iDRY Vacuum Kilns

Sponsors:

WM Electrical Warning Signs?

Started by pnyberg, December 06, 2010, 07:49:08 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

pnyberg

I had a job yesterday where I milled a bit over 1100 bdft of spruce (by log scale), which is an all day job for me.  The day went pretty smoothly, but there were a few events that I took little notice of at the time, but now think they may be warning signs of trouble headed my way.

Just before lunch the head stopped moving in the middle of a cut.  It didn't take me long to figure out that the breaker had tripped.  I reset it, and was back in business, but began to notice that the head was moving more slowly than normal.  I was having to twist the speed control knob further than usual going forward, and the head return speed seemed sluggish. 

I figured the slow head speed could be due to a loose drive belt, so during lunch break I tightened the belt, which didn't really seem very loose.  Unfortunately it did not occur to me to put my hand on the drive motor while I had the cover off.  After putting things back together I moved the head to the end of the rail to change the blade, and thought the speed was still on the slow side. 

The lunch break was about half an hour, and when we started up again everything seemed normal.  Until a few cuts from the end of the day, when the head stopped again with a tripped breaker.  Again resetting the breaker allowed me to finish the cut and the job, and I didn't think much more about until about 4:00 this morning when it occurred to me that these events are probably related and a sign of trouble.

A couple more data points...  The first is probably just a coincidence, but both times the breaker tripped I was making my last cut, an inch off the deck, and the head was near the center of the mill.  It might have been exactly the same spot both times, but I can't be sure.

Second, the air temperature was in the low to mid 30's, so if something was overheating, the lunch break and the weather would have given it a good opportunity to cool off again.

I'll be doing a general inspection of the mill, and calling Wood-Mizer this morning, but I wanted to throw this out to the forum for any additional ideas or suggestions. 

Thanks,
    Peter
No longer milling

northwoods1

 You know my lt40 mill has started doing the same thing. It is a new mill. I noticed it 1st when returning the head back, it seemed like it was hesitating. Thought to myself that it seemed I had to turn the speed up more than usual also. This just started happening the last time I was sawing so now with your post I am thinking maybe there is something wrong. I will be interested in reading what others have to say as I haven't had a chance to look things over and try to figure it out.

Magicman

Check to be sure that you haven't picked up a sliver of wood that is preventing a cam follower from rolling freely.  Remove your power feed belt and move the head from end to end.  Does it move freely?  Also, sometimes one of your outriggers will settle in.  (the one closest to the axle) It will not be properly supporting that portion of the mill and actually allow the mill frame to flex a bit.  This will show up when you are ¾ through a heavy log.

After checking the above, which I consider being the normal stuff, look at power feed motor brushes, tighten electrical connections, etc.

Keep us posted.
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

LeeB

Look for shiny bolt heads on the fram just abovethe axle. My battery guard will some time get a little bent somehow and catch right there. Also watch for sawdst build up in the same place causing the battery box to drag.
'98 LT40HDD/Lombardini, Case 580L, Cat D4C, JD 3032 tractor, JD 5410 tractor, Husky 346, 372 and 562XP's. Stihl MS180 and MS361, 1998 and 2006 3/4 Ton 5.9 Cummins 4x4's, 1989 Dodge D100 w/ 318, and a 1966 Chevy C60 w/ dump bed.

jdtuttle

I was having similar problems while sawing for long periods of time. The following is from Woodmizers trouble shooting guide on their website. Let us know what you find out.
Jim

The hydraulics on the sawmill run directly off the battery.The alternator only comes into play after the hydraulics stop running.It replaces what you have taken out. If the battery loses it's reserve capacity the hydraulics pull the battery down quickly.When this happens you may see other functions falter or quit running. When a battery loses its reserve capacity, it causes additional strain on the alternator and shortens it's life. On average, a hydraulic sawmill that is used 4 or more days a week will require a battery every 12 to 16 months depending on the load it is handling.
Have a great day

sparks

Since you tripped the breaker I would be looking at the brushes of the motor. Take the wires off the motor, put a volt meter across the wires and hold it in reverse. If your voltage is 11 volts or higher the reverse should be coming back at a fast speed. If it isn't then we are back at the motor. Take the belt off the motor and if the head moves easily then it is not a bind.
\"America will never be destroyed from the outside. If we falter and lose our freedoms, it will be because we destroyed ourselves.\" Abraham Lincoln

pnyberg

The Wood-Mizer tech's best guess was that at the core I was experiencing a mechanical issue, not an electronic one.  Something on the head was running into something that didn't want to move which stopped the head and tripped the breaker.  He seemed to feel that the fact that the head was in the same place both vertically and horizontally both times it happened made this the likely scenario, which does make some sense. 

One the other hand, the fact that in both cases the head was able to continue through the cut once the breaker had been reset without my having to clear anything leaves me wondering. 

Anyway, based on both the tech's suggestion and LeeB's, I look around the mill, above and below, for anyplace that the head might be catching on some other part of the mill and came up with nothing.  I also opened all the electrical boxes looking for anything loose or unexpected (like a mouse nest), but found nothing.

