Power feed LT 40 stopped moving forward?

richhiway · September 06, 2023, 07:25:04 PM

A few times today the power feed going forward stopped working. It seemed to work again after I shut the mill off and restarted it. It worked fine in reverse. It did it a few times then worked the rest of the day. It is a LT 40 with simple set. 200 hours. I replaced the pentometer about 150 hrs ago, the knob is tight. No binding, belt tight. Motor was not even warm to the touch. Drum switch is lubed and looks OK. No loose wires I could see.

Any ideas?

SawyerTed · September 06, 2023, 07:31:17 PM

Check the brushes in the motor.

GAB · September 06, 2023, 07:44:09 PM

richhiway:
The next time it happens back up about a foot and check to see if there is bark on the drive chain that interfered with the drive sprocket's travel. I have had that happen numerous times especially when sawing cherry. If that is the case get your pocket knife out and remove the offending bark and continue sawing.
The first time it happened to me I forced it and I believe it is what cost me a circuit board.
If your problem is something else I sure would appreciate knowing.
GAB

Dan_Shade · September 06, 2023, 08:02:04 PM

I had to replace a feed module a few years ago.

https://forestryforum.com/board/index.php?topic=60110.0#msg878583

Lots of troubleshooting info in the thread link above.

Crossroads · September 06, 2023, 10:22:53 PM

I agree with Dan, the power feed control module could be on the fritz. If you end up replacing it, check the diode as well, if its bad, you'll smoke the new PFCM. Once the smoke leaves, you can't put it back...

Sixacresand · September 07, 2023, 10:46:54 AM

I recently replaced the potentiometer (the variable speed controller) which fixed mine.

richhiway · September 09, 2023, 08:09:07 AM

Quote from: Dan_Shade on September 06, 2023, 08:02:04 PM
I had to replace a feed module a few years ago.

https://forestryforum.com/board/index.php?topic=60110.0#msg878583

Lots of troubleshooting info in the thread link above.

TY for the link.

Bruno of NH · September 09, 2023, 08:53:24 AM

I just went through this last winter
It might be the computer that's in the electrical box on the mast.

richhiway · September 16, 2023, 02:22:08 PM

I called Wood-Mizer and the tech guys were good but they said if it does not stop working completely it is hard to figure out. Because by the time you go to diagnosis it it would be working.
Today as soon as it stopped working in forward I pulled off the back cover and the over voltage light was on, on the control box. It soon went off and it started working again.

Nothing is binding and the alt is putting out 14.7 volts. When I was checking the alt. the two bolts that hold it the lower bracket to the mill were broken off so I have to drill these out and replace them.

Any idea why the over voltage light is on.

Magicman · September 16, 2023, 03:40:46 PM

Did you review the link in Reply #3?

Dan_Shade · September 16, 2023, 04:09:02 PM

Is it over voltage, or high current?

Excessive current can be caused by making the motor work too hard. You could have a bad bearing somewhere in the drive or a cam follower, it could be a moter problem, or even a wire that's damaged from a mouse or chaffing.

SawyerTed · September 16, 2023, 08:11:08 PM

Check the motor brushes. It's cheap and eliminates that as you work to the more complex.

My LT 35 did the same thing. Jerky movement forward but back just fine.

Turned out to be brushes.

Dad2FourWI · September 16, 2023, 09:00:38 PM

I had very similar situation and I agree with Sixacresand.... I replaced the potentiometer and life is good again! Actually running better than for the last two years!!!

!

Hope you find out what the problem is and let us know when you do.

-Dad2FourWI

richhiway · September 17, 2023, 07:12:52 PM

Quote from: Magicman on September 16, 2023, 03:40:46 PM
Did you review the link in Reply #3?

Yes I did Len, it was informative and I think the control module is propably the culprit. I am going to call WM on Monday and let them know the OV light is on when it will not move forward and see what they say.
Thanks all.

richhiway · September 29, 2023, 07:39:12 AM

Spoke to WM in Hannibal NY they suggested the module was bad. Came from indy in two days. I was away for work so I have not installed it yet. Update as soon as I get it working.

richhiway · October 08, 2023, 04:02:02 PM

It ended up being the control module. When I ordered it from Hannibal they said to check continuity from the blue wire to ground on the diode, it should only be one way. It was both ways hooked up but if you unhooked it it was one way. So I ordered a new one and it tested the same. Not sure I was testing it correctly. So I replaced both and used the mill for a few hours today and it is working good. Sorry it took so long but I have been busy at work.

OlJarhead · October 09, 2023, 08:11:18 AM

Glad you sorted it out! I had the entire back panel on mine go but I think it was a nearby lightening strike that got me (and it was around 600hrs). Tough to diagnose when they work, then they don't, then they do again! Grrrr