The Forestry Forum

General Forestry => Sawmills and Milling => Topic started by: Lawg Dawg on October 10, 2018, 10:01:58 AM

Title: Drive belt tension. 2018 LT 40. 300HRS
Post by: Lawg Dawg on October 10, 2018, 10:01:58 AM
I've been sawing Poplar and getting some nasty looking cuts with reverb...not wavy just the chatter.  New reshape blades from Albemarle...it's raining steady here now so I trying to track down the problem. Should I have this much play in my drive belt when it's out of gear? Also looks like I've run out of adjustment. Any advice is well appreciated! Dawg


(http://forestryforum.com/gallery/albums/userpics/26820/1009181459.jpg?easyrotate_cache=1539180020)
 


(http://forestryforum.com/gallery/albums/userpics/26820/1010180951.jpg?easyrotate_cache=1539179900)
 

Or maybe I'm tightening the wrong way


(http://forestryforum.com/gallery/albums/userpics/26820/1010180958.jpg?easyrotate_cache=1539180011)
 

Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: pineywoods on October 10, 2018, 10:06:08 AM
Slipping drive belt. Lengthen the vertical link about 1/4 inch and try that.
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: Ben Cut-wright on October 10, 2018, 10:44:10 AM
I've been sawing Poplar and getting some nasty looking cuts with reverb...not wavy just the chatter.  New reshape blades from Albemarle...it's raining steady here now so I trying to track down the problem. Should I have this much play in my drive belt when it's out of gear? Also looks like I've run out of adjustment. Any advice is well appreciated! Dawg

Or maybe I'm tightening the wrong way.
 
The drive belt is supposed to be loose when "out of gear", not tensioned.  It is not supposed to be adjusted or checked for proper tension while "out of gear".   Engage the blade, engine off, and use the belt tension tool or similar belt tension test tool.  Instructions in the owners manual. 

Your photo shows the turnbuckle has been turned the wrong way, possibly to the extreme loose position.
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: barbender on October 10, 2018, 11:03:49 AM
Get the drive belt tension guage from WM and adjust it according to the manual. The drive belt tension is a critical adjustment and you don't want to do it by guessing, you can bust your engine crankshaft👎
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: MartyParsons on October 10, 2018, 06:51:35 PM
Hello,
  This picture below is the correct location when the drive belt is loose and the brake band is engaged on the brake drum.
To tighten the drive belt tension. Engage the drive belt using the auto clutch. Using the belt tension tool that you would have in your binder with your owners manual. Check the tension of the drive belt as described in the auto clutch manual. If the tension is not correct. The nut on the top  horizontal loosen and turn the long aluminum part away from the nut. When you disengage the clutch the distance between the collar at the bottom will decrease. Recheck the belt tension with the belt engaged then tighten the nut.

Hope this helps.
Marty

(http://forestryforum.com/gallery/albums/userpics/26820/1010180958.jpg?easyrotate_cache=1539180011)
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: YellowHammer on October 10, 2018, 09:49:16 PM
I second what Barbender says, get a WM drive belt tension gauge.  The mill is pretty sensitive to it.  Too loose, poor cuts.  Too tight, engine breaks.
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: Jjoness4 on October 10, 2018, 10:35:11 PM
Chatter in the cut can also be due to cutting too slow, particularly at the entrance to the cut.
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: SawyerTed on October 11, 2018, 08:37:13 AM
Chatter can also be caused by bad bearings in the roller guides. 
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: Lawg Dawg on October 11, 2018, 09:30:04 AM
Ok, it's raining so I'm working on my chatter in poplar problem...wasn't doing this in pine or oak...

I got 22lbs. at 7/16" deflection


(http://forestryforum.com/gallery/albums/userpics/26820/1011180916.jpg?easyrotate_cache=1539264337)
 


(http://forestryforum.com/gallery/albums/userpics/26820/1011180916a.jpg?easyrotate_cache=1539264462)
 

I installed a BRAND NEW 10 degree, I know this blade should cut poplar smooth as glass, but this is my result  :(


(http://forestryforum.com/gallery/albums/userpics/26820/1011180920.jpg?easyrotate_cache=1539264430)
 

Any more suggestions would be greatly appreciated!
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: Smithkp on October 11, 2018, 09:58:04 AM
I got something pretty close to that using the turbo blades and went back to 10 degree double hards and it went away.
(http://forestryforum.com/gallery/albums/userpics/50877/IMG_4036.JPG?easyrotate_cache=1533660721)
 
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: Crossroads on October 11, 2018, 10:03:01 AM
This is really grasping for straws, but it the blade level with the bunks? Could the front of the blade being low cause that? I hope you find the cause and get it resolved 
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: terrifictimbersllc on October 11, 2018, 10:11:47 AM
My guess, I cant see everything in the photos and the last 2 posts may be showing different things, but.....

