First time cutting mortises with the router tomorrow

[Ryan W Taylor]

Well gents, the day is fast coming. Tomorrow after I make my jig, I am going to take the DW618 and cut my first mortise joints. 1/4 bit and I am doing a 1/2 inch plunge. My question aside from everything is, what speed would you guys suggest running the router at? My normal default for everything in life is FULL SPEED AHEAD.... but that might not be the right move in this case. The wood is 3/4 white oak.

[Aaron Rosenthal]

For me, I use 3/4 to full speed, but I'm not seeing.......
How much depth are you cutting per pass?
Do you have a feel for the feed rate?
Are you planning a full plunge at the start and end, first, then going back to remove the remainder?
How about a few test strips, first, to get the feel of the machine/bit combo?

[Ryan W Taylor]

I am only planning on a 1/2 inch plunge in total. Figured two passes though I suspect with only a half inch..I could probably plunge the first way across, and then do the cleanup on the second circuit down it.

[Andrew Hughes]

With a 1/4 inch bit I recommend your first pass at 1/8 inch deep. You can tell by the sound when your pushing it or when the bit breaks. That’s a sure sign too :)

[Thomas McCurnin]

I am only planning on a 1/2 inch plunge in total. Figured two passes though I suspect with only a half inch..I could probably plunge the first way across, and then do the cleanup on the second circuit down it.

+1

Mortises, especially on smaller diameter bits, take huge toll on the bit. Please do a practice mortise or two or three, and you'll figure it out.

[Bud Brinkley]

You should make your mortise with a series of overlapping plunges. Then a final clean-up pass in one direction only.

[Derek Cohen]

You should make your mortise with a series of overlapping plunges. Then a final clean-up pass in one direction only.

That is what I do. Plunge to full length each time. Finish with a sweep.

Regards from Perth

Derek

[Jim Dwight]

If you are using a normal 1/4 straight bit you should expect it not to plunge in too well. You might want to drill at least one hole, could be a little undersize so it doesn't go into wood you don't want to mortise, to ease the entry into the wood. A Spiral upcut bit or a straight bit with a bottom cutter would but it's way in better. But a regular straight bit will work, but it may protest on the intial plunge and may even burn the wood a little. I made 8 chairs cutting mortises with my router but I used a carbide spiral upcut bit. Worked well.

[Prashun Patel]

Don't underestimate the force the router can generate if it starts to run on you if you are not careful about your direction. This is important if the mortise or your jig slot is any wider than your bit.

If it runs, it can unseat clamps and gouge your wood or at least your jig slot.

This is mitigated by taking very shallow passes so you can control the machine even if you're moving with the cut rotation.

However, nowadays I almost always never purely route a mortise. I prefer to take it the drill press first and hog out the waste with a forstner bit. This is more efficient, less dusty, preserves the router bit life, and alleviates all the stresses above. Your router can then just be used to clean up the sides and bottom.