Router guide bushing on aux table

[jdon]

I'm interested in using PC compatible template guide bushings with the router mounted in my BT3100 aux table. Bushings fit perfectly in one of the plastic insert rings, except they do not recess (the flange sits on top of the ring).

Any ideas of an easy fix? I'm weighing getting a whole new router table setup (a space and $ crunch at the moment), or trying to make a custom insert with a recess- doesn't seem easy, esp. given the small rim at the edge of the opening.

[LCHIEN]

its probably not going to work real well.
Bushing plates need to be recessed as you are aware, so that the entire surface is flat except for the bushing itself. Usually the bushing plates mount to the router baseplate or table in a stepped hole that allows the bushing plate to be flush. The little red plastic plates from ryobi are too thin to support a recessed lip. Also depending upon how the mounting holes were drilled for the router, the bushing needs to be perfectly centered with the router axis to give you problem free template routing.

You could mount the router plus baseplate (some aftermarket baseplates can also take bushings if your router's OEM plate does not) under the BT3 Aux table but then it would sit pretty low. And then you would need to co-center the router and bushing.

Not an easy thing to do.

[jdon]

Thanks, Loring- you've confirmed what I was suspecting... will need to work on a plan B.

[mpc]

As a stop-gap measure, how about using a sheet of plastic, acrylic, or even hardboard to make a new router tabletop... and fit the guide bushing to that. Mount the whole thing on top of the BT's accessory table with some creative cleats around the edges or something similar? I'd probably just make it large enough, and stiff enough, to straddle the BT3 rails directly and just clamp it to the rails - skip the accessory table. You don't have to worry about making the BT3 fence work with it when using guide bushings... all you need is a flat work surface that doesn't move around.

Many guide bushing sets come with an alignment tool: basically a metal piece that slips into the router collet and then has a cone-shaped "bit" end that you use to align/center the bushing. Some of the universal router plate adapters (i.e. the things that replace your factory router plate with one drilled for oodles of router brands/models and includes provisions for Porter-Cable style bushings or their own bushings - e.g. Milescraft) come with the alignment bit as well. With an alignment tool you don't have to make a precision router-mount-adapter-bushing assembly. Drilling the router mounting screw holes (in the new tabletop) perfectly aligned with the bushing opening is tough... so don't - make them a tad oversize to allow adjustment. This would allow proper bit-to-bushing centering when using a home-brew plastic/hardboard table top. The other trick is to drill the router mounting holes first, install a straight bit that has flutes on the bottom too (i.e. not an edge trimmer/cutter but one designed to cut slots)... with the router running, plunge it through the new tabletop. Now you have a starter circle/hole perfectly aligned with your router collet. Use that hole with typical arber+hole saw sets to expand the hole to fit the bushings.

mpc

[cabinetman]

As a stop-gap measure, how about using a sheet of plastic, acrylic, or even hardboard to make a new router tabletop... and fit the guide bushing to that. Mount the whole thing on top of the BT's accessory table with some creative cleats around the edges or something similar? I'd probably just make it large enough, and stiff enough, to straddle the BT3 rails directly and just clamp it to the rails - skip the accessory table. You don't have to worry about making the BT3 fence work with it when using guide bushings... all you need is a flat work surface that doesn't move around.

Many guide bushing sets come with an alignment tool: basically a metal piece that slips into the router collet and then has a cone-shaped "bit" end that you use to align/center the bushing. Some of the universal router plate adapters (i.e. the things that replace your factory router plate with one drilled for oodles of router brands/models and includes provisions for Porter-Cable style bushings or their own bushings - e.g. Milescraft) come with the alignment bit as well. With an alignment tool you don't have to make a precision router-mount-adapter-bushing assembly. Drilling the router mounting screw holes (in the new tabletop) perfectly aligned with the bushing opening is tough... so don't - make them a tad oversize to allow adjustment. This would allow proper bit-to-bushing centering when using a home-brew plastic/hardboard table top. The other trick is to drill the router mounting holes first, install a straight bit that has flutes on the bottom too (i.e. not an edge trimmer/cutter but one designed to cut slots)... with the router running, plunge it through the new tabletop. Now you have a starter circle/hole perfectly aligned with your router collet. Use that hole with typical arber+hole saw sets to expand the hole to fit the bushings.

mpc

+1. Bushings need to fit a recess either in the handheld base, or in a table, or an insert for the table. Making an insert to fit isn't that difficult. A stepped recess can be done with the right sized Forstner bit. Machine the recess first, and use the pilot point left by the Forstner to center for drilling the hole, with the smaller sized Forstner bit.

