I want to thank any and all comments in advance. I really appreciate the help from the forum! I am looking for advice on how to route out fairly large parts on cnc from 1-1/2” thick wood (pine). I am including video at bottom of a recent job that will hopefully provide visual and audio of cut. Details: I am cutting 1-1/2” southern yellow pine. I am using a 1/2” straight bit. Link: https://www.homedepot.com/p/DIABLO-1-2-in-x-2-in-Carbide-Straight-Router-Bit-DR12128/100660640 This is the very first cut with this particular bit. Design is made in fusion and the basic manufacturing settings are the default for aluminum stock (there is no option for wood for some reason). The feed rate I believe is 126 inch per minute(default), but in the video I have it throttled down with control to 70% (88 IPM). My step down and step over are set at .2 inches. I am using a metabo hpt m12vcmr 2-1/4 hp router. Set at max speed 24000 rpm. I am wondering what the best way to improve the speed of these cuts would be? Should I be using a smaller diameter bit? I know I am routing a A LOT of wood with each pass and making A Lot of sawdust, but the larger diameter bit seems to a handle the cut/speed better than I have ever had with 1/4 diameter bit. Would a spindle do much better? Quality of bit make a big difference? Is there a better method to cut these parts out? Some other kind of cutter besides router? It sounds much better when it is traveling in one direction than the other. I assume this is because of how the bit engages the wood, but should I adjust setting to help this? Immediately after cut (45 minutes), I felt the bit with my hand and it was cool. Not much warmer than room temperature. So, I don’t think that I am maxing out the bit, but if I try to increase speeds very much, I get issues. Belts slip, motor stall, something and the machine gets off and ruins cuts. What is my best and most inexpensive way to cut these faster? Thanks all!
Won't increase your speeds, but try conventional rather than climb milling on wood - you will probably have less chatter and might (depending on the grain of the wood) get a better quality finish. Otherwise you are cutting chips, not overheating the bit and if you push the machine any harder you get problems, so I'd say you were at the maximum your machine can handle. Alex.
Combined with Might be the root of your issues. Belts stretch. For the heavy a cut you should be using Leadscrews
Changing bit would be easiest solution. What kind of bit specifically, and from where do y’all suggest to get them from? A lead screw may work for my x axis (4’ wide) but the x is 8’ long, I assume this is too long for lead screw and rack and pinion would be best bet? Also, what speeds could I expect if this were a “professional” machine? Thanks @Alex Chambers and @Peter Van Der Walt
Ok. I will check this out. Should I be using a different diameter bit? It seems like a waste of wood to be using a 1/2” bit. Thanks!
I’m trying to cut through 1-1/2” material. I have had a hard time finding a 1/4” bit that will cut that deep. Plus, it seems to slow Job time down bc my step down and step over are reduced to half.
Thanks! If I used a quarter inch bit, I assume I still should only use about an 1/8th inch step down and a little less for step over. Which is half of what I am doing with the 1/2” bit. Could I expect to be able to cut at twice the speed? The machine itself will do it, but idk if it will do it while cutting.
An issue I see, is that you need an extra long endmill to cut through 1.5" material. The longer the endmill, the more flex in the the endmill while it is cutting. This means less aggressive cutting. I cut with longer endmills for 3D carves. I cut at 3000-3500mm per minute with them at 1/2 the diameter's depth. But, only the first pass I make takes a full width cut. After that it is only 10 - 40% of the endmills width being removed. I would not go deeper than 1/2 the endmill's diameter with the extra long. I also don't with normal endmills. I have never had issues cutting at 2500mm/min (100ipm) with any endmill in any kind of wood and I use a Makita 1hp router. I do have lead screws driving it though. If my router sounds like it is struggling I just speed up the rpms. With wood, I usually start with the RPMs around 10,000 to 12,000 and adjust as necessary. When I am pocketing in wood and some plastics, I use between 70 and 90% stepover an a depth of 1/2 the end mills diameter. If I need everything to be real precise, I will do a roughing then full depth finishing pass where it removes about 1/3 of a millimeter - as long as the flutes are long enough.
great info! Thanks! I am trying to contour pieces created on fusion and cut them out of 1-1/2” pine. With the 1/2” bit it seems to do fine until it gets toward the bottom of the cut and then I often have problems where the cut gets off if I go above 60-70 IPM. I guess this is just my limit? Thanks!
It probably may be the limit. A 1/2 inch end mill is removing 4 time the material (roughly: twice the width and twice the depth since you were cutting nearly .25" deep) so if compared to a 1/4 inch you are sort of getting 240 ipm when pocketing or cutting a slot. But, my math skills are weak so I may have over estimated that.
