Retrofitting spindle to old Router mount

I was in the process of upgrading my 2020 pro4848’s router to a spindle (non Hiteco), and mistakenly thought the slightly older plate would have the same mount holes as the Hiteco, but it is in fact only the new plate that has the 90mm x 30mm hole spacing.

So, I ordered just the new mount, and of course… the whole plate system was made larger so it’s not even compatible with the plate that mounts to the z axis. I believed I noticed it was bigger when building out our second, never machine, but I guess just never connected the dots.

So, with a little help from AVID customer service, thanks Jack! I was able to turn the drawings for the previous part into a fixture, and locate the plate directly on the fixture, as well as plan out the holes exactly. I would have done it by hand, but couldn’t find a good solution to counterboring the holes, aside from maybe just using countersunk hex flat heads. Just using a larger drill to make the counterbore gives the head less to sit on because the bottom of the hole wouldn’t be flat.

I used the corner radius endmill with a ramp entry, 18000 rpm, 100 IPM feed, 40 IPM plunge, 1mm DOC. The holes were small relative to the endmill so 40% stepover was used. Make lots of beautiful long chips, used some wd40 as lubricant and some air to clear the holes and long chips that would wrap around the top of the endmill. Turned out great, counterbore was a little deeper than I wanted, but still able to use 16mm screws to lock it in place.

The holes that were added are the two on the very bottom and the two counterbored holes that are almost inline with the alignment pin.