prop shaft straightness

[Dean Smith]

Originally Posted by stringy

Thanks SamSam for the link, will check with the formulas provided tomorrow! and yes the hp increase has exaggerated the problem with the prop shaft, but this has been the only downside!

Dean, researching away, and no I don't really know what you mean by "sag" in regards to a shaft, just to make sure that the weight of the shaft between centres was not causing the bend I set up the shaft between two centres vertically, with no discernable change!

how far between centres did you set up.sorry if i missed that and if you clock it does the 12 thou read at 180 degrees too, in other words is the (bend) same at the bottom as a top when you turn 180

[glasser]

you can get a center bearing and make a mount for it this will reduces Anny bends and make it run smoother at all times shafts are made of a staneles mix steel and bit soft over the length in bigger boats is not a second thout to add center bearings and even on drag boats this is done to give more stability to the shaft the more stable things run the better this is for your motor bearings to as Anny out of out of balance is transfer to the motor to plus with the center bearing is not a weary of a shaft flying out if something brakes

[glasser]

1 more note take a good look at the back shaft bearing if you have in the past hit things or the old shaft was Reilly bad it can and most likely damaged the back bearing this is something to use tools to check not your eyes

[stringy]

I have finally installed the new 1" 431SS shaft and ran the boat Saturday. The end result is good! Won't need a whip skeg!

Did a fair bit of work on the boat over the last couple of weeks including;
Machined 1" propeller shaft, upgraded from 7/8", extended skeg nearly 2", built up skeg to bore out to fit 1" skeg bush, bored out drive flange to 1", bored out gland to 1", reamed hull (looks like it had been cut out with an adz)and centred log.

Built new aluminium fuel tank and fitted fuel gauge, had a stick before, the old fuel tank was from some 50's car and had seen better days!

Fabricated a new foot throttle and added a hand throttle for my wife who has trouble keeping the rpm steady.

Thanks for all the advice.