|Attention DW733 owners. | |I was thicknessing some glued up panels for some frame and panel doors |using my DW733. | |These were 12" wide and about 22" long and I was getting terrible |snipe. I damn near lost one of them as I neared finished thickness |because of a huge divot on one corner. | |The design of this thing is pretty bad as far as the alignment of the |in and out-feed tables, and snipe is always a PITA but this was really |bad. | |I decided to dismantle it and see if there was another problem. Sure |enough, one of the headlock dodads is broken. This is difficult to |see and a casual look won't notice the break. | |The semi-circular steel band (#66 on the parts drawing) that contacts |one of the four cutterhead guide rods (#24) was fractured, so when the |lock arm was activated there wasn't any pressure on that side. I |believe this allowed the head to move on one side only causing snipe |on the opposite side of the workpiece. | |If Dewalt ever ships the replacement parts I'll report back on whether |this is the cure.
Reporting back.
I *finally* got the replacement parts. I ordered online from Dewalt on a Saturday. I expected that the order would be processed on Monday. Wrong, it went out on Wednesday, UPS lost it on a flat car and then claimed that I don't live where I've lived for 12 years. Finally, the regular driver came back to work and got it to me.
While I would have liked to run experiments to separate the possible causes of snipe with this machine, a lot of hand sanding on a project has aggravated an old shoulder problem and is pretty much keeping me out of the shop.
After replacing the broken head lock with the side panels still off the machine it was a lot easier to use a straightedge and look for other misalignment that could contribute to snipe.
The first observation was that while the base of the machine is cast iron, the "skid plate" seems to be stainless steel and isn't flat. Viewed from the side, it's actually humped in the middle. With enough pressure, it flattens out to the level of the iron base, but it seems to me that before this occurs, it would tend the push the leading and trailing edges of the workpiece up into the cutter; potential causes of snipe.
I removed the plate and judiciously massaged it flat by reverse bending it over the edge of the workbench. With it reinstalled, my straightedge actually sat flat rather than rocking back and forth. This made it much easier to see the misaglignment of the in and outfeed tables.
It almost appears as if Dewalt designed the tables to align with the cast iron surface of the base and then added the skid plate which throws the whole thing off as an afterthought.
I decided that what was needed was a shim on the surfaces of the in and outfeed tables about the same thickness as the skid plate. I had a piece of laminate handy so I cut a couple of pieces slightly smaller than the tables and glued them on.
Hint: Permatex makes a spray adhesive that is very tacky but doesn't harden, so things can be peeled apart if necessary.
A little tweak of the leveling screws and I had almost perfect alignment of the tables and base. I quick spray of topcoat and I was ready for a trial.
I grabbed a 4/4 poplar board almost 12" wide and about 5' long. I believe there was a little bit of twist in the board, but I don't have a 12" jointer, so I ran it through as is. There was some snipe of opposite corners at the ends of the board, indicating the twist.
When I flipped the board and ran the opposite face through, it was essentially free of any snipe. At this point my shoulder was killing me again so I called it a night. But I think I've solved the problem.
Wes
| |Wes |