Aligniment crankshaft S6

[Kalle]

Hi Michael
Wishing you a Happy New Year, it will be brighter now for every day that goes.
Thank you for your tip. I wonder if you made an alignment on this S6 axis that has three-pin pins see the photo as it is not possible to knock around the crankshaft pin. My thought is to put the crankshaft in a press and push it in the corresponding direction. Another method I was thinking of is putting it in a vice and using a tube to break back the shoulders
BR Kalle

[douglas1947]

Hi Kalle,
sorry, I have never seen this kind of crankshaft (S6) and no expirience with it!
I have only repaired T35 crankshafts and some single crankshafts, all have no stops on the crank bearing pin.
May be you will find out you have a better alignment, when you control the crankshaft on a prism (so you have no difficults with mistakes you can get, when controling in your lathe).
This construction of the S6 crankshaft seems to be for constant fixing with no possibility for changing the position!?
May be someone other can let us know about it!

Michael

[Bert]

Hi Kalle,
It looks like you have no radical adjustment with the pinned crankshaft. You should still have lineal adjustment which can be done by using wedges between the cheeks (vertical parts) to open them up or a vice to squeeze them together however this would apply even pressure on both cheeks. To move one cheek only you could try resting one cheek on a solid surface and striking the other side with a mallet. Go easy, a thou or two each time.

[Doug]

Kalle,

The factory practice with the S6 crankshaft (and probably others from the EW to the Aero) was to get it very closely aligned, pin the joint, and then do the final grinding of the main journals. For it not to line up, the throws have to be sprung or it is a crankshaft built up from components of more than one crankshaft.

First, study if springing the crank as Bert suggested will bring it closer to true. If it needs a radial twist and the pins are preventing you from doing that, the accepted practice is to remove the pins, do the alignment, and then re-bore the pin holes for a slightly larger dowel (like 5mm).

Do not be tempted to leave the pins out, you cannot tighten it up enough to stop it from slipping.

-Doug

[Kalle]

Hi Douglas friends
Feel very good that you are on the forum to discuss the alignment of crankshaft.
I'm trying to insert the screw and nut and try to change the shafts position.
If that fails, I would probably ask a workshop to align and lock the position with 5mm pins that Doug writes about.
Thank you for your help and Happy New Year to you
Br Kalle

[douglas1947]

Hi Kalle,

I think you will let us know the result of trueing the crankshaft in "next year".
I hope you can mange it without touching the pins.

All the best to all for 2018!

Michael

[Kalle]

Hi Michael
Have a good start for the new year
I will notify you when I get the crankshaft in the best way, maybe I will leave it to a workshop so I will be satisfied
Br Kalle

[Kalle]

Hello Douglas friends
I promised to hear from me when I had rebilled my crankshaft for my S6 1930.
Luckily there are such information from Doug, Eddie, Bert, Cardan and Douglas 47 that it will be the correct information regarding the alignment of crankshaft. My flywheel side discs were well-worn from rollers so after modifying it to 1/4 rolls, the surface against the crank was wrongly wrecked that I got so much radial play on my axels. The surface was grinded down  0.20 mm horizontally in both directions and not 90 degrees to the flywheel axle. After cooling down with carbonic acid and warmed axel discs and pressed together. I made a v tripod and got 2/100 mm radial throw and think it's ok. The engine is assembled, and flywheel throws in visible and goes very well. I have 8 mm crank rolls that are 3/8 "long and demagnetized
for sale if you hear someone who needs it
Thanks for your help
Kalle

[douglas1947]

Hi Kalle,

thanks for your interesting report of S6 crankshaft rebuild, well done!

I have had also now expierience in that kind of crankshafts, I had overhauled a 1930 H3 crankshaft.
It was possible to repair it with oversize rollers (.001" front + .0005" rear oversize). The surfaces of pins and the conrods were okay!
The crankshaft is back in the engine, but it is not finished, because still some parts are missing.

Michael