I work with veneered material the most and I went looking for a better way to remove those stubborn tabs without tearing up the precious veneer. Obviously a router table with a flush trim bit is perfectly fine, I just don’t own such a uni-tasker.
If you flip a router table over it looks a lot like a caveman’s CNC router, so I decided to use my 3D robot of death as a lobotomized stand-still appliance.
I bolt down a piece of MDF with a relief hole near the center, lower the spindle down to the right height for the tab/material thickness, and run 'er through. You may also like to add a support post to help guide material but I’ve found it got in the way of some curvy sections so I freehand it. Still have all eight fingers (thumbs don’t count, right?). Afterward, you can’t tell a tab was ever there, and it saves so much time compared to osc tool and endless sanding.
I chose a Whiteside Router Bits 2602 Down Shear Flush Trim Bit with 1/2-Inch Cutting Diameter and 1-Inch Cutting Length [Amazon]. If I were to choose again, I might opt for the 1/2" shank model 2605. I haven’t run into an issue with the 2602 1/4" shank, but I wouldn’t mind having twice the diameter chucked up in the spindle. The down shear action is important for eliminating tear-out. You want the cutter pulling down toward the bearing. Some brands advertise as down shear but the direction is reversed…or Internet product pictures are wonky…either way, this is the right combo. I run this at 9000rpm, which is quiet enough that I don’t need hearing protection, but for longer runs I typically do anyway.
I broke down and purchased a Bosch portable router table and a flush cut bit because my vacuum table is in the middle of a rework. I didn’t even think about it. Could have saved myself a few bucks.
You’ve created a pin router mode. I did something similar with a top-bearing up-cut bit. I like your idea of lowering the bit into a relief hole.
If someone didn’t have a bearing bit, they could bore a hole for a pin and then position a down-cut bit over the pin. Pop in the pin, command to the position, and you’re in tab trimming mode. Might work with a compression bit, too.
Can you explain what’s different about this bit and method?
Tighter nesting, smaller pieces, and more aggressive cutting all increase the need for workholding, e.g., tabs. Tighter nesting means less waste which means small or narrow remnants, which can get floppy and interfere. Tabs help hold those remnants in place. Smaller pieces mean the pieces are more likely to shift. More aggressive cutting than the 60 ipm in the video means higher forces.
It would be great to cut without tabs though, so I’m interested if you can still use that bit and method in tougher situations. Is there something special about the leads? I don’t think I’ve seen those.
I have used this single flute compression bit quite a lot on 3/4" baltic birch and MDF with great success. It packs chips in the kerf so tightly that it easily supports the part as well or even better than tabs. It is limited to 60 IPM and only up to 0.8" thick material but it cuts in a single pass without having to deal with tabs afterward. Both top and bottom surfaces have no chip out and the edges are very smooth. That trade works for me but may not be suitable for some production environments. At $11 per bit you can hardly go wrong to at least try one. You need to use a 35 degree entry ramp and set the plunge rate to be equal to the feed rate so their is no sudden jerks during the cut that could break the bit. I bought several bits thinking that I would have a larger breakage rate but I have yet to break even one.
This is a situation where the cheap laminate trim router from Harbor Freight shines. It’s a $25 dedicated tab-cutting router. Drill a hole in a scrap of sheet material, screw the router to it, flip it upside down on sawhorses, or literally anything else. Dedicate the router bit and router for tab cutting and leave it in a “ready to go” state. Store it out of the way or hang it from the ceiling when not in use. Super cheap, convenient, and ready to go without any real setup.
That sounds like ‘Tab Destroyer 100’, and according to Tool Time law section 132.1478(d) sub-section (iii), 4000 > 100 which makes this 40 times more better.
