This is the first Internal Combustion engine I`ve built and I think after many weeks reading and thinking, I just about get the basic concept of how the engine runs. I have been looking to build an IC engine for a while. A friend and fellow model engineer is currently building “The Project” G1 steam engine and although I was extremely tempted to follow him in a build, I thought I`d stick to my original plans of building an IC engine. I expect “The Project” will be next….
So deciding on the Webster as a simple build (I use the word simple loosely) I started to get materials collected. I snagged a lot of aluminium plate from the scrap heap several months ago and finally I`ve been lucky in the fact that I`ve got pretty much all the sizes I`ll need.
Unfortunately I did not have the cast iron or leaded steel for the cylinder so I purchased that a few weeks ago
I`m also moving from the plans and will be using 8mm silver steel for the crank rather than the imperial .313″ that is stated. I`m also going to run the crank in bearings rather than brass bushes as stated and these arrived last week:
I also ordered a small NPK spark plug that cost £3 on ebay but I`ll need a M10 x 1.0 tap which is annoying, my M10 taps are all M10 x1.25mm.
I then had to think about the carb. The thought of purchasing a RC IC engine pre-built carb seems like cheating when it plays such a pivitol part of the engine runnings but maybe I`m wrong in those thoughts!! I haven`t read about too much success with the carb design with the Webster but I believe that the carb from drawings published in ME for the Nemett 15S works very well so I think I`ll run with that.
Then it comes to the gears!! I`m going to try and cut the gears. Thankfully in my efforts in my continuing clock build I`ve attempted several gears so I`m quite comfortable about giving these a crack. Involute spur gear cutters are MUCH cheaper, at about £20 a cutter than Cycloidal clock wheel (gear) cutters which sell for about £60-80 a cutter! Despite this fact, I`m going to try and make my own cutter again using the methods and calculations provided by John Stevenson on the web. I`ve done all the calculations, they are here:
Well after all that thinking … time for some swarf
It always takes me ages to just cut the pieces, infact it took me a few nights just to rough out a few pieces from the big sheets of aluminium. Here are the two side supports, the one blued up is to size, the back longer support is just roughed out.
I`m in a bit of a pickle with regards to the base. I`ve nothing really suitable and can`t justify the large costs of a piece of ally big enough just for the base of this. I think this piece will do, but it is a little bit thin, then again my plan is to raise the base on pillars so the electrics can go under it.
I`ve also been preparing for cutting the cylinder bore which I`m going to do between centres.
In preparation I made this bore setting device:
And with so much success, I had to fall over some where!
The cylinder was looking good so far:
Then I thought I could just not show it hence the angle of the photo…but look at the fins
..but hey ho! I`m going to go and bore it and continue as it`ll have no bearing on running, just the gap between the fins is wrong. Two stupid errors, I misread the plans and then to compound the issue, the work managed to move from the 3 jaw during grooving! At least now it is unique! – I often seem to say that!
Here is the cylinder with the roughed out cylinder support piece:
…and that is pretty much where I am up to right now. Next job is to mount the cylinder again for boring between centres.