Best tool for half laps

[Rainger Pinney]

Hello, I'm looking for a good solution for repeatable 3/8" deep by 3" wide half laps in 3" wide basswood of varying lengths. Ideally I would be able to cut it in one pass, be able to set up a fence and stop system, have good dust collection and be safe.


Right now I am using a shop made router x/y axis carriage made with two sets of drawer slides. It functions a bit like a strike jam router with solid stops on the sides rather than a pattern follower.
This works but is slow, has poor dust collection and is not as safe as I'd like.


From what I can tell a Hauncher would be perfect but is out of my budget. So I'm considering a radial arm saw with a dado or molding head, or maybe a radial arm router.

Any suggestions would be greatly appreciated thank you

[Frederick Skelly]

So I'm considering a radial arm saw with a dado or molding head, or maybe a radial arm router.

A series of dados is what came to my mind too. You can set up stops to make it repeatable. Depending on the quality of your dado set, you might not get a smooth bottom. If that's so, you could quickly correct that with a block plane or rabbett plane.

It'll be interesting to see what others think of - there's a TON of experience around here.

Please let us know what you end up deciding to do and how it worked for you. And BTW, welcome to the Creek.

Fred

[Andy Giddings]

Radial saw approach would work but I would have thought it would be messy and less safe than the router option you have. Another way to do it with fewer passes is a wider router bit (think they are called bottom clearing bits). Personally I would use a dado stack in a table saw. Either way you will need multiple passes as most dado cutters are going to be 3/4 wide max

[Mark Bolton]

https://www.youtube.com/watch?v=Lcn2ksnMc04

[Van Huskey]

https://www.youtube.com/watch?v=Lcn2ksnMc04

Funny I was just about to post Jack's video too.

Personally, I would use a RAS with a dado stack, no RAS and I would use a sled on the TS with a dado stack.

[pat warner]

The 1/2 lap process removes a lot waste. The process is usually slow. Maybe bandsaw the waste first. You can get >75% with the bandsaw in seconds. I made a sliding carriage router table (http://patwarner.com/images/new_router_table1.jpg). Very precise and my hands are always on the carriage, never near the cutter. The cover around the cutter has been changed for 2 vacuums, so no mess. A wild alternative; took 4 months to design and make. But does the job well. (http://patwarner.com/images/dovetailed-lap.jpg)

[Ole Anderson]

Pat, that is one incredible piece of work. Congrats.

[Frederick Skelly]

The 1/2 lap process removes a lot waste. The process is usually slow. Maybe bandsaw the waste first. You can get >75% with the bandsaw in seconds. I made a sliding carriage router table (http://patwarner.com/images/new_router_table1.jpg). Very precise and my hands are always on the carriage, never near the cutter. The cover around the cutter has been changed for 2 vacuums, so no mess. A wild alternative; took 4 months to design and make. But does the job well. (http://patwarner.com/images/dovetailed-lap.jpg)

I remember when you showed that to us once before. I was in awe then, and I still am. Geez, I wish I could come up with something as well done as that.

[Lee Schierer]

I use half laps in most of the frames I make for inside cabinets. I cut the shoulder cuts on my table saw and use my tenon cutting jig to remove the cheeks. I can dial the cut in to get perfect thickness alignment. The cut offs make great clamping pads to protect finish pieces from clamp damage.

For joints in the middle of a board like you show, I would either nibble out the material in the middle with multiple cross cuts or after making the edge cuts for each slot I would remove the remaining material with a dado blade.

[Jim Dwight]

I usually use my 6 inch stack dado on my radial arm saw. Minor variations in stock thickness can affect the results, however. Cutting slightly oversize and trimming with a shoulder plane improves my accuracy.

[Rod Sheridan]

Hi Rainger, I use half laps, or bridle joints and cut them on a shaper with a sliding table.

If I'm making half laps in the middle of a board I use a slotting cutter in a sliding table saw............Rod.

[Bill Adamsen]

Pat, that is impressive. Are there bearings or just the XY dovetail way on the sliding table?

[pat warner]

" Are there bearings or.)
************************************
No roller bearings. All close fittings, needing occasional steel wool and wax.
No discernible wear after 16 months.
Some scratches (http://patwarner.com/images/new_router_table3.jpg) evident. Phenolic and aluminum, however, are simpatico.
Aluminum on Aluminum, without lube, will gall in 2".

[Dave Cav]

If the laps are within the capacity of your dado stack, cutting them vertically in one pass using a tenoning jig is going to be the fastest way. You won't be able to cut 3" laps with a 6" dado stack, but an 8" stack should do it. Don't forget a backer board to keep the back side from blowing out.

If your dado stack won't cut them in one pass, then cut the cheeks on the bandsaw (rip cut) then the shoulders on a RAS or table saw (crosscut). This is a good place to use stop blocks to insure repeatability on your cheek crosscuts, but if you're doing it on a TS, don't let the cheek offcuts get trapped between the blade and fence. Clamp a stop block to the fence.

You can cut them flat with multiple passes of your dado stack on the TS or RAS, but I have always had problems getting the cheeks perfectly flat and don't do it that way except for laps in the middle of a stick.

If I was doing a bunch of laps, I would probably use my tenoner.

[Prashun Patel]

Because you know the exact dimensions of your half laps and your stock, and you want the joints at various points along the length of the stock, IMHO, your fastest way is to make a plunge routing jig.

If you really have to do a lot of these, and do not want to mark each location individually, you can make 'indexing pins' that align your shop-made base at the precise locations relative to the ends of each stock.