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How do I cut full blind splined mitres?

9.9K views 21 replies 11 participants last post by  runswithscissors  
#1 · (Edited by Moderator)
The title says it all. I dont have a Festool Domino so im not sure how to do this otherwise and accurately. It needs to be precise so that the mitre edge is clean.

Something like this

Image


The only thing I can find is this jig which is something that could be manipulated so that the router bit cuts into the center of the miter. Then I can clean up the edges with a chisel and install the spline.
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#8 ·
You can make that cut on your table saw. However it obviously needs to pass thru the top and bottom edges of the boards, which will expose the miter. I guess it would be possible to use the same species for the spline and that would somewhat camouflage the spline. The alternative would be to band the top and bottom edges with the same species, to conceal the spline.
 
#9 ·
You can make that cut on your table saw. However it obviously needs to pass thru the top and bottom edges of the boards, which will expose the miter. I guess it would be possible to use the same species for the spline and that would somewhat camouflage the spline. The alternative would be to band the top and bottom edges with the same species, to conceal the spline.

- builtinbkyn
I'd like it to be hidden. This would definitely work but i really do want it fully blind.
 
#11 · (Edited by Moderator)
I didn't see how wide your piece is?
You could clamp the piece to your table saw fence and raise the blade, making sure the piece is centered so that you don't come out the front or back. Move the fence and do it a second time if you want a fatter cut.
Then make 1 big football/sawblade shaped spline to fill it.

*NOTE: My saw doesn't come straight up.
You would have to raise the blade to the height you want, and then make your marks where to put the piece on your fence.
 
#12 ·
You can make that cut on your table saw. However it obviously needs to pass thru the top and bottom edges of the boards, which will expose the miter. I guess it would be possible to use the same species for the spline and that would somewhat camouflage the spline. The alternative would be to band the top and bottom edges with the same species, to conceal the spline.

- builtinbkyn
This would work. Mill the pieces slightly wider than needed, rip a thin veneer off of each edge, cut the slot on the table saw, glue the cut off veneer pieces back on. Should be virtually invisible.
 
#13 ·
Router table?

Cut your miters first. Install a bit the correct size for the spline. Establish a start and stop point on the fence, set the fence to where the slot is centered in the end of the board. Cut will be a plunge cut. Plunge down at the start point, slide over to the stop point.

You might rig up a sled to hold the piece at the 45 degrees needed, and have it so you can slide the part onto the bit to start the cut. When you reach the end of the cut, you can slide the piece either back a bit, or shut off the router, and remove the finished piece.
 
#14 ·
I didn t see how wide your piece is?
You could clamp the piece to your table saw fence and raise the blade, making sure the piece is centered so that you don t come out the front or back. Move the fence and do it a second time if you want a fatter cut.
Then make 1 big football/sawblade shaped spline to fill it.

*NOTE: My saw doesn t come straight up.
You would have to raise the blade to the height you want, and then make your marks where to put the piece on your fence.

- jbay
Its roughly 2ft wide so this would work. not sure how to control the height of the blade so that the depth is consistent on both cuts.
 
#15 ·
Router table?

Cut your miters first. Install a bit the correct size for the spline. Establish a start and stop point on the fence, set the fence to where the slot is centered in the end of the board. Cut will be a plunge cut. Plunge down at the start point, slide over to the stop point.

You might rig up a sled to hold the piece at the 45 degrees needed, and have it so you can slide the part onto the bit to start the cut. When you reach the end of the cut, you can slide the piece either back a bit, or shut off the router, and remove the finished piece.

- bandit571
That's what i was thinking except the pieces are too large to be held up at a 45 degree angle. I think i'd need to hold the router at a 45 degree angle and use a template and a straight bit to cut the spline slot.
 
#17 · (Edited by Moderator)
There's no easy way to do it on a 2' wide
workpiece I know of. You're better bets
are an elaborate router jig or the table saw.

If you can accept ripping the ends off
and regluing them back on after cutting
a through slot on the table saw, then the
problem of how to make a stopped cut
on the saw is not a problem.
 
#18 ·
A hollow chisel mortiser with a tilting table, or a JDS multi-router would be my choice for that cut. Both are really expensive. Perhaps one of your WW buddies has a mortiser you can get some time on? Short of those tools, I think your original idea is likely the best bet to get an accurate, clean mortise.
 
#20 · (Edited by Moderator)
Router table?

Cut your miters first. Install a bit the correct size for the spline. Establish a start and stop point on the fence, set the fence to where the slot is centered in the end of the board. Cut will be a plunge cut. Plunge down at the start point, slide over to the stop point.

You might rig up a sled to hold the piece at the 45 degrees needed, and have it so you can slide the part onto the bit to start the cut. When you reach the end of the cut, you can slide the piece either back a bit, or shut off the router, and remove the finished piece.

- bandit571
Yep, I'd rig up a 45 degree jig with handles toward the back (to protect the hands), with a few sturdy hold-down clamps, maybe glue some sandpaper where the piece will sit to insure it doesn't move. I'd put in start and stop blocks to safely enter the cut, and use a simple 1/4 slot cutter to pop in the slots. The jig will take a while to design and build, and the cuts should be really quick. Good news is, this jig can be stored and used for years.

you could also rig up a jig for a plunge router and collett- I honestly hate using a router free hand, but this depends on your comfort level- but I would make that jig very study and well thought out- safety first.
 
#21 ·
This seems to be way overthought. It's a shallow cut that can be accomplished with a single dado blade on the table saw. If the boards are 2' wide, cut them oversized - maybe 26". Make a plunge cut to start the kerf and run it to an equal distance at the other end. Mark those start and stop points on the fence. Do all four the same then cut the boards to the 24" size leaving the ends intact. Square up the kerf with a chisel or router plane. Not knowing the thickness of the stock, the kerf more than likely won't be deeper than 1/2". Not a lot of clearing out to do. Obviously test this method to ensure you can get good alignment of the splines and tight miters.