Dot/Stip Center Tool

thingiverse

This is a tool to help place/paint a dot in the exact center of a circular or square object (dish/saucer, approx. 5 - 19cm). It was designed to help with the hobby of 'ceramics dotting' where it is important to start from the exact center of the object. Centering is done by rotating the cross (clockwise=smaller), the studs will simultaneously slide in/outwards keeping the object in the center.After printing the tool needs some tweaking. Holes are under-sized, use 2.6mm drill and 3x8mm self-tapping countersunk screws (Farnell: 2474970). For mounting the tripod I used M3 set-screws to fit the holes (3mm) of the 'Guide-disk', leave them sticking out about 3mm, this way the tripod can easily be removed. You can also opt to screw the tripod from the bottom (countersink the holes) fixating the tripod to the guide plate (my pref.).It helps putting some PTFE(teflon) spray on the moving parts (petroleum jelly also helps).The penholder is designed for standard 8mm diameter pens. The holder has 2 parts, one fixed (A) and one loose (B). I use 2 O-rings (12x2.5mm) to keep the parts together but that fits rather tight. Using the tool without part B works also fine :-)I also added a clip-on version of the pen holder (parts A2 and B2). This version needs more skills to make. It needs support when printing. I used a piece of a paperclip (d=1.1mm) for the hinge and a spring (5.5x20mm) from a Pilot gel ballpoint for the clip (attached with a drop of super glue).Have fun building/using it.