Bluekingfisher":252q0ad3 said:
Gents,
I have decided to go for a 1.5HP motor for several reasons, mainly due to the size of motor frame size in relation to arbor pulley size, belt size etc and the fact that I have a newish 1.5 hp motor and suitable switch gear from another machine which will fit straight in ( with the inclusion of a flange face mounting plate) I will have to for go the anticipated and hoped for power but the engineering issues proved to big a deal. The original motor is a type 90 frame with a 19mm drive shaft. I have found out that motors above 1.5hp have a type 90 frame but this also means that they have a 24mm arbor. This would mean sourcing a pulley with a 24mm drive shaft hole and a 40mm o/s dia pulley size which isn't possible because that would allow enough "meat " left for the pulley belt recess. This would then mean mucking around with pulley sizes to attain the desired blade speed, not to mention the unusually small and narrow pulley belt. So as I say it will have to be 1 1.5hp motor for the time being at least.
It's definately much easier to put on a 1 1/2 hp motor and if you already have one to hand then it makes complete sense to try that first and see how you get on.
Having said that, the 3hp motor I replaced with on mine makes a huge difference on deeper ripping. The increased arbour size isn't an issue, the motor supplier just sent a pulley with taperlock to fit for another tenner.
The pulley was a bit larger and had a deeper groove but wasn't a problem to fit, just eased a mil or two chamfer round the outside edge on the grinder and it fitted easily.
The old drive belt was too narrow section for the extra power though and chewed up quite quickly, so replaced with the smallest size one I could find in Halfords which was about the same length but much meatier and it has made a big difference and stopped the slipping under load I was getting with the old one.
Turned out to be worth fitting a 16a supply in the end for the larger motor as once the belt slipping was sorted the startup started to blow the 13a fuses after all and a C type mcb on a dedicated 16a supply sorted that out.
So sounds like a lot of complications, but really quite straightforwards, and the pulley, belt and new circuit and mcb probably only added another £30 or so to the £100 for the motor, and made it all work very well indeed.
No need though if you can do everything you need to using the smaller motor, but may be worth looking see if you can fit a meatier belt anyway if you find you get a bit of slippage rather than just the motor slowing under load.
Cheers, Paul