I was just wondering how many of you put faith in G-Wizard for calculating speeds and feeds?
I broke 3x 3mm bits over the last week so thought it was time to get a bit more technical about it. However, I notice that what G-Wizard suggests is different from what I have read on this forum, mostly it uses higher spindle RPM. For example I know Jonathan likes to cut aluminium using a single flute 6mm bit at 8000RPM and 600mm/min. However G-Wizard suggests more like 13000RPM. Though actually I just noticed now, it suggests pretty much what Jonathan said for an HSS cutter instead of carbide.
I broke my 3mm cutters on acrylic. I understood that it is best to have quite a high feed rate and a low RPM or else the plastic can melt. However, G-Wizard suggests that for a 3mm cutter with 3mm cut depths, I should use 22000RPM (!) and 770mm/min. IS this what you would expect, or is it going to melt the plastic? