Indexing Pins

[robinsoncr@naxs.net]

Howdy,

I was wondering what's the best method to create or install indexing pins for locating panels on the table?

Our table is 60x120". Our primary materials will be sheet goods and solid surface panels, so panel placement is critical. I wanted something that is more substantial than simply leaving some material on the spoilboard when flattening it. I thought about creating steel index pins that would be raised when loading a panel and then pneumatically lowering them before initiating the cut.

Any ideas? What would be the best method to locating the pins?

Chris

[gerald_d]

Before you think of such precision indexing, decide if you are going to use the edge of the board as supplied. We normally trim all edges and therefore don't have to worry about setting up a board that accurately.

[rgbrown@itexas.net]

Chris,

I have holes bored in my table that accept a 3/4" dowel/aluminum tube/plastic rod as a stop. When I hit one of the non-steel stops - and I do, I don't have to replace the bit.

Every time a nwo project appears, my table requirements change a bit. I think I may be at a point where I have what I need to do about all I need. Of course there are still dry-wall screws and clamps for when "all else fails".

BTW - Gerald, I have decided to simply mill "T-slots" in my table, eliminating the expense and such of aluminum extrusions.

[gerald_d]

Ron, your T-slots will probably be stronger than the screwed down T-Track - especially if you make make your own bolts with oversized heads. Stainless steel flat bars (40mm long) with holes threaded into them for your nylon screws/studs . . . . .

[robinsoncr@naxs.net]

Gerald, I won't be dustcutting the panels prior to machining on the router. It adds another step and I'm conscience of efficiency. After dust cutting hundreds of panels on the slider, they're seldomly off more than 4mm and I'm allowing more waste than that when layout out the nesting on the sheet.

Ron, great idea about simply locating sacrificial dowels in holes on the table.

Chris

[gerald_d]

Chris, the edge is trued up with the SB router as part of the program. Board widths do vary a bit between suppliers and often edge-damaged boards can be purchased at a substantial discount. We never nest the parts so tightly that we demand pristine boards from the supplier who has given us the widest board.

The pneumatic steel pins mentioned in your first post would have been a total overkill. If you cut 3/4" dowel holes in your table with your SB to get them accurate, you lose 3/4" on the y-travel for a board butting against the dowel.

We have a strip of MDF glued down the edge of the table that stands about 1/4" proud of the surface. This strip is faced with a 1/4" cutter while y=0 (almost hitting the mechanical limit}. When we do the facing cut, we also sink about 1/4" below the surface of the table to form a gutter for sawdust. This gutter is very useful because:
- it indicates where the limits are for a 1/4" cutter (used for 99% of our outer edge cutting. (The damaged part of the board must be over the gutter)
- it holds 1/4" thick blocks of wood standing vertically, to act as the location "dowels" that are being spoken about.
- it holds that tiny piece of sticky dirt that refuses to be swept off the table. You get a clean reference edge without using a blow gun. In fact, for all locating fences, it is a good idea to cut a little groove in the corner where it meets the table.