Using a Router and MDF template

[ged.clink]

Guys

Making a dolls house for the girls xmas. Putting about 10 windows in it..so made up a nice template from a 9mm offcut of mdf - basically 8 windows about 1 inch square in a row of 4 x 2.

Bought a template bit ( with a bearing at the top of the cutter) and off I went with my router. I am cutting through 9mm mdf with the bit...

First window went fine..Then noticed as I cut more that the bearing appeared to be reshaping the mdf template...Suffice to say, after 1 usage some of the template was wonky and cutting curvy window shapes...

Essentially the bearing was routing the edge of the template...I presume this is the soft MDF..any clues as to what wood to use to avoid this...Would ply work before I buy a bloody big sheet..

Cheers

Ged

[Weatherlawyer]

MDF is soft but you must be pressing really hard to notice a problem after such little usage. You could try plastic electrical tape f it's a one off or recut the edges and put some formica or something equally hard in as a lining. A strip of tin or some such or even lollypop or chopsticks. Whatever is hard and handy will fit the bill.

You might be able to drill out most of the orifices with an auger bit to ease the load. I don't know if if that helps?

[Weatherlawyer]

PS

You might prefer to get a router guide that follows a template laid over the work:

follower will need to run in a hole marginally larger than the one the cutter is making -by the difference in the size of the follower and the diameter of the bit.

E.g.:

If the bit is 1/8" smaller than the guide, the template has to be 2 x

1/8" larger or 1/8" larger for each edge cut. The followers come in as many varieties of sizes as the bits do. Just make sure the bit isn't too large for the one you buy.

[ged.clink]

The follower looks a perfect solution. Thanks for your advice..

Ged

[Weatherlawyer]

Take the router with you or make a note of the make and model and remember the cutter size too. Some makes will need different followers to others. Bloody silly really, like battery chargers and other manufacturing hazards.

You could screw a thin mdf plate to the sole of the router if you can't find one to fit and screw it to that.

[dennis]

MDF works. Are you sure your bearing is working? If its not rotating freely you will wear or possibly burn the MDF.

As others have said a template collar is probably better but it will leave a bit more waste in the corners. You probably want rounded corners on a dolls house if its for kids as they are easier to clean.

[The Medway Handyman]

Either bearing not working properly (common on cheap bits, or too much pressure. Coat the edge of the template with PVA glue to harden it up, that helps.

[Owain]

Could you introduce the girls to the delights of Modern Architecture and make circular windows?

Owain

[Pete C]

With moderate pressure against the guide the outer part of the bearing should not rotate.

It sounds like the bearing is sticking, try a drop of oil on it and then rout some scrap to get rid of the excess.

Also consider fitting some small aluminium strip or angle to the edge of the template to protect it.

cheers, Pete.