TS issue: burned edges on ripped boards

Ned Bulken

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Lakeport NY and/or the nearest hotel
Hi gang,
burned edges.jpg
look 'closely' at the edges on the maple in that stack and you can see that I have an alignment issue on my TS.

I'm trying to figure out Where the problem is though...

when I start a cut, it goes fairly smooth until about 20" into the cut, at which point i need to Both slow down and increase the pressure I'm pushing with... to the point of popping a breaker if I push too hard/fast. taking it slowly, I can get through, but with burnt edges. I've switched blades, both of mine are either 'in dire need of sharpening....' or something is out of whack.

stopping point.jpg

I've checked and as near as I can tell the blade is parallel with the fence, and with the miter slots.

teeth on fence.jpgteeth on fence r.jpg

now this is the 'best' evidence I've got that the blade and fence are parallel.. I don't have a gauge, so I've used a square, marking a tooth and measuring distance fore and aft to the miter slot and the fence.

HOwever in mid cut, I'm getting a gap:
big gap.jpg

reference flat.jpg

and yes, the board itself is straight as near as I can tell.

what am I missing in the equation?
 

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1. The wood appears to be cherry, which is very prone to burning during rip cuts;

2. The wood is 'reaction wood' and the kerf is closing up behind the blade (which makes it harder to push thru, since it's binding.; and

3. I don't see a splitter on that saw. A full kerf-width splitter will help in tow ways: a. it'll keep the kerf open, and b. it'll help keep the board's edge tight against the fence.
 
Too many teeth on that blade for ripping IMHO. I know people do it and do it with success. In the second shot it looks like the material is pretty well away from the fence; splitter alignment? That may just be the shot. If you can trip the breaker at ALL, I would resolve that. It is probable that your saw is under-performing if you can trip a breaker just by loading the motor ;-)
 
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It could be a combination of just about everything mentioned. A board that "looks" flat isn't the same as one that's actually flat and has been face and edge jointed.....if they haven't been, it doesn't help your situation, and could be a contributing factor. The blade also looked plenty dirty, which can cause more burning, which causes more gumming, etc. Glenn's point about the blade having too many teeth could also be a factor....it looks like you've got a full kerf blade on a 1.5hp (13 amp) motor cutting wood that's 4/4" or 5/4", which is a challenge for that combination.

Fewer, cleaner, (maybe sharper) teeth should help....a 24T TK should loaf through that.
Perfectly flat straight wood should help.
Raising the blade a little higher could help too.

Just to cover all the bases, have you checked the fence for flatness? Is the saw hooked to an extension cord? (Too long and/or an underrated cord could starve the saw of juice, making it bog)
 
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Mostly with that many boards burned I'd suspect too many teeth and perhaps a dulling blade. I hardly ever use more than a 24 to 32 tooth blade for hardwoods, more for ply, but not for hardwoods.
 
Man, these guys covered all the based already. :thumb:

Ned, going to a thin kerf, 24 tooth blade made a world of difference on my Ridgid saw that's similar to yours. Adding a MicroJig splitter helped a lot, too.
 
First off, Thanks to Everyone for chiming in and helping!

1. The wood appears to be cherry, which is very prone to burning during rip cuts;

2. The wood is 'reaction wood' and the kerf is closing up behind the blade (which makes it harder to push thru, since it's binding.; and

3. I don't see a splitter on that saw. A full kerf-width splitter will help in tow ways: a. it'll keep the kerf open, and b. it'll help keep the board's edge tight against the fence.
There is some cherry in there, but much more maple... and 'reaction wood' it was indeed. I set that shot up to illustrate the issues, after swapping blades back over to my Woodworker II from my CMT cabinet shop blade. Both blades had similar issues with performance. After my kickback week before last, I've been using my stock blade guard and splitter for all but the narrowest of rip cuts, that one particular cut didn't have the splitter on, but it had been for most of the day's cutting with perhaps one or two boards where I couldn't fit my push block between it and the fence.




Too many teeth on that blade for ripping IMHO. I know people do it and do it with success. In the second shot it looks like the material is pretty well away from the fence. That may just be the shot. If you can trip the breaker at ALL, I would resolve that. It is probable that your saw is under-performing if you can trip a breaker just by loading the motor ;-)
This is a 'new' problem, the WWII has always just mowed right through maple, walnut, you name it... 4/4 5/4 with equal aplomb. & trust me, resolving it is high on my priority list right now, hence this thread. I've got too much stock to deal with in the next couple of weeks to be forcing it through the blade like I had to today.

are you jointing an edge and face before you run it through the blade?

if its off just a hair, it will not run through the blade smoothly, and cherry and maple burn easily.

Cherry I expect to burn, and maple just a bit too, but this was seriously bogging down more than it ever has in the past.

As for jointing, I'm doing 'prep' for cutting boards, and I generally don't edge joint,before ripping. However one step I did not show was that all of the boards were 'guided' by a piece of 'factory' edge plywood screwed to them so I was getting a straight registration off of the fence. The stack in the first shot was the result of that process. I hadn't even begun to rip them down to 'working' width of 1.5 to 2.25" or so.


