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General Forestry => Sawmills and Milling => Topic started by: Larry on December 07, 2009, 05:15:29 PM

Title: Drum switch wiring help needed
Post by: Larry on December 07, 2009, 05:15:29 PM
I'm changing the up/down switch on my mill from a toggle to a drum type hoping for longer service.  The new switch is just a standard Dayton drum switch...forward, stop, and reverse.  The switch DC schematic shows a coil between 1 and 5 and I don't understand why.  I don't think I need the coil but thought I would ask for guidance...just to prevent the magic smoke from appearing.


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Title: Re: Drum switch wiring help needed
Post by: Jeff on December 07, 2009, 05:48:28 PM
As a side note, while yer helping Larry, can any one tell me what the approximate price is for the drum switches on my old LT30 ?  The one for the feed and also the one for up and down.   I signed in to the wood-mizer online store and every part number I have comes back as either not a valid number or not for sale on-line.  I need to replace them before next spring.
Title: Re: Drum switch wiring help needed
Post by: WH_Conley on December 07, 2009, 06:17:38 PM
Larry, sorry I don't know why either.

Jeff, seems like the last ones I bought were about $35.00 each. Can't cross the numbers at the local refrigeration place either, made just a little different.
Title: Re: Drum switch wiring help needed
Post by: Fla._Deadheader on December 07, 2009, 06:38:33 PM
 
Bought ours from Surplus Center, and did not put anything in line. It's gonna take some fancy cypherin to figure out the cross wiring. I had to modify ours to take the heavier wire.

  Larry, you sure that's not a resistor in line ???

Not Woodmizers price, but, Surplus Center sells them for $50.00 or so, last time I looked. They are NOT cheap.  ::)
Title: Re: Drum switch wiring help needed
Post by: Slabs on December 07, 2009, 08:22:58 PM
Larry, if 3 and 4 are the wipers(the terminals that go to the moving parts of the switch) take out the coil and toss it, connect the battery and ground to 1 and 2, cross wire 2 to 5 and crosswire 1 to 6.  You may have to reverse the wires coming from battery and ground to get the switch working in the right direction because it's a crapshoot when initially connecting anyway.

Added note: Wires can also be reversed at terminals 3 and 4 or on the motor terminals.

If that's hardly clearer than mud, I'll make up a schematic similar to yours and post it.

Good luck
Title: Re: Drum switch wiring help needed
Post by: gmmills on December 07, 2009, 09:09:08 PM
  Jeff,
     
      For my LT70 the switches are $63.00 a piece. No plastic switch covers they mount in the control box. Not exactly the same as yours but should give you a good idea on price.
Title: Re: Drum switch wiring help needed
Post by: MartyParsons on December 07, 2009, 09:46:30 PM
Jeff the part # are.
Power Feed A07799  qty 1 $ 76.24
Up Down A11758 qty 1 $ 75.86
Newer mills
E20440   $ 69.95
E20439   $69.95

Wiring for a standard LT30 or LT40 up down would be as follows
Terminals are # 1-6 Even # on one side and odd # on the other
1, 3, 5=     1 and 5 wired together and to to motor +  #3 wire to ground  1,5 have jumper wire
2,4,6=     6 and 4 together go to motor -    # 2 Bat+ through curcit breaker     6, 4 have jumper wire
note : every model may be different. if you dont have a wiring diagram please call us we will get you a copy
Marty
Title: Re: Drum switch wiring help needed
Post by: pineywoods on December 07, 2009, 10:03:08 PM
Is that coil part of the switch? I'm guessing not, it probably is showing the connections for the field windings on a shunt wound dc motor. Your motor doesn't have any field windings, uses a permanent magnet. I think slabs has it right.
Title: Re: Drum switch wiring help needed
Post by: bandmiller2 on December 08, 2009, 07:17:11 AM
Possibly the coil is there to reduce arching or possibly a softer start.Get your multimeter set on continuity turn the drum then find continuity to to where you want it to go.Frank C.
Title: Re: Drum switch wiring help needed
Post by: Larry on December 08, 2009, 10:24:56 AM
Quote from: pineywoods on December 07, 2009, 10:03:08 PM
it probably is showing the connections for the field windings on a shunt wound dc motor. Your motor doesn't have any field windings, uses a permanent magnet. I think slabs has it right.

I think your right piney.

I'll set up the meter as Frank suggested before I wire it into the mill.

