Re: Any insight into how I can improve surface finish on this part
Originally Posted by
CadRhino
Hi Fellow Tormachers,
I am making a run of these parts in 6061 aluminum and I am not really happy with my finish results so far.
The non-corner rounded part is held .2" deep in a vise very snugly and the corner rounded side is held .5" deep very firmly in a vise.
As you can see from the photos, there are lots of tiny vertical lines left over from the cutters.
Here is what I am using;
1) Main cutting (on vertical sides) is a Tormach 1/4" HSS E.M. in an ER20 collet at 5100 RPM and 12 IPM.
2) Chamfering is done with Maritool 1/4" 4-flute carbide cutter in 1/4" dia. tool holder 5100 RPM and 12 IPM.
3) Corner round is done with Maritool .187 radius 4-flute carbide cutter in 1/2" dia. tool holder running at 5100 RPM and 5 IPM.
I originally cut the corner round at 5100 RPM and 12 IPM but it had the same line issue so I reduced the feed to 5 IPM and it is better but as you can see it still has a bunch of small vertical lines from the cutter.
Any thoughts on what might be happening or how I can get a better finish? Change the speeds/Feeds?
If just one of the tools was having this issue I would think it was that particular tool but all of the tools are creating these lines in surface finish.
I have some Lake Shore carbide 1/4" 2-flute EM's coming to see if they are better but I need to stick with the MariTool profile cutters for now.
Thanks,
Nathan
You're just running the spindle too fast. I get a great finish on my PCNC 1100 Series II. I have experimented with feeds and seeds with my machine since I got it in July 2011. I learned that at 5100 RPM, the finish on both the walls and the floor sucks, but if I leave .015 to .025 on the floor and walls for a finish cut, use a 3/8 3 flute end mill and reduce spindle speed to 3500 RPM at 25 to 30 IPM I will get a beautiful finish.
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