Apparently Gary from Salmon Arm Woodmizer is in Indiana getting "upgraded". He is my usual troubleshooting guy and unavailable at the moment.
Problem: After nearly 11,000 hours of flawless operation, my autoclutch mechanism went silly thismorning. Fired up the mill, everything fine....after warmup, engaged the blade and it just kept cycling between idle and wideopen. No matter what I did with the activation switch, it just kept cycling. I shut the mill off and took things apart. Hadda look for loose wires...nadda....turned the key on an the cycling continued. The only way to stop the cycling is to turn off the key....
I checked in my parts book and Im assuming it is either one or both of the magnetic sensors (Part# 024627) or the mosfet module (Part# 024618). Dont have the knowedge to trouble shoot/diagnose this condition.......any help appreciated as I have to bus parts in from Salmon Arm and Im non-oprerational... Thanks
The top of the cover is hitting a power source inside or the cover has pinched a wire. Take the back bolt out. (mines at the bottom at the rear). Then loosen the 2 front bolts and then position the cover until it is not touching anything and the recycling stops.
This has happened to me. When my cover was touching a power source the engine would go up and down like its possessed. :)
When you do this leave the key on while you put the cover back on and this will tell you when you have it positioned right.
To check to see if its a bad part...leave the cover off and activate the auto clutch.
It is possible while sawing a big log that the log will clear the saw opening but will bump the auto clutch housing......this is not good if it does,
That explains why Gary didn't call me back today :D. I once had a similar issue, if I remember correctly, there was a nut stuck on my magnet sensor. Quite possibly the same one that I lost when installing my lights.
Quote from: highleadtimber16 on February 13, 2018, 10:08:06 PM
That explains why Gary didn't call me back today :D. I once had a similar issue, if I remember correctly, there was a nut stuck on my magnet sensor. Quite possibly the same one that I lost when installing my lights.
Its a tight fit for that cover but it has to clear everything and it just takes a "bang on the box" for it to ground something.
Note: It is good to take the cover off the Auto Clutch from time to time and blow it out. Sawdust gets trapped in there and once it starts caking up....ya gonna have problems.
Quote from: POSTON WIDEHEAD on February 13, 2018, 10:09:51 PM
Quote from: highleadtimber16 on February 13, 2018, 10:08:06 PM
That explains why Gary didn't call me back today :D. I once had a similar issue, if I remember correctly, there was a nut stuck on my magnet sensor. Quite possibly the same one that I lost when installing my lights.
Its a tight fit for that cover but it has to clear everything and it just takes a "bang on the box" for it to ground something.
Note: It is good to take the cover off the Auto Clutch from time to time and blow it out. Sawdust gets trapped in there and once it starts caking up....ya gonna have problems.
My cover is off, and it still is possessed as you put it :D :D :D I blew it all clean with compressor. I have added several modification pieces attached to the cover over the years. Couple of 12 volt air solonoids to operate my debarker in/out but they are still attached to the cover and its laying on the frame by the motor. I wiggled and shook and cut zip ties hoping for some intermittant action but no luck. Still possesed :D :D :D I will check again for pinched wires. Could it be something else??
Quote from: Percy on February 13, 2018, 11:09:05 PM
Could it be something else??
Sounds good Percy. Keep us posted as I will be learning something. :)
Could it be a bad switch?
Quote from: POSTON WIDEHEAD on February 13, 2018, 11:11:30 PM
Quote from: Percy on February 13, 2018, 11:09:05 PM
Could it be something else??
Sounds good Percy. Keep us posted as I will be learning something. :)
Could it be a bad switch?
I thought of that but logic tells me that a bad switch would either leave it off or on. Not cycling, or possessed(that kills me :D :D :D :D). I didnt try swapping switches but will give that a go first thing in the morning. I have an LT70 2003 vintage. The autoclutch mechanism is in a different place than a LT40-50. It just tightens the belt with an idler as opposed to tilting the motor. Other than that, Im assuming its similar. We'll getter figured. As my dad used to say "There aint a thing in the world what cant be fixed." Thanks for the help.
I remember my first "possession" with my mill.
That engine started going up and down......sheeeeeet.......I took off! smiley_horserider
Percy, there are 3 likely causes for this ...
- Metal touching the sensors (they're magnetic). Could be small parts, could be chips of metal (from drilling holes in the cover), could be metal filings from something rubbing.
