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WZ9V
I'm curious as to how you machined the bolt heads with the ball head mill.
I was looking at magnetic arms for a MK but they used cylinder magnets in the arms with steel balls on the effector and carriage.
Your way seems cleaner to me since it seems like it would have more surface area for the the attraction between the parts and be easier to assemble. I have a feeling my MK will be busy making parts for one of these once I get it going. I wanted to scale up to a 250mm build surface and 2020 extrusions anyway. Would the Misumi 2020 be an adequate substitute for the Bosch/Rexroth extrusions? I already have some 360mm and 750mm handy.
They do work really well. I made a simple jig out of a scrap piece of 3mm mild steel bar. Just tapped a M5 hole in the middle of it. The steel is then clamped into my pillar drill vice. I put a 3mm round rod into the drill chuck and line it up so that it goes into the Allen socket of the M5 SHCS. I use BZP screws. Once the screw in the jig is lined up with the centre of the drill chuck I replace the 3mm rod with the 10mm ball end mill and just unscrew the SHCS when it's been milled and screw in another, etc. takes about 15 minutes to do all 12. The edge of the 'cup' is sometimes a little bit sharp so I normally smooth it's edge on my scotchbrite wheel as well. Dead easy. You only need to mill to the edge of the knurling on the screw head and this leaves half of the Allen socket free so you can use an Allen wrench to self tap the rod end into your 5mm ID aluminium tube rods.
Andy
