Fool-proof flush-trim method?

[Robin Dobbie]

I can't get the plane to work with the oak I use that has grain in whatever direction. Card scrapers don't work for the same reason, but also there's no way to control depth.

Using the router and a flush trim leaves a bearing groove. (http://tinyimg.io/i/58Fdm0w.jpg) At any rpm or bit or router I have. Maybe they're all dog crap and have balance problems?

I think using a router with a jig like this (http://tinyimg.io/i/uOE8oyf.jpg) only works if the ply is perfectly flat.

Using a table saw and an aux fence like (http://tinyimg.io/i/FH7wPbq.jpg) this only works if the ply is perfectly flat.

I suppose my next step would be to buy a new router and bit and see what happens.

[Jamie Buxton]

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.

[Robin Dobbie]

Wow those are neat. But yeah, that's a bit much for me. Saw a Lamello and started getting the feeling I got when I bought the Domino. Clicked away immediately. Whew.

[Lee Schierer]

What router bit are you using? I have flush trim bits that leave no marks at all.

[Robin Dobbie]

What I've just done for my current project is get the edging trimmed to less than 1/16" with the table saw and an aux fence, then using the router and bit I have trim as flush as it would get. For some reason the A face of the ply would not trim flush. Although the A faces of this ply weren't getting bearing indentations, so that was nice.

I was able to finish with a card scraper gently pulled along. No bending the card with the thumbs, just keeping it flat, and the majority of the scraper over the plywood as a guide, but almost all of the pressure at the edge. Most of what came up was powdery. I believe if I got aggressive enough to make shavings it would tear or take too much off the paper-thin veneer. I actually went ahead and did that, on the bottom panel, luckily.

[Osvaldo Cristo]

I never used that but I imagined a lunch box planer or even a heavy duty one could help.

If you have to trim in a single side a flat piece, just use the opposite face from trimming as the reference and pass the piece thru the planer. If you have to trim both sides, support one of the sides temporary with a flat piece of wood in order to have the surface as reference and trim the opposite side followed of other side after remove the support.

It looks simple and "fool proof".

All the best.

[Robin Dobbie]

This is a plywood project, and it's thin and a bit warpy so using the planer is out. I have edging on all four corners, so even if the ply was perfectly flat and the veneer not paper thin, the planer wouldn't like one of the two orientations of edging. A drum sander would be nice, though. Someday.

[mark kosse]

How about a spiral flush trim bit?

[Wayne Lomman]

Use a laminate trim router. They are manufactured for this purpose as well as thinner edge strips. It has an independent and adjustable guide wheel that leaves no marks. I have done actual thousands of metres of trimming this way when working in a shop that refused to replace the edgebander that would not trim accurately. Cheers

[Brian Holcombe]

This is an easy job for a hand plane.

[Robin Dobbie]

How about a spiral flush trim bit?

The cut isn't the problem, it's the bearing sporadically indenting the veneer. I've seen larger flush trim bits, so they may be less likely to cause damage due to the larger mass being more difficult to imbalance, and the force being spread over a larger area?


Use a laminate trim router. They are manufactured for this purpose as well as thinner edge strips. It has an independent and adjustable guide wheel that leaves no marks. I have done actual thousands of metres of trimming this way when working in a shop that refused to replace the edgebander that would not trim accurately. Cheers

Can you go into more detail? I thought laminate trim routers were just *smaller* routers? I'd love to see a video of this guide wheel in action. I just spent 10-15 minutes looking at offset bases and various brands but my google fu must be at white belt levels.


This is an easy job for a hand plane.

I've seen people use hand planes to trim edging. But I don't understand hand planes well enough to be that careful with them. I only have one plane and I haven't flattened the bottom. I think that could be why I have difficulty with it randomly grabbing too much.

[Brian Holcombe]

It’s grabbing because you’re hitting grain reversals. The fix is to prep and set the chip breaker. I set it closely for work like this, very closely.

Also, the blade needs to be quite sharp.

This is the tip of the iceberg, indeed, but working it out for this will provide much insights to later use.

[Jim Morgan]

If this is edging you have cut yourself, it is worthwhile to take the time to select straight-grained stock so you do not encounter the grain in "whatever direction" in the first place.

A fine wood file, skewed and held at a slight angle to the surface of the plywood, will do the trick. Taking light passes, you can approach in whichever direction is the most convenient.

[Robin Dobbie]

It’s grabbing because you’re hitting grain reversals. The fix is to prep and set the chip breaker. I set it closely for work like this, very closely.

Also, the blade needs to be quite sharp.

This is the tip of the iceberg, indeed, but working it out for this will provide much insights to later use.

I've spent almost $200 on sharpening supplies, but I still haven't gotten or made a honing guide. I was able to get shavings from a hand sharpen, but I think this kind of thing could use the guiding touch of a honing accessory. Plus I still need to flatten the plane sole. It's a contractor-grade Stanley and it's quite dished. And I need to make a new tote. So hand plane is out for this project.


If this is edging you have cut yourself, it is worthwhile to take the time to select straight-grained stock so you do not encounter the grain in "whatever direction" in the first place.