- Bad sensor. Easy to troubleshoot with an ohmmeter. Turn the key off, disconnect a sensor wire, and connect the ohmmeter leads to both wires from the sensor. Then move a piece steel past the face of the sensor. If the sensor is faulty you won't see any change in the ohmmeter.
- Faulty Mosfet module (that's the circuit board inside your autoclutch housing).
Other than that, anything that interferes with the wires from the sensors could cause the problem.
Quote from: Brucer on February 14, 2018, 12:33:07 AM
Percy, there are 3 likely causes for this ...
- Metal touching the sensors (they're magnetic). Could be small parts, could be chips of metal (from drilling holes in the cover), could be metal filings from something rubbing.
- Bad sensor. Easy to troubleshoot with an ohmmeter. Turn the key off, disconnect a sensor wire, and connect the ohmmeter leads to both wires from the sensor. Then move a piece steel past the face of the sensor. If the sensor is faulty you won't see any change in the ohmmeter.
- Faulty Mosfet module (that's the circuit board inside your autoclutch housing).
Other than that, anything that interferes with the wires from the sensors could cause the problem.
Allrighty!! Thanks. I have a multi meter at the mill. I will check carefully for metal filings. It wont take long to check the sensors. smiley_thumbsup smiley_thumbsup
It will be one of your sensors. I have had it happen a few times. I have always just replaced both of them when I was in there. The placement of the sensors is very critical, so you will want to put little marks to make sure you put the new one on in the same place. It might be that one of the sensors got moved and is no longer close enough to sense the small cam as it goes around. My bet is that it has failed.
Quote from: customsawyer on February 14, 2018, 02:52:59 AM
It will be one of your sensors. I have had it happen a few times. I have always just replaced both of them when I was in there. The placement of the sensors is very critical, so you will want to put little marks to make sure you put the new one on in the same place. It might be that one of the sensors got moved and is no longer close enough to sense the small cam as it goes around. My bet is that it has failed.
Quote from: Brucer on February 14, 2018, 12:33:07 AM
Percy, there are 3 likely causes for this ...
- Metal touching the sensors (they're magnetic). Could be small parts, could be chips of metal (from drilling holes in the cover), could be metal filings from something rubbing.
- Bad sensor. Easy to troubleshoot with an ohmmeter. Turn the key off, disconnect a sensor wire, and connect the ohmmeter leads to both wires from the sensor. Then move a piece steel past the face of the sensor. If the sensor is faulty you won't see any change in the ohmmeter.
- Faulty Mosfet module (that's the circuit board inside your autoclutch housing).
Other than that, anything that interferes with the wires from the sensors could cause the problem.
Two good quality replies
Hello.
There was many at Wood Mizer Indy the last two days. We had training.
Auto Clutch is controlled by a mosfet module. There is always power to the motor Red wire. The mosfet controls the ground on the motor. When you see this issue with the motor will not stop the rotation, best guess it the mosfet module is shorted and has grounded the motor. There are three terminals on the mosfet. You will see two 1/4' studs that has black wires one will have motor ( wire goes to the motor) and Ground. There is also a single wire that has a blade terminal ( male) on the mosfet and a female on the wire. This wire goes to the prox sensors. When you get a run away motor on the Auto Clutch remove this single plug. ( best to turn key off then turn it on to test). If the motor stops the prox sensors are most likely the issue. If it keeps running then it is the mosfet. This little terminal is the Gate Lead and it is controlled by 12 volt input. You can test with an ohm meter. The prox sensors can also be shorted they should be closed when not close to metal. So normally closed and open when magnetized.
Hope this helps.
Marty
(https://forestryforum.com/gallery/albums/userpics/11823/A7B081C0-4723-40BF-A7F8-A8CC6497F1A1.jpeg?easyrotate_cache=1518662057)
(https://forestryforum.com/gallery/albums/userpics/11823/919CDD26-1F67-4159-A72B-870C9B73D8D7.jpeg?easyrotate_cache=1518662056)
I know you got yours figured out. Just in case someone else has an issue here are some pictures.
Allrighty...Thanks everyone...Im headed out there after Dental appointment....yetch.....I'll let you know
Quote from: Percy on February 14, 2018, 11:03:16 AM
Allrighty...Thanks everyone...Im headed out there after Dental appointment....yetch.....I'll let you know
NO NO NO......You're mill comes before your teeth. :D
Back out here. Unhooked both sensors,
Turned key on and still possessed 😂. Hooked up ohmmeter and both are operating ala normally closed. I'm gonna remove the mosfet module to see if it has somehow shorted to ground. If it looks fine I will order a new module and prolly sensors too if they ain't stupid expensive. Thanks all for the encouragement/help
My new mill did same thing. Had a stray nut stuck to the sensor. Never did figure out where it came from.
