Disengaging blade between cuts

5quarter · December 07, 2011, 01:34:36 AM

I think excessive tension, not dressing the gullet and dirty logs do more to shorten blade life than the # of revolutions around the wheel. I've only broken 4 bands...2 fairly new broke at the weld. the other 2 jumping off the wheels due to operator stupidity.

5quarter · December 07, 2011, 01:38:21 AM

Having said that, I do disengage between cuts to save wear on the guide and bandwheel bearings.

ladylake · December 07, 2011, 05:47:08 AM

Quote from: Paper Maker on December 07, 2011, 12:15:44 AM
Quote from: TGS on December 06, 2011, 11:21:39 PM
What about TK owners? Do you guys disengage? I'm honestly afraid of burning a flat spot on my belt. I run a B20 and it just doesn't seem like a good idea.
I run a B20 and right or wrong I just bring the motor down to a idle. I rarely ever disengage the band. If I'm not going to make a cut anytime soon, for whatever the reason may be, I shut the motor down. I usually keep the hydraulics motor running all the time about 1/2 throttle or a little more. I also never run either one without earplugs.

Same here, with the setworks, a offbeareer and the fast head speed on the B20 it would be foolish to disengage the clutch on up to 14' logs, 16 and longer I may slow the engine down, remote throttle sure is nice for that. Even sawing by myself with a little time between cuts I'll just slow the engine as I think it's just as hard on everything kicking the belt in and out as it is leaving it idle. I'm getting excellent band life . Steve

tcsmpsi · December 07, 2011, 06:29:12 AM

At the end of each cut, I throttle down, which disengages the clutch. Knocking off a band while dragging back due to any myriad reason, is a shock enough to the mill and meself to inherently make that decision. Then I go to fuel, wear, etc. I used to like to leave it running as I drag back. The personal set up then takes place, as well. I am the sole hp (human power) at the mill. All in all, I have found that my blades do last longer.

Alas, I know I may wear out the throttle one day. A catastrophe I am willing to chance. ;D

In the end, each person has their own mill and develops their own way.

Cedarman · December 07, 2011, 07:17:32 AM

We saw a lot of 8,10,12' logs 10" and up of ERC. I disengage manually our electric mill just as the blade is about to leave the cut. I stop the forward movement just as the teeth clear the end of the log, but before the body of the blade exits. I leave the board on and bring the blade straight back. I do this leaving all the boards on the cant. I like to leave the boards on the cant to keep the cant from springing up making thick and thin boards.
It is extremely rare that I will knock a blade off. For me it is much faster than exiting the cut, raising the blade, then lowering it back down to start the next cut.
Started this way in '83 with all manual mill and forward step switch and 3 sizes of pulleys. It would be tough to change my habits now. Don't make my way the best way, it is just my way.
My gut reaction is that blades can only go so many times around the mill. But we all know guts stink.

ladylake · December 07, 2011, 07:36:30 AM

Don't know how you can bring the blade back through the cut, if I have to back up in the cut I get about 4" and it's stuck. Steve

toolman18 · December 07, 2011, 08:07:37 AM

Thanks guys for all the input, this is one of the few topics I've ever seen where everyone agrees with everybody. :D I run a TK B-20 and don't disengage unless I'm loading another log onto the mill. Unlike a lot of you guys however mine is just a hobby mill and I don't go through anywhere near as many blades as you'll. Thanks again for all the feedback!

Cedarman · December 07, 2011, 08:25:00 AM

If the cut is not completed, then you must raise the slab on top to get the blade to back up. Sometimes it takes a wedge driven in to get the needed lift. But if the cut is completed, the blade should slide back with minimal difficulty. Splinters that catch the blade is the only time I have problems.

paul case · December 07, 2011, 08:33:28 AM

cedarman,
what mill and what size blades are you using? My saw will not come back in the cut with a board on either. There must be some big difference here.

Noone has taken into account some mills have a brake that stops the band when the motor is disenguaged and some don't. My mill doesnt and if I disenguage the blade, It is usually still turning when I am back and ready for the next cut. That can't save much blade life.
I get good blade life. Very seldom do I break one before it has been sharpened 6 or 8 times. If I only get 300 bdft per sharpening(which is low) my blade cost is around a penny/bdft. Thats cheap. I usually get more bdft per sharpening than 300 bdft.
Just saying. PC

ladylake · December 07, 2011, 08:41:00 AM

Mine will come back if I raise the slab-board but cant imagine doing that all the time. I've done that cutting over length logs. Steve

5quarter · December 07, 2011, 09:12:21 AM

Cedarman...ERC might be the exception. The wood is relatively dry and sawdust probably clears the cut better than wetter or more resinous woods. Still, it seems physically impossible unless you release just enough tension with each board to lift it just enough to slip the blade back through the cut. I'll try it tomorrow on some small walnut I need to cut and see what happens.

