Dan Gelbart inspired Laser Drill Guide (OPENSCAD + STL)

A laser drill guide based on the drill guide developed by Dan Gelbart (see links below). My work on this design is free to use.

There are some other designs on Thingverse but I wanted one that would fit both my 51mm and 42.5mm bench drills, hence the flexible sides of the frame. The design houses a laser, batteries and switch in one arm and the other 'arm' is for ballast.

You will need:

• Laser dot module. This should be focusable, 12mm diameter and powered by 3-5V. Available for a few dollars online. See included photo.
• Battery compartment for 2xLR44 batteries with on/off switch. See included photo.
• 2x M3x45mm screws.
• 2x M3 hex nuts.
• Some fishing weights for balance (to make the ballast arm weigh roughly the same as the laser arm) and I used a plastic cap to close that chamber.

The laser should be focused about 100mm from the emitter so that it makes a sharp dot on the workpiece, and oriented so that the oval runs tangential to the axis of rotation so that the line created is as thin as possible while spinning.

Could probably still be improved, specifically the 12mm laser module sticks out a lot and might be able to be replaced with a smaller module, though I had a hard time finding an alternative that was also as easily focusable. Also, there may not be sufficient space in the ballast chamber for enough weights to balance the device, so that part could be tweaked.

I Printed in PETG, which I found to be suitably strong and flexible.

Links:
Dan Gelbart_Building Prototypes Dan Gelbart part 15 - https://www.youtube.com/watch?v=otSjut1iGGk
Discussion on Practical Machinist forum where Dan Gelbart himself chimes in with some tips - https://www.practicalmachinist.com/forum/threads/laser-centering-jig-for-deckel-using-dan-gelbarts-concept.292450/