How would I do this

[LarryG]

Then, use any of a number of dado jigs, with some stops tacked on.

Or if you have a steady hand, do like David Marks does when he cuts mortises for loose tenons using a plunge router: start out in the middle somewhere, and gingerly work your way out to both ends, by eye.

[radhak]

Not sure I understand the problem -- is it that you don't have a plunge router? Or do you have a straight bit that's not exactly meant for plunging?

Keep in mind, you don't have to start with the router at one end. You can start somewhere in the middle, plunge in, then go to one end, and reverse course to the other end.

Then, use any of a number of dado jigs, with some stops tacked on.

Regards,
Tom

Sorry, now that I read my own post again...i am not very clear there

ok, lemme try again.

the dado jigs i have seen (here and elsewhere) and understood the use of, work like this -
(a) clamp the jig with its cutting-guide-edge(s) aligned to the the desired dado line(s)
(b) position the router on the jig, with the bit at the exact depth as needed, but not touching the workpiece - just slightly outside it's edge.
(c) when the router is started, the bit rotates in thin air, and i move the router onto the workpiece within the jig's guides and thus rout the dado. keep moving the router till it clears the workpiece at the other end.

and if i understand all your post(s), i could do all that with a plunge router, except that i'd plunge the spinning router bit into the workpiece and take it out before i reach the other end. and i guess those stop-blocks might be vital for exact positioning.

NOW i get it!!! thanks for being patient

and i need crokett's beer now.

[ragswl4]

Router Dado Jig

Here is a general, simple idea for a jig to use with a router to make stopped dados. Not my original idea, saw it some magazine a while back. Save attached zip file then open with Word or WordPad.

[LCHIEN]

Here is a general, simple idea for a jig to use with a router to make stopped dados. Not my original idea, saw it some magazine a while back. Save attached zip file then open with Word or WordPad.

yeah that's good. If you put a vertical board on the end, a "hook", then you can get consistent spacing of the start point from the edge of the board.
If you extend one of the side boards and put a tab there then you can also use that to index to the last slot and get consistent spacing of the slots.