Anyone ever flatten a router plate?

[keith ouellette]

I finished my new table after scrapping the last one and its pretty flat so I 'm very happy with it.

My problem now is my router plate.

it has been sitting in the makeshift table I built when I started putting my shop together with my hitachi m12v2 router attached and for some reason has defied the laws of physics and crowned in the center. I could have understood if it sagged but even with the heavy router attached to it the plate bowed up in the middle. I'm pretty sure it wasn't like that before.

so it makes a little more than a 1/32 height difference between it's center and the table. Kinda defeats the purpose of having made a flat table.

Could I make this thing flat again? maybe heating it up and then clamping it to a flat surface or sanding? I'd hate to have to buy a new one.

[Lewis Cobb]

I finished my new table after scrapping the last one and its pretty flat so I 'm very happy with it.

My problem now is my router plate.

it has been sitting in the makeshift table I built when I started putting my shop together with my hitachi m12v2 router attached and for some reason has defied the laws of physics and crowned in the center. I could have understood if it sagged but even with the heavy router attached to it the plate bowed up in the middle. I'm pretty sure it wasn't like that before.

so it makes a little more than a 1/32 height difference between it's center and the table. Kinda defeats the purpose of having made a flat table.

Could I make this thing flat again? maybe heating it up and then clamping it to a flat surface or sanding? I'd hate to have to buy a new one.


Hi -
I have had the same problem with my router plate for oh, about 15 years now... One of those "got to get around to it" projects. Mine is phenolic and has a big router hanging underneath it as well.

I was thinking I might tune up my dad's old No5 jack plane and have a go at it sometime but I am not sure how that material would react to the plane blade.

Will stay tuned to this thread and see what the experts come back with.

Just figured I'd let you know you are not alone :D

Cheers,
Lewis

[Mark Carlson]

My tenoning jig base was not very flat. I taped some large sheets of ~220 grit sandpaper to the top of my table saw (largest flatest surface i have) and ran the base over it for a couple of minutes. I ended up with a very flat tenoning jig base. You didn't mention what your router plate was made of but this should work for aluminum or phenolic or whatever.

~mark

[Jason Beam]

Shot in the dark, Is it a Rousseau plate?

If so, it ain't never been flat. They make 'em crowned on purpose. They say it's to ... uh ... well they claim it'll ... erm ... heck I dunno WHY they do that!

[Chris Padilla]

Crowning is supposed to keep dadoes/grooves the same depth throughout the cut since you are only referencing near the cutter. Imagine if a bump somwhere else in the router top cause your dado/goove to be a different depth.

[Curt Harms]

it's designed that way I think. Mine is the same way. The theory it is that a LITTLE hump at the cutter won't cause problems. A little DIP at the cutter will cause problems so the hump allows for a little "sink" without causing a low spot. I haven't had a problem that couldn't be attributed to user error:o. Someone who has one can verify this but I believe the aluminium plates are dead flat.

Curt

[Joe Jensen]

I know that at least one premium brand of router plate is purposely crowned for two reasons, 1) to offset any sag 2) to make sure that the wood always contacts the bit at the right distance from the table.

Don't obsess too much about a few thousands of an inch. If it's 1/16" or more then you need to do something.

[Vince Shriver]

If the plate is phenolic - get or make a new plate. If the plate is attached to a router lift and not removeable, or if the plate is metal, then the sandpaper on a flat surface is your next move. 3-m makes a great adhesive you can spray on a flat surface (like a jointer table, or even a piece of mdf) and you can work it back and forth with heavier grit, then with a finer grit. 3-m also makes a wonderful adhesive remover to clean up the mess if you need to. Get 'er done, good luck.

EDIT; I suggest you take whatever advice you can get from Pat; he is far more knowledgeable than most in the world of routerdom. He has written router books, makes router accessories, teaches and makes custom furniture. He knows his stuff. Vince

[keith ouellette]

My tenoning jig base was not very flat. I taped some large sheets of ~220 grit sandpaper to the top of my table saw (largest flatest surface i have) and ran the base over it for a couple of minutes. I ended up with a very flat tenoning jig base. You didn't mention what your router plate was made of but this should work for aluminum or phenolic or whatever.

~mark


Shot in the dark, Is it a Rousseau plate?

If so, it ain't never been flat. They make 'em crowned on purpose. They say it's to ... uh ... well they claim it'll ... erm ... heck I dunno WHY they do that!

It is one of the black phenolic plates but I don't know the maker.

Sand paper taped to a flat surface sounds like a good idea but now that I am working that out in my mind I am wondering if it will mess up the way the concentric rings will fit in its center.

[Wes Grass]

I doubt you can bend it flat. And if it uses inserts, since it's high in the middle you'll have a problem if you sand it down. Have to blend all of them too.

My Jessem router lift had a nice hollow in it. But the bottom details were perfect so I fixtured it by that and face milled the top. Cleaned up the insert pocket, and did all the inserts in place while I was at it. Took so much off to get it flat that I had to recut the index mark for the elevation dial. And most of their logo is gone now too.

