Fool-proof flush-trim method?

[Bohdan Drozdowskyj]

Using the router and a flush trim leaves a bearing groove.

That's not a bearing groove. It looks like the cutter was set too close to the base timber or if not adjustable the bearing is slightly too small.

[Wayne Lomman]

Robin, google 'laminate trimmer' and look at images. I will post a link when I get to a computer which may not be for another 14 hours or so.

In general, this is not an unusual job. Solid timber edges require a top end edge bander which plenty of shops don't have. As a result they are often applied by hand and trimmed with a common edge trim router operated with the base plate on the edge strip and the guide wheel on the face veneer.

Edge trim routers always have a separate guide wheel. They need to trim against finished surfaces all the time. Bearing router bits will always mark somewhere as the bearing goes skids at starts, stops or where hand pressure varies.

The criticism of the edge strip Robin is using is unjustified. As he rightly points out, timber quality can vary as does grain direction. This is a common challenge in any commercial environment. Picking and insisting on perfect timber is rarely possible and environmentally questionable in many cases. What needs to be done is develop skills to work with what timber is available, which is what is happening here. Cheers

[Jim Dwight]

A larger diameter flush trim bit definitely helps. I don't think a trim router will necessarily be better. You need to keep the base flat on the workpiece, the bases of trim routers are small. I have an offset base for my PC 690 - mid sized router - that I like for this.

Sometimes if I get tense, my pressure on the router can be too high - that can cause the bearing to indent the wood. Voids are bad for this too.

I am most successful if I don't try to get totally flush with a plane or router bit. Once the difference is really small a ROS will remove the remainder really easily. When I try to get totally flush with other tools, I invariably dig in a little and damage the face veneer of the plywood.

I tried a bunch of sharpening methods before getting a WorkSharp 3000. It works well for my planes and chisels. When I am flush trimming, I use a cheap block plane (that is sharp if I expect to get decent results).

I also find it easier when I use thin edging, 1/8 or so. I use thicker edging sometimes but that increases the effort and makes it harder to stay flat.

[Edwin Santos]

I recently trimmed solid wood edge banding with a Bosch Colt using the edge trimming guide that came with the kit. I'm sure there must be aftermarket accessories that do the same thing. You might like this route because it eases using the router horizontally and the guide's bearing surface is large so you shouldn't see any grooves. Here is a link that shows the accessory I'm talking about:

https://www.boschtools.com/us/en/bos...evsk-195773-p/

Hope this helps, and if you were looking at buying one, I heard there is an new Bosch colt out, but I would also consider the DeWalt 611. The edge guide #DNP618 is fairly inexpensive and I think you could make it work with any trim router with a little ingenuity.
Edwin

[Steve Jenkins]

Check out betterly tools.com look under laminate and flush trimmers. It trims with the end of a straight cutter. I refer you to this because it’s easier than trying to explain how I made something similar years ago. Replace the round baseplate with a rectangular mdf one and glued on a sub base also of mdf similar to his. I didn’t add the roller. Just lower the cutter until the end is flush with the sub base. In use be sure that rotation is into the edge. Works like a charm with no tear out.

[Robin Dobbie]

I have an offset base for my PC 690 - mid sized router - that I like for this.

Good to know, I think I have a 6902 which may be close enough to the same thing. It's older, USA-made, but I think it's compatible. 690 may be a kit number and 6902 is a motor number? But I'm not picturing how I would use one of those bases. The part I'm trimming edge of the face, unlike trimming laminate which is parallel to the face being trimmed flush with the edge. I would have to make or buy a little fixture like this which I think would be less stable than the way I'm doing it now.

Sometimes if I get tense, my pressure on the router can be too high - that can cause the bearing to indent the wood. Voids are bad for this too.

I read several places that too much pressure can be a common cause for this. I really don't think my pressure is too high, but I'll try as little pressure as possible.

I am most successful if I don't try to get totally flush with a plane or router bit. Once the difference is really small a ROS will remove the remainder really easily. When I try to get totally flush with other tools, I invariably dig in a little and damage the face veneer of the plywood.

I did that by accident when I was doing the outer "A" faces. Not only were the outer faces of these particular panels not indenting, but in some places I couldn't get the final bit of glue and trim gone with the router. I ran the pieces through several times and increased pressure each time, but in the end I had to get rid of the last bit by hand. But yeah most of what I'm doing with this project is 1/8", but there are some 1/4" thick sections I'm looking forward to.

I recently trimmed solid wood edge banding with a Bosch Colt using the edge trimming guide that came with the kit. I'm sure there must be aftermarket accessories that do the same thing. You might like this route because it eases using the router horizontally and the guide's bearing surface is large so you shouldn't see any grooves. Here is a link that shows the accessory I'm talking about:

https://www.boschtools.com/us/en/bos...evsk-195773-p/

Hope this helps, and if you were looking at buying one, I heard there is an new Bosch colt out, but I would also consider the DeWalt 611. The edge guide #DNP618 is fairly inexpensive and I think you could make it work with any trim router with a little ingenuity.
Edwin

I'm not sure how those work. Their 360 degree view doesn't work and I've never used one. I'm just not picturing it.

