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General Forestry => Sawmills and Milling => Topic started by: BenTN on October 29, 2018, 09:53:57 AM

Title: LT35 debarker slowing cut and dogging motor
Post by: BenTN on October 29, 2018, 09:53:57 AM
We have a new LT35 and working thru a few logs we have collected.  Yesterday sawing 16" soft maple log the debarker would slow the head and dog the motor to where the cut suffers. The log had a sweep to it so I was constantly adjusting the debarker in and out. If I dialed up the head speed the engine would load to the point where I felt band speed was slowing. I know I am still in the middle of my learning curve, but this just felt funny yesterday. If I didn't run the debarker the new 4* blade cut great. Does this sound typical for an LT35 with the gas engine?

Thanks, Ben
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: Southside on October 29, 2018, 12:15:52 PM
I have never had my debarker dog the motor, I have jammed it on a nub and stopped the head travel, but that doesn't dog the motor or slow band speed, unless it caused the head to ride up as a result.

Are you really jamming the debarker into the cut? Is the front part of the bottom guard catching on the log? 

My 35 never really cut well with 4's so I went to Turbo 7's and never looked back.
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: BenTN on October 29, 2018, 02:11:14 PM
There doesn't seem to be a lot of finesse in the in/out switch for the debarker. It moves pretty fast and far with a tap. I have stopped the debarker motor if I dig too deep.  I will check clearance of the guard but like you I have had it stop head movement without dogging the motor. I should probably check my electrical connections, thinking maybe a large alternator load would slow engine some with both debarker and head forward motors pulling.
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: Southside on October 29, 2018, 03:15:14 PM
At idle, when cold, you will notice the alternator load on the engine. I would think the debarker breaker would trip before the alternator dogged the engine at operating speed. 
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: Rhodemont on October 29, 2018, 04:08:24 PM
My debarker does the same thing.  Need to be careful as to how much pressure against the log. This requires adjustment due to variation in the log taper, curves, burrs, etc.  Too much pressure and it pulls power from the band and the drive.  Have tripped the breaker on it several times (which is a pain to reach up into and reset).  On a really nice straight log of uniform diameter it runs right along once the debarker is set.  Any non uniformity in the log and I have to pay attention.  
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: BenTN on October 29, 2018, 05:59:56 PM
I am going to check a few things when I get back over to the mill, It is Dad's mill, I just get to play with it.  Sounds like it maybe just more of newbie learning their equipment.
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: Dozer_Man on October 30, 2018, 10:28:38 AM
My Lt 35 does the same thing. On bigger logs with wide cuts my debarker slows the machine down to the point you have to disengage the debarker or it seems its gonna choke the motor off. It works fine at first but saw a couple logs and use the debarker on everyone and it will start to act up.  I have tried a different breaker and made sure that the debarker is lined up properly with the blade. I am at the point that I only use the debarker on logs with alot of dirt on them. Wierd thing is once you leave the debarker off an hour or so then you can debark a couple logs no problem. I have also tripped the breaker on a knot that was stuck out but this is not the same issue. The breaker never trips when it slows the engine down and I have also in a cut swing the debarker away and re engaged again thinking that maybe it was too tight against the log still the same results.
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: Lawg Dawg on October 30, 2018, 12:33:00 PM
Make sure the debarker blade bolt is tight!
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: loganworks2 on October 30, 2018, 06:08:03 PM
Do you have the gage washer on the blade. If not contact woodmizer for one. It keeps it from cutting to deep and bogging down or stopping the debarker motor. 
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: BenTN on October 30, 2018, 06:26:20 PM
Dozer, sounds we having a very similar experience with the debarker. Do you notice it a few logs into sawing or right away on the wider stuff? This weekend we were only sawing one log and it did this the second cut into the log.

I am adding the bolt and this " washer" to my check list. Does anyone have a pic of this washer?

