Pattern cutting on Rout table. Help!

[rgum]

Hi All. Rgularly at work I cut shaped shelves for pantrys. You know, Shelf patt placed on top of blank to be cut and a short diam collar around the bit. Away i go.
Soon I will own a Router table. I need advice on which type to buy also.
I am going to have a winder on it too. Change bits above the table. $6oo or less I hope. Plus the Router ha he.

Can I cut a rounded, shapely pattern chair side ( kiddies chair ) with just a freehand pin and obviously no fence? Bearing needed I think?
Blank on the bottom ( contacting with cutter ) and then original on top in contact with bearing?

Any pics to share or sites?

Thanks Tony. :p

[Tex B]

That's the normal way, Tony. A router bit with a bearing (usually) at the top. Raise the bit until the bearing is just above the workpiece, attach the template to the workpiece (I use double sided sticky tape) and away you go. Usually best to cut close to the line with the bandsaw or jigsaw, and just trim the last mm or 2 with the router bit.

For templates, I normally use 6mm MDF or similarly inexpensive but stable stuff.

Tex

[Tex B]

Here's the first pic I found. It shows a commercial template used for cutting radiuses (radii?). The template can be home made in whatever shape you want.


Tex

[bsrlee]

You may actually need both top AND bottom mounted bearing bits - reason being with curved parts to be routed, somewhere you are going to be routing against the grain, which leads to tearout.

Basically you have to flip the piece over and change the bit (or have 2 routers & tables, 1 up & 1 down bit), or rip the template off & try to stick it back on in the correct position which isn't easy. Most 'experts' I have read go for 2 bits, leave the template in place & flip the work over.

If you are only going to rout MDF or ply, or straight shelves, then no problem, but as soon as you get into intersting shapes, like chair sides, then you have to be able to flip it.

I have a nagging suspicion that I have seen a 'new' router bit with top & bottom bearings so you can go with the template on top or bottom without changing anything- can't remember where tho' - could have been Lee Valley or Rockler.

[Stuart]

Can you get a spiral bit with a bearing - that'd help wouldn't it?

[bsrlee]

I've already replied by PM to rgum, but I'll post the info here so anyone interested can find it.

I just got the latest Lee Valley cattledog this afternoon, and it has the bit I was thinking of - 16J04.90 is the part number for the 1/2" bit, they also make a 1/4" version, the 1/2" handles stock up to 1.25" (32mm-ish) but the 1/4 only does up to 5/8 (16mm-ish).

Very easy to use - you just adjust the bit up and down with the router and flip the piece being routed over - no need to swap over bits or rip off & re-stick templates.

[aniceone2hold]

Although I haven't seen one, a member of www.routerforums.com (http://www.routerforums.com) mentioned a "compression" cutting bit for trimming plywood with no tear out top or bottom. It sounds like an elegant solution.
Rgum, look at the potty chair I posted in another thread. This is done following a simple pattern as you described, and can be made as a "time out" chair, or with the additional cutout and bowl + supports a potty chair.

[Gwhat]

Can you get a spiral bit with a bearing - that'd help wouldn't it?

Stuart

Whiteside have a solid carbide bit with a bearing and a UP/Down Spiral set up, I will add a few to our next order and let you test drive one.

See pic

Regards

The Woodworker