Title: Re: Drum switch wiring help needed
Post by: Magicman on December 08, 2009, 09:08:31 PM
Normally, when your switch is in the neutral position, you then want the coil (shunt) across the motor windings.  This effectively acts as a "brake" and prevents the motor armature from easily turning.

Note:  When a motor is turned, it then becomes a generator.  If the terminals are shorted (shunted) then it is looking at a loaded circuit, and thus becomes very difficult to turn.  On my WM, the saw head is very hard to push.  If you remove a wire from the motor, you remove this shunt and the head is now easier to move.  This shunt is your brake.
Title: Re: Drum switch wiring help needed
Post by: solidwoods on December 09, 2009, 07:24:08 AM
Larry
I have a Kasco.
I use drum switches for feed and up and dwn.
I also use a 20amp home light switch after the up/dwn, this allows a much finer blade height adjustment.  The drum just doesn't work fine enough.

On the rtn. I put a 20amp home light switch from the + to the feed motor, this allows full power to the feed motor.  I use it on the head return so I am bypassing the rheostat.  The rheostat at full resists electric a little so the full power to the feed motor makes a faster rtn than going through the rheostat.
jim
Title: Re: Drum switch wiring help needed
Post by: Magic Smoke on December 10, 2009, 10:07:22 AM
Magicman is correct, the shunt is used for dynamic braking of the motor. Without the shunt the motor will coast when trying to stop, making it difficult to hit your mark. As Magicman states, the wire or shunt should be shorting the two motor wires together when in neutral.

FYI:
Just in case someone out there is having a problem with their head drifting down while sawing, it is important to note that dynamic braking doesn't really hold a motor in place, it just stops the motor. The motor has to be turning (acting as an generator), as Magicman says, in order for dynamic braking to be effective.
Title: Re: Drum switch wiring help needed
Post by: sparks on December 11, 2009, 08:35:14 AM
The up/Dn drum switch wires differently depending in the year of the mill. I have attach the wiring diagram for a pre 1992 standard mill and one for standard mills 1992+. I hope this helps.
Title: Re: Drum switch wiring help needed
Post by: Larry on December 14, 2009, 01:19:36 PM
I got my new drum switch wired up this morning.  Wired it like the pic in my first post with nothing on contact 1 and 5.  Electrically it's identical to the factory toggle switch.  Put a bit of NO-OX on the contacts...hope it lasts longer than the toggle's I've been using.

Here is the drum switch I used if anybody is interested.

http://www.grainger.com/Grainger/wwg/search.shtml?searchQuery=2X440&op=search&Ntt=2X440&N=0&sst=All

Contacts appear heavy and it is made in the USA.

While wiring this morning I put in a heavier gauge wire back to the battery.  Also put a new switch in to bypass the rheostat on the return.  I don't think it made the return faster, but it sure did eliminate messing with the rheostat all the time.  Thanks for the idea Jim.
Title: Re: Drum switch wiring help needed
Post by: solidwoods on December 14, 2009, 09:51:35 PM
Quote from: Larry on December 14, 2009, 01:19:36 PM

While wiring this morning I put in a heavier gauge wire back to the battery.  Also put a new switch in to bypass the rheostat on the return.  I don't think it made the return faster, but it sure did eliminate messing with the rheostat all the time.  Thanks for the idea Jim.

That means you have been good at not turning on the feed with the rheostat not at low speed.
When we engage the feed with the rheostat up a bit (usually at your last set feed speed), that causes arcing on the rheostat windings and it degrades it.  So when you go to full speed you can't get full amps through the rheostat because of the degraded winding.  So when that happens the bypass switch advantage can be seen.

Also should/when you arc/degrade the windings you will see a dead spot on the rheostat, usually around the 3/4 speed spot.  Your choices are less feed (yuck) or more speed (yeow) or replace the rheostat. 
You can reverse the 2 wires on the rheostat.  Yes this causes the rheostat to operate back wards.  But the dead spot will be at the 1/4 feed speed spot which we really don't use and you can get more use out of the rheostat if you choose. 
The rheostat is about $70.

Also another prob I see is the engines alternator just doesn't put out enough amps to keep the battery charged.  Those 2 dc motors, engine starter and XM radio :D draw a bunch of juice.  So I use a battery charger on 10 amps when I mill (I'm stationary so no prob).

I also added a second track wiper on the dust discharge side.
Title: Re: Drum switch wiring help needed
Post by: Chico on December 15, 2009, 10:56:47 PM
you also use momentary switches for the same purpose and adjust them to be as finite as you would like