Re: [electricboats] Flange coupler for Thunderstruct gear reduction

The Thunderstruck kit has a 1" shaft.  I think it has a standard keyway.  Fitting a standard flange should not be a problem.  But, there are some caveats. 

Flanges come with the shaft bore slightly under-sized and are fit to the shaft using a lathe.  Simple job for a machine shop.  They need the coupler and the shaft to do the fitting.  It would also be worthwhile to face the coupler to the shaft which means mounting the coupler then cutting the face of the flange to make it truly perpendicular to the shaft.  Another simple job for a machine shop. 

The flange on your prop shaft has a boss on it that fits into a counterbore on the face of the transmission shaft coupler.  This locates the coupler laterally.  If you buy a coupler to put on the thunderstruck shaft it will also have that boss.  That needs to be removed and the counterbore needs to be cut into the face of the flange to fit the boss on your prop shaft coupler. This is what I did in my installation.  I didn't use the Thunderstruck unit but my process was analogous.  There are some photos here:
http://dan.pfeiffer.net/10m/electric_drive_unit.htm

You may be able to get a flange with the counterbore already in it.  I couldn't find that.  You may have more luck.  But I have a lathe and modifying the flange was an easy option for me. 

You can get that flange off your prop shaft with a puller.  A steering wheel puller would probably work or a medium sized three to two armed puller.    If it is a proper snug-slip-fit you can put it back on with  mallet with the prop shaft in place if there is room to work. 




Dan Pfeiffer

On 2022-07-06 9:45 am, anton.slutsky@gmail.com wrote:

Hello group,

New here, question for the group.  Converting a Cal 2-29 to electric using Thunderstruck kits.  The kits come with a chain coupler, but was wondering if anyone had any experience using a flange coupler instead?  Not that I mind pulling the current coupler off the shaft, but the boat is in the water and if I can avoid tugging and banging on the shaft, would definitely be better I think :-).  

Would anyone had any experience with Thunderstruck kits and flange couplers?

TIA!