If you’re cutting a sign and the letters are artsy, then 1mm won’t matter. You can skip the finishing pass. If you are trying for a tight fit part, or measuring the result because you want precision, use a finishing pass. That is where Ryan’s 1mm came from. The tolerances.
The number you leave in the finishing pass is a different number. The hope is the finishing pass is essentially zero load, so you want it small. I have used 0.1mm even though the initial cut wasn’t that close. The first pass leaves 0.1mm plus the flex. The finishing pass goes right to the final dimension and cleans it up. You can gear the difference, but it doesn’t make many shavings.
Ok, that makes sense. The picture is horribly crooked, so I thought that might be part of the problem.
Tool deflection might be involved, which is where the finishing pass will come into play (rough cut to within x.x mm, then get the exact dimensions with a cut that doesn’t have much load/deflection.
Climb versus regular milling can also have an impact on direction of deflection, making the rough pass smaller or larger than expected.
If you are using climb milling, I’d choose a bigger finishing pass since the deflection will be towards the workpiece. For my 6mm endmill I use 0.4mm. Also, the finishing pass can be full depth to make the surface nice.
Thank you all for the advice! Definitely going to dive into finishing passes. I obviously have to get it square first too. I cant imagine that wont help immensely. I just got impatient!
Hey everyone. I’m back after a hiatus. Working on cutting @DougJoseph parametric table so that I can finally finalize my final build. Lol
Running into two things.
#1 I’ve got this weird lead in issue. And I don’t know why it’s happening. I have a 30degree lead in and a plunge of 10mm/s. Seems to only do it on the lead in. There is a tab there as well but I don’t know. It’s not the same on every lead in. 1/4 in up cut bit running 4.5mm doc and 30mm/s if memory serves me.
#2 one side of my z axis almost “hops” on the way down only. Going up is smooth. No binding. But going down I guess maybe it would be called binding and therefore hopping? Any ideas on what to check?
Thanks in advance!
Happy to be cutting again at least!
Ironically I stole the feeds and speeds I saw in one of your videos but toned down a bit. Only other thing I cant think of is maybe my work holding is a little lacking and its pulling the bit into the work enough?
The weird thing is that it only really does it in that spot. When it plunges again for a tab for instance a long the long straight edge it seems completely straight.
