# Advice on building some cranks



## kvom (Jul 30, 2010)

My current build requires 2 single-crank crankshafts. The shafts and journals are all 3/8" and I plan to use drill rod. The webs are to be 3/16" thick separated by 1/2". 

My current idea is to use aluminum for the webs with press fit for the drill rod. There may be problems getting everything lined up accurately.

Another idea is to use brass webs with a sliding fit and silver solder.

Thoughts?


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## ksouers (Jul 30, 2010)

Since everything is 3/8, how about press fit with Loctite? Use two longish pieces of drill rod and set them across a couple 1-2-3 blocks to make sure they are parallel to each other. After the Loctite sets, cut away anything that doesn't look like a crankshaft.


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## mklotz (Jul 30, 2010)

Press fitting creates opportunities for distortion. I would simply assemble with Loctite to hold things in place while I drill for roll pins to secure everything. Cranks don't generally get very hot but I still wouldn't trust just the Loctite.


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## bearcar1 (Jul 30, 2010)

If you do use the loctite method, it would probably be a good idea to pin the journals and shaft together for piece of mind. Personally, I've always fancied using silver solder, it provides me with a bit for latitude in the final 'adjustments'. Whenever I use Loctite, I get real tense as once the pieces are pressed together and they are not 'right', for me it becomes a major PIA to undo the pieces and start over again. Silver solder, no sweat, a strong application of heat and presto, the pieces release and I can go on. When making up cranks in pieces, I like to fabricate holding jigs out of Aluminum to keep the shafts in-line until the pieces have been secured together. Then, like K' said, "anything that doesn't look like a crankshaft gets cut away.

BC1
Jim


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## johnthomp (Aug 4, 2010)

i build m7y crankshafts useing drill rod and instead of just brazing it all together i do the main shaft in 2 pieces and tap it all out then screw it together so i can set evry little thing before pinning evrything then silver solder it all or is it just me going too far with the effort ;D
  regards
  john


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## kvom (Aug 4, 2010)

I am making the webs from aluminum, so I plan on using loctite and roll pins to keep it together. Just got a pack of pins delivered from Enco, so am good to go.


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## itowbig (Aug 5, 2010)

johnthomp  said:
			
		

> i build m7y crankshafts useing drill rod and instead of just brazing it all together i do the main shaft in 2 pieces and tap it all out then screw it together so i can set evry little thing before pinning evrything then silver solder it all or is it just me going too far with the effort ;D
> regards
> john


i never though about threading those darned things good idea thanks ill give it a whirl


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