Magicman · December 07, 2011, 09:24:37 AM

ERC would be the only species that I could drag the blade back through.

This thread goes to clearly illustrate that different sawyers develop sawing techniques that work for them. Not necessarily right or wrong, just different.

Cedarman · December 07, 2011, 01:05:38 PM

The mill I am using now is an electric with 25HP motor LT30. It does have a band brake that stops the blade in about a second or two. If I push forward on the engage handle, it will stop in a 1/2 second. Cedar is dryer and the sawdust acts more like ball bearings I think. I can tell by the drag back whether I am in danger of pulling the blade off. Most boards are 6" to 12" wide.
At end of cut, I flip the forward handle to neutral as I disengage the blade. As soon as it forward handle hits neutral I pull back on the box with my left hand stopping all forward momentum. Very seldom does the blade go off the end. If it does, I slowly bring the mill back to make sure it enters the cut without catching. Once in the cut it is full speed back. As soon as it is out of the cut, then down, then up a fraction to get on the mark. (No accuset). Forward, repeat process. It is amazing how fast I can cut a bunch of 1/2" lumber.

Larry · December 07, 2011, 01:41:30 PM

I was thinking...I know its dangerous. I've never seen a circle mill disengage. Guess there too busy making boards.

With my TK, left hand is on the feed and right on the up lever. As soon as the blade clears the cant the carriage moves up, for maybe a second or two. Pull reverse lever back and soon after hit the setworks down button with right hand to repeat sequence.

If I were to disengage that would add a four step sequence. Slow engine, hit clutch off button at end of cut. Hit clutch on button, and finally bring engine up to speed for the next cut. I guess one could skip the slow engine part. Seems to me this is gonna slow production, and wear out my clutch. Maybe I can grow couple more hands to help but than I would need a faster brain. :D

customsawyer · December 07, 2011, 03:32:22 PM

I only disengage the blade if I am going to turn the log or something occurs that will slow me down on the return trip. Even if it is a 40' log. You have to remember that I am running the LT70 which has the larger blade wheels.

Banjo picker · December 07, 2011, 05:58:21 PM

I disengage the blade just after I turn the key off.. ;D. I do idle it down when turning a cant . Banjo

Dave Shepard · December 07, 2011, 06:10:01 PM

I used to slide back under the board like Cedarman. White pine, no problems. On the super mill it's so much faster up and down I don't have to.

red oaks lumber · December 07, 2011, 06:16:21 PM

i just can't see cutting air, i shut down between cuts

ladylake · December 07, 2011, 06:53:34 PM

I can't see shutting it down for 5 seconds and extra strain on the blade starting and stopping it. Steve

Brucer · December 08, 2011, 12:57:36 AM

I've done just what Cedarman does, with white pine, lodgepole pine, and grand fir. It doesn't work very well on Douglas-Fir, however. The saw drags back OK at first, then the sawdust piles up on top of the blade and it starts to drag the whole board back.

Quote from: customsawyer on December 07, 2011, 03:32:22 PM
I only disengage the blade if I am going to turn the log or something occurs that will slow me down on the return trip. Even if it is a 40' log. You have to remember that I am running the LT70 which has the larger blade wheels.

It also returns faster than a regular LT40. That's one of the factors that would make me change my ways.

ladylake · December 08, 2011, 05:10:22 AM

You hit the nail on the head Brucer, time between cuts. On my B20 there is no time to disengage between cuts. Steve

Brucer · December 09, 2011, 02:32:03 AM

I've tried leaving the blade running a couple of times. I was sawing short logs, making thin boards (3/4" as I recall), and I had a helper clearing the boards as the dragback pulled them back. I got a nice rhythm going but it took a lot of concentration to keep track of where to drop the head to on the next cut. Accuset would have been nice for that job.

Magicman · December 09, 2011, 07:49:59 AM

Actually disengaging/reengaging causes me no lost time. I disengage when the blade clears the log/cant. I reengage immediately after I hit the down lever (SetWorks). The mill comes up to speed before the blade reaches it's next saw target.

It's a rhythm that each of us develop whether we disengage or not. No right or wrong, just different.