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Scary Time Ripping Maple

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Forum topic by Dustin posted 10-25-2016 01:21 PM 901 views 0 times favorited 19 replies Add to Favorites Watch
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Dustin

408 posts in 580 days


10-25-2016 01:21 PM

Topic tags/keywords: question maple tablesaw

So, I thought I would post this as an anecdote/question:

After reading some great posts here about making your own carbide tools, I figured I’d give it a go. Ordered some bar stock and cutters, and picked up some maple (it was the best looking turning stock they had) at the local woodcraft to make the handles. I started by ripping the 2” maple stock in half to rout a square channel for the bar stock, and expected some resistance due to the hardness of the wood and lack of power on my saw (Delta 36-725). But I’ve got a nice sharp Freud blade (only a couple months old, and lightly used) and made sure my riving knife was installed correctly, so I was surprised when the wood felt like it was completely jamming. As in, it wouldn’t move at all, and I could feel the blade trying to throw it back at me. As soon as I felt that, I shut off power to the saw.

After powering down and unplugging the saw (this freaked me out a bit, so I wasn’t taking any chances), I removed the stock, and found that the partially split stock was pinching inwards horribly and binding up on the blade. I’ve never seen wood warp like that while ripping, and wanted to know if anyone else has had any harrowing experiences with such. I still consider myself a novice and a hobbyist, so what could cause this? Is this due to improper drying, so a differential in moisture content causes this immediate bending upon being cut?

Also, if this happens again, what would be the safest way to proceed without throwing out the stock? Would it be safe enough to rip roughly half the depth, then turn it over and rip from the other side?

This was the most nerve-racking thing that’s happened to me in the roughly 5 years I’ve been doing this, and it rattled me pretty good.

-- "Ladies, if your husband says he'll get to it, he'll get to it. No need to remind him about it every 6 months."


19 replies so far

View DrDirt's profile

DrDirt

4414 posts in 3581 days


#1 posted 10-25-2016 01:25 PM

By any chance do you have a standard riving knife (1/8 inch).... and were using a thin kerf blade?

Trying to get a thin groove to go around the fat knife doesn’t work well.

-- “The two most important days in your life are the day you are born and the day you find out why.” Mark Twain

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CharlesA

3294 posts in 1637 days


#2 posted 10-25-2016 01:25 PM

I’ve only had that happen cutting construction lumber from a big box store.

-- "Man is the only animal which devours his own, for I can apply no milder term to the general prey of the rich on the poor." ~Thomas Jefferson

View DavidTTU's profile

DavidTTU

141 posts in 1475 days


#3 posted 10-25-2016 01:27 PM

Wood has internal stress, some of which you will never know until you cut into it. I have the same Delta 36-725 and have in fact had the same thing happen to me. If I have good control of the work piece, I will place a small wedge behind the saw blade kerf to make sure the kerf will not pinch, and then finish running the piece through the cut. Might not be the safest way, but it has worked for me.

The safest thing you could do would be to rough cut it on a band saw perhaps.

-- -David -- Lubbock, TX

View HokieKen's profile

HokieKen

4515 posts in 978 days


#4 posted 10-25-2016 01:48 PM

I would recommend using a bandsaw as well to rip it in half or try another piece of the stock, could just be some internal stress in that one piece.

Was there burning on the cut? Are you sure your fence is set properly and the fence isn’t pinching the wood against the blade?

-- Kenny, SW VA, Go Hokies!!!

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Dustin

408 posts in 580 days


#5 posted 10-25-2016 01:58 PM

Thanks for the response, folks.
Dr.Dirt, the riving knife wasn’t the problem (I actually tried it without the knife, though I know that wasn’t the smartest idea: same problem). The wood was visibly pinching inward so severely that after the first attempted cut (about halfway through the 30” piece), the end that had been cut was pinching in enough to touch.
David, a bandsaw is on my list of tools, but my shop is still relatively small. This was a single work piece for making two lathe handles, so I don’t have anything else to compare it to.
Kenny, there was next to no burning on the cut. And out of fear of binding, I keep my fence a few thousandths farther out at the trailing end. It is worth investigating, though, as I’m afraid the cheap aluminum face that comes standard on the fence may be deflecting, causing this and potentially other problems (though it hasn’t affected other projects thus far). Either way, maybe about time to add an auxiliary fence to eliminate that possibility.

