EDIT 17/02/2020 : I uploaded all files separately. All with V10 version number.
Here's the list and some infos :

• Body V10.stl : the main body. Prin it solid, with at last 8 walls and 40% infill.
• Side panels V10.stl : they're the "legs". if needed separate them in slicer and/or rotate them (25 degrees) to align them along the X axis.
• spacer - bearing 22x8x7 V10.stl : a new spacer made for 22x8x7 bearings (8mm drill). Split it on two parts in your slicer, it will be easier to print. And use it like a unique piece, no prob with that.
• Spacer - bearing 30x10x9 V10.stl : the original one for 10mm drill.
• Crosshair V10.stl : removable crosshair to align the tool on your mark.
• Self centering dowel jig V10.3mf : 3MF file containing every file above, including splitted spacer - bearing 22x8x7 V10.stl

You can make new spacers for your own needs. Just make them 29.8mm large and remember the whole cylinder you need to fill with it (and the 2 bearinbgs you'll choose) is 29.4mm

You'll still need 2 screws (M6x55) and rubber to protect your wood.

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EDIT 19/10/2019 : I added file "Gabarit de perçage auto-centré v7.stl" wich contains 2 differents legs to fix the jig with one clamp. (see first and last pictures)
Not shown on pictures but I also added some rubber to the legs, to prevent damages on the wood.

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I needed to drill a 10mm hole, 70mm depth. This will give you a 30mm heigh guide to drill without accidentally going outside of the wood.

You'll need 2 screws (M6x55) with nylon nuts. And two bearings 30x10x9.

The 3 little parts need to be printed at 0.2mm height, the main body must be printed at 0.3mm height.