Table Saw Blade Tightening Question
aakBoston
| Posted in Power Tools and Machinery on
So I’m playing with my new Grizzly cabinet saw and what I’m noticing is that it’s kind of hard to get a lot of leverage on the saw blade when I’m tightening it to the arbor. SO my question is how tight is tight enough and what sorts of techniques do people use to tighten the blade. I’ve been holding on to the blade with one and and using the wrench with the other. Do I need to worry about the blade flying off while it’s spinning? (I’ve never seen it happen but I can imagine it would be pretty bad)
Replies
Tightening or loosening the blade nut is an easy operation as long as you have a scrap of wood about 12"+ long. Remove the throat insert and place the scrap vertically against the teeth. Push down on the scrap to apply pressure on the blade, just enough pressure so that the blade does not turn as you remove the nut with the appropriate sized wrench. Tightening the nut usually requires the pressure to be applied at the rear of the blade as tightening the nut turns the blade in the opposite direction.
aaKBoston,
Congrats on the saw...the nut that holds the blade is a reverse thread...it can't fly off. I do not tighten the nut too much...firm is fine...
I just lay a piece of wood (3/4" thick, maybe?) across the front of the blade without removing the insert. I tighten it snug and then give it a little Hrumph. The blade will slip on the wood before the nut gets tooooo tight.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Another proud member of the "I Rocked With ToolDoc Club" .... :>)
aak',
I would highly recommend not holding the blade bare handed while tightening the nut. The amount of leverage that the blade wrench produces can easily cause the blade to spin out of your (bare handed) grip. If this occurs, you will most likely end up with a "...I wasn't cutting anything, I had the saw unplugged, and I still managed to get my hand cut up by the blade!" injury. Even though the blade is spinning backward from its normal cutting action, the points of the sharp carbide teeth cause damage.
On many table saw arbors, there is a flat section to the outside of the flange on the motor side where a second wrench can be used. Using two wrenches offers you the best control over tightening and loosening the nut, and most importantly, keeps your fingers away from the blade.
I have found that using one of the wrenches from an old Porter Cable 690 router works very well as a second tool. When tightening the blade, turn the nut until it is just tight, and then turn it a fraction more.
Using a block of wood to restrain the blade will work, but it too can slip, and may damage one or more of the teeth on the blade.
As always, make sure the saw is unplugged before any blade changing is done.
If you have any questions, please feel free to ask!
Dan Kornfeld, Owner/President - Odyssey Wood Design, Inc.
Edited 6/24/2004 10:40 pm ET by Jackie Chan
Edited 6/25/2004 12:20 am ET by Jackie Chan
When I had my Craftsman TS I needed a scrap of wood to loosen and tighten the arbor nut. My Delta Unisaw came with two wrenches, one to hold the pully side of the arbor and another to loosen or tighten the nut.
The nice thing about the latter is you do not touch the blade while loosening or tightening the blade. I always worried about bending the blade using the scrap-of-wood method, but cannot say whether it ever happened cause, hey, it was a $220 TS!
The blade won't fly off in any event...the reverse thread makes sure of that. But as said by others, never use your hands to hold the blade except to pick it up. I suspect most of us cut ourselves on blades that are not attached to any power tool...or on blades attached to power tools that are turned off.
Enjoy your new saw.
I believe you ment to post your reply to aakBoston - but I'm sure he'll read it.Dan Kornfeld, Owner/President - Odyssey Wood Design, Inc.
I don't think the "how tight" part of the question was answered clearly.
Many years ago I was taught to only finger tighten the nut on the blade. That the wrench was only to loosen the nut. The natural cutting action will tighten the nut, not loosen it (as several have said).
Since using the saw tightens the nut, if you start with it too loose, it will slam tight, and be very hard to remove. So realistically I tighten it with the wrench, but only a tiny bit.
________________________
Charlie Plesums Austin, Texas
http://www.plesums.com/wood
Friends,
Just to recommend on DO TIGHTEN the blade, however it be done.
