Re: Keeping it cool

jdunmyer · April 26, 2004, 07:43:13 AM

One more thing that can cause a saw to heat as you describe is badly worn shanks. If they're not square, the sawdust will spill out and get between the plate and the wood, causing heating.

But, as the others suggest, the FIRST thing to do is install new bits. If that fixes it, look at your sharpening technique. When I first got my mill, I tried filing by hand, with little success. Borrowed a jig that clamps to the blade and holds a regular mill file, and it worked fine except it was very slow. Finally caved in and bought a Jockey Grinder.

Ron Wenrich · April 26, 2004, 03:56:20 PM

Cutting in may also be caused by the teeth not being square. They may be high to the log side and that will pull the saw in every time.

Another thing to check is the saw guide. It can be pretty easy to screw them up. You must set the saw guides with the saw running. Not for the faint of heart and make sure you don't have any loose clothing or strings and sturdy footing.

Saw guides should have enough to see daylight along the side of the guide and the saw. If you push too hard on one side, then it will lead in that direction. If you do it while the saw isn't running, you won't know where the saw will be when it stands straight.

Guides should be far enough back to clear the shank. If it hits the shank, you'll ruin your shanks, and may be the saw. Too far back and you'll have headaches. I just had that problem when changing from a B pattern to an F pattern saw. I got lazy and didn't change the sawguides forward. Big problems.

Also, the saw guides have to be square to the saw. If its mounted in an angle, you'll have one saw guide ahead of the other. Might not be as critical, but something to check.

Jeff · April 26, 2004, 04:25:58 PM

Another word on getting the guides set correctly. The saw needs to be at neutral temperature. If you try setting them once the saw is running warm, they will be wrong. You should start with a cold saw, and the guides backed off.

Frickman · April 26, 2004, 05:29:24 PM

I have never set the guides with the saw running. I know too many old timers named Stubby and I don't want in that bunch. I know my saws well enough that I can adjust them when they're standing still. If things go well I can usually saw about a week or so before readjusting them. I do set them cold, first thing in the morning, usually when the motor is warming up. I've seen some guides that have adjusting rods leading back toward the sawyer so you can stay away from the saw. They're mounted on the end of the husk.

If new teeth don't fix the problem, and the shanks are not worn, I'd take the saw off and check the collars. If the loose collar has a smaller diameter on the mating surface than the fast collar, even slightly, the saw will dish toward the log side when the mandrel nut is tightened. If you have a dial indicator with a magnetic base mount it on a headblock and measure any deflection in the rim at the saw guides when the nut is loosened. You can check for this too when you tighten the nut. There should be no movement of the saw. Sometimes when a nut is overtightened it will cause the saw to dish.

Sometimes saw collars need to be remachined. The collars should be exactly the same diameter and only touch the saw along a fine line on the outside edge. With use this edge will get flattened out, especially if you shear the pins and spin the saw. I had a local machine shop remachine mine when I was having some troubles and it fixed things right up.

Of course, the problem might be in the saw itself. It might need looked at by a sawdoc. I'd check everything else first before I went this route.

sawhead · April 26, 2004, 05:56:41 PM

Feeding a saw too slow will cause heating and diving in also. A new sawyer will usally go to one extreme or the other too slow or too fast, only time and experiance will cure some saw problems.I suggest changing teeth ,check the guides and try it again , payin close attention to your feed rate. too fast you will run out, too slow and probably run in either way it gets hot( thats about as clear as mud isn't it :D)

Frickman · April 26, 2004, 06:13:25 PM

Yep sawhead, clear as mud. To add a little to what you said, if you saw too slow it makes a fine sawdust that spills out the side of the gullet and gets between the saw and log, causing friction and heat. It usually isn't a problem on the board side as the board usually bows away from the saw. The ideal feed rate in hardwoods in average logs is 1/10" per tooth. Every 1" of of sawn wood should have 10 tooth marks. Now this changes with the size of logs. A large log will have a slower feed rate so you don't overfill the gullets. If you feed too fast in any size logs you'll overfill the gullet and stall the saw. If you have enough power to not stall the saw it will force the sawdust out the sides of the gullet and have the same effect as sawing too slow.

