Wiring 3 position switch to run motor forward/reverse without rewiring

Discussion in 'Knife Maker Shop Talk' started by Geoffrey, Nov 15, 2012.

  1. Geoffrey

    Geoffrey Active Member

    Hi all,

    I am just waiting on delivery of my NWG parts and I am starting to plan out my build.

    I have a Baldor 1.5hp single phase motor and I am planning out the wiring.

    I got thinking it would be nice to be able to run the grinder for edge up grinding so belt running towards the floor. Then running belt up towards the ceiling for polish and convex edge with cork/scotchbrite belts so also edge up.

    My motor can be wired for either direction.

    My question is can I wire in some kind of 3 position switch that can run forward, reverse, and off?

    Can this be done?

  2. Mark Behnke

    Mark Behnke Well-Known Member

    Google drum switch- images
  3. Sampson knifeworks

    Sampson knifeworks Well-Known Member

    Drum switches are what to use, I bought one for my homemade disk grinder and it works great. It was a little complicated for me to wire and ended up taking it to a electric motor shop to get it wired. I think there was a tread here about wiring a drum switch? I am sure somebody here can direct you! Funny story, I had a house electrician try and wire this switch when I first got it and he gave up after he almost smoked my motor, he tried to be a welder. Ha Ha
    Good luck,
  4. EdCaffreyMS

    EdCaffreyMS Forum Owner - Moderator

    Just a caution..... think about what you're doing before wiring a grinder for reverse......it creates a lot of safety issues, and a lot of stuff will get thrown up into your face. But, if you still want to do it, a drum switch is what's called for on a single speed machine. If you're using a VFD, you can get an optional Foward/stop/reverse switch.
  5. Geoffrey

    Geoffrey Active Member

    Thank you sir for your response.

    It is safer to have the belt running towards the ground then so I would grind edge up and polish edge down? That is a safer way to do things is it?
  6. Geoffrey

    Geoffrey Active Member

    Sorry if that sounded rude, just re-read my post.

    I have never used a 2x72 so ideas that are "good" in my head might not transfer to safe operation in reality. Better to learn here before making the mistake and hurting myself.
  7. Sampson knifeworks

    Sampson knifeworks Well-Known Member

    I have a variable speed DC motor grinder with a reverse switch on my controller and I never have the need to use it. My belts are always turning down towards the ground and I do my hollow grinds with edge up, also sharpen with edge up. But with that being said, different strokes for different folks and everybody develops there own way of doing things. I would lean towards what Ed recommends or at least try your sander with your belt running down towards the ground before investing in a drum switch. If you need to sharpen with edge down, flip the knife over and give it a try or play with scrap metal to see what you like. Belt polishing is usually done edge up. When I gave advice earlier I was thinking switches not practicality on belt sanders, Thanks Ed !
  8. Adam Vigil

    Adam Vigil Well-Known Member

    I was considering installing a drumswitch but after reading this thread I just changed my mind and saved some $$$
  9. 12345678910

    12345678910 Well-Known Member

    If you still decide you want to give it a try, a drum switch will work, but may not be necessary.

    For example, you want to use this motor on a fixed speed disc later.

    I would still keep your original on off switch and just add an additional direction switch.

    Drum switches are expensive and have lots of connections and that scares lots of people away.
    You can just add another $10 toggle switch and skip the $100 drum switch.
    The toggle switch will also fit into existing boxes easily too.

    On you baldor motor, you give no info to work with- photos and motor model numbers help.
    Baldor and Leeson and the good motor mfgrs have websites with diagrams based on model numbers.

    Take off the cover plate for the wiring box, there is usually instructions on the inside of that cover, or on a data-plate on the motor

    On the reversible motors the instructions are often "to reverse direction swap wires # and #" Those may be labelled with colours or numbers.

    "CW rotation shaft end as shown, to reverse rotation interchange black and red"

    That's easy to understand with the wires themselves, but to wire that to a switch is not so obvious

    Start with a DPDT toggle switch rated for the motor.

    Connect the centre switch pins to the tabs on the motor for those two wires.

    Connect the wires to one end of the switch.

    Now it's just running in that direction

    Now, run two short jumper wires kitty corner in an x pattern across the switch.