.

[cabinetman]

It is if you're trying to make an insert to fit the BT3x00's cast aluminum accessory table, as the OP is doing. It uses proprietary, snap-in inserts that are both considerably thinner and very different in design than most other systems.

I agreed with a previous post (the +1), and added some info on creating a recess.

As a stop-gap measure, how about using a sheet of plastic, acrylic, or even hardboard to make a new router tabletop... and fit the guide bushing to that. Mount the whole thing on top of the BT's accessory table with some creative cleats around the edges or something similar? I'd probably just make it large enough, and stiff enough, to straddle the BT3 rails directly and just clamp it to the rails - skip the accessory table. You don't have to worry about making the BT3 fence work with it when using guide bushings... all you need is a flat work surface that doesn't move around.

.

[vaking]

Thinking outloud:
Craftsman style router will fit Ryobi accesory table natively without a Ryobi aluminum plate. Also Craftsman offers a set of plastic base plates for their routers and one of those base plate fits PC style bushings. So you could mount a plastic base plate and Craftsman router directly to accesory table and it will be at about same total depth as most routers with aluminum plate. Be carefull - base plate probably mounts to the router on same screws as router mount to accesory table. It means you will need to get longer screws and centering base plate becomes more complicated. I have never done it, just a thought.

[LarryG]

Thinking outloud:
Craftsman style router will fit Ryobi accesory table natively without a Ryobi aluminum plate.

Alex, it's been a while so I may be remembering things incorrectly, but I don't think that's correct. IINM, the situation is that a Craftsman router will mount to the Ryobi aluminum plate using the factory-drilled holes; i.e., you don't need to drill new holes, as is necessary to fit most other brands of routers. I don't think it's possible to dispense with the aluminum plate entirely, because the bosses cast into the accessory table to accept the plate aren't in the right place for the router to mount directly.

But you may be on the right track. What one COULD do, I think, is fabricate a custom base plate in the same size as the Ryobi aluminum plate, and mount the guide bushing to that. A lot of BT owners who don't have the factory Ryobi aluminum plate have made their own substitute, using plastic or plywood or MDF. This would take things a step further, by machining the center hole to accept a P-C style guide bushing. The only caveat I can think of is that the collar on the guide bushing would have to be long enough to reach through the hole (with suitably-sized red plastic insert) in the accessory table. The bushings with collars that are only about 1/4" long probably wouldn't work.

[vaking]

Larry, You are correct. Aluminum plate mounts to accesory table with 4 wide-set rectangularly located screws, router mounts to a plate with 3 closer positioned screws. It had been awhile for me too since I used router in accesory table.
Thanks.

[jdon]

Thanks for above comments.

I like mpc's and c'man's idea of an overlay sheet- I'm thinking 1/4" hardboard would work. I'm thinking that I could drill the recess and hole to fit the Porter Cable type bushings in the sheet, but keep the router mounted in the aux table. I can use my centering cone tool to fine tune the position of the sheet, and clamp to the aux table at the edges when centered. Not permanent or elegant, but adequate for my needs at the moment.

Unless I'm not visualizing correctly, the issue I see with base plates (mine does fit PC bushings) is that the base and/or mounting plate mounts on the bottom of the aux table, so the bushing would not be flush with the top of the aux table. The recess and mounting hole really need to be at the surface.

[pelligrini]

If the bushings are needed for just a one time thing, I'd just fab up a quickie temporary router table out of scraps use my router baseplate that already has a bushing hole.

The sheet as posted above sounds like a practical solution. Make sure your clamp placement doesn't get in they way of your workpiece flow. I doubt you're planning on using a router fence with the bushings.

[LarryG]

Unless I'm not visualizing correctly, the issue I see with base plates (mine does fit PC bushings) is that the base and/or mounting plate mounts on the bottom of the aux table, so the bushing would not be flush with the top of the aux table. The recess and mounting hole really need to be at the surface.

That's what I meant when I said you'd need a bushing with a long collar. Some brands of bushings are short, typically 0.240" to play nicely with the 1/4" materials that are commonly used to make patterns. Other brands have collars as long as 1/2" or so. You'd need one of the latter to make what I described work, else the collar wouldn't be long enough to extend through the accessory table's top.

On reflection, what mpc proposed is probably the best answer if you'll be doing a fair amount of this type work; or pelligrini's quick-and-dirty idea for a one-time job.