TESTED: Kreg mortise mate
Words and photos: Raf Nathan
This jig makes domino sized mortises at an entry level price. It uses your drill with a special long cutter supported in the body of the jig which is moved side to side to make a mortise. It makes 6, 8 and 10mm mortises with the width and depth adjustable in workpieces from 13mm to 38mm thick although you can use larger workpieces by flipping faces.
Initial set-up is straight forward fixing the jig to the shaped plywood base, attaching the lever and dust shroud. The supplied cutter is a beautiful tri-toothed spiral bit running in two bushes mounted on a sliding carriage. As you drill you sweep the handle side to side activating a clever ratchet system that increases the depth of the cutter about 1.6mm each time.
Your cordless drill supplies the power with the jig cradling the special cutter.
The sliding mechanism and fence are all beautifully made from thick milled anodised aluminium and stainless steel. The fence and cutter height adjustment system are 3mm steel running on slots with guide pins and a large lever to lock the position. In practice there is quite a bit of flex at this point.
The plywood base when fitted to the jig was not 90° to the fence initially so the first few mortises went in at an angle. To rectify this quickly I placed a few strips of blue tape on the plywood to bring it to 90°.
You set the cutter height by releasing the lever and raising or lowering the jig. There are some 1" based markings on the fence which are useful as a guide only. I found it easier to mark the mortise location on the wood and raise or lower the cutter to suit. Dialling in a perfectly centred mortise is fiddly but is also on a domino tool.
Mortise depth is set with a collar on the drill bit which is simple to locate. Again, there are some markings as a guide, but I found setting the collar a few millimetres past the 3/4" mark gave me the correct depth for a 40mm tenon.
The mortise width can be fine adjusted with two small allen screws at either side that control how much the metal bump-stops project.
To begin cutting, connect a dust extractor to the dust port which works quite well. Clamp the workpiece to the plywood base, and in my use two clamps were critical to secure this. Mount your drill and depress the centre release button and apply forward pressure whilst moving the lever side to side. It is quite simple and the cutters work well. Whilst not as quick as a domino my estimate is about 7 seconds to make one 6mm mortise which is pretty fast.
It is critical the cutter enters the wood at 90° to the edge and if not you will have joints that don’t meet on both faces. I found trial and error, and practice were needed to find the sweet spot to hold the drill when in use. Having said that in using my domino it is the same situation.
The price quoted includes one 6mm cutter – extra cutters are $129 each. Whilst the 6mm and 8mm cutters worked very well, the 10mm cutter tended to block the dust port a little making that mortise size not as easy to make.
This is a well made jig that sets you up to make standard domino style mortises at an affordable price. The work proceeds quite quickly with professional results and I would suggest the 6mm and 8mm sizes were optimal.
Test jig supplied by www.carbatec.com.au