Adjusting the kerf on a saw

Atlas Knife Company

Atlas Knife Company

Joined
Feb 16, 2010
Messages
3,668
It's an 8" hole saw at 350RPM cutting into insulating firebrick. The holesaw is rubbing on the bricks causing the belt to slip. Even if I tighten the belt enough, it doesn't really solve the issue of the kerf needing adjustment. I need to make the kerf thicker on the holesaw. Maybe just 3-6 teeth in and 3-6 teeth out should adjust the diameter to what I need. The problem is that I can't grip the tiny teeth tight enough to bend them outward or inward. Any ideas?
 
Hammer and a punch should bend them in easily


Rig up some version of the three point straightening vise setup
 
You might also look at lightly grinding down the weld around the circumference of the holesaw. I've done thousands of hours of custom tube and most all of it gets notched with holesaws; I've often had to modify them to get clean, straight deep holes. My go to saws are Lennox but Morse carbide saws are on a whole `nuther level.

Bob
 
I also want to add that you are probably using the wrong drill press for your 8" holesaw. That is a lot of teeth active in the cut and needs a lot of torque to keep it cutting. I would want a industrial geared head drill press for this task.

Bob
 
I can see on the side of the saw where the paint rubbed off. The tooth setting tool is on my purchase list. At this point I'm considering cutting and having a few carbide teeth welded in. That should be sturdy enough, and at $250 per blade it should last longer. Interestingly, I bought two 5" hole saws, ground the top off of one and welded them together and it cuts perfectly. It's only the expensive saw that is giving me fits.

Come to think of it, I shouldn't be having issues with a new $250 hole saw, should I? Maybe it's time to contact customer service.
View attachment 563469
 
Great customer service at Customholesaw.com. After a few minutes discussing it, they are sending me a new blade.

He tried claiming that the torque involved with an 8" holesaw was causing it to slow down. I explained that the first 1/2" cut fine and only as it cut deeper that it slowed down considerably.
 
Those teeth are so fine,



Being the soft firebrick is so soft, I think chip clearing = dust clearing would be more important


You could make your own hole saw from pipe with some ange grinder slots cut in, bigger coarser teeth.

Vaccum to remove the dust.
 
I have a 6 inch hole saw that I use to cut vent holes in houses, and if I don't clear the chips it will bind up in a short hurry, I would try compressed air and lift the bit out many times during the cut
 
On the inside of the hole saw, at the weld, there is a BIG rub about 1" from the teeth about 1" long. The other pic is the extended 5" that I made. It cuts flawlessly and easy.

The manufacturer is letting me keep the flawed blade. I might modify it and see if I can make it work better. Cut some slots or holes, add carbide teeth, remove some of the existing teeth.

Thinking about it, I might see about converting this press to gear instead of belts.
View attachment 563953 . View attachment 563954
 
Last edited:
If the new one is also binding, I'd consider taking a hammer and punch and increasing the kerf. I'd just set it on a soft board and tap a tooth out every so often. I'd also tap one in every so often. probably about 1/2 inch is so often...

If I recall the Lenox blades have some form of chip transport slots. May look at adding something like that to allow the dust to travel. I'd bet it's the cuttings that are getting you since they are like sand and quickly form wedges that bind the saw blade. You may also try drilling four holes say 1/4 inch in diameter through the brick first to give the cuttings a gravity fed exit hole. Maybe a single larger hole may work also.

Lastly, unless the belts are really slipping badly, the gearing is probably way overkill. IMO, this is a cuttings clearance problem.
 
You must log in or register to reply here.
Back
Top