AOG's version of Elmer's number 4 "Four square"

[AOG]

After my last project I decided I wanted to do something relatively easy. I dug into Elmer's book and decided on the number 4. It doesn't seem to be one of his most popular engines but I decided to give it a go.



I started off by squaring up a piece of aluminum to be the column. Then I drilled starter hole for the crankshaft and the four pivot holes.



Next I turned up the bearing and drilled it out.



The column was put onto the lathe and I drilled the center hole out to 3/8 using an end mill to get a flat bottom.



Then I bored out the center hole to take the flywheel.



Elmer calls for peening the bearing into the column. I have never had good luck with peening and this was no exception. While the bearing was retained ok it would spin in the hole. I ended up putting some Locktite 603 on the joint. I spun it around a few times and let it set. That seams to have locked it down.

Next I made the jig for positioning the port holes.



Using the jig, the ports were laid out and center popped.



The intake and exhaust holes were drilled part way so as to not interfere with drilling the intake passages.



Then the primary intake passages were drilled up from the base side to intercept the intake ports.



Then the cross port and mounting holes were drilled and tapped.



Then I extended the ports to meet the passages and drilled the exhaust ports all the way through the column. Naturally on the very last exhaust port I broke the number 56 drill in the hole. The port was drilled out, plugged and drilled finishing the column. The Next part was the base. I squared up a piece of stock and drilled the mounting holes. Then I counterbored the column mounting holes for socket headed cap screws.



Then the base was flipped and face milled flat.



That leaves us with this.



Till next time.

Tony


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[b.lindsey]

Wow Tony. That is more than a good start!!!  This will be a quick one if you keep up this pace  Always nice to see a new build started though.

Bill

[90LX_Notch]

Following along Tony.  I don't believe that I have ever seen this particular Elmer engine.  It will be a neat runner.

-Bob

[AOG]

Thanks guys. I wanted something relatively simple to keep me busy while I decide on my next big project. I think this will do the trick.

Tony

[bent]

I'm following with interest, AOG. 

[AOG]

I had to work this weekend so time was somewhat limited. I did get the four cylinder assemblies done. I started by cutting four blanks and facing them to size in the lathe.



Then the bores were drilled and reamed.



The pivot holes were drilled and counterbored.



The pivots were threaded and cut to length.



Then it was time for soldering. Three out of four went ok but I kind of overdid it on the heat for the fourth one. On top of that while cleaning up the good ones I noticed I had punched a pin hole in the end of one of the good cylinders while drilling. Well if you have to remake one you might as well remake two.

Here are the results including my problem children.



Till next time.

Tony


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[b.lindsey]

Bummer on the remakes Tony, but the final results look fine (less the problem children of course ). This will make a nice little engine and hopefully you will find some shop time this weekend.

Bill

[AOG]

Between work and a bad case of the local death crud going around the office, I haven’t felt up to doing much lately. I have managed to get this project most of the way done so let’s get caught up. I needed four pistons to go with my cylinders. As a certain UK car show used to say “How hard could it be?” The answer is very hard when they are as tiny as these are. I made nine pistons the get four usable ones. I started by milling a flat on a piece of brass bar that was a good fit in the cylinder bores.



Then the offset was milled. The amount of offset is different depending on where the piston is in the stack up. At the same time I drilled the hole for the crank pin and cut the sides back to final dimension.



Then the blank was taken to the lathe and the profile turned and the piston parted off. This is where I lost the majority of my failed parts. The rod diameter is 3/32 of an inch (about 2.3 mm).



With the pistons finished I was able to use Elmer’s jig to drill the ports on the cylinders.



Next I turned up a little pulley from some aluminum scrap and drilled it to take the crankshaft.



After parting off I drilled and tapped it for a 2-56 setscrew.



Then I turned down a piece of steel bar to fit the recess in the column. With the flywheel turned I drilled it for the crankpin.



The crankshaft and crank pin were pressed  into the flywheel and Locktited together. Here is a final family shot.



I need to find some springs and then I can get it assembled and hopefully running.

Till next time

Tony




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[AOG]

It’s finished. Pics and a video can be found here:

http://www.modelenginemaker.com/index.php/topic,7725.msg163190/topicseen.html#new

Til next time

Tony