Cross cut jig

There are plenty of designs for a cross cut jig out there. I have a couple of extra requirements: My saw has a limited depth of cut: 55mm and the motor protrudes from the foot, with about 10mm clearance. This means most of the wooden rail designs aren't suitable. They also require that you set up everything perfectly square: there's no adjustment. I'm a pretty rubbish carpenter. That's why I want the jig. I don't think that approach will work out for me.

I think I can use t-slot to make everything adjustable, and perhaps even be able to add a mitre fence.

Anyway, here are my requirements:

  • Cut shelving up to 400mm deep
  • Cut timber up to 47mm thick
  • Cut t-slot profiles (20mm)

The shelves are going to be 15mm thick, so an intermediate goal could be to cut something t-slot thick (20mm), and then upgrade it later.

I've experimented, and found that 1/2x1/8" aluminium angle will support the weight of the saw over the required span (500mm) without much flex, so I only affect depth of cut by 1/8" (about 3mm), so I can comfortably manage 47mm timber.

I've built the low profile version, and here are some pictures:



I cut the fence in place, using the new aluminium/plastic blade. It made light work of it, and gave a reasonably clean cut. I'm certainly thinking this will work out. This should mean the fence tells me exactly where the cut will be.

Here's a picture of the many toothed aluminium/plastic blade:

These are quite affordable on e-bay: about £20. The price seems to go up with the tooth count which is unsurprising. It means that for larger saws, a suitable blade is very expensive. It seems like this is a suitable blade for shelf cutting, and will probably be fine in thicker materials, if a little slow, so this will just be the blade I use from now on.

My saw is 1050W, while my jigsaw is 700W, so there is a power difference, but the circular saw blade removes twice as much material, and yet cuts effortlessly, in a fraction of the time. I guess it's just way more efficient.

The main cost is the t-slot. Here's a shopping list:

  • 3m 20x20mm i-type slot-5 cut to 3x700mm, 2x250mm, 2x50mm.
  • 210mm of 20x40 i-type slot-5 (for the fence)
  • 10 x M5 slot-5 nuts
  • 6 x M3 slot-5 nuts

You can get the above from Motedis for about £15 + £11 delivery. Of course, if you buy some more lengths, you will have an easy and accurate way to cut them to size for future projects, and the postage won't seem so bad; which is the point of the project, really. You will also need

  • 10 x M5x6mm button head allen screws. I used flanged ones. A bit one in five didn't fit.
  • 6 x M3x6mm counter sunk screws.
  • 2 x 800mm 1/2x1/8" equal angle

It will probably cost £20 to get that lot together on Ebay.

That seems not bad. T-slot is as cheap as using timber. It's way more accurate and forgiving. The result is easily adapted, and the components can be re-used. So if there were a premium, it would be worth it.

I think I'm going to make a desk using it now.

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