WM drum switch "Fun"......

[Jim_Rogers]

Ok, so Friday, late afternoon, just before it was too late to get parts, my sawmill starting acting up.
First it wouldn't go forward right, then it wouldn't back up right.

Then it went forward full speed, luckily I was over the 20" pine log when that happened.

It seemed that the power feed rate switch wasn't working. No matter what setting I put it on it went forward at full speed.

Well, I had a spare feed rate switch on hand. So I called WM; talked to electrical help and they said it wasn't that feed rate switch and to look for something else.....

I took the cover off (dash board that the key is in) and looked in. Sure enough the forward backwards drum switch had a broken off contact, it was laying in the bottom of the control box.

First I looked through my spare parts inventory, and found a new switch in the pile with a bunch of old broken ones, and wouldn't you know it, it was an up down switch. Just my luck.

So, I called WM home office knowing that they were earlier in their day, and managed to get one on order, along with some other miscellaneous parts. But needing this switch right away, I instructed them to ship it next day air so I'd have it this morning.

Sure as shootin the truck rolled in right before 10 am with the parts. I figured I was golden and all set.

After lunch, I took the mill apart and put in the new switch, making sure that the battery was disconnected and that each wire went to the correct terminal and put everything back together. I have done this switch changes at lease twice on each side, for sure.

Ok, so before putting all the power feed belt guard back on and tightening every thing up, I figured I test it to make sure it worked correctly.

Well, it went forward ok, feed rate switch worked ok, (I swapped the old one out anyhow just to make sure it wasn't that). And went backwards ok, just one little problem.

I had to hold the switch in the forward position to make it go. The switch wouldn't "lock" in forward and go on it's own. That's strange, I said to myself.

So I took the dashboard back off and looked at the drum switch to make sure I didn't order the wrong one. Yup, right one, yup hooked up right, took it back out to look at label on bottom, yup right switch. Looked closely at old switch and new switch.

Seems that this new switch didn't have the dent cut into the cam thingy and it couldn't lock forward. What a bummer.

Right on the phone to WM, they assured me that they sent the right part. We checked box numbers and sure enough it was the right part. He went to the stock room and got another switch and checked it out and it had a dent cut into the cam to lock it in forward.
He thought that my drum switch could have been turned 180 degrees out, but we checked that and nope it was correctly positioned.

So, now what?
I have to wait for another part to be shipped in?

I looked closely at the two drum switches and figured out that I could swap the drum.
He said if I wanted to do that to keep running then I could.

So I did. And it worked.

Here is the new and old drums switch drums:



The point of this story, is that you can with a little careful inspection get by with a minor change of parts.

New part due here tomorrow.

Some fun, heh.....

Jim Rogers

[Bibbyman]

If it happens again...  Here is a trick that I have used more than a couple of times that may get up and running in 20 minutes or less.





Take a drill and cut the old contact off under the screw and cut a good contact off an old switch.  Then replace the bad contact with a good one.  It'll work find.  But order a new switch because it will work but not work indefinitely. (Although I've used a repaired switch for maybe a year or more.)

[Chuck White]

Jim;
I had my first introduction to drum switches at almost the same time that I was introduced to my FIL's 92 Wood-Mizer LT40G18 manual mill.

He almost flipped out when he came back to the saw site from a break and saw that I had the whole drum switch out of the control head.

I got all the contacts cleaned up and greased, and reinstalled and he ran the saw.  He told me that the drum switch hadn't worked that smoothly or positively in 10-12 years.

I told him that that is what that little white container of purple grease is for.  I guess he never greased it before, but he does now.

I do need to get myself a "burnishing tool" to clean the contacts with.  It'll work better than crocus cloth or emery cloth!

Glad to hear you're back up and running again though.

[Jim_Rogers]

If it happens again...  Here is a trick that I have used more than a couple of times that may get up and running in 20 minutes or less.





Take a drill and cut the old contact off under the screw and cut a good contact off an old switch.  Then replace the bad contact with a good one.  It'll work find.  But order a new switch because it will work but not work indefinitely. (Although I've used a repaired switch for maybe a year or more.)

Take a drill and cut the old contact off under the screw and cut a good contact off an old switch.

Exactly how do you do that and not damage the threads for the wire screw?

I have lots of broken switches to get parts from.

Jim Rogers

[Jim_Rogers]

Inventory problems for sure.

As I was loading up lumber to a drop in customer, my portable phone rang and seeing that the call was coming from Indiana I took the call.

It was WM calling me.

Somehow the inventory at the warehouse has gotten crossed up and they send me a second bad switch. And they were calling me to tell me so, very nice of them to do that.

It seems that all mills made for or sold in Europe have to have this style switch so that the operator has to hold the switch in the forward position to make the mill saw head travel forward. Some safety regulation they have to comply with over there.

I do have the old drum in the new switch body and it's working fine this morning.

I suppose I could try and get a Dremel tool and cut a dent into these new drums to make them work correctly, would beat trying to file one in by hand.....

Jim Rogers

[Bibbyman]

If it happens again...  Here is a trick that I have used more than a couple of times that may get up and running in 20 minutes or less.





Take a drill and cut the old contact off under the screw and cut a good contact off an old switch.  Then replace the bad contact with a good one.  It'll work find.  But order a new switch because it will work but not work indefinitely. (Although I've used a repaired switch for maybe a year or more.)

Take a drill and cut the old contact off under the screw and cut a good contact off an old switch.

Exactly how do you do that and not damage the threads for the wire screw?

I have lots of broken switches to get parts from.

Jim Rogers

The contact is just kind of flare riveted into the threaded brass insert in the plastic block.  Use a drill bit just a bit larger than the hole and drill just the thickness of the contact - say 1/32".  Just like cutting the head off a pop rivet.  The threads are undamaged (unless you drill too deep).

Cut a good contact off a donor switch the same way.   The only small downside is that the replacement contact will be loose.  But you can run the screw in most of the way and then insert the wire connection and tighten it up.

You say you have some spare switches.  I'd say there is nothing lost by giving it a try.

[Jim_Rogers]

Thanks, I may give it a try, some day.

Right now, I may try cutting the indent for the lock first..... maybe easier to do.....

[sparks]

What we found was that some of the power feed drum switch were what's called German Standard. These are used overseas where a locking drum switch is not allowed. They got put in with the ones we use so that is why it does not lock. Inventory has been corrected.   Thanks for bringing it to our attention.