A fine wood file, skewed and held at a slight angle to the surface of the plywood, will do the trick. Taking light passes, you can approach in whichever direction is the most convenient.

That's always a good idea. Sometimes hard when I have panels like the ones I'm working with that are 52" long. There's going to be at least something going on along its length.

All my files are made out of metal, but I'll keep an eye out for a fine wood file! :D

[Vince Shriver]

Whenever it's practical I like to over cut the dimensions a tad, then use my jointer and/or table saw to trim to the required size. Otherwise I use a trim bit with a bearing at the bottom, or my route table with the bearing over the cutters. I use Whitside bits because they are quality tools, if that's useful for you.

[Bohdan Drozdowskyj]

Using the router and a flush trim leaves a bearing groove. (http://tinyimg.io/i/58Fdm0w.jpg)



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/boschtools-ocs/palm-routers-pr20evsk-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 (http://tinyimg.io/i/8LRgQD7.jpg) which I think would be less stable than the way I'm doing it now. (http://tinyimg.io/i/23CMA88.jpg)


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/boschtools-ocs/palm-routers-pr20evsk-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.

http://tinyimg.io/i/OV7AtDa.jpg

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? (http://tinyimg.io/i/LfUPPJn.jpg)


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:

389765

Something like this takes less:

389764

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.

http://tinyimg.io/i/HWf3ijh.jpg

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.

[Wayne Lomman]

Robin, here is a link to the Makita version. I neither confirm nor deny that this brand is good, they just have clear images. The key design feature is that the guide wheel is entirely independent of the cutter. This allows you to adjust the cut to as close as you dare. It also removes the risk of friction marking from cutter bearings. It is the tool for the job. It is small enough to use one handed. All the rest are the hard ways to do the same job. Like any task, practice on a scrap first. Get one of these little routers and you will wonder how you ever managed without one. Cheers
https://www.makita.com.au/products/power-tools/categories/specialty-woodworking/3707fc-6-35mm-1-4-laminate-trimmer

[Joe Jensen]

I used a router and flush trim bit for years. I eventually made an L shaped bracket that I clamped on the opposite side from where I was cutting to function as a shelf to help stabilize the router. I found that imperfect results were always because the router was difficult to hold perfect. I considered making a jig that would hold the router perfect, and also a router like Makita with a stabilizing bearing. I eventually found a like new Cantex lipping planer that I was able to buy on an auction site for just over $300 with shipping. The Cantex had a learning curve too but it's really really good. If you have space in your shop, maybe a jig like a router table that would hold the router horizontal and fixed, and a table that you would slide the wood over? It would need a micro adjust but it would be even better than a Cantex I think.

[Wayne Lomman]

Laminate trimmers are simple and quick to set up. They have be when using them to make a living. They are made this way so that you can adjust for straight or bevel cutters and different thickness laminates and edge strips. They really are designed specifically for this type of application. I don't know why so few appear to have heard of them.

If you have a router table, use the same principle - a fixed bearing surface separate to the rotating cutter. This principle is used on spindle moulders as well. Cheers

[glenn bradley]

If I could get that sized bearing I could just make something to go on the router table.

The problem with flush cutting trim on the router table is as you described earlier. The long fence contacts a long section of the all-to-irregular plywood surface. The small bearing can better ride the hills and valleys of the plywood surface. Wait, I may have gone off base. Do you mean to use the bearing as a guide but, mount the bit in a router table?

[johnny means]

A couple of really rough sketches of a "straight line trimmer".

[Brian Holcombe]

He's building a four sided (or at least one corner) panel, so that sort of thing won't work. Otherwise it seems like something like that would be really easy to setup with a router table or with a large auxiliary fence on the normal router.

[johnny means]

Why would a jig like http://tinyimg.io/i/uOE8oyf.jpg require perfect flatness?

[Brian Holcombe]

It’s going to lift when you run over the adjoining edges at the corners.

[Robin Dobbie]

The problem with flush cutting trim on the router table is as you described earlier. The long fence contacts a long section of the all-to-irregular plywood surface. The small bearing can better ride the hills and valleys of the plywood surface. Wait, I may have gone off base. Do you mean to use the bearing as a guide but, mount the bit in a router table?

Yeah I was thinking either remove the bearing or change to a straight bit, then mount a bearing attached to the table just over the bit. I started shopping for bearings but I realized I have some 13mm bearings already. 1/2" is 12.7mm so close enough. I can make it so I can change how close the bit gets by slightly angling my direction askew.

I think I like everything about my current setup (http://tinyimg.io/i/23CMA88.jpg) except the unpredictable bearing digging. The router is in the table, and the work piece is held relatively stable at 90 degrees with the free fence.

[Robin Dobbie]

Why would a jig like http://tinyimg.io/i/uOE8oyf.jpg require perfect flatness?

It might work if the distance between the handle and the cutter were shorter. The smaller the router footprint, the less opportunity for the plywood warp to affect things in a negative way. The one I made was a little shorter, but not shorter enough. From one piece to the next the bit was just barely above the veneer to digging in. I was able to repair it, and that was the bottom inside rear, so no permanent harm done.

[johnny means]

It’s going to lift when you run over the adjoining edges at the corners.

That's why you do the long edges first then go back and hit the corners.