    That does the same thing as pulling the wires off and crossing your arms and reconnecting them the opposite way.

    This diagram is more clear if it would be in colour, but it works.

    Last edited: Nov 22, 2012
  10. Stew

    Stew Well-Known Member

    Count, that's great. :)

    It would be nice to have my disc snader reversible but cost is always a premium - I'll be looking into that some more. :D
  11. Geoffrey

    Geoffrey Active Member

    So for polishing is it "safe" to run the belt in reverse of standard direction... ie... belt running towards ceiling...

    Safety wise, what extra considerations would need to be made?

  12. Adam Vigil

    Adam Vigil Well-Known Member

    So for this motor http://www.globalindustrial.com/p/m...ax-56c-footed-115-230v-1ph-15hp-1800rpm-motor

    would this switch work?
  13. 12345678910

    12345678910 Well-Known Member

    RE the motor:
    Maybe, I'd say most universal use motors like that are reversible -it's just cheaper to make them all the same.
    but you have to check.

    The listing does not say if the motor is reversible or not.
    Some motors say "reversible" some wiring diagrams list CW and CCW for directions
    Contact them and ask if it is, also ask for a good photo of the connection diagram- that will let you know even if they person on the other end doesn't have a clue

    Like the line on this one
    "CW rotation shaft end as shown, to reverse rotation interchange black and red"

    Re the switch:

    The rating looks good, you may also go up to 2HP for no real difference in price-

    It will technically work HOWEVER probably not the way you want it to.

    The Momentary means that you will press against a spring pressure and the switch will snap back off as soon as you let go.

    I also look for screw terminals like the one you picked, rather than solder lugs

    Probably you want this

    I like to go up a rating.
    That way it will handle the startup load better
    Check these are screw terminals, the text says solder lugs, the photo shows screws

    Get these to keep the dust out - the thread matches on these, but there are other thread standards so on different switches be sure the boot and switch thread matches.
    Last edited: Nov 22, 2012
  14. Adam Vigil

    Adam Vigil Well-Known Member

    Thanks Count

    Yes the motor is reversible. Thanks for the links!
  15. JawJacker

    JawJacker Well-Known Member

    I cant figure how to wire this up to a DPDT switch so I can reverse the disc sander anyone done this?
  16. 12345678910

    12345678910 Well-Known Member

    It says interchange leads T5 and T8 to reverse

    so pick your voltage, 220 or 110

    Then let's see a better photo of the diagram, I can't tell one number from the other

    But see if you can figure it out from this

    This X pattern is the key However this diagram is for a DC motor so ignore the motor and power supply labels

    This switch will only change direction, you still need a power switch


    Make A and F T5
    Make C and D T8

    You will have to attach little wires to form the X

    Whatever it says for the other wires, put them on the respective center post B or E

    If it says tape, bundle those together with a wire nut

    Shoot me an email when you have a better phhoto or I'll forget to look at it.
  17. JawJacker

    JawJacker Well-Known Member

    I know its hard to see its
    P1 then tape P2 T8 T3 then T2 T5 T4 need to be able to switch T8 and T5 for CCW with the DPDT. I can add a power switch or what ever does it, I am just stumped here. I want 110 voltage setup
    Yeah the confusing part is the T8 is bundled how do switch with the T5?
    Last edited: Jan 15, 2014
  18. 12345678910

    12345678910 Well-Known Member

    This X pattern is the key to the T5 T8 swap

    However this diagram is for a DC motor so ignore the motor and power supply labels

    This switch will only change direction, you still need a power switch

    View attachment 45552

    You will have to attach little wires to form the X
    A to F and C to D

    Make A and F T5
    Make C and D T8

    B on the switch
    T2 T3

    E on the switch
    T2 T4 and the white neutral from the 110 power source

    Now take that and draw yourself a diagram.
    That will help you to understand it.
    Last edited: Jan 15, 2014
  19. JawJacker

    JawJacker Well-Known Member

    OK, I made a diagram how does the on off switch work?
    The P2 wire is normally taped I know I can run power to the P1
    Last edited: Jan 15, 2014
  20. 12345678910

    12345678910 Well-Known Member

    connect the black wire - live - from the 110 to P1

    Put the switch in the middle it interrupts power

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