# What am I doing wrong, flush trim routing



## Zerk (Jun 24, 2014)

I got two sheets of plywood glued together, with 3/4 thickx 1.5" oak around it. 
I have a Diablo flush trim bit, bearing on bottom. 

Started out 10rpm,really wavy, 13 better. These are the speeds I used when ding edge over, or atleast the dial was left there. Do the RPMs need to be faster? Do I need to move faster?

I am glad I did this on the bottom. It is just a reloading bench so not a big deal. I use projects like these to practice stuff.

But for the most part I am happy with my edge stuff. So not sure what I am doing wrong. Most of edge stuff is on table, not free hand.

Thanks.
Ridgid combo router, using fixed base.


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## Gene Howe (Jul 10, 2007)

Are you flushing the top edge with the plywood? 
What is the diameter of the flush trim bit and it's shank?
The wider bits i.e. 1/2"-5/8" with a 1/2 shank will give you better results. Also, you might up the rpms a bit. Maybe to 15K.


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## kp91 (Sep 10, 2004)

Wavy could be two things.

First, the router is wobbling side to side on that skinny edge, and diggin deeper and shallower in spots.

Second, you could be feeding the wrong direction. If you are climb cutting, the router can be pulling itself forward and skipping down the edge of the wood. There is a good picture of this on the first link below

Climb Cutting/Chip Cutting
Router Jig; Flush-trim stabilizers


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## Zerk (Jun 24, 2014)

I tired going both directions, but one way it ran off on me. I thought you don't want it to pull you. I was cutting the oak banding, using the plywood as the guide.

With an edge over but you can do a little more and a little more. With a flush trim bit it seems to be all over nothing.


This is the bit I have DR42110. Only one they had at Home Depot. I really wanted something 1.5" deep.
Diablo 1/2 in. x 1 in. Carbide Flush Trimming Router Bit-DR42110 - The Home Depot


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## Stick486 (Jan 4, 2013)

Zerk said:


> I tired going both directions, but one way it ran off on me. I thought you don't want it to pull you. I was cutting the oak banding, using the plywood as the guide.
> 
> With an edge over but you can do a little more and a little more. With a flush trim bit it seems to be all over nothing.
> 
> ...


when it runs away on you that's the results of you climbing cutting...


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## todd628 (Mar 8, 2015)

Zerk, I believe what you are doing is wobbling the router while balancing it on the edge.
If you clamp a wider block of wood to the opposite side you are trimming it will give you more are for the router base to set on, making it much easier to control.

Have a blessed evening, and fun making dust, Todd


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## Zerk (Jun 24, 2014)

todd628 said:


> Zerk, I believe what you are doing is wobbling the router while balancing it on the edge.
> If you clamp a wider block of wood to the opposite side you are trimming it will give you more are for the router base to set on, making it much easier to control.
> 
> Have a blessed evening, and fun making dust, Todd


I was having issues with that, holding the router horizontal, instead of up and down. The piece is 30x60", and only 1.5" thick.

I'll try that next time.


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## DonkeyHody (Jan 22, 2015)

How much oak is hanging past the edge of the plywood? If it is more than about 1/4 of the diameter of the router bit, you're likely to have problems with chipping and splintering. Also, can you stand the plywood vertically on edge and let the router base rest on the edge? I think you'll have better luck holding it straight that way.


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## Stick486 (Jan 4, 2013)

DonkeyHody said:


> How much oak is hanging past the edge of the plywood? If it is more than about 1/4 of the diameter of the router bit, you're likely to have problems with chipping and splintering. *Also, can you stand the plywood vertically on edge and let the router base rest on the edge? I think you'll have better luck holding it straight that way.*


go vertical, clamp on say a 4x4 to the side not being trimmed and flush to the OS edge...
if the edging hasn't been trimmed yet on the side the rest will be clamped to rebate the rest to accommodate the edge....
you now have an expanded router rest...
a single 2x4 may even work...


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## kp91 (Sep 10, 2004)

Stick486 said:


> go vertical, clamp on say a 4x4 to the side not being trimmed and flush to the OS edge...
> if the edging hasn't been trimmed yet on the side the rest will be clamped to rebate the rest to accommodate the edge....
> you now have an expanded router rest...
> a single 2x4 may even work...


Check the second link in my post above for another easy solution


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## Stick486 (Jan 4, 2013)

kp91 said:


> Check the second link in my post above for another easy solution


that it is...
another couple of methods...

you could skip the dadoed end boards and put pieces of 2by between the shelves(?) and side clamp...


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## Zerk (Jun 24, 2014)

Since it is 5' long standing on it edge is not an option. But clamping a board, might help steady it. There was one or two areas that had a big chunk to cut. Maybe try a jug saw to get closer?

Maybe turn up the speed I started at 10k.


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## Stick486 (Jan 4, 2013)

Zerk said:


> Since i*t is 5' long standing on it edge is not an option. * But clamping a board, might help steady it. There was one or two areas that had a big chunk to cut. Maybe try a jug saw to get closer?
> 
> Maybe turn up the speed I started at 10k.


sure it is...
set on the floor and clamp it to a table leg, saw horse, work bench.... 
set it in a shop made door holding jig... use tow if you are nor sure....


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## Phil P (Jul 25, 2010)

Zerk said:


> Started out 10rpm,really wavy, 13 better. These are the speeds I used when ding edge over, or atleast the dial was left there. Do the RPMs need to be faster? Do I need to move faster?


If you mean 10,000 rpm, then WAAAAY too slow for lipping. You need to start by sizing your lipping so that it overhangs only 2 to 3mm (no more than 1/8in) either side of the material, or you'll have problems. I suspect that the trimming bit you are using is very small diameter, which canl lead to waviness because you are simply trying to take too much material off with a small diameter cutter. I'd recommend going to a 1/2in or 3/4in diameter trimmer in a decent sized (2HP+) router. Lastly get the speed UP - to 18 to 22,000 rpm. You need work support - if you think you can't support a 5ft long piece on edge you are mistaken. I routinely support longer and larger items (i.e doors) when I relip them or cut hinge recesses. The type of jig Stick shows trakes all of 5 minutes to make up from scrap with a cordless screwdriver - that or make-up a deadman for your workbench. Lastly the base of your router is tipping, so you need extra support - effectively you need to make the material wide enough to support the router base. This can be done simply by tacking/screwing a piece of 2 x 1 softwood onto the face of a piece of 4 x 1 softwood and using spring clamps to hang that on the side of your workpiece (once it's helf in the vice/jig)

Regards

Phil


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