Worn shanks will cause the sawdust to spill out the sides too. If you don't have a good, square edge, your shanks are too worn and need replaced.

UNCLEBUCK · April 27, 2004, 12:04:21 AM

I run off a p.t.o. tractor and I have aircraft cable that goes out through the shed to the pto lever on back of tractor and I can reach up and pull the handle and 30 seconds later the blade has stopped , its a nice feeling to know its there if I ever needed it for a emergency . Hey Frickman I am taking out a nice 671 from the bottom of my old crane and want to put it on the mill , do you have any pictures of yours that show engine mountings or anything like that . Since I been sawing with my new Simonds blade I have sawed through hardwood like butter , 100 horse tractor and 48 inch and 6/7 gauge with 36 teeth , wish I would have got about 30 teeth , but it really is nice . Just makes for a great day of sawing. I also closed in the south side of the sawshack and the sun does not see the blade anymore , before with my old disston you could burn your hand just from the sun shining on it because it was darker in color ,now I need to rig up a darn light bulb but it sure is nice to be in a almost closed in shed ,kind of makes me feel like I am working in a factory or something .

Ron Wenrich · April 27, 2004, 04:00:24 AM

One other thing I thought of. You don't want to overtighten the saw nut. That smashes the collar. I've heard stories of guys putting them on with a sledge hammer. I just kick my saw wrench a couple of times.

Also, make sure your saw is back against the shear pins before you tighten. Otherwise you'll bend them.

Sawyerfortyish · April 27, 2004, 04:52:58 AM

I had the nut come loose while sawing

Whooooo couldn't figure out why the saw was wobbling all of the sudden til I stuck my head over to look at the log side of the blade. The nut was hanging on by a thread and the saw guide was keeping the blade on. I gave the signal to kill everything and got the %ell outa there. Never had it happen before or since but that was a scarry momment. Don't know why it came loose it had been a couple weeks since I had changed the blade. But you can bet I check it every time I work on the teeth now.

ronwood · April 27, 2004, 07:04:28 AM

Thanks for all the input! My friend is going to realign the saw again. He also notice that the carraige needs some adjustment so that it does not move back and forth from the blade.

Passed on your suggestions also. Hopefully he will get it running better.

Once again thanks for the help.

Ron

Jeff · April 27, 2004, 12:51:59 PM

Sawyer40, I have never had the nut come loose but I have been informed how it usually happens. Usually its a bulge in the log that is hanging down below the carriage bunks. The bulge hits the nut on your gig back and loosens the nut.

Sawyerfortyish · April 27, 2004, 07:52:01 PM

Jeff thats exactly what I thought happened. Since I saw low grade I figured that a limb on the log just touched the nut for a second long enough to unscrew it. I don't even want to think about what could of happened if that blade got loose and left the mandrel. Where do you run if you even have time to get away from it. There's so many things that it could bounce off of in a differant direction.

Jeff · April 27, 2004, 08:07:19 PM

Maybe its like Nascar. Steer into the wreck... ???

Sawyerfortyish · April 27, 2004, 08:30:52 PM

:D :D :D :D :D :D :D

Frickman · April 28, 2004, 06:54:11 PM

Unclebuck, On both our mills the engine is mounted on its own base along with a Rockford clutch. We just line the engine up so both pulleys are in line and block it sideways to keep it tight and the belts from moving. Gravity holds it down and your 4" x 4" 's or whatever keep it from sliding around. If your engine is on a good solid base there's nothing to it. Just bolt some 6" x 6" 's to the floor around the engine, about 2' or so away, and anchor your blocking against them. Our 4-71 came from an engine rebuilder who sets up outfits like this. It is a common way to power a mill around here. I used 2" x 4" 's and plywood to build a box over each pulley and the belts as guards. On the one over the clutch we cut out a slot for the clutch handle.

I had a saw nut come loose one time. It didn't come way off, just enough to make the saw run funny. I thought the saw was dull and we shut it down to check on it. I happened to reach down and rest my hand on the nut and turned it. I too was fortunate that I didn't have to duck a flying saw. We tightened it up and it fixed the problem.