Circle saw problems.. dull teeth, hot center on saw blade

[mclean]

Was cutting up some maple, and the blade started throwing sawdust places it hadnt been.  I had just switched from cedar to maple, so I just figured it was the different wood.  After 3 cuts the blade dished and was almost too hot to touch in the middle area.

Any idea on cause?  Dull teeth?  Log moving on carriage during the cut?  It was the first time I had cut a log that was not laying flat on the 3 legs of the carriage.  this maples not very straight..

Does the saw need to be hammered because of the heat?  While spinning once cooled off its was still flat not much deflection..

Thanks for any advice!
Chris

[Tim]

How was it cutting in the cedar?

Sharpness can bean issue in both the teeth and the shanks. This is especially true if the logs had been frozen (likely not today though) or siting around for a while. I'd start there. If that didn't work, I would check if the mill were level and the lead on the saw at the guide. If no improvement... Was the rpm dropping off? I'd look for rust in the collar. If that is clean, check to see if the arbour is straight as well as considering getting a hammer job done to the blade.

[sigidi]

Chris, I run a circle saw down in A us and also been on a Lucas 11 years. By the sound of it, with the maple not being flat on the carriage, as the blade has cut through it, the log has been pulled down onto the carriage and this has caused friction on your blade.

If my blades get hot to touch, then asawdoctoring they go. I've been able to get away with getting them 'warm' but 'hot' is out. Its always best to run sharp teeth, but by the sound of this it was log movement that brought ya undone.  Good luck

[Tim]

sigidi has some good advice there too... Sharpen and see how it runs in the next log after it cools down.

[sigidi]

sigidi has some good advice there too... Sharpen and see how it runs in the next log after it cools down.

Tim, he's already mentioned its cooled and is flat. He'll need to get the blade hammered by the sound of it.

[Ron Wenrich]

Time to sharpen up.  Cedar isn't as hard as maple.  Maple needs a good, sharp saw to cut.  You won't get as much footage per sharpening in maple as you will cedar.  You may also have to swage your teeth to make them wider.  Depends on how short your teeth are.  Put in new teeth, and that will tell you if it's in the teeth or another spot.

Other things to look for is if your saw guides have moved.  They probably need to be a little tighter in the maple than in the cedar.  Also look for any debris that may be between your saw and your off bearing table.  A little piece of bark or sliver of wood will make a saw hot.

I've gotten saws plenty hot.  I had one look like a pretzel one time.  All due to a piece of wood that rubbed the saw.  I let it cool down, and it straightened right up.  I didn't have any problems with it.  Your results may vary, but I'd try it after you sharpen.

Log movement can happen.  Sounds like you had a crooked one.  I've cut many crooked ones.  You may have some movement.  Log positioning and good dogging goes a long way.  But, to cause the problems you're describing sounds like you would have seen that log move.  Especially on 3 cuts.   You should have stopped after the 1st cut was throwing saw dust.  It was an indication of something wrong.  My first inclination is always dull teeth.

[Gearbox]

Mclean Just do  all the simple things first . I to have heated the saw it happens . If you sawed ceader and did not sharpen after your saw was dull . ceader bark will dull a saw . Your saw guides need to be close with the saw up to speed . Run your saw up to speed and if it stands up with no flop your good to go . Gearbox

[mclean]

Is the guide the ushaped piece on the cutting side of the blade?

There was a piece of wood in there, but the thing is lined up so the wood was cut off by the tooth sockets when the saw dished.

I think I need to do some research on guides..  Should it have a roller on it? How often should the saw touch the guide?

[mclean]

Rollers..

[beenthere]

mclean
This .pdf of a circular saw document may be a help to you.

http://www.fpl.fs.fed.us/documnts/misc/circsaw.pdf

The wood guide pins should have been behind (not in line with) the shank sockets, and sounds like yours were not.

[Ron Wenrich]

The U shaped thing is the guides.  If your guides weren't tight enough, and your saw was dull, it could have opened up your saw and that made it hot.

The guide pins can be made of wood.  I made my own for a number of years in the older mills.  But, your tooth socket should not be in line with the guide pins.  You need to adjust the guide so it is below the sockets,  Probably about ½", at most.  Your shanks sit in the sockets, and are wider then the saw.  You don't want anything rubbing the shanks.

I always adjusted my guides with a running saw, but I don't suggest that unless you're comfortable doing it.  Proper adjustment is that there should be light on either side of a running saw.  If the board side pin is too far away from the saw, you will heat up the saw.  Most times when I had a slight heating problem, it was in the board side guide pin. 

[Gearbox]

X 2 what Ron said . I look at the pins then shut down to adj. then run up to speed and check . Gearbox