Rather annoying that with all the machining they did on it they didn't bother with the most important part, the top face. I guess they didn't want to lose the 'finished' surface of the phenolic.

I'd look at the aluminum versions if I were doing it again, and take a straight edge to the store with me.

[keith ouellette]

Crowning is supposed to keep dadoes/grooves the same depth throughout the cut since you are only referencing near the cutter. Imagine if a bump somwhere else in the router top cause your dado/goove to be a different depth.


it's designed that way I think. Mine is the same way. The theory it is that a LITTLE hump at the cutter won't cause problems. A little DIP at the cutter will cause problems so the hump allows for a little "sink" without causing a low spot. I haven't had a problem that couldn't be attributed to user error:o. Someone who has one can verify this but I believe the aluminium plates are dead flat.

Curt

Not unusual for me but now I'm confused. If the plate has a hump in the center won't that raise the work piece up at one end while the other end sits down on the table?

I'm trying to picture that and it seems to me it would cause the work piece to feed upward through the first half of the cut and then downward through the second half.

From what i read about the aluminum plates they are dead flat.

[Myk Rian]

There is a lot of controversy over the Rousseau plate. They have a slight crown. I have one.
The theory is that you will be guaranteed to route the same depth across the entire workpiece.
Mine has never caused me problems with anything I have routed with it.

[Frank Berryman]

... if the plate is metal, then the sandpaper on a flat surface is your next move. 3-m makes a great adhesive you can spray on a flat surface (like a jointer table, or even a piece of mdf) and you can work it back and forth with heavier grit, then with a finer grit.
As Vince said, flatten it just like you would the sole of a plane. You'll know your getting close when your arms start to ache. ;)

[Rod Sheridan]

Not unusual for me but now I'm confused. If the plate has a hump in the center won't that raise the work piece up at one end while the other end sits down on the table?

I'm trying to picture that and it seems to me it would cause the work piece to feed upward through the first half of the cut and then downward through the second half.

From what i read about the aluminum plates they are dead flat.

Think of it as a handplane, if a plane is short, it can follow the contours of the workpiece. If it's long, it averages out the contours.

A bump in the router table at the router is a short upside down handplane.

I have to admit though, it sounds like BS to me. If it's not BS I'll e-mail General and complain that my shaper is flat.

Regards, Rod.

[pat warner]

1/32" = mile of trouble if you're routing joinery.
You can sand the phenolic but you may indeed spoil the fit of the rings.
Moreover, you may sand a taper into the thickness. Then the router will sit at some angle.
Phenolic has almost no thickness spec & an enormous amount of cup is not uncommon, taper is ubiquitous. I'd opt for aluminum but not just any alloy. Extruded stock can be even more of a problem. Ground stock is pretty flat.
Routs (http://www.patwarner.com)to .001"

[Chip Lindley]

You Can Do this Keith!! Flatten that phenoic insert with silicone carbide paper. But beware, it will not be shiny and bright when you are done! But, it will be flat! Everything is a trade-off isn't it?

[Doug Shepard]

Would heat do anything to flatten phenolic? Like maybe popping it into an oven for a while, pulling it out and sandwiching between MDF in a beefy vise? Dunno - just asking.

[Lewis Cobb]

Would heat do anything to flatten phenolic? Like maybe popping it into an oven for a while, pulling it out and sandwiching between MDF in a beefy vise? Dunno - just asking.

I recall a machinist I know that told me phonelic is basically epoxy and linen. If that's the case, I would think that heat might not work as some epoxies are pretty "set in their ways" once they cure.

[keith ouellette]

You Can Do this Keith!! Flatten that phenoic insert with silicone carbide paper. But beware, it will not be shiny and bright when you are done! But, it will be flat! Everything is a trade-off isn't it?

Dull and scratchy looking I can handle. Un Flat! I obviously have a problem with that.

It looks like the consensus is sand paper attached to a flat surface.

Thanks for the help.

[Mike Gager]

i wouldnt sand it if i were you, the insides of that phenolic stuff arent as smooth as the outsides!

im guessing the crown is intentional and has always been there

leave it alone!!!

[Jason Beam]

Yeah, i'd leave it, too.

I've got a Rousseau lift and haven't EVER had the slightest problem with that crown. Ever.

[keith ouellette]

The router plate is now flat.

I was getting ready to put some sand paper down on my table saw. Then a thought came to me.

Why not run it through the drum sander?

I worked great.

It took the crown away enough for me to get it level; almost level enough for my standards. I could have kept going but it would have made the concentric rings to thin.

I know some of you say the crown is supposed to be there but I really don't like it. I Know ground or cast steel router tables and aluminum router plates don't have that design.

If your like me and you want it flat... a few very light passes through the drum sander will do the trick. You have to put it through light and as fast as your belt will move so the heat won't build up. Thats the trick.