Part 8 By Vince Cutajar

I decided that the next part to be made (actually attempted) will be the crankshaft. I will be making the first attempt from flat bar stock that came with the kit. If that fails, then I will try and fabricate it. Both methods are described in Westbury's article.

First order of the day is to make the tool to turn the crankshaft. It has to have a reach of at least 1.25". I have an HSS parting tool that I have never used (see photos).

Started attempt No.1 on the crankshaft. Used the flat bar which came with the kit and scribed some lines on it. The lines are not very visible in the photo. Also started grinding the crankshaft turning tool from the parting tool.
Centre-drilled the sides of the bar for the live and dead centres then chain drilled the inside of the webs. Used a hacksaw and coping saw to remove the material. Most probably later on I will mill the inside of the webs to clean it up.
Cleaned up the insides of the webs on the milling machine. Set it up in the lathe between centres. Used a live centre in the tailstock and a dead centre in the headstock spindle. Bolted an 8mm threaded bar in the chuck backplate and fixed the part to be machined between centres with a nylon tie-wrap. Started machining the crankpin but stopped at 10.1mm. Next time I will continue machining the crankpin to 9.95mm.
Finished the crankpin to dimension. Started work on one of the main journals. Chain drilled and hacksawed the excess material. Inserted a brass packing piece inside the webs and just to make sure it does not fly off I secured it with a nylon tie-wrap. Drilled and tapped 6mm a hole on the side and screwed in a 6mm bolt. Put the piece between centres and secured the bolt with nylon tie-wrap (third photo). Turned down to 10mm and then the end was turned down to 8mm. To turn the 8mm section I had to change the live centre to a half dead centre as the tool was fouling with the live centre.

One side finished but the sides of the web turned out a bit rough. Most probably when doing the other side I will mill the sides of the web first before putting it between centres.

Chain drilled and hacksawed the other side for the other journal (photo 1). This time milled the outside of the webs (photo 2). Put it in the lathe but instead of between centres, I held the part in a collet and the other side with a live centre (photo 3). Same as the other side I had to change the live centre to a half dead centre for the final 8mm cut. And this is how it looks after lathe work was finished (photo 4).
Crankshaft is not finished yet. I threaded the ends of the shaft 8mm fine (1mm pitch) with a die. The plans do not specify the length of the threads so I made them short and will increase as required at a later stage. The top and bottom of the webs need to be rounded off but I intend to do that when the bronze counterweights are in place. Also I need to drill the oil passageways. I will be drilling them 2.5mm and then tapping 3mm. Yesterday I went shopping for a long series 2.5mm drill which I could not find so I settled for an extra long version. Hope I do not break it in the hole.
I fitted the crankshaft in the crankcase and tried to turn it by hand. It was binding at a particular angle. Took the crankshaft out, put it in the collet which was still fitted to the lathe and started the lathe. There was a slight wobble at the end which was confirmed with a DTI. I suspect that the brass packing I put between the webs was too tight. Lesson learnt.

Using the DTI and a plastic hammer the crankshaft was trued. Tested again in the crankcase and it was much better. Gave it some running in on the lathe (photo).

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