Thanks for the suggestion Michael, will look at that tonight. The axe shaft is down as 80g in my spreadsheet so I think some holes could help. The supports holding the axe head to the shaft are also bigger than I intended. My main issue is probably nuts and bolts and wires - I don’t think I took account of them in my design and they are possibly contributing to the mystery extra ~130g.

In other news I made a carrying cradle out of some wood I found lying around, so that will keep the wheels off the ground when it is in the pit. I mounted the wedge, using my dremel with a carbide cutting bit to “adjust” some of the holes I put in the wrong place. I also replaced the 500rpm brushed motor with one of the brushless motors with a 300rpm gearbox on it, and it was scary! However it shook itself apart after a few “good hits” on a block of wood, so more work required. It also jumps a bit.

Finally, any recommendations for sharpening my wedge? I have access to a bench grinder, will that do the job? I did the axe using a sharpening stone, but it took ages and I think it might be too small.

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