Sideshaft i.c. Horizontal engine

[Brian Rupnow]

I found a piece of 1144 stress-proof steel big enough to turn a one piece crankshaft from. I'm thinking about bolt on counterweights. The model I show here is doable, but I'm not terribly impressed by the look of it. Has anyone seen bolt on counterweights on another model? If so a picture would be appreciated.

 

[Brian Rupnow]

Here we have the first video related to this engine, showing the action of my $12 helical gears from China. I am very pleased with the action, and more than pleased with the price. The gears are made in China and sold thru Ebay. They are metric "modulus" gears rather than diametral pitch gears, but that means very little to me as they only have to mesh with each other.

 

[werowance]

bolt on crank weights from this thread

https://www.homemodelenginemachinist.com/threads/water-cooled-webster.23224/page-6
was actually considering doing this on my Webster when I get to that point

 

[Brian Rupnow]

Dang--I knew I'd seen bolt on weights before. Didn't know it was on one of my engines from a few years ago. Thanks Werowance.---Brian

 

[Brian Rupnow]

The camshaft housing has a 1" long oilite bronze bushing in each end. The shaft is 3/8" diameter, the hole inside the square piece is 1/2" diameter. There is an oil hole to squirt a bit of oil into the cavity to keep the oilite bushings lubricated. I finally had to break down and spend some money today--beyond the cost of the $12 helical gears. I was right out of 2" diameter cast iron to make the cylinder from, so I bought a 12" length today at my local metal suppliers for $45.00. I only need about 1/3 of the length I bought for this engine, but I'm sure there will be more engines in future.

 

[Johno1958]

Good day Brian .
Really liking your engine and those bolt on crank weights . Those helical gears look perfect and for 12 bucks!!
Cheers
John

 

[CFLBob]

Brian, could you private message me? I tried to start a "conversation" about two weeks ago.

Bob

 

[Brian Rupnow]

Oh Yeah---we got cast iron cylinder!!!!

 

[Brian Rupnow]

CFL BOB---One of the big determining features of building your first i.c. engine is whether or not you have gear cutting knowledge or gear cutters. If you don't, then you are pretty well stuck with building an engine which you can buy gears for. The Webster is a great engine, because the gears for it are sold commercially. All of my gear cutters are 24 DP, so if you build one of my engines, you must be able to either cut 24DP gears or be able to cross reference them to a different DP number, and you may not be able to buy them commercially.---Brian

 

[CFLBob]

CFL BOB---One of the big determining features of building your first i.c. engine is whether or not you have gear cutting knowledge or gear cutters. If you don't, then you are pretty well stuck with building an engine which you can buy gears for. The Webster is a great engine, because the gears for it are sold commercially. All of my gear cutters are 24 DP, so if you build one of my engines, you must be able to either cut 24DP gears or be able to cross reference them to a different DP number, and you may not be able to buy them commercially.---Brian

"... whether or not you have gear cutting knowledge or gear cutters." Unfortunately, that would be no and no.

That's a hill I should climb some day, but I do tend to get impatient when I'm building things, so stopping to learn a new skill set is probably not the best idea. I'm working on that impatience, too.

Right now, with my wife on a walker and me doing everything around house, shop time is close to zero for another several weeks. This is a good time to gather information and read background info. There's a lot of good looking modifications to the Webster on YouTube.

 

[Brian Rupnow]

I had a piece of 1144 stressproof long enough to make a crankshaft from. Since you can only buy this stuff in rounds, I always find it difficult to machine the first side flat as seen in the picture. Today I made up a wooden "fence" to mount on my bandsaw, and trimmed the first side off, then mounted it in my mill and took it down to size. Now that I have one flat side, I can mount that flat side to my mill table and mill down the opposite side to end up with a piece of bar stock. With a steel straight edge held against the flat side now, there is no visible warping or bending. If you tried that with a piece of cold rolled, or even A36 mild steel, it would look like a banana now.--I did find out one other thing today about my gears--they are hardened. Harder than the devil's horn. I was going to open the crankshaft gear out to 3/8", but I tried it with a file first, and a file just skates off it. Not wanting to ruin a drill or reamer, I decided to leave it at 8mm. They come with a stock bore of 8 millimeters (0.3150"). The only real difference that makes to me is that the flywheel on the gear side will have to have an 8 mm bore.

 

[Brian Rupnow]

CFLBob--Have a look here.--Brian
https://www.homemodelenginemachinist.com/threads/anybody-want-to-guess.7687/

 

[Brian Rupnow]

Now we have the round 1144 stressproof steel reduced to a flat-bar. The edges are still rounded, but that's okay. I had to remove a 3/8" depth of material from the rounded side. I can only comfortably take a 0.015" depth of cut in steel with my mill, so that's a lot of cranking back and forth. There is a little tip in this picture. If your milling vice is narrow like mine is at 3" and you are concerned about setting up a longer piece to keep it perfectly parallel to the mill bed, then block the ends up with 1 2 3 blocks and parallels so the piece is truly level, and just use the vice to squeeze it there and keep it in place. A couple of good raps with a dead blow hammer make certain that the piece didn't lift up at one end or the other when you tighten the vice.

 

[Brian Rupnow]

This is the part of crankshaft turning which had by far the highest "pucker factor". I got thru it okay--I'm always thankful for that. I'm off to Tim Hortons to buy a bagel, and then if I'm lucky I'll get the two ends done this afternoon.

 

[Brian Rupnow]

This morning we have a finished one piece crankshaft. It looks good, and has minimal run-out. I'm not a big fan of turning between centers, but for pieces like this crankshaft it is really the best way.

 

[Brian Rupnow]

Each counterweight will be held in place by one socket head capscrew. The counterbored hole for the capscrew will have a brass plug Loctited into it to hide the hole.

 

[CFLBob]

I assume you're concerned about the balance? Do you calculate the Moment of Inertia or just what? In other words, how do you know how heavy to make those?

 

[Brian Rupnow]

CFLBob--There is indeed a formula which I don't have just off the top of my head. I could look it up, but in this case it would mean nothing anyways. I know that there will be some imbalance without weights. The counterweights are more for "show" than for "go". This will never be a high revving engine, so I'm not worried about it. Even if I was concerned, it would involve buying a very sensitive scale and weighing the piston and the connecting rod and calculating the center of mass of the crankshaft.

 

[CFLBob]

Understand. This is where your experience gives you a feel for what you need to to.

I recall calculating the MOI of an assembly like that way back in college. One of those tools they put in my mental tool box that I would never need.

 

[Brian Rupnow]

Drove 185 Km up north to see my 98 year old mother today. She was ill around Christmas time, but is up and about and doing much better now. My metal supplier was supposed to be sawing off two pieces of 5" diameter cold rolled for me today to make flywheels from, but he never got to it. Ah POOP!!!--That's okay. I have material to make a connecting rod and piston over the weekend.