drilling and tapping the rails

[siliconbauhaus]

A long time ago I got rid of the accessory table as it always would catch the stock on the edge of the router opening.

I've been fine without it until today when I was trying to rip a sheet of melamine down and I couldn't keep it flat on the area surrounding the blade.

I'm looking to knock up a quick extension table to use until I have time to make a knock off of LarryG's one. My thoughts were a piece of 3/4 mdf with a frame to the underside and then drill and tap some cap screws into the rail.

This table isn't going to have any weight on it apart from the stock and I need to get this stuff cut now so I can't wait to send off for t nuts.

I'd appreciate any suggestions or alternative ideas for this.

[Bill in Buena Park]

Sounds reasonable. Unless its for the neatness factor, why bother tapping the holes and not just use self-tapping metal screws?

[Uncle Cracker]

Remember that the rails are extrusions of relatively soft aluminum. I would not trust them to tap reliably. If you are going to drill, I would use through bolts and nuts. However, another good solution with a lot of possibilities is to use the T-Nuts that are made to work in the rails. They are available from a couple of sources. Search this forum for links.

[siliconbauhaus]

In a ideal situation I'd happily use the t nuts. Unfortunately I'm trying to get this sorted out today.

Having looked at the rails again I don't think there's a lot of meat to be able to tap so I'm off to blowes to see if I can find any 1/4 aluminium and make my own bodged t nuts.

[pelligrini]

I considered using some 1/8" angle material, before I used my T-nuts. I had an idea of using 2 angles per rail with a spacer between that would also act as a ledger for the table. The angles would be oriented so fit into the top and bottom lips of the inside slots on the rails. The assembly would slide in from the end.

I also considered just using 1 angle per rail that would fit into the bottom lip of the inside rail tracks and some sort of clamping device that would go under the bottom of the rail. I couldn't rely on gravity to keep the table in place as I fold my 21829 vertical all the time.

[siliconbauhaus]

Well I managed to find some 1/4 x 1" aluminium at blowes and I'm going to knock out some DIY t nuts. I have some 2x2x3/4" blocks of maple that I will drill to take the pan head screws an then I can screw the top to them (after everything it aligned).

The thing I'm looking up about now is milling aluminium with a router. I only need to take off 1/8" on either side and they should slide nicely in the rails.

[Uncle Cracker]

In a ideal situation I'd happily use the t nuts. Unfortunately I'm trying to get this sorted out today.

Ahhh... Remember that you can't spell "Preparation H" without "preparation"...