set screw problem again

[wa2crk]

RFGuy
just an additional thought

https://www.shopsmith.com/ss_forum/wood ... 6-s20.html

[JPG]

Like pushing with a wet noodle.

Just insert a torque converter in the drive path.

[RFGuy]

RFGuy
Just read the first part of the paper you referenced and I am convinced that the response time speed of the regulator to control the speed would need to be modified to slow the reaction time of the speed controller. I think that this would soften the impact of the rapid on/off switching and the resulting vibration. Much of the applications of the SRM motors are in machines that run at a relatively constant speed. An example would be a drill press. Once the drill bit is engaged in the stock, load variance is, I believe, at a minimum. Cutting many small pieces as I do for segmented turning would vary the load considerably. I am not as educated as you seem to be in electrical theory But I was wondering if SS would consider redesigning the coupler shaft to include a coil spring mounted axially inside the tube to absorb the rotational forces. Just a WAG. ( wild a$$ guess)
Bill V

Well, I am pretty well versed in electromagnetic theory, hence my screen name "RFGuy", so I know the basic theory of motor design. I don't know the PowerPro though since I don't own one and switched reluctance motor design is a niche of a niche of engineering so it is pretty far removed from me. So, please don't take my comments indicating that I know it all...far from it. All of your comments make sense to me and you have way more hands on experience with the PowerPro, so I defer to you. For all the benefits of switched reluctance motors, this is one of the problem areas for it, I believe. It can be managed, I guess, but would be nice if there is a more long term fix from Shopsmith/Striatech to address it. Reading the other thread you posted from 2011, am I to understand that the problem is more isolated to SPT's meaning that the coupler could help/hurt the issue? OR, are there a good number of failures directly on the main arbor setscrew, e.g. sawblade coming off? IF the PowerPro is causing it on the main shaft, i.e not SPT, then doesn't this mean it isn't just a coupler issue? Just asking out of curiosity. Wish I had a fix for you...

[JPG]

If anything, I think backlash in the coupler/hub connections would help mitigate the torque step vibration. I am sure the coupler has a softer impact at backlash extremes.