If the marks are parallel to the blade, then the blade has a set issue with one or more teeth, or, 

if the marks are diagonal relative to the blade, it is probably the very common band harmonic that often happens at the beginning of a cut and goes away further down the board.  If the harmonic thing it will change dramatically or go away if you cut at a different speed, most likely faster. 
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: Magicman on October 11, 2018, 10:21:18 AM
Verify your engine RPM's when sawing, vary your blade tension, (higher/less) or flat spot on blade guide or bad guide bearing.  Is the idle side of the head shaking/vibrating while sawing?
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: Lawg Dawg on October 11, 2018, 12:27:20 PM
After talking to Marty on the phone this morning I think I figured out my main problem...too slow feed rate...plus he gave me a nice little tip to tap the blade tracking bolt head on the idle side with a rubber hammer and that would drop the tension about 300 or 500 lbs. sure enough it did, so tourqed it on down good. The drive belt was too loose, tightened that up, then run it right against the governor, like riding a wave!  Results 100 times better! I can live with this!


(http://forestryforum.com/gallery/albums/userpics/26820/1011181213.jpg?easyrotate_cache=1539274971)
 

But I think my manual is for a different style turnbuckle..when I turn mine counterclockwise it loosens the drive belt. Plus I have an adjustable collar with a set screw on the turnbuckle. It doesn't show that in my manual.


(http://forestryforum.com/gallery/albums/userpics/26820/1011181127.jpg?easyrotate_cache=1539275040)


Thanks everyone! I don't know what I'd do without Forestry Forum, probably be on a roof somewhere putting on shingles!  :D
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: Dave Shepard on October 11, 2018, 03:05:10 PM
What does your mill call for for tension? My Super is 18 pounds at 7/16". As soon as I saw that washboard photo I suspected slow feed rate. 

I like that hole in the guard for the gauge. I know what I'm doing to my guard soon. 8)
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: terrifictimbersllc on October 11, 2018, 04:27:40 PM
I like that hole in the guard for the gauge. I know what I'm doing to my guard soon.
Me too there's going to be one there on my mill shortly.
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: John S on October 11, 2018, 06:18:01 PM
I don't think the diagram you show is for AutoClutch, it looks like the manual version.  Which do you have?
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: Magicman on October 11, 2018, 06:43:11 PM
I believe that here were several of us that noticed that hole.  :o

Yes, wrong diagram.  ;)
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: esteadle on October 11, 2018, 07:17:32 PM
>>> I think I figured out my main problem...too slow feed rate...plus he gave me a nice little tip to tap the blade tracking bolt head on the idle side with a rubber hammer and that would drop the tension about 300 or 500 lbs. sure enough it did, so tourqed it on down good. The drive belt was too loose, tightened that up, then run it right against the governor, like riding a wave! <<< 

But, Did you actually figure it out? 
You changed 3 things there. 
- Was it feed rate? 
- or the tracking bolt head? 

- or was it the drive belt? 

Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: MartyParsons on October 11, 2018, 08:01:26 PM
The drive belt adjustment is in the auto clutch manual. It is confusing, but you will need to look in that manual to get the correct information. The operators manual for the sawmill is different than the Auto clutch manual.


Glad things worked out.

Feed rate is how fast the saw head moves through the cut. You should saw as fast as the blade will cut and the band speed should not change ( don't bog the engine) but be within 50 rpm or less than max load RPM. :o It will not feel comfortable at first.

Marty 
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: Lawg Dawg on October 13, 2018, 07:33:24 AM
But, Did you actually figure it out?
You changed 3 things there.
- Was it feed rate?
- or the tracking bolt head?

- or was it the drive belt?
I'm not sure because I pretty much did all 3 things at the same time...but I did figure out, the first time I adjusted the drive belt, I just loosened it up because I was looking at the wrong manual.  I have auto clutch, and that's the one I should have been looking at.  Maybe Woodmizer should address this issue since it's such a critical adjustment.

(http://forestryforum.com/gallery/albums/userpics/26820/1011181310.jpg?easyrotate_cache=1539430235)
 
Good thing is, I think she's sawing like she supposed to now!

(http://forestryforum.com/gallery/albums/userpics/26820/1012181144.jpg?easyrotate_cache=1539430290)
 
Title: Re: Drive belt tension. 2018 LT 40. 300HRS
Post by: tawilson on October 13, 2018, 10:43:34 AM
Marty probably told you to get the jam nut good and tight. I have a feeling if you slow your feed rate back down the marks would come back.
Woodmizer has a pile of maintenance videos available, including a LT40 drive belt one.