Box corner mitre jig

[colinc]

Hi,

I have been meaning for a while to make a few boxes with mitre corners. Past attempts have been less than perfect and gone to the bin. I don't have a good table saw so sawing isn't an option.

I decided to make a bit of a jig for the router table to see what could be achieved. Photos below hopefully explain it. The jig is simply a platform set at 45 degrees to which the work is clamped. It references the table edge and after adjustemt cuts mitres quickly and accurately. I have a few spacers that fit between the fence and the table edge which allow me to take increasingly smaller cuts as I approach the finished length. The cutter is a Trend 1/2 inch worktop bit. Initial tests seem promising.

I just need to devise some guarding and I'll be very happy.

The whole thing is made of 10mm ply and a few oak offcuts. After a bit of tuning it is very accurate and the results very good. The small steel rule is set into a rebate and held with double sided tape after a bit of 'calibration' on some scrap and helps repeatability.

I just thought I'd post the pictures in case anyone else has a similar need.

The idea is surely not original but I sadly don't recall what I have read that gave me the idea.

regards

Colin

 

[Philly]

Nice job, Colin.
Look forward to seeing it in action,
Philly

 

[brianhabby]

This looks like the perfect solution. Even if you had a table saw it is not easy to get perfect mitres.

Now you just need to make one with a 22½% mitre for eight sided boxes....

regards

Brian

 

[gwaithcoed]

Well done Colin, must have a go at making one.

Alan.

 

[nickson71]

Nice jig ....... I may make one too

 

[woodbloke]

Colin - nice jig - I've done some deep (65mm) picture frames by using a 200mm disc sander with an accurately set up 45 deg fence - just another way of achieving the same result. If you intend to make some boxes a useful little jig to make which would run on your router table would be one to cut some splines for reinforcing the mitre, assuming that you've got a smallish cutter, only a couple of thoughts - Rob

 

[colinc]

Thanks for the comments, am quite pleased with the results.

Colin - nice jig - I've done some deep (65mm) picture frames by using a 200mm disc sander with an accurately set up 45 deg fence - just another way of achieving the same result. If you intend to make some boxes a useful little jig to make which would run on your router table would be one to cut some splines for reinforcing the mitre, assuming that you've got a smallish cutter, only a couple of thoughts - Rob

Funny, but I was already thinking about how best to create a jig for splines. I have a feeling that something to use on the horizontal table would be good. It would be very handy if the same jig transferred from table to table so I could clamp the piece in and cut the mitre, then move it to the other table and do the spline shots without removing the workpiece. That way the results should be very consistent and suited to preparing small batches.

On a negative note, in my enthusiasm to test the jig I made the mistake of making some test box parts from some dimensioned sycamore stock that had been sitting in the workshop for a while. I was so pleased with the results I taped it together and brought it into the house saturday afternoon and by sunday morning it had cupped so much as to be totally unuseable

Saturday those mitres were a perfect fit

My own fault I know, and nothing important was lost as it was only a test of proportions and to see what the spalted beech/sycamore combination looks like. Just another entirely predictable wood preparation error. I'll let it dry out, flatten it and recover something from it though. The nice thing about boxes is you just use whats to hand and make the best of it. And if the first attempt fails you can often make a smaller box out of it.

regards

Colin

 

[woodbloke]

Colin - timber for that lid looks stunning - Rob

 

[dedee]

Colin, shame about the box but I expect you can recover it if even the box becomes a little smaller.

The only time I have cut splines in mitred corners I used the TS (without guard nor riving knife ) I cut a lump of 4x2 at 45 degrees then held the box to the block and pushed the whole lot over the blade.


Andy

 

[colinc]

Interestingly, the sides are slowly flattening. I think that when I brought it in and stood it on a table it allowed the outside to dry faster than the closed interior so causing the distrortion.

Another lesson learned and shared!

Colin

 

[colinc]

Rob and Andy,

Sorry I realised that we were discussing different things (I think). I was looking for a way of machining a slot for a pair of hidden loose tenons in the base and lid sections rather than sawn slots for veneer type splines visible from the outside.

Thanks for the ideas though.

Colin

 

[colinc]

Colin - timber for that lid looks stunning - Rob

I have about six pieces of that which just cry out to become box lids, hence the experimental one. They came from truning blank that I bought from Craft Supplies. It was quite moist when I bought it but I split it into 15mm sections and left for 12 months or so to settle down.

Colin

 

[j]

I had a similar idea the other day,
but as I haven't even built the router table yet I didn't design it or anything, now I don't have to

Looks very useful. I think I based the idea on the birdhouse shooting board in one of DC's DVDs