sinking Wood-Mizer

[WH_Conley]

Something new started today. When dropping the saw head down my LT40 has always stopped in about 1/8 of an inch when you let off the lever. Today it started stopping  anywhere from an 1/8 to 1/2 sometimes more after releasing lever. Could not see anything to cause this, mechanically. Too late in the day to call tech support.

Anybody got any ideas?

'97 LT40HD24

[WH_Conley]

Had me scratching my head for a minute.

Don't think is limbering up, 600 plus hours on the mill, started all at once.

Don't have any trouble going up, same as ever.

Going down, first time I thought I had just simply held it too long, human error, which I am prone to do. Has went way past where it is supposed to stop. After a couple of times of this happening I really paid attention. Responds nowhere the same as it always did since day one.

[Jeff]

Slabs, nobody can delete someone elses post.

'cept the admins.

[pigman]

Bill, Sounds like the dynamic braking is not working correctly. If I turn the key off while I am lowering the head it will continue down up to an inch or more. I think the problem is electrical, maybe in the drum switch. It is losing contact or something. I really don't know but the smart people will quickly correct me.

[Tom]

It may be that the belt is slipping. 

On my 1990 LT40 I always wore work gloves because I used the big pulley on the up/down to stop the head movement.  I also turned it by hand to make minor adjustments instead of bumping the drum switch.    Bumping the drum switch caused arcing and burned up the contacts so I tried not to do that.   The habit of using my left hand on the pulley worked real good.   I think the head of my mill would regularly drift a half or even as much as an inch after I let go of the drum switch handle.  I just never gave the distance much thought because I was controlling it anyway.

[pigman]

See, I knew someone smart would have an answer.
Tom, on the newer mills there is a shield covering the pulley. I supose a person could take the shield off to check for slippage of the belt. My mill will only drop about an 1/8 in after I release the down lever, and that is with the heavy diesel.

[WH_Conley]

Pigman,
I was wondering about electric also.

Tom,
Have to remove guard to check belt tension, seemed tight, no sign of slipping, to control it like you did I will have to take the side panel off the mill, under fuel and water jugs.

I will check for signs of arching on switch tomorrow, almost dark when I quit tonight.

Thanks for all ideas.
Bill, the confused one.
Bob has got me doin it now .

[Tom]

Hmmmm   Can't get to the pulley, eh?    I guess that's progress.

Things do change.

I used to be able to climb into the motor compartment of my Buick and sit beside the straight eight while I worked on it.  Now, with the new truck, I can't even see the ground when I open the hood.   Yep!  Progress'll get you every time. 

[Minnesota_boy]

Every now and then the drum switch on my mill will stick a little, just enouigh to overrunn the setting I had planned.  You may need to lube the contacts with contact grease or you might have to check on the detent roller on the switch itself to see if it needs lubed too.

[Minnesota_boy]

Tom,
It's a lot harder to stick your finger under the belts when there is a guard in the way.

I removed the guard from the feed belt drive after it collected sawdust in the shroud and then froze.  It makes it real hard to feed the mill when the pully won't turn.  Bet that hasn't happened to you yet. 

[Tom]

I had a guard too.  It was a flat piece of metal on the outside of the pulley that kept you from getting you finger under the belt.     I wore a heavy glove and could stop the pulley with a bit of flat handed pressure on top of the pulley.  Didn't want my finger under there.  No siree bobcat!!   

Nope!  my feed belt was along side of the speed control housing just above the level of the upper rail.   Sawdust wasn't a problem there.  It wasn't until later that they improved it and put the fool thing down under the sawdust shoot at the the chain.   But, that's progress. 

[Kirk_Allen]

Do you have set works or Accuset?

I had an issue with mine a couple weeks ago and had to reboot the system to correct the problem.  After rebooting the system the head would take close to 20 seconds to drop to the desired hight selected.  Turns out that after rebooting I needed to reset LOTS of numbers.  WM said once I load those numbers back in all should be back to the quick speed it was. 

It was a real pain waiting 20 seconds for the head to finally stop dropping down 1/32 of an inch at a time. 

[sparks]

WH, I know you do not have a Setworks so here are a few things to check when it comes to the head drifting.
1 We rely on the friction of the mast pads to help the head stop. I would verify they are adjusted properly.
2 If the up down chain is not adjusted properly, that will allow a drift.
3 To make the head to stop we basically shunt the motor terminals together. Terminals 5 and 6 of the drum switch created this shunt. If either finger is worn and not making a good contact it will not brake the motor. Once the motor stops the head the gearbox is what holds it there.
4 Worn brushes will not allow the motor to brake properly. I would check those also.
5 Aloose belt will also atribute to the drifting.

I hope I gave you some ideas to help.   Thanks

[VA-Sawyer]

I think Sparks pretty much hit it with item #3 and possibly #4.  The drum switches need to be lubricated on a regular basis. There is a special grease for this. You can get it from WM for a small fee. The little tub will last a long, long time. I just use a Q-tip to put a tiny amount in place in each set of contacts. This reminds me that mine are due for greasing again.    Better do it next time I park the mill up by the house.
If it isn't in the drum switch then double check for a loose connection close to the motor. I had a short time where the FWD on my feed worked fine , but the reverse was pretty jumpy. Found a loose wire at the motor. It would make ok contact in one direction but when the motor reversed it shifted just enough to cause a bad connection.  I started to pull the motor for more troubleshooting and 'found' the loose connection. Tightened it up and the problem went away. I like cheap fixes like that.

[WH_Conley]

Thanks for all the advice guys, try to get back to the mill tommrrow, been remodeling a kitchen for my mother-in-law last couple of days and taking them some tie siding slabs for firewood. They have helped mr over the years, so I guess when they need something the least I can do is try to help.

A guy loafing at the store down the road saw the load of slabs I had on the old log truck and kind of sarcastically asked if slabs were a real profitable business. Didn't take me long to point out that for the last 30 years any time I was around I had a hot meal and a warm fire to sit by, yeah, I think slab hauling is real profitable.

Maybe that should be another thread.

Thanks again guys.

[WH_Conley]

Fixed

Burnt terminals, nail file from the wife, little bit of contact grease, good as new.

Did seem like excessive arching when engaging.

Thanks for the help guys.