I did something really dumb..

[Derrick]

The problem is, I'm not sure what it was. I was starting to resaw a piece of walnut 3" thick. When one of the teeth of the 1/2" TW 3tpi grabbed the board and actually shoved it down and through table insert. Needless to say the blade is toast as well as the insert. I was running the BS on high speed (it is the HF 4 spd model). I went through the settings before attempting the cut. Everything looked set correctly but obviously something wasn't. I'm glad it was a scrap piece. I then put on the 3/8th blade and re-adjusted everything and it seemed to work fine. Any ideas what I might have done wrong would be helpful.

[Salty]

HF...that may be the problem.

I have decided to only buy things there that can't possibly hurt me. Which doesn't leave much.

[Warren]

Obvious question. Was it clean wood? No nails or stray pieces of metal?

[Derrick]

It appeared to be clean. It was a cutoff from my local hardwood supplier that had been run through their planer and straight line ripped. I am wondering if the pc might have needed to be longer. It was approx. 6"-8" in length and maybe I didn't have a firm enough grip.

[LCHIEN]

It appeared to be clean. It was a cutoff from my local hardwood supplier that had been run through their planer and straight line ripped. I am wondering if the pc might have needed to be longer. It was approx. 6"-8" in length and maybe I didn't have a firm enough grip.

That's what I was thinking, in order for what happened to have occurred, the front end was pushed down with sufficient force to break the insert (plastic or metal?) which would have raised the back end stright up in the air.

I haven't really done much resawing but I guess that would be a question, do you have to have a good grip on the workpiece, or was the insert just not strong enough. Obviously the edge of the insert hole is the fulcrum and a longer piece would have reduced the force needed to hold the back end down and the front up.

[drumpriest]

Loring, from my experience you don't have to have THAT good of a grip. It's best to think of it as guiding the board through the cut. I hold the back down, but it's not like I worry that much about it.

I agree with you guys though, it seems like there was something immovable in there, so that the irresistible blade pulled the board down through the insert.

[RayintheUK]

Likely to have been a combination of things - blade speed + feed rate + support. Walnut is very close-grained, but should have been no problem for the blade you used. However, if fed too fast, or not fully supported against the fence, it's just possible that a weird grain pattern caused a slight sideways effect, which the blade speed increased until it couldn't cope. If you've still got the offending piece, have a look at it along the cut line.

Thanks for the post, Derrick - doesn't hurt to remind ourselves now and then that tools can bite back!

Ray.

[Popeye]

Let me toss a couple of questions in the pot. Using a fence? What kind? If it was a flat fence was it compensated for drift?
Ditto on the others quesstimates.
I made new inserts for my BS from 1/4" ply to level them with the table but I doubt the insert had anything to do with it.
Oh, and I doubt you did anything really dumb Derrick. Pat

[Russianwolf]

glad the insert on my Hitachi is metal.

[Wood_workur]

If he was using a flat fece not comphensated for drift, that would have done it. It would be the size of the workpiece, or the feed rate, because I tried resawing a piece of poplar about 4" long once, and it was the stock blade (timberwolfs didn't arrive yet), and the saw started bogging dow, but there wasn't much pull on the workpiece to tip like his did. But something in the wood...
Are there any raised ridges in the wood that they planed for you? what about holes, or some knots?

[Derrick]

Thanks for the replies everyone. I am beginning to lean toward the idea that I had damaged the blade somehow after it's last use. I had used it previously with no problems at all. I was using the fence that had the chamfered edges, so I could compensate for blade drift, and about 2.5" tall. I learned about the fence in the Tage Frid book. It really didn't even start to cut before it grabbed the board. I now think it was possible that I had bent a tooth or two and should have inspected that blade a lot closer before installing it. I don't know how I could have bent the teeth but I have been doing alot of rearranging in the shop so it is possible. If it was the blade it would have totally been due to my own carelessness and not the quality of the blade. I think this was a wake up call to make sure I check everything, and not take anything for granted before I turn on my equipment.

[Martin]

My High School shop teacher (1951) said; when he was a young man, just starting wood working, all the old timers had stories about ruining wood working machines while cutting hard woods which had grown over and embeded Civil War rifle balls.
A few years ago, I believe a National Geographic program interviewed wood workers in Viet Nam who complained about embedded metal in the trees.

[jl]

I like to suggest another possibility: was the end of the piece cut square?

If not and the long edge was on the top you could have a problem when starting the cut. The blade would enter the wood at the top and push it down. And since it would not be supported the back would lift. The sharper the top angle, the higher the risk.

If the end of the piece to resaw is not square, the long edge should be on the table. In that case the blade enters the wood close to the table where the wood is fully supported.

[AlanWS]

The weakness of the thin plastic HF throat plate is probably part of the problem. I replaced mine with oak. Another thing that might have contributed to the problem would be if the workpiece tipped sideways a bit as the blade touched. That would catch the blade, making it pull down much harder, and with the weak throat plate, it goes from there.

An alternative to making a close-fitting replacement plate would be to cover the bandsaw table with a sheet of plywood. Just cut halfway into a piece the size you want your table, and clamp it to the metal bandsaw table. That creates a nice zero-clearance surface, without any edges around the insert to catch the workpiece. Make sure it's smooth enough for sliding workpieces.