cutting box joints on a router table with sledge

[kityuser]

ok, so i've starting rouging out Mrs KU's otterman using a load of beech block worktops donated to the cause.

I've sized and thicknessed the boards and am now experimenting with cutting some box joints.

The sort of dimensions I'm talking about are 50mm wide fingers that are 25mm deep.
My question is about the safety and accuracy of using a sledge to cut the joints on my router table. I'm considering a "on end" method, with a full table wide sledge and a wacking great big vertical fence to keep the 26" (longest) pieces supported.

I've took some pictures but have been relegated to the netbook and can't seem to post the pictures up onto photobucket bloody websites not supporting FF on linux :roll:

Assuming the sledge is a viable solution, how many passes should I make to sneak up on the 25mm depth of cut (25mm high, 25mm deep, 50mm long).

Steve

 

[bodgermatic]

Steve, Imageshack seems to work with FF on Linux - old versions at that.

 

[Mike Wingate]

I cut mine on an Incra jig setup. For 3/8" finger joints with a 3/8" cutter, I do 2 passes, the first at 3/16" and then full depth. Go for half the diameter of the bit (I am using 1/2" shank bits in a DW625 router).

 

[kityuser]

for the interested, here is my mock up sledge:

It'll have handles, and be guarded from the back.

The scrap supporting the fence is the first thing that came to hand, the slots have no relevance.

Steve

 

[jlawrence]

Interesting to see I'm not the only one with photobucket problems - only with FF3 though, version 2 seems fine.
I'd start erring on the safe side and take 5mm cuts - so 5 passes to get to depth. If you've some suitable scrap then experiment with the depth until you find what's possible.