I'm surprised the lifetime of the mill battery is as short as stated.  Since I've still got less than 200 hours on my mill, the battery should still be good for a while, but parts do sometimes fail early, so I'll certainly keep that in mind as a possibility.

One other thing that did occur to me was that I did not do a good job of keeping sawdust from building up on the battery box and track cover area.  I'm sure I should be spending a bit more time during the day clearing off sawdust and removing chunks of wood lodged places where they may cause trouble.

If anything happens in upcoming jobs that shed any light on Sunday's gremlins, I'll be sure to post an update to this thread.

Thanks,
    Peter
No longer milling

pnyberg

Quote from: sparks on December 06, 2010, 04:03:16 PM
Since you tripped the breaker I would be looking at the brushes of the motor. Take the wires off the motor, put a volt meter across the wires and hold it in reverse. If your voltage is 11 volts or higher the reverse should be coming back at a fast speed. If it isn't then we are back at the motor. Take the belt off the motor and if the head moves easily then it is not a bind.

The motor was what came to mind when I was mulling things over at 4:00 in the morning, but I didn't want to send everyone down that path by suggesting it.  Also, it was just replaced in June, so it doesn't seem all that likely that it's gone bad in 6 months of part time use.  If it's possible for the performance of the motor to degrade after a period of heavy use, and the return to normal after resting a while, then it could be the motor.  If motor's don't degrade that way then it's probably something else.

But, I'll do both tests suggested in the morning and report back.

Thanks again,
    Peter

No longer milling

Magicman

Peter, your battery life will be much more than that, unless you have a defective alternator.  Place a VOM across your battery so that you can monitor the voltage as you operate.  The back of your alternator is a good connection point.  Your voltage should be over 13 VDC.  As a note, low voltage will cause high current and kick the breaker.

You stated; "I was having to twist the speed control knob further than usual going forward".  This indicates blockage.
My first items to eliminate were detailed in the first couple of sentences of my first post.  I've seen splinters and bark do strange things. 
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

Peter Drouin

Hi pete in cold weather sawdust freezes under the track cover. It happin to me last year' And the head stopped??. I look and the felt was coming out from under the track cover.  :o So I removed it ,No problem know,Maybe this helps  8) 8)
.       
A&P saw Mill LLC.
45' of Wood Mizer, cutting since 1987.
License NH softwood grader.

pineywoods

There are a couple of bolt heads sticking out of the frame rail right about where you are seeing the slowdown. The back side of the battery box just barely clears them. Had the battery box open lately? or dropped a slab on top of it ?
1995 Wood Mizer LT 40, Liquid cooled kawasaki,homebuilt hydraulics. Homebuilt solar dry kiln.  Woodmaster 718 planner, Kubota M4700 with homemade forks and winch, stihl  028, 029, Ms390
100k bd ft club.Charter member of The Grumpy old Men

terrifictimbersllc

How about the return of the head, does that seem slowed by something?    It should return pretty fast and even coast a bit after you turn off the switch .  I would use that coasting freedom or lack of it as a signal and test that all the way along the return path.    Also if you were not set up level and going uphill this can be much harder.   Just sounds like some wood is stuck in there somewhere, i'm sure you've jammed the head with an edging laying beside the top rail before, or had something get wedged under the battery box...something like that....there's probably other opportunities for similar gremlins?
DJ Hoover, Terrific Timbers LLC,  Mystic CT Woodmizer Million Board Foot Club member. 2019 LT70 Super Wide 55 Yanmar,  LogRite fetching arch, WM BMS250 sharpener/BMT250 setter.  2001 F350 7.3L PSD 6 spd manual ZF 4x4 Crew Cab Long Bed

Slingshot


  Seems most everything has been covered but I have had chips of bark become imbedded in the
drive chain and would keep the sprocket from riding through smoothly.



______________________ sling_shot






terrifictimbersllc

On my LT40 if I didn't keep the battery box and wiper area clean I would certainly risk jamming up the drive system with sawdust and chips in fact the area to the rear of the battery box (opposite the operator) is like a funnel right down to the drive system.

I carry a blower and blow this area out every 3rd log or so, as well as blasting off the blade guides, wheels, drive chain, bed rails,  and main guide rail.
DJ Hoover, Terrific Timbers LLC,  Mystic CT Woodmizer Million Board Foot Club member. 2019 LT70 Super Wide 55 Yanmar,  LogRite fetching arch, WM BMS250 sharpener/BMT250 setter.  2001 F350 7.3L PSD 6 spd manual ZF 4x4 Crew Cab Long Bed

customsawyer

The only thing that I have not heard that I have had is a idler sproket that the bearings are gone.
Two LT70s, Nyle L200 kiln, 4 head Pinheiro planer, 30" double surface Cantek planer, Lucas dedicated slabber, Slabmizer, and enough rolling stock and chainsaws to keep it all running.
www.thecustomsawyer.com

Bandmill Bandit

One thing that i have gotten in the habit of doing is clearing debris off the top rail guard especially when sawing pine. If you are doing 4/4 boards and you have 2 or 3 large 6 or 8 inch wide cants (16 inches or more deep) on the deck at the same time you can build up enough saw dust on top of the rail guard sawing one 16 foot log so that the saw head will put enough pressure on the rail guard in the last 2 cuts to turn that guard in to a very effective head brake. if you tighten the thumb screws tight enough they will hold the guard down after the saw head has forced the guard down hard enough even after you lift the head a couple inches to return it for the next cut. The breaker will hold till just past the axle ish, depending the the cut speed and how hard your pushing that speed. Also the amount of saw dust build up under the guard will have an affect on the distance you will be able to travel before the breaker trips too.

