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Forum topic by Dan Corbin posted 10-16-2013 02:03 PM 775 views 0 times favorited 14 replies Add to Favorites Watch
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Dan Corbin

57 posts in 849 days


10-16-2013 02:03 PM

Topic tags/keywords: tablesaw sled saw blade

Is it normal for table saw blades to “sing” when using a table saw sled? What about when that “singing” sounds more like a middle-school rock band than a Gregorian chant? Is there any physical danger of something being flung off at ridiculous speeds?

After several failed attempts at other styles, I finally made a table saw sled in the style of Matthias Wandel (http://woodgears.ca/delta_saw/small_sled.html). But when I use it, my saw makes a TON of noise! No sled is the normal quiet whirr (I have a Ridgid TS4512), and with the sled it is a loud racket probably louder than all my other tools combined.

I’ve checked the flatness of the keeper on the arbor, and it’s .001” out. The blade is .001” out of square with the miter tracks. I tried to check the flatness of the blade with my dial indicator, but it was never repeatable.

what’s causing the noise, and is it dangerous? Thanks for your helP!

-- ~ Dan, North Carolina, http://www.facebook.com/torahanjyuu/


14 replies so far

View Bill White's profile

Bill White

3496 posts in 2647 days


#1 posted 10-16-2013 02:37 PM

I noticed my TS being louder when using a zero clearance insert and the sled. I think it’s just the aerodynamics of the blade, confined slots, etc.
I have nothing on which to base this astonishing claim. :)
Bill

-- bill@magraphics.us

View crank49's profile

crank49

3456 posts in 1658 days


#2 posted 10-16-2013 02:37 PM

Lower the blade and it might quiet down.

The arbor mounting design of these saws is so weak that it deflects out of alignment when the blade is raised. When you lower the blade it drifts back into alignment on the saws that don’t have the alignment defect..
Since you were basically in alignment when you checked it I am assuming your saw doesn’t have the defect.

And Bill made a good point. A zero clearance insert, or a sled that has basically the same kerf opening, can make a blade sing due to the aerodynamics.

Even if it is aerodynamics lowering the blade might help as more of the gullets between teeth would stay below the surface of the sled.

-- Michael :-{| “If you tell a big enough lie and tell it frequently enough, it will be believed.” ― A H

View ZacD's profile

ZacD

34 posts in 446 days


#3 posted 10-16-2013 03:26 PM

What Bill said is true. Think of how a dust collector works, with an impeller fan. The very narrow opening will cause it to create a slight bit of vacuum pressure because it is constantly whipping air into the slot, faster than the air wants to go. In turn, this can cause the blade to resonate/vibrate/oscillate, at a high pitch, due to the air resiting this motion against the blade. Older saw blades that didn’t have dampening slots (those little finely cut lines on the blade plate) were actually even worse about this. Those slots allow the blade to flex in the radial of the blade, just enough to almost eliminate the whirring sound in an open environment. However, closing the gap around the blade increase the air pressure once again and the problem reappears.

View Rick  Dennington's profile

Rick Dennington

3468 posts in 1881 days


#4 posted 10-16-2013 03:36 PM

I hope it’s singing on key…..I hate hearing someone or something out of “pitch”........

-- " I started with nothing, and I've still got most of it left".......

View Dan Corbin's profile

Dan Corbin

57 posts in 849 days


#5 posted 10-16-2013 04:05 PM

I know about alignment issues with arbors in the full up position, so I always lower mine done a bit from full up when I’m making adjustments, and I never run with it full up.

The only thing I’ve used the sled for is to cut some 1/4” square pieces, so I think that the saw was raised a total of 1 1/2” above the table (3/4” for the sled, 1/4” for the material, and another 1/2” or so for the carbide tips to clear). It wasn’t even half-way up….

The blade I’m using is the stock one that came with the table saw. I haven’t had the money to buy a good blade yet. I have no idea who made the blade as the only marking it still has on the side is the lower half of the word “Ridgid”. Everything else has been rubbed off.

My concern is that while I’m using this blade, either a piece of carbide will fling off, or the blade itself will break and fly apart. Neither scenario is good for my health. Are those valid concerns, or will everything be fine?

-- ~ Dan, North Carolina, http://www.facebook.com/torahanjyuu/

View Rick M.'s profile

Rick M.

