Real Router Basic Question

[leevis]

I have a 40mm worktop I want to cut. I have drawn a line where I want the cut to be made. What is the measurement for working out where it will actually cut?

I will be using a 30mm sleeve so I am guessing that that I need to put the router 15mm away from the line and then half the radius of the cutter? if the cutter is 12.7mm then then I would need to put draw a secondary line 15mm plus 6.35mm away from the line I want on the inside of the cut?

Draw line and put baton 21.25mm away from the cut line (on the inside)

This sound about right?

 

[big-all]

the guide bush is only used with a suitable matching jig you run the side off the router base against a baton
look up routing worktops

 

[leevis]

Aaaah ok

So mine is 165 in diameter so half that is 82.5 plus half of 12.7 is 6.35

82.5 plus 6.35 is 88.85 lets say 89mm away from the line I want to cut and use a baton not guide bush

 

[big-all]

i assume you have a half inch router and a 52mm long specific worktop cutter

the middle 2 cutters cutters in this box
random example
https://www.screwfix.com/p/shank-kitchen-worktop-cutter-set-4-pieces/9701x

 

[Deleted member 174758]

I have a 40mm worktop I want to cut. I have drawn a line where I want the cut to be made. What is the measurement for working out where it will actually cut?

I will be using a 30mm sleeve so I am guessing that that I need to put the router 15mm away from the line and then half the radius of the cutter? if the cutter is 12.7mm then then I would need to put draw a secondary line 15mm plus 6.35mm away from the line I want on the inside of the cut?

Draw line and put baton 21.25mm away from the cut line (on the inside)

This sound about right?

No. 30mm guide bush and 12.7mm (1/2in cutter). So the difference betwen them is 30 - 12.7mm = 17.3mm. The offset from the edge of the cutter and the outside of the guide bush is therefore 17.3 / 2mm = 8.65mm.

So when you set up your straight edge it should be on the retained material side 8.65mm set back from the actual cut line. The router should run on top of the straight edge with the straight edge to the left and the cutter to the right, moving the router away form the body. I'd also recommend making an initial cut with a hand or circular saw to within about 3mm of the cut line to reduce the amount of work the cutter and router have to do as well as reducing potential for a climb cut occurring, and I'd recommend making the cut in multiple passes

Edit: It can be a lot easier if not using a worktop jig to actually a buy a metric cutter, such as a 12mm diameter one. In that case the offset would be 9mm (30 - 12 = 18, 18/2 = 9) which is a bit easier to measure

As an aside, if your worktop has a rolled or profiled edge you will need to form some type of mason's mitre joint as opposed to doing a straight cut

 

[leevis]

Yes and yes

 

[Deleted member 174758]

Yes and yes?