That's not a bearing groove. It looks like the cutter was set too close to the base timber or if not adjustable the bearing is slightly too small.

No, the bearing and the cutters are precisely the same size. The bearing does make a dent and the subsequent cut is just a little too deep.



You can see that the gap between the work piece (left) and a scrap piece(right) is pretty uniform between the bearing and cutter. You can see there's practically no gap between the work piece and the scrap piece where the bearing and cutter did not contact the work piece.

Robin, google 'laminate trimmer' and look at images. I will post a link when I get to a computer which may not be for another 14 hours or so.

I'll wait because I looked at hundreds of images, videos, and couldn't find a single guide wheel. All I saw were tiny routers, some with offset bases for cutting laminate trim, some with home-made bases, but those all had standard flush trim bits or straight bits just like what I have.

Edge trim routers always have a separate guide wheel. They need to trim against finished surfaces all the time. Bearing router bits will always mark somewhere as the bearing goes skids at starts, stops or where hand pressure varies.

The only wheels I've seen on these are a micro height adjust wheel. Which would certainly be handy...

The criticism of the edge strip Robin is using is unjustified. As he rightly points out, timber quality can vary as does grain direction. This is a common challenge in any commercial environment. Picking and insisting on perfect timber is rarely possible and environmentally questionable in many cases. What needs to be done is develop skills to work with what timber is available, which is what is happening here. Cheers

I'm currently in a hobby environment, but it still holds. I can't bring myself to just not use a piece of oak because there's a grain reversal. As long as there's not an ugly hole, I'm going to use it. Heck, I might use it anyway and fill with epoxy.

[Steve Jenkins]

I looked at the betterly site again and what you want is the flush trimmer. I used my homemade version for years to trim edgebanding until I bought a Lamello Cantex.

[James Zhu]

I looked at the betterly site again and what you want is the flush trimmer. I used my homemade version for years to trim edgebanding until I bought a Lamello Cantex.

Lamello Cantex is definitely the best edge lipping planer, and fool-proof. But very expensive.

For a hobbyist, the edge trim kit from P Power Tools plus the dish carving bit should work.

https://www.youtube.com/watch?v=Z88bctiSUq0

[johnny means]

We use a shop made straight edge router. It consist of an 8" - 12" fence that sits below the cutter and rides against the face or edge of your material. The long fence glides over imperfections and voids while being to long to dig in anywhere. Lexan is the usual material of choice.

[Robin Dobbie]

I looked at the betterly site again and what you want is the flush trimmer. I used my homemade version for years to trim edgebanding until I bought a Lamello Cantex.

That'd be an interesting jig to see, if you still have it. Are you talking about something like the betterley 185?

We use a shop made straight edge router. It consist of an 8" - 12" fence that sits below the cutter and rides against the face or edge of your material. The long fence glides over imperfections and voids while being to long to dig in anywhere. Lexan is the usual material of choice.

How do you adjust the height of the cutter? Is the router on a lift or something? A picture would be neat, if they'll allow it.

[Martin Wasner]

Well, lipping planers are really good. But you're talking upwards of $700. Me, I carefully use a flush trim bit (the kind with the bearing in the tip) in a palm router. It works most of the time. You might need a new sharp flush-trim bit.

We just bought a Lamello lipping planer. $1800.

So far, worth every penny.

[andy bessette]

A quality carbide flush trim router bit will do this job easily. For odd shapes it can be done using a hand plane and scraper. Size the edge banding so as to leave a bare minimum of material to remove after gluing.

[glenn bradley]

In the search for something fool proof we must acknowledge that the world is always coming up with better fools .

If the router arbor is spinning well (no bad bearings) and the router bit is truly cutting flush you've got a good start. Now the only way to fail is to not keep the router flat on the reference surface or to apply so much pressure that you sink the bearing, and therefor the cutter, into the into the thin, thin ply veneer. Now the bit is cutting flush but, the reference surface is below where you want it.

The times I have had difficulty with this involved a shot bearing in my router once and a flush bit that wasn't really flush twice. Glue up some dummy edging on the same ply you are using for your project. Take some test runs to get a feel for the minimum amount of pressure required to guide the cutter along the path. You are, of course, adding something to the panel to supply an adequate width surface to run the router base on, yes?

This takes skill:

Flush Trim-1.JPG

Something like this takes less:

Flush Trim-2.JPG

Apply a strip of tape along the surface that the bearing will ride on. Mkae you cut. If you cut into the tape, solve for that issue before cutting on your keepers.

[Warren Lake]

better european employee shops here usually made custom tools. One of them was taking power planers and jigging them up to flush trim solid edging. Normally they set it so it was back a few thou and the remainder was taken off with chisel. Virutex had a specific lipping planer that was what they based their idea on, a power planer with a side jig that kept it at flush level. Lots of ways to do it but the lipping planer or custom set up were better than most of the ways. Everything works just some ways slower, more limited to the amount they remove and more prone to have issues.

[Robin Dobbie]

Robin, google 'laminate trimmer' and look at images.

Ok I see it now. I don't know why I didn't see that earlier when I searched, maybe I used a different term.



So this is like a reach-around bearing. How much of a PITA is setup? If I could get that sized bearing I could just make something to go on the router table.