Most of the work I do is smallish stuff that sits in the vice mounted on the table. I recently started doing multiple parts the span most of the table and was finding parts were coming in slightly thinner or fatter. Since it is thin, long pieces of metal stock that can only be supported at the ends I thought it might be from the metal warping at various degrees and might be just one of those things where I'd have a certain amount of waste parts because of factors outside my control, but on the second run I noticed the parts followed a similar pattern depending on where they were on the table.
I put my DI all over the table and turns out the table is out of the spec in a couple places, as much as .020" differential from highest to lowest. The table isn't the actual table... it is a an aluminum 6" riser that is mounted to the actual table. It has been on there forever and has never been trammed since it was installed and precision ground.
Now I'm not doing super precision stuff, +/-.005" on any given part makes me happy. I would normally just throw an EM on there and program it to make the nice skim cut to get it in spec but the problem is the edges/corners are well beyond the range of travel. To be able to hit the further parts out of reach from the spindle (corners/edges) it requires a 5" radius tool to reach out there. I don't have any fly cutters close to 10" in diameter so what I did was make one using a stout carbide tipped boring bar by making an adapter that it could be mounted in at an angle of around 20 degrees or so.
It works fine except the finish is not great, maybe akin to vinyl record. I know the carbide is probably not ideal but I didn't have a HSS boring bar in that size. I feel like the carbide drags/gouges a bit more than it cuts trying to flycut aluminum. In general I never seem to get very smooth results from fly cutting even when I turn the feed super slow with a generous RPM and more than one pass, but a rarely ever have needed to fly cut anything so it could be the nature of things or something I'm doing.
What I'm wondering, does anyone have any suggestions on the best approach for this? Maybe make a different tool that holds a HSS lathe bit and put a certain profile on it? I suppose the being mostly pointed tip profile from the boring bar isn't helping. IIRC a lot of fly cutters have kind of a swooping profile where it hooks upwards a bit so it takes a wider cut?
In all reality I'm sure the results as they are now are better than before but hoping to get a finer finish. Just from the differences in the cutting actions I doubt I can cut as good as finish as with an EM but hoping to at least get it to where I can't distinctly feel the finish like I can now.
Thanks!
I put my DI all over the table and turns out the table is out of the spec in a couple places, as much as .020" differential from highest to lowest. The table isn't the actual table... it is a an aluminum 6" riser that is mounted to the actual table. It has been on there forever and has never been trammed since it was installed and precision ground.
Now I'm not doing super precision stuff, +/-.005" on any given part makes me happy. I would normally just throw an EM on there and program it to make the nice skim cut to get it in spec but the problem is the edges/corners are well beyond the range of travel. To be able to hit the further parts out of reach from the spindle (corners/edges) it requires a 5" radius tool to reach out there. I don't have any fly cutters close to 10" in diameter so what I did was make one using a stout carbide tipped boring bar by making an adapter that it could be mounted in at an angle of around 20 degrees or so.
It works fine except the finish is not great, maybe akin to vinyl record. I know the carbide is probably not ideal but I didn't have a HSS boring bar in that size. I feel like the carbide drags/gouges a bit more than it cuts trying to flycut aluminum. In general I never seem to get very smooth results from fly cutting even when I turn the feed super slow with a generous RPM and more than one pass, but a rarely ever have needed to fly cut anything so it could be the nature of things or something I'm doing.
What I'm wondering, does anyone have any suggestions on the best approach for this? Maybe make a different tool that holds a HSS lathe bit and put a certain profile on it? I suppose the being mostly pointed tip profile from the boring bar isn't helping. IIRC a lot of fly cutters have kind of a swooping profile where it hooks upwards a bit so it takes a wider cut?
In all reality I'm sure the results as they are now are better than before but hoping to get a finer finish. Just from the differences in the cutting actions I doubt I can cut as good as finish as with an EM but hoping to at least get it to where I can't distinctly feel the finish like I can now.
Thanks!