Have had one long-ago case in which the 12" blade somehow separated from the nut partially due to following the practice of 'soft' tightening.
Even after the stop-button was pushed immediately, the blade continued spinning for about a minute, with a fellow in the fetus position somewhere away from the path of the blade.
The nut did not come out, but it was not gripping the blade. It is very difficult for a blade to fly out, but it can damage anything it touches while spinning loose. If the arbor is short, with only a few threads, or if a dado blade is used, all this needs to be considered.
While it is true that the left-thread supports tightening, do not count it in increasing the initial tightening, because the nut has no opposition either while spinning, and even if it does tighten it, one can not tell how long it will take. It could be 'tomorrow', and the incident happen today, the first time the start button is pushed.
How tight? Probaly at least 1/2 a revolution of the nut beyond hand-tight? It's better for each to build his own self-confidence, without exagerating one way or the other, though.
Best wishes.
-mbl-
I had the same situation of having a Craftsman saw and then getting a Unisaw which has the two wrenches. I used scraps of wood until I ran across this handy little item: http://www.woodcraft.com/Woodcraft/product_family.asp?family%5Fid=3686&gift=False&0=dept%2Easp%2Cdept%5Fid%3D10000%26Tree%3D%2CDepartments&1=dept%2Easp%2Cdept%5Fid%3D1040%26menu%5Fid%3D%26Tree%3D0%2CSaws&2=dept%2Easp%2Cdept%5Fid%3D2126%26menu%5Fid%3D%26Tree%3D1%2CCircular%20Saw%20Blades&Gift=False&mscssid=4ECB590AAB0C44C7AF5A8636D549E25D
at Woodcraft called Blade-Lok. Benchdog sells a similar item. I was very happy with how well it worked. It grips the blade tightly in plastic so it does not harm the blade and eliminates the chance of cutting your hand. It works well for tightening and loosening the blade.
Firmly ditto MBL.....do not rely on the reverse thread to keep that blade in place. Yes, it will have a tendency to tighten rather than a tendency to loosen, but you still need to get that nut on there firmly. Only takes one time.
Also second the motion to use two wrenches; this is the only satisfactory way I have found to do it.cabinetmaker/college woodworking instructor. Cape Breton, N.S
Wow, this post sure proves hobbyist habits vs pro habits. I've probably logged close to 10,000 hours behind my tablesaw since turning pro back in '87, not to mention all the time before that, and I routinely change blades daily due to material changes, using only one hand grip on the blade to tighten no more than a 1/4 turn, and RARELY have I ever needed to use a stick of wood to loosen a blade (I just grip the blade). If you need a stick in the throat to loosen the blade, you're tightening too much. Trust me, it makes a difference when you're switching from a melamine blade to a rip blade during a project ten - twenty times a day.
Have I ever had blade slippage, or worries in all those years? Never.
Don't want to sound arrogant, because I learned the "hand tightening" method when I studied furniture design in college, and I suppose that I take it for granted, as many haven't had that priveledge.
"The furniture designer is an architect." - Maurice DuFrenes (French Art Deco furniture designer, contemporary of Ruhlmann)
http://www.pbase.com/dr_dichro http://www.johnblazydesigns.com
Dr. Di, your routine makes great sense and obviously has served you well with no problems. I just want to make a distinction between "need(ing) a stick in the throat" and just preferring to do it that way. Many of us do not want the palm of our hand poised over those carbide teeth, and at least one of us (moi) has relatively weak grip strength in the fingers. It's safer in that case to use a piece of wood.
As a relative novice, I've found that after starting out tightening blades pretty tightly, over a period of time I've backed off of that progressively. Having read your post and others with tons of experience, I'll probably lighten up even more!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
That's how the pros do it, eh? Must have missed that somewhere along the line.....let's see, I've been doing it at least as long or longer than you have....I also went to college....now teach industrial woodworking at a college.....worked in many shops, and am constantly in and out of working shops and plants....picked up two sets of journeyman papers on the way.....can't recall seeing many pros using hand-tight as a preferred method. Have seen several blades come loose when people got sloppy, and it's no fun....potential damage to work, machine, and people. But what the heck....probably saves a good second, second and a half per blade change not to snug it up.
Now....partly I'm razzing you....but a lot of people on this forum are not professionals, and not every one has the experience to tell good advice from bad.
I'm sticking with my way: two wrenches, nut snug but not overtight, doublecheck the blade is up tight against the flange. Never had a blade come loose that way, never had a hard time getting the nut loose and the blade changed in a timely manner.cabinetmaker/college woodworking instructor. Cape Breton, N.S
Friends,
Just for the sake of each one making his/her own decissions, will say that the application discussed is no different than the hand-held circular saw, and the Radial Arm Saw.
If one would not dare to use a hand-held circular saw with the nut tightened by hand, or would not dare to use a Radial Arm Saw with a blade or a dado blade tightened by hand, what basis would there be to change criteria in using the table saw?
If the criteria in mounting the table-saw blade is decreasing cost, improving profits, decreasing effort, or other ideas, the proper relation to safety could be overlooked.
When the blade here turned loose, it was right immediately after it was installed and right as the start button was pushed. It was not cutting anything yet.
Hence, another precaution is not to be on the line of cut when starting the saw, no matter how confident we may be of our methods of work, specially right after just after a blade change.
Teachers and books do their best, but it still an incomplete job. All tasks require paying attention and realizing the unteachable.
Best wishes.
-mbl-
Sorry to ruffle any feathers Adrian - I do respect your viewpoints. The "time is money" mentality that is forced upon small business owners like me force me to adopt quicker methods as long as they work and are safe (relative to ones experience). I felt that this was safe enough for others to benefit considering I've never had problems. If my experience cannot be of help, (and I certainly understand if you prefer a stick, Forestgirl, or others that would rather not grab sharp teeth), then allow me to offer this advice as well:
Blade stiffeners. These little babys live on my arbor at all times. They are very slightly hollow ground on the inboard face and dramatically reduce blade chatter/vibration. They also serve a secondary benefit of constant pressure on the nut & flanges, which dramatically reduces the tendency to create a loose nut.
Go out and buy blade stiffeners - hopefully that little tip will reduce any hard feelings.
"The furniture designer is an architect." - Maurice DuFrenes (French Art Deco furniture designer, contemporary of Ruhlmann)
http://www.pbase.com/dr_dichro http://www.johnblazydesigns.com
Prefer the double wrench if you are fortunate to have a TS with a slot for the second wrench. I do have that slot. When I didn't used a 1/4" piece of oak to chock the blade.
I have used the hand in the beginning on occasion and don't recommend it to anyone. But I would never use it without a thick leather glove on the left hand before I grabbed the blade. Just made that up somewhere along the way as I didn't go to college. Just kinda made sense.
Hand tight and then a little extra "ummmph" as Forest Girl so artisticly described. ha.. ha...
sarge..jtProud member of the : "I Rocked With ToolDoc Club" .... :>)
I confess, I overtighted my table saw blade for many years before I got smarter. "ummmph" good.
Enjoy, Roy
I've hand tighten the nut then I place the wrench in the nut, rest the handle of the wrench against the front of the insert opening (with the insert removed) grasp the blade (carefully) and pull the blade toward you - presto, tightend blade.
(I've never come even close to cutting myself)
Custom Cabinetry and Furniture
http://www.BartlettWoodworking.com
The wrench that comes with your saw is an open end 7/8" ( I believe ) that goes on the inside arbor nut. You need another wrench to tighten the outside arbor nut. You do not have to hold or block the blade. Tighten outside nut firmly, not with all your might . The nut is left threaded so it will not spin off, over tightening is not neccesary.
mike
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