Making perfect router slots, How?

[leehljp]

I made a router dado jig last week and really like it. However, the adjustment part - where a slot is needed was done with a jig saw. In the two picts below, both have a slot through which a bolt/knob tightens and loosens to allow one part of the jig to be adjustable.

My question is: How do you make perfect slots like those in photos, picts and diagrams? I have tried drilling two holes and then "routing" a straight line between the two holes, or cutting with a jig saw. In the case of router, even with a router table and fence, it tends to jerk and make crooked holes, -especially in making the hole through two different materials. And with a Jig saw, two different materials seem to make the blades want to deflect just enough to make the slots ugly.

Mine are very functional but they are just ugly. How do you make perfect knob slots as in the two pict/diagrams below? BTW, With the jig on the top, I made perfect dados!

[mm1992]

When I replaced my router fence I created slots like that. I used a forsner bit to get it as close as I could and cleaned it up with a chisel. Not perfect but close. I'm curious if there's something better but I can think of anything.

[Jim Frye]

My first router dado jig was a pair of shop made large try squares that I could clamp on either side of the dado. Sometimes I set them up so the router base plate would run between them. Sometimes I used router template collars that ran between the try square guides. The try square guides got lost/tossed when we moved. I now use a pair of adjustable aluminum (up to 48") guides that I set up to allow the router base plate to slide between them. I use a router, usually a Ryobi 1803, that has a circular base with the collet centered. Set up takes a bit more time, but things come out smooth and straight. The adjustable guides have no brand name on them and I think I bought them at a woodworking show some years ago.

[twistsol]

I've made slots like that once on the router table and they came out perfect. I needed a 3/8 slot about two inches long.

I needed the slot in a block that was about 2" by 3" so here's hjow I did it.

• I ripped a piece of baltic birch to 2" about 2 feet long
• I drilled a 5/16 hole in the near one end of where the slot would be.
• I put a 1/4 spiral bit in the router and with the router off, adjusted thje fence so the bit was centered in the hole I drilled.
• I started the router and cut a 1/4" slot nearly the full length.
• I replaced the 1/4 bit with 3/8 spiral bit and with the router on, lowered the piece over the bit through the slot.
• I pulled it backwards to the start of the slot and then pushed it forwards to the end of the slot and shut down the router.
• I then cut off the 3" piece at the miter saw.

[mpc]

I use the router table as well. Typically I start with a piece at least a foot long, even for short slots. I also drill holes at each end of the slot typically, though sometimes only at the starting (left) end. I clamp stop blocks to the each end of the fence. The router bit is raised to cut only 1/8th to 1/4 inch at a time. I put the workpiece against the right hand stop, lower it carefully onto the spinning bit, then push it left into the next stop. Then I hold the workpiece while turning the router off. Once the router is off, I lift the piece up, raise the bit, and repeat.

A longer workpiece helps. A featherboard keeping it against the fence - lightly so it doesn't fight me as I try to evenly slide the workpiece - helps too.

No router table? Use an edge guide on the router, make several passes slowly increasing depth. A Stop blocks for the router base, or for the edge guide, to hit help. For small pieces like the ones in the pictured jig, consider making the slots into a workpiece not only longer than the final block... but wider as well. That will give the router more support for an easier cut. Once the slot is done, cut the piece to final size. By cutting the slot first, you can put the slot 2 or 3 inches away from the edge of the workpiece which, again, gives the router more support.

For slots that do not match available bit sizes, you'll have to do one edge at a time. Pay particular attention to feed direction; cutting one side, moving the fence, and trying to cut the other side is a recipe for a climb/self-feeding cut. In these cases, I'll flip the workpiece over (upside-down) for the second cut so I'm always feeding it in the normal direction on my router table.

I would expect a scroll saw to work better than a jig saw too.

mpc

[leehljp]

I see a pattern developing: use longer pieces and cut it down after making the slots. I think this was my problem, It is hard to use short pieces in slot cutting! Duh on me!

As to Jim's: router totally guided so that it can't go either way.

Thanks Fellows.

I would love to hear more input an stories.

[LCHIEN]

I am told that you need to cut slots or grooves like this in steps... maybe 1/16 or 3/32" at a pass. For 1/4" straight groove router bits. The bits when you look at the flutes are rather thin walled and can easily break if pushed too hard or burn if pushed too slowly. The spiral carbide bits are even worse, being brittle, the thin wall dues to the flute depth makes them very easy to break.

In making multiple shallow cuts it is probably easier to guide with less wander and more control so you get cleaner cuts when using a guide.
I find making drill a hole at the ends helps precisely locate the start and stop points. It also helps locate the slot -to fence distance, you drop the hole over the bit then snug up to the fence (router off of course).

Two stop blocks can also set the length; Sometimes its also easy to stop the router, raise the bit, then place the piece against the fence and lower onto the spinning bit (the spiral upcut bits are fine for small plunges.

And clearly if the piece is too short it is also hard to control on the fence. Route a long piece and then cut to length.

[sanderzz011]

For my purposes there is no better tables than Bosch router tables. They make them perfectly, and every detail of their tables are think-through pieces of a great mechanism. I've got Bosch benchtop RA1181 couple of weeks ago, and it's awesome. It includes many accessories for woodworking and even for acrylic processing as well.

[leehljp]

For my purposes there is no better tables than Bosch router tables. They make them perfectly, and every detail of their tables are think-through pieces of a great mechanism. I've got Bosch benchtop RA1181 couple of weeks ago, and it's awesome. It includes many accessories for woodworking and even for acrylic processing as well.

https://www.sawdustzone.org/forum/di...r-construction

I made a "router center" when I lived overseas (Japan) but ran into problems bringing it back with all my tools and all the things LOML wanted to bring back. SO I left the carcass and brought back only the routers, fence and organized router bit drawers containing the router bits (150+) mostly 1/2 inch.

I enjoy making rail and style and other things so one day I decided to make a router table with three routers Two 1/2" and one 1/4" along with a horizontal router. Since leaving the carcass over in Japan, I recently decided to make one very similar in size and looks. I haven't finished adding the horizontal fittings yet but the space is there for it when I want to do it.

If you look at the picture, you can get a good idea of the function. The enclosed top was because it had a vacuum in the bottom and one in the fence;
The second row of 3 drawers was for router bits. The third row of drawers was for router accessories, wrenches, etc. The bottom row is for extra routers and cords. That is full on the new one,

[Gabreilriley]

You have a tricky piece here!

Since you are making a groove and not a rabbet, you will need a 15mm Wing Cutter for grooving.

It looks like a small circular saw blade with 3 to 5 carbide cutters, and companies such as Amana, CMT, Whiteside and Bosch make these.

15mm might be a custom size and if so, you’ll need to contact a company like Whiteside to make a custom size for you.

Once you have your bit, a router table with a fence will do the trick.

If your stock has irregular edges, you may construct a round or semi teardrop shaped guide in which the bit would poke out from.

I make these guides from hard maple and face the edges that touch the stock with UHMW plastic.

These styles of guides can be bolted fast on one end as the hinge, and the other end made adjustable with a slot and carriage bolt with a nice hefty adjustment knob.

This allows the guide to be rotated around the bit, and a small bump with a wooden mallet allows for very accurate micro adjustments.

Be sure to run your stock against the direction of the cutter, just as you would push a piece of stock into the blade of a table saw router table extension .

If you approach the cutter in the direction it is running, the likelihood of your stock being violently flung across the shop is very high, and there is the possibility of your hands ending up in the cutter, which would be tragic!