dowel pins & corresponding drill sizes to get a tight fit....

[HankMcSpank]

Thanks chaps....re changing the glue, my thoughts here are that the problem isn't likely to be the acrylic (the drilled hole will likely be providing a degree of 'keying' for the glue), but more likely the stainless steel dowel....probably little for the glue to grab onto.

RE stressing & cracking over time....this is of little cause for concern, as this is all for a just a cheap winding jig that I've made & I can make another quickly if the acrylic fractures - I'm more miffed that the pins presently have a tendency to work loose than worrying about the acrylic fracturing over time.

Re the increments irving mentions (ie 0.01mm/0.002mm) ....alas I can only source the dowel pins in increments of 0.05mm (& the cost/sourcing options gets out of hand if I start trying to source drills in sizes like 1.58mm!)...I therefore might take a punt & see if I can coax a 1.65mm dowel pin into a 1.6mm hole! (put the pin in the freezer & warm the acrylic in a low heat oven & then see if it fits!)