It could be a combination of just about everything mentioned. A board that "looks" flat isn't the same as one that's actually flat and has been face and edge jointed.....if they haven't been, it doesn't help your situation, and could be a contributing factor. The blade also looked plenty dirty, which can cause more burning, which causes more gumming, etc. Glenn's point about the blade having too many teeth could also be a factor....it looks like you've got a full kerf blade on a 1.5hp (13 amp) motor cutting wood that's 4/4" or 5/4", which is a challenge for that combination.

Fewer, cleaner, (maybe sharper) teeth should help....a 24T TK should loaf through that.
Perfectly flat straight wood should help.
Raising the blade a little higher could help too.

Just to cover all the bases, have you checked the fence for flatness? Is the saw hooked to an extension cord? (Too long and/or an underrated cord could starve the saw of juice, making it bog)

Well I'm pretty well sunk then... my entire shop runs off of a 'long' extension cord. Today was the first time I've had major issues like this. I'll see what I can do to 'shorten' the cords (ie, I'm using an extension cord to get power over to the north side of my shop, I can eliminate that, etc...) I did a bunch of cutting on pine over the summer, so I'm sure I have lots of resin on the blade. Google here I come for blade cleaning how to's.
As for blades, what I have is what I'm Going to have right now. I have the CMT cabinet shop blade, my stock blade (somewhere...) and the WWII, there is zero in the budget for new tools until this batch of cutting boards pays off with some sales. A sharpening/cleaning I could swing, a new blade, no way.




Mostly with that many boards burned I'd suspect too many teeth and perhaps a dulling blade. I hardly ever use more than a 24 to 32 tooth blade for hardwoods, more for ply, but not for hardwoods.
the WWII has always been a stand out performer in the past, I think it needs a good cleaning. I did closely inspect the blade for missing/chipped teeth and didn't see any that were any different than the others.


Man, these guys covered all the based already. :thumb:

Ned, going to a thin kerf, 24 tooth blade made a world of difference on my Ridgid saw that's similar to yours. Adding a MicroJig splitter helped a lot, too.

I have a microjig in the drawer somewhere, I just have never installed it.

Again, I Was using my stock, wobbly as all get out blade guard, and that helped with the reaction wood (the rock maple was incredibly twisty/reactionary), but today species didn't seem to matter. I think Scott nailed it with the extension cords and it being underpowered... I can easily 'lose' 25' of impedence simply by plugging the TS in a different spot.



Another option I have which I've just thought of is to set a fence on my bandsaw and put my 1/2" blade on it (14" HF with riser, so 1/2" is as big as I dare put on it). I'd get more 'yield' per board from that system, then I could joint and rip etc... with relative ease.


Again, Thank you all for your advice!
 
I spent a little time last weekend installing a new zero clearance insert and micro jig splitter. Well worth the minimal time it takes...
 
I was having similar problems. I ended up needing to loosen the trunion and squaring the blade to the miter slot and them squaring the fence again. Made a huge difference and no more burning on rips or power problems. I don't use extension cords but the power in my garage isn't much better.

Sent from my PC36100 using Tapatalk 2
 
On further examination, I think I see the culprit...

Dirty Teeth.jpg


I'm betting the cleaning will help your results. Also, tightening and aligning your splitter can't hurt, either. I agree with Billy's observation on the one photo with the splitter. Check that it's a aligned with the fence as accurately as the blade.
 
Definitely give both blades a good cleaning....10 minutes from start to finish, and can be free (household cleaners). Cleaning them will keep your blades working like new a lot longer. Clean them often.
 
If the lumber doesn't have a jointed face and edge to use as a reference against the table and fence you are going to get an irregular cut and have to re-do those edges anyway so the burning doesn't really matter. The bogging seems to be the primary problem and is due to the same thing that contributes to the burning I would think. :huh: I never put un-jointed wood through a rip operation on a tablesaw. The irregular reference surface causes a fouled path and the material is captured as is runs past the blade during the cut. That is just asking for kickback IMHO, use the bandsaw.

Larry had a simple, cheap jig for ripping non-jointed lumber that I can't seem to locate. It was a slab of ply or MDF with a jointed piece of hardwood attached along the edge to ride the fence.

Here's a 24T, TK rip (Freud LU87R010, about $30 - $35 on Amazon with free shipping) on the 1HP contractor saw my dad got from me. The saw was waxed, aligned, plugged into a dedicated circuit and had PALs, featherboards, link belt and machined pulleys and just about anything else that you can bolt to a contractor saw in the aftermarket world but, it does a great job on cuts. :rofl:

beech (7).jpgbeech (3).jpg
 
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I was using a primitive version of that, I screwed a piece of ply to the top of the boards when I edged them, however I'll see about making a smaller version of that. (I generally cut things down to 4' or less)

blades clean.jpg
I picked up some simple green, diluted it and let the blades soak awhile in it...

cmt.jpg
Not perfect, but should do a lot better.
wwII scrubbed.jpg
despite my best efforts there is a bit of material behind the carbide, however the 'wing' just behind that used to be Black, so it too is much improved.
 
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