Quote from: CCCLLC on February 14, 2018, 04:05:34 PM
Had a stray nut stuck to the sensor.
If theres a stray nut around my mill its usually me. ::)
Quote from: POSTON WIDEHEAD on February 14, 2018, 07:37:32 PM
Quote from: CCCLLC on February 14, 2018, 04:05:34 PM
Had a stray nut stuck to the sensor.
If theres a stray nut around my mill its usually me. ::)
Possessed stray nuts :D :D :D
Got a hold of Sean down at Salmon Arm Woodmizer. Ordered the mosfet and for another 50 bucks apiece, I ordered the sensors as well. If I dont order them, my karma tells me they will die within a week. Once I havem in stock, the originals will outlast any possessed stray nuts at my mill. He didn't have that cute lil belt but mine is surprisingly good considering its age. I will put the new shelix head in my dewalt D735 planer tomorow while I wait for mill parts to arrive.
Thanks again everyone for the help. smiley_thumbsup smiley_thumbsup
You will love the new shelix heads. My dad changed his planer and jointer over last year. They work pretty sweet. No more tear out and chipping on that darned hard maple.
I shook my family tree and a bunch of nuts fell out of it.
Quote from: Percy on February 13, 2018, 11:09:05 PM
Quote from: POSTON WIDEHEAD on February 13, 2018, 10:09:51 PM
Quote from: highleadtimber16 on February 13, 2018, 10:08:06 PM
That explains why Gary didn't call me back today :D . I once had a similar issue, if I remember correctly, there was a nut stuck on my magnet sensor. Quite possibly the same one that I lost when installing my lights.
Its a tight fit for that cover but it has to clear everything and it just takes a "bang on the box" for it to ground something.
Note: It is good to take the cover off the Auto Clutch from time to time and blow it out. Sawdust gets trapped in there and once it starts caking up....ya gonna have problems.
My cover is off, and it still is possessed as you put it :D :D :D I blew it all clean with compressor. I have added several modification pieces attached to the cover over the years. Couple of 12 volt air solonoids to operate my debarker in/out but they are still attached to the cover and its laying on the frame by the motor. I wiggled and shook and cut zip ties hoping for some intermittant action but no luck. Still possesed :D :D :D I will check again for pinched wires. Could it be something else??
I once thought the same as you did. Only when I took the cover off (lt40) and blew it out with compressed air, it reverese tightened some wires and I had to redo a bunch of those connections lol. After that I said I ain't touchin that nomo
Thanks to the relentless snow, I didn't get a chance to fix the LT70 till today.it was the mosfet module that was the culprit. I have two spare sensors now. 🤓. All back to normal. After fixing I plowed and plowed and plowed and plowed and plowed and plowed
Quote from: Percy on February 17, 2018, 07:51:27 PM
it was the mosfet module.
glad you found the problem Percy. By the way, did you get any plowing done today? :D
My auto clutch needed an exorcist last year, but I think all the loose nuts have finally rattled off.
Sawing way to wide a maple, the cover pinched the red power wire and kept blowing the circuit breaker (accessory power), so nothing would move. Took a bit trying to figure out which red wire in the controls was the culprit.
Then a few months later, the auto clutch stopped working at all. Turned out the cable by the hitch had rubbed in someone's awful driveway (probably my own).
Maybe feeling left out, the mosfet decided to go, and for some reason I had enough faith in the mill that I needed to saw that day, so my quick fix involved wiring in a new automotive relay.
And not to be forgotten, one of the prox sensors decided to get in the family business and start intermittently failing. So I took one of my blade sharpener magnets and stuck it on the tail end of the chunk-o-metal that is supposed to trip the sensor.
Two months into the new year and no problems whatsoever, aside from the bitter cold and waist high mud. And a pump motor failed, but it actually had a brand name and not one of those cheap knock-offs, so I know I hadn't replaced it yet.
One thing I have recently found on my mill is some of the spade connectors on the sensors have started to fail. They will look fine and will work when the sun, moon, and stars line up. Found the connector that was bad and then found another that was getting ready to go. Keep a eye on them folks.
When you say the spade connector failed, are you saying that the wire came loose from it or the tension was lost between the male/female connection?
The spade broke off of the crimped end.
Did the wire break at the crimp or did the connector break?
I had 2 where the connector broke and one where the wire broke at the crimped end.