-- "Ladies, if your husband says he'll get to it, he'll get to it. No need to remind him about it every 6 months."

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Aj2

1178 posts in 1637 days


#6 posted 10-25-2016 02:05 PM

For me that’s what I’d expect from maple.Esp flat sawn.
I use my bandsaw for deep cuts.Cut over size face and joint side square to the face then rip.Its a extra step but much safer and more predictable.

Aj

-- Aj

View DrDirt's profile

DrDirt

4414 posts in 3581 days


#7 posted 10-25-2016 02:09 PM

Dustin – I would say you have some wood that was either cut with stress, or was not kiln dried correctly.

I would do like Hokie Ken and cut it with the bandsaw to rough shape.

You will need to mill it flat, and let it set for a day or so and see if it wants to move/cup/twist etc once cut – - or if it had stress but will stay put.

Since you are cutting a channel to make tool handles – the movement may not affect you. But if you were making a frame for a floating panel cabinet door… I would say get different wood

-- “The two most important days in your life are the day you are born and the day you find out why.” Mark Twain

View GR8HUNTER's profile

GR8HUNTER

2966 posts in 552 days


#8 posted 10-25-2016 02:18 PM

no doubt ….... it is hard maple ….. that does seem to bind …...... I would add a shim and keep cutting ….....that if you don’t own a bandsaw …..... good luck to you sir

-- Tony Reinholds,Pa. REMEMBER TO ALWAYS HAVE FUN

View johnstoneb's profile

johnstoneb

2642 posts in 2012 days


#9 posted 10-25-2016 02:43 PM

This happens occasionally usually due to internal stress in the wood. The purpose of the riving knife is to keep the wood from closing on the blade and throwing it back at you. Before I got a saw with a riving knife I would drive a wedge in the kerf if it was starting to close. Some times the wood will close tight enough on the riving knife that you experience what you did. Either wedge it or cut it on a band saw.

-- Bruce, Boise, ID

View brtech's profile

brtech

1006 posts in 2762 days


#10 posted 10-25-2016 03:24 PM

I’d first try lowering the blade and see if you can cut say 1/3 of the way through the blank. Then raise and do another third and then cut through. If you will plane the surfaces before you join them back, you could flip the blank around after the first cut so that the last cut is the middle third.

The wedge might work well, but you probably can’t use it with the riving knife, and you might end up having a split where you don’t want it just before the end of the cut.

This is the kind of a cut where a Grrriper is just what you want (with the gravity heel).

View hotbyte's profile

hotbyte

989 posts in 2815 days


#11 posted 10-25-2016 03:45 PM

Like CharlesA, I’ve had it happen with construction grade SYP 2X material. And, similar to DavidTTU, I was able to get rip past back side riving knife and put in a small wedge into the kerf to hold it open.

View Stewbot's profile

Stewbot

199 posts in 923 days


#12 posted 10-25-2016 04:04 PM

I’ve got the same saw and have had this happen with both construction lumber and hardwood. I’m not necessarily advocating this as a safe solution (I don’t know what the safest solution is only what I’ve done) but what I’ve done in this instance is once I feel the wood binding too much I’ll power down the saw remove the piece and run it through again leaving the fence in place. Usually it removes enough of the material to clear the riving knife to finish the cut, otherwise I run through that same process again further down the board. After that I’ll rip it to my desired width without a large off cut (although unfortunately sometimes I won’t know a board will react this way until I’m already set-up to cut my final width). I only do this with longer pieces which I feel I can handle safely, anything too short that I think will too easily shoot back at me, I cut my losses.

-- Hoopty scoop?

View Dustin's profile

Dustin

408 posts in 580 days


#13 posted 10-25-2016 04:36 PM

Wow, thanks everybody for all the thoughtful replies!

(Gotta say though, you’re killing me here. How do I justify a new table saw to the boss if it could be argued that I can make do with what I have?)

-- "Ladies, if your husband says he'll get to it, he'll get to it. No need to remind him about it every 6 months."

View oldnovice's profile

oldnovice

6433 posts in 3207 days


#14 posted 10-25-2016 05:33 PM

Ditto on what CharlesA said!

-- "I never met a board I didn't like!"

View cebfish's profile

cebfish

151 posts in 2527 days


#15 posted 10-25-2016 05:47 PM

lie to the boss she probaly does it to you when she wants shoes or a dress

showing 1 through 15 of 19 replies

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