4123 posts in 1067 days


#6 posted 10-16-2013 04:33 PM

My saw is higher pitched with a sled or zero clearance insert, it’s normal.

-- |Statistics show that 100% of people bitten by a snake were close to it.|

View ZacD's profile

ZacD

34 posts in 446 days


#7 posted 10-16-2013 04:58 PM

Dan, have no worry. It is completely normal for table saw blades to emit a high pitched ringing type sound. Also, the risk for carbide flying off is probably extremely low. However, if you are at all concerned, take the blade out, clean it well (and properly) and then inspect each of the carbide tips. If you see ANY gaps around the teeth, it is best to either knock that tooth off or replace the blade. I really can’t say I’ve heard of anyone being injured by a carbide tooth that sheared off. I have sheared them off myself, but they tend to continue downward and end up under the table. Another safety measure is to keep your blade guard on. This would prevent any shrapnel leaving the blade, from getting anywhere near you. Honestly though, unless what you are talking about is unbearably loud (louder than a router), it sounds completely normal.

View Rick  Dennington's profile

Rick Dennington

3468 posts in 1881 days


#8 posted 10-16-2013 05:33 PM

It’s normal…...I’ve got two saws….One’s a 3 horse, and the other is a 5 horse….It’s a Unisaw X5, and you ought to hear that beast hum…...No worries…..Just keep on keeping on…..!!!!!!!!!!!

-- " I started with nothing, and I've still got most of it left".......

View bowedcurly's profile

bowedcurly

482 posts in 416 days


#9 posted 10-16-2013 06:42 PM

Forrest blades can sing and dance but really Forrest does have a super high pitch more than Frued and Infinity

-- Staining killed the wood<<<<<>>>>>Dyeing gave it life

View bowedcurly's profile

bowedcurly

482 posts in 416 days


#10 posted 10-16-2013 06:43 PM

I guess it’s my Grizzly tuning the blade for a woodmunchin

-- Staining killed the wood<<<<<>>>>>Dyeing gave it life

View hydro's profile

hydro

208 posts in 438 days


#11 posted 10-17-2013 01:00 PM

Better singing than rapping

-- Minnesota Woodworkers Guild, Past President, Lifetime member.

View bigblockyeti's profile

bigblockyeti

1659 posts in 407 days


#12 posted 10-17-2013 01:09 PM

On modern blades, most of the heat expansion slots are laser cut rendering no danger of anything flying off. That combined with modern brazing technology for attaching the carbide to the steel renders a very safe blade. Some older blades still have little chance of flinging a tooth off, but some of the expansion slots were plugged with a copper or brass slug. While these stand little chance of coming out if they are still nice and tight within the plate of the blade, if they do become loose they can be very dangerous. Heard one come out on a 14” blade and saw the after effect, if someone had been in it’s path it would have been bad. Though it’s not very heavy, we calculated it was traveling at least 128.5mph when it let go and embedded itself into a cinder block wall.

View Dan Corbin's profile

Dan Corbin

57 posts in 849 days


#13 posted 10-17-2013 04:52 PM

I put a decibel meter on my iPad to see just how loud the blade is through my tablesaw sled. I won’t talk about the accuracy (or inaccuracy) of the decibel meter, but I figured it would be good enough for comparative purposes.

ZacD specifically mentioned “louder than a router”, so I first pulled out my router and measured just how long it is. It’s a variable speed, so it’s loudness ranges from 60 db at the lowest speed to 90 db at the fastest speed. I started the tablesaw without the sled on it, and it hummed away at 80 db. When I pushed the sled onto the blade, the sound level only increased to 90db, which was just as loud as my router. I definitely think that it’s the side of each carbide tooth hitting the wood to either side of the zero clearance slot.

Thank you all for helping calm my fears.

I think the only thing worse than a flying sawblade (or flying pieces of sawblade), is a rapping sawblade. And I think that we would all agree that a sawblade sounds best as a percussion instrument; that is, an instrument without pitch. ;) But perhaps best of all would be a sawblade that follows the old adage of children—better seen than heard.

-- ~ Dan, North Carolina, http://www.facebook.com/torahanjyuu/

View NiteWalker's profile

NiteWalker

2710 posts in 1263 days


#14 posted 10-17-2013 06:15 PM

Nothing to add, but I think the title of this thread is awesome! :-p

-- He who dies with the most tools... dies with the emptiest wallet.

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