Engine Alignment

[doug748]

I need to align my engine. Standard gearbox spider at one end - Centaflex drive at the other (or the shaft itself with coupling removed). No clear place to mount a dial test indicator or to place feeler gauges ( cos the drive has four studs sticking out of it and even if it did'nt it is still floppy being rubber mounted and heavy).
Any ideas? Ta.

 

[sailorman]

http://www.centa-uk.co.uk/contact.htm

 

[alf1]

there are two articles in ym on engine allighment can be purchased for three pounds

 

[Poignard]

I asked Centa Transmissions about this when I installed a Centaflex M coupling in 2002. The answer I got was:-

"....... As these couplings are much more forgiving in respect to misalignment than other coupling designs, no actual alignment instructions are given, which we agree may be an oversight.

A suggestion would be to carry out a trial assembly by nipping up the clamping hub in the coupling body on the propeller shaft in the correct position, and offering up the whole assembly to the gearbox output flange. Make sure the spigot on the coupling smoothly enters the recess on the flange, and then check angular misalignment in the usual manner by means of feeler gauges. The coupling can accept up to 2 degrees of angular misalignment, but in the way of achieving a long and trouble-free life, the alignment should be as accurate as possible."

The trouble with this method [as you point out] is that you have the weight of the coupling unsupported on the shaft whilst you are trying to line up so great accuracy is impossible. However, I supect that, given how awkward lining up an engine can be, many boats do not have their engines accurately lined up and a flexible coupling allows you to get away with some misalignment.

The most accurate method is to temporarily fit a plain coupling on the shaft [if you still have the old one handy] and line up with that, then remove it and install the Centaflex.

 

[rogerthebodger]

Has anyone used one of these laser alignemnt tools to align engine and prop shaft ? If so pls describe the process ?

 

[doug748]

Thanks for that response. It all seems a bit hit and miss. Even with the flexi coupling I am sure there will be less stern bearing wear with good alignment.
I bought the coupling for the old engine some years ago and have lost/thrown away the old one, sod it!

 

[Poignard]

You could get a dummy one turned up in aluminium quite cheaply, I should think.

 

[doug748]

Thanks, I think I have managed to borrow one.