Title: Re: LT35 debarker slowing cut and dogging motor
Post by: Dozer_Man on October 31, 2018, 09:30:49 AM
If cutting wider stuff or harder wood it usually starts acting up before i square the log up. In smaller diameter soft wood material I can make it several logs before it starts dogging the motor.  I am too going to look into the bolt and the washer discussed earlier.
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: Southside on October 31, 2018, 10:02:16 AM
@MartyParsons (http://forestryforum.com/board/index.php?action=profile;u=1823) any thoughts on this? 
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: MartyParsons on October 31, 2018, 11:40:33 AM
Hello, 
  You can notice just a slight engine hp decrease when the Debarker is working because the alternator is working more. I think you may be pushing the in/ out button more than needed. There is a spring that keeps the debarker engaged in the wood. I would bump the switch in not hold the switch. This may be your method. Just thinking out loud. 
Marty 
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: Rhodemont on October 31, 2018, 03:11:47 PM
Marty, I agree with what you write.  If I hold the in/out button and slam the debarker against even a straight uniform log it will bog down the mill/stop the debarker /trip the breaker. or if I swing it in too early before it actually will hit the log.  There is just the right touch to make contact enough to let the debarker do it's job.  The non uniform logs require attention to adjust the swing in or out as needed.
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: SawyerTed on October 31, 2018, 09:04:20 PM
So I've tried for two days of sawing, about 1200 board feet, to pay attention to the debarker.  I did notice a slight change in engine rpm upon engaging the debarker but no bogging that would change blade speed.  My mill has something over 160 hours.  Even swinging the debarker hard into the log and holding the switch to the left didn't change the engine rpm significantly.

My question is whether the debarker motor is still spinning at full rpm or is it running slow?  Could the debarker motor be drawing high amperage for some reason?
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: BenTN on November 01, 2018, 06:30:12 AM
yeah, this seemed to start overnight. Last log (an ugly 30" red oak) we played around with Qsawn technique and used the debarker all over this dirty log with no such symptoms. Took a 2 week break, unwillingly, and now on a soft maple log it does this. My thoughts are leaning towards heavy current load. Maybe a misaligned debarker head, loose connection, debris jammed somewhere it shouldn't be. I haven't had any time back to mill this week and sitting at work trying to wrap my head around what could have changed between last runs. I don't want to exclude the head forward motor as culprit either as current sink. Low battery, alternator. Hopefully something simple and a "face-palm" moment when I find it.
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: BenTN on November 03, 2018, 07:39:26 PM
Ok, back at the mill today and found out most of this issue seemed that be my bonehead fault. On a couple smallish ash logs today used debarker as usual and could actually see that when it dogged the engine speed the debarker blade was not spinning. Tried to feather it into the log and it worked much better than starting it at the very end. I think the maple log had enough sweep and we were cutting thick slabs that I could not see what exactly the blade was doing. There is a noticeable rpm difference when engaging the debarker with nothing else moving, but I am assuming right now this is normal. Thanks for the responses and help. Ben
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: SawyerTed on November 03, 2018, 08:33:02 PM
I "try" (not always successfully) to start the debarker into the log just before the saw blade enters the log.  It sometimes skips the first few inches that way but always enters the side of the log.  This works for me because I try to start my cuts slowly then raise the head speed. 
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: Brucer on November 04, 2018, 12:11:36 AM
Which way is the debarker blade turning? Does it throw the bark (and mud) back toward the operator, or does it throw it down the length of the uncut log?
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: BenTN on November 04, 2018, 06:19:03 AM
Brucer, the debarker spins so that the chips and debris are thrown away from the operator, mostly into the guard, similar to an angle grinder.
Title: Re: LT35 debarker slowing cut and dogging motor
Post by: Brucer on November 05, 2018, 12:57:48 AM
So, not toward the hitch end?

If that's the case, here's something that can affect the load on your debarker motor and on the sawmill engine. On my 2006 LT40, the debarker blade tries to throw the chips back toward the hitch. When it's turning in that direction, the blade will try to push the debarker away from the side of the log. The spring tries to counteract this and push the debarker toward the log. The push from the blade will balance the counter-push from the spring and the whole arrangement is very forgiving.

I've heard of newer mills where the debarker spins in the direction. This will cause the blade to dig in and pull the debarker in toward the log. If you're just skimming the surface, or if the wood beneath the bark is very hard, no problem. But if you're taking too deep a bite in bark or softer wood, the blade gets dragged in deeper and deeper. This configuration is pretty touchy. A large "washer" acting as a depth gauge would limit the tendency to dig in.

Just a thought.