which operates the timing gears and the ignition points.

[brian Rupnow]

So, here's a view "Down the hole" as it were. The crankshaft fits in nicely, nothing rubs or scrapes when rotated through 360 degrees. There is one tight spot in the rotation, but it's only a minor tight spot which I'm sure will wear away once the engine is ran for a few minutes. There are supposed to be spacer rings incorporated into the crankshaft, just behind each web, but I'm going to wait until I have the cylinder, piston, and rod in place to determine their final thickness.

[brian Rupnow]

And now, since I have the material setting right here on the corner of my desk, I think I will machine some bronze.

[brian Rupnow]

No machining today. I did however work 8 hours in a design office across town, rush home, gobble supper, drive to new house, install 3 smoke/carbon monoxide detectors, put new locksets (without keyholes) on two doors, measured up the partially rotten deck for new planks as required, and remove one door and bring it home to trim the top so it will close properly and install a cat door. Now I'm going to drink my herbal tea and go to bed!!!

[Cuttings]

Brian
Thought I would pop by to let you know I am still riding along.
I have been away for a few days and I had quit a bit catching up to do on your project.
I am beginning to agree with George that this thread should be renamed.
At the rate you are going the engine will be finished before fall officially arrives, although we had a few days out here that were starting to feel like it lately.

[brian Rupnow]

Cuttings, I'm really glad you stopped by to say hi!!! Fall is a very fluid term around here. As far as I am concerned, fall begins when the kids go back to school and the fall fairs begins. It then lasts until the first fall of snow. This can be as long as two months or as little as 3 weeks. The kids went back to school on Tuesday. The first and easiest part of this engine went like lightning because I had worked out the plans over the course of the summer. I am only now getting to the more difficult parts, so I am sure this really will be an engine for "this fall" by the time it comes to life. Add into that the fact that I now have a second house to do a bunch of improvements on, and you will see more reason that this will be a "fall" engine---Brian

[brian Rupnow]

Had time for a "quicky" before I left the house this morning.---No, not that kind of "Quicky" ya dirty buggers!!! I finished and installed the tappet guide, in bronze. The corners aren't mitered yet, as I thought it best to bolt all the mating pieces together and miter them all at the same time so the corners line up nice.

[brian Rupnow]

Making a 4" diameter flywheel from a 6" diameter slab of bronze x 1 3/8" thick may be cheap---(I got the bronze for nothing), but it sure isn't easy!!! That's a lot of cutting on my old "push as you go" 14" jet bandsaw!! I have a good center punch mark where I anchored one leg of the compass that drew the 4 1/8" circle, and I will use that center punch mark for setting up in my 4 jaw chuck in the lathe to turn the flywheel.

[brian Rupnow]

Slowly the flywheel is taking shape. I centered it in my lathe 4 jaw chuck around the center punch hole that I mentioned in a previous post, then turned most of the outer diameter (except the part held by the jaws) and drilled and reamed the center hole and the two large counterbores and faced the exposed side. My 3 jaw chuck will hold up to a 4 1/8" diameter piece with the reversed jaws in it, and the flywheel was now 4" diameter on the machined outer diameter, so I changed chucks, flipped the flywheel around, and carved away the material to leave the 2" diameter spigot as shown in the picture. I still have to take my evil trepanning tool and put the recessed annulus in the exposed side, and then add the 3 tapped holes to hold the starter ring and put in a keyway and set screws. I an very busy with other things right now, so I just do a bit of machining whenever I can fit it in.(And if I have any energy left!!!!)

[Deja Vu]

I'm enjoying your posts, Brian.