Reversing a Motor.

tkhudson · Post by **tkhudson** » Wed Feb 24, 2010 7:53 pm

Just got into the "meat and taters" of tearing down my 10E project. I noted a switch by the peckerhead on the motor ... and by golly, its a reverse switch...

How does one go about this? Id love to change my MkV around to that.

billmayo · Post by **billmayo** » Wed Feb 24, 2010 9:04 pm

tkhudson wrote:Just got into the "meat and taters" of tearing down my 10E project. I noted a switch by the peckerhead on the motor ... and by golly, its a reverse switch...

How does one go about this? Id love to change my MkV around to that.

The Mark V motors (3/4 & 1 1/8 HP) are build as non-reversible motors. This was required by OSHA for any table saw and other rotating equipment. If you have a reversible motor, it is most likely not an original but a replacement motor someone ordered with this reversible feature. You will need a DPDT switch for a reversible motor plus the ON/OFF switch. Unless you use a knowledgeable motor shop or have worked in a motor shop, I would not recommend trying to convert a Shopsmith Mark V motor into a reversible motor.

I now have a motor repair and rebuild section in my shop. When I am feeling really lucky, I will convert one or two Shopsmith motors to be reversible. Not all attempts are successful (a trashed motor) so I normally do a 3/4 HP first and if it works, then I try the 1 1/8 HP motor. You need the knowledge and special equipment to do this type of work.

Contact me off-line if you would like to gamble with trashing your motor for an explaination of what I do.

a1gutterman · Post by **a1gutterman** » Wed Feb 24, 2010 10:27 pm

billmayo wrote:The Mark V motors (3/4 & 1 1/8 HP) are build as non-reversible motors. This was required by OSHA for any table saw and other rotating equipment...

This wood knot surprise me; so how are they "getting away with it" with the new up and coming Power Pro headstock??? It is reportedly a reversible motor!

charlese · Post by **charlese** » Wed Feb 24, 2010 10:44 pm

[quote="a1gutterman"]This wood knot surprise me]

And the 'Shopsmith Crafter's Station" came with a reversible motor. There were two switches.

tkhudson · Post by **tkhudson** » Wed Feb 24, 2010 11:36 pm

I will double check the plate tomorrow and give you the specs... I THINK it is the OEM motor with the DPDT switch on it... I am assuming that the motor needs to be at a DEAD stop before switching it? Sure makes me want to go out and blow a hundred bucks on a speed control for the old 10E now

billmayo · Post by **billmayo** » Thu Feb 25, 2010 1:23 am

tkhudson wrote:I will double check the plate tomorrow and give you the specs... I THINK it is the OEM motor with the DPDT switch on it... I am assuming that the motor needs to be at a DEAD stop before switching it? Sure makes me want to go out and blow a hundred bucks on a speed control for the old 10E now

The FWD/REV switch can be switched at any time. It will only take effect once the motor centrifugal switch closes when the motor stops. Then the action of the FWD/REV switch will take place when the motor is turned on.

Reversible AC motors do not need or use any speed control.

Equipment with reversible motors has to meet different specs than equipment with single direction motors. They required specific methods of preventing any threaded arbor from coming loose. I believe the Mark VII had some liability problems in this area. I am only trying to remember what I heard when I worked in a motor shop in the 60s so it may not be the same today.

billmayo · Post by **billmayo** » Thu Feb 25, 2010 1:27 am

[quote="a1gutterman"]This wood knot surprise me]

I would only guess as the PowerPro headstock can be used a a power source for many pieces of equipment. It is not just a table saw which requires a single direction motor.

paulmcohen · Post by **paulmcohen** » Sat Feb 27, 2010 12:38 am

billmayo wrote:I would only guess as the PowerPro headstock can be used a a power source for many pieces of equipment. It is not just a table saw which requires a single direction motor.

They may have to come out with a new arbor that has a way to lock the nut so it will not come loose then the saw reverses.

dusty · Post by **dusty** » Sat Feb 27, 2010 9:03 am

paulmcohen wrote:They may have to come out with a new arbor that has a way to lock the nut so it will not come loose then the saw reverses.

Why would you ever what to reverse direction of a "saw blade"?:eek:

iclark · Post by **iclark** » Sat Feb 27, 2010 10:06 am

dusty wrote:Why would you ever what to reverse direction of a "saw blade"?:eek:

I think the question is:
what do you want to happen if you make a mistake and start the saw blade in reverse?