Problem with DW735 Planer

[Charles Bechle]

I'm in the middle of making a piece of furniture using quarter sawn white oak. The planer blades are in good condition and it does a beautiful job on all the pieces that are around 3/4" thick, most of them needing little or almost no sanding. The problem is on the 1/4" thick infill panels. On a couple of them, it actually ripped off parts of the last few inches of each panel. I pay attention to the grain direction but that doesn't seem to make a difference. Has anyone else experienced this? Is there an adjustment I can make to the machine, or am I going to have to resort to using a sled for all thin stock from now on?

[glenn bradley]

If the pieces being pulled off are at the very ends of the stock believe your stock isn't strong enough to tolerate the stress of the milling operation. Milling longer pieces and then cross cutting to length would solve this. If this is tearout (material pulled out of the face of the material) - and occurring at the start and finish of the cut - this is not uncommon for me in thin pieces of white oak. Similar to the first problem, the thin stock is uncontrolled due to its size/mass and a bit of "flutter" (for lack of a better word) causes a poor result.

If is is only at the start and finish areas, again I would mill oversize in length and then cross cut the blank to finished size. If it is throughout the stock, you may get some relief by double-stick taping the thinner stock to a thicker carrier board of MDF or other consistently dimensioned stock. Another alternative is milling to near thickness and then hand planing at a shear angle to avoid the tearout. Also, a local shop may have a wide sander and could do the final thicknessing for a fee.

I'm sure folks will mention insert heads as the primary cure for tearout in figured woods but, one has to calculate the cost of that against having a shop do a bit of work for a fee every now and again. I do a lot of figured work and so have insert heads in milling machines and use spiral or shear cutters in others. This doesn't always make economic sense for the occasional piece.

[Charles Lent]

+1

Your stock is too thin and flexible. Either attach it to a thicker carrier, or use a drum sander. You should also be doing this if your work is 12" or less long. Running thin pieces diagonally, if they are narrow enough, sometimes helps.

Charley

[Jim Morgan]

You don't say whether you have the extension tables. Toward the end of the cut, when the infeed roller is no longer holding the stock down, the free front end of the board can sag downwards, levering the back end of the board upwards, causing snipe or worse. The extension tables move the fulcrum further from the cutterhead, helping to minimize this. Supporting the stock on the outfeed side or even levering it upwards keeps the back end of the board down on the table.

[Charles Bechle]

Thanks for all the great suggestions. If these pieces were the 3/8" thick that I planned on (by resawing from finished 4/4 stock), this probably wouldn't have happened. This was my first real attempt at resawing for a furniture project and it wasn't quite perfect, so I ended up with 1/4" thick panels which I was nervous to run through the planer. I've known about leaving extra length for snipe, but was so short on wood for this build, I took my chances. I didn't expect this extreme result. The "flutter" explanation makes sense. I do plan on adding a drum sander to my shop sometime soon and getting the spiral head for this machine as soon as the blades need to be replaced. Going forward, I'll make sure I get enough extra wood to allow over-sizing for snipe (or worse) and making replacements for parts that get botched. Now, it's another long and expensive trip to my hardwood dealer.

[Grant Wilkinson]

To add to what you and others have concluded, use the slow speed on the planer and take very light cuts. I pass 1/4" and even a bit thinner through mine frequently and things go well with the slow speed and half a turn cut depth. Finally, if the piece you are planing is not full width of the planer, feed a scrap piece that is a bit longer than your "real" piece beside it at the same time. The scrap will keep the rollers up and not only prevent snipe, but take the pressure off the end of your "real" piece.

[David Utterback]

Good information above on how to avoid this problem which is not limited to this particular planer. I believe it occurs with wood grain runout. If the grain runs parallel to the surface, as with riven wood, the problem is much less of a concern. Thin sections of cherry have decomposed in my planer with damage to the straight blades. It was not limited to the ends of the pieces either.

The preset minimum thickness dial goes to 1/8" leads one to believe they should go for it, but I have learned that with more figure in the wood, the greater the chance of decomposition. I hesitate to power plane any wood that is <1/4" thickness, especially if it is a narrow piece.

Thanks for sharing.

[Zachary Hoyt]

I have planed wood for guitar sides and backs down to about 3/32 with my 733 but had a high rate (up to 50% sometimes) of loss and damage due to grain runout. Now I have a drum sander and it's much much better, I can cut just what I want knowing that they'll all come out perfectly flat and with no chips or destruction.
Zach