Another thing to look for is "wood shavings" about a 1/16th wide and about 2 to 4 inches long caught on the head drive chain. I have this happen fairly regular when flat sawing frozen pine. They tend to come out in the second and third cuts mostly and they like to get caught in the chain for some reason.

i keep a windshield snow brush handy to just reach in a swipe of the saw dust of the guard once or twice per log.  

   
Skilled Master Sawyer. "Skilled labour don't come cheap. Cheap labour dont come skilled!
2018 F150 FX4, Husqvarna 340, 2 Logright 36 inch cant hooks and a bunch of stuff I built myself

NMFP

I had the same exact thing happen.  Exactly!  The problem I had was a bad circuitbreaker.  As the breaker would heat up, it would malfunction and trip.  Took the breaker out and found the one connection was black.  To test it out, I changed my power feed temporarily over to the debarker circuit and everything worked great. 

May or may not be the problem but check it out.  Doesnt hurt to try it out.

Good luck and keep us posted and happy sawing!! 8) 8) 8)

NMFP

MartyParsons

The Accuset 2 H bridge has diagnostics for the power feed if is is used as the control for Power feed. If you push the up button from manual mode and go into diagnostics and scrol down to power feed it will show you how many amps the power feed motor is drawing. It is used on all mills built this year 2010 not sure you have it, it depends on your revision Accuset 2. If you do have dual access Accuset 2 H bridge, check the amps early and see if it is changing.
All the comments have covered just about all it could be.
Marty

"A pessimist sees difficulty in every opportunity; an optimist sees opportunity in every difficulty." -Winston Churchill

ladylake

Hydraulic head drive is nice.  No trouble in 8000 hours on mine.   Steve
Timberking B20  18000  hours +  Case75xt grapple + forks+8" snow bucket + dirt bucket   770 Oliver   Lots(too many) of chainsaws, Like the Echo saws and the Stihl and Husky     W5  Case loader   1  trailers  Wright sharpener     Suffolk  setter Volvo MCT125c skid loader

Magic Smoke

The head should move relatively easy (maybe 30-40 lbs pressure...just guessing here) but see if you can push the head by hand (with key off), if it takes three men and a boy scout to make it move down the rail then you have a mechanical bind. Check your cam-follower bearings. Don't bother looking for bad brushes or loose connections as they do not cause breakers to trip on a DC mill...unless the breaker is faulty of course. Also, see if the motor is getting real hot, this is also an indicator that the motor is doing too much work (i.e. mechanical bind).

woodmills1

my 70 is very forgiving of sawdust build up

my 40 however would bind if sawdust built inside the wipe boxes
James Mills,Lovely wife,collect old tools,vacuuming fool,36 bdft/hr,oak paper cutter,ebonic yooper rapper nauga seller, Blue Ox? its not fast, 2 cat family, LT70,edger, 375 bd ft/hr, we like Bob,free heat,no oil 12 years,big splitter, baked stuffed lobster, still cuttin the logs dere IAM

Chuck White

About 5 years ago, my FIL had a problem similar to this one!

The head would get just about to the tire and it would bind and then with a little shove, it would take off again and finish the cut under it's own power.

He said it did that for quite a while, then we got "down and dirty" with it and found a wafer cut from a 2" diameter limb sitting in the small gap between the back of the battery box and the main beam.  There was a narrow gap there and it would bind everytime.

Removed that and everything returned to normal.

~Chuck~  Cooks Cat Claw sharpener and single tooth setter.  2018 Chevy Silverado and 2021 Subaru Ascent.
With basic mechanical skills and the ability to read you can maintain a Woodmizer  LT40!

pnyberg

Quote from: pnyberg on December 06, 2010, 04:43:37 PM
But, I'll do both tests suggested in the morning and report back.

I didn't actually manage to get to this until several mornings had come and gone, but I've got a bit over 12 volts across the motor connection wires, and moving the head by hand didn't reveal any binding at any point along the rail. 

I've got another job tomorrow, and I'll let you know how it goes.

--Peter
No longer milling

pnyberg

I milled all day Saturday with no recurrence of any of the prior weekend's issues; no tripped breakers, no sluggish head movement.  So it seems that these were not 'electrical warning signs' of eventual motor failure.  My best guess is that the events were related to the build up of sawdust and other milling remnants on the mill, and the problems went away when the mill was thoroughly cleaned up.  So, the lesson is to pay more attention to keeping the cleaned up.

Thanks for all your suggestions,

--Peter
No longer milling

customdave

Hmmm good to know , Thanks I will watch also!

                                     Dave
Love the smell of sawdust

Thank You Sponsors!