# Edge trimming jig for the router table



## sploo (11 Jan 2015)

This is a relatively simple jig, that was created because I needed to trim the edges of an end grain chopping board. It was made quickly from bits of scrap I had; hence the hole in the top sheet (it's not an intentional feature!).

I put a length of ~44mm square timber along the front edge of my router table (trying to find the straightest piece I had), cut a sheet of 6mm MDF, and screwed it to the timber. The width of the MDF sheet was such that it would just foul a 1/2" router bit coming up from the centre of my table.

I then ran the jig, holding it against the front of the table, and used the 1/2" bit set just high enough to trim the MDF perfectly straight.

Using a framing square against the newly trimmed edge, I screwed another length of timber on the top side of the MDF, ensuring that it was perfectly square to that edge.







The timber on the top of the jig protruded beyond the trimmed MDF edge by less than 1mm. The jig was then run along the table again with the bit extended to its full height, to trim the end of that timber flush with the MDF. The thickness of the timber was obviously chosen such that a fully extended bit would be tall enough to trim it completely.

I then added a pair of small toggle clamps I had, and finally put a coat of shellac sanding sealer on the bottom of the MDF and table side of the bottom timber, a light sand, and then applied a coat of Liberon Lubricating Wax.

I was then able to clamp the cutting board - pushed up against the top timber (with a couple of shims to keep it held tight under the clamps). Care must be taken to ensure no part of the workpiece extends more than ~0.5mm over the edge of the MDF (otherwise it's going to give the router a hard time).






That trims the edge perfectly flat/smooth, plus it ensures it's square to the face that's pushed against the top timber beam. Then I spun the board and repeated until all sides were smooth.

The fact that the router bit is perfectly flush to the end of the length of timber on the MDF top supports the work piece, and prevents tearout at the end of the cut.

As I was cutting across the grain in this instance the quality of the cut wasn't perfect, but with a sharp bit it was more than acceptable after a bit of sanding.


----------



## chippy1970 (11 Jan 2015)

A nice simple idea


----------



## sploo (11 Jan 2015)

chippy1970":v6fhpj8t said:


> A nice simple idea


Thanks. Assuming the router bit is perfectly square to the table, it's a bit like a poor man's jointer (~50mm capacity max). It will however get one face square to the face that's against the top timber, so you can square up a board.

The write up of the board itself is now here: my-first-end-grain-chopping-board-t86198.html


----------



## 8squared (12 Jan 2015)

Simple but looks really affective... I'll certainly be making my own smaller version, will be useful for dad is on small works I've been wanting to do.

Thanks


----------



## sploo (12 Jan 2015)

8squared":jx7xprh6 said:


> Simple but looks really affective... I'll certainly be making my own smaller version, will be useful for dad is on small works I've been wanting to do.
> 
> Thanks


Thanks. It worked surprisingly well for something that was so quick to make.

I've had the small toggle clamps for ages (partly thinking of using them on the CNC machine), but they proved perfect for that jig. I suppose I could have put a t-nut or insert nut on the bottom of the top timber for some bolts to hold stuff down if I didn't have them.

IRC It was these http://www.amazon.co.uk/Holding-Capacit ... B0087YBL5E "Pair 27Kg 60 Lbs Holding Capacity Metal Horizontal Toggle Clamps". They're tiny, but seem to do the job well.


----------



## jumps (19 Jan 2015)

I especially like the way the jig 'makes itself' in the order described!


----------

