gvijil wrote:I also, forgot to mention that to cut the roughing cut, I used ( 2) 3 1/2 inch length 1/4 inch diameter end mill bits , and (1) 3 1/2 inch length 1/8 inch diameter ball nose for the finishing cut. I purchased these extra long life & length bits that are spectra coated from ToolsToday.com.
Firstly, it looks good, nice job.
Your cut times are ridiculous and the reason is apparent. Why in the world are you ROUGHING something that big with a 1/4 diameter end mill? I have posted some larger work here and a video using a 10mm end mill for roughing that is running at a 10mm depth of cut and 350 IPM. I was also cutting pine, but I glued my own up which cost me about $15.
There is no reason to finish that entire piece using a 1/8 ball nose end mill. The vast majority of it could be done with a large endmill. For instance, most of the model (the phoenix) is sunk well below the upper surface. That could be a pocketing cut wasting away lots of material quickly, the same goes for the area beneath the lettering. The entire background could be pocketed around the model with a large endmill. Way, WAY faster. The idea is to waste away as much wood as you can with the biggest tool you can possibly use. Then start using the smaller stuff. I cannot imagine roughing that entire job out with a 1/4 end mill. Your feeds had to be incredibly low because you had a small tool sticking way out past the collet.
Not beating up on you. That was quite a project to undertake and it looks good. BTW, your friends are the cheaper chinese HSS end and ball nose mills. When cutting pine they do a better job than carbide, they are sharper. It takes quite a bit of planning to do thicker work like that but it saves a tremendous amount of machine cutting time not to mention tooling.
One of the issues with work like that is the large roughing end mill leaves does not get into some areas at all. That is ok, what I do is then follow up with a smaller ballnose mill in a roughing cut that is set so it will make only one pass over the piece. There have been times when I needed to do that twice, but it goes fast because the stepover is fairly large and the feedrate is cranking at 300+ IPM.
Here is a link to the video I mentioned above:https://www.youtube.com/watch?v=tFA_1PJS32U&t=23s
Notice also that I created a "gutter" around the outside of the piece so I did not have to use extra long tooling. Also made sure to put a draft on the model that was slightly larger than the angle on the tapered ball nose bit used to finish it.
Looking forward to seeing some of this type of work, like I said, nice job.
"If you see a good fight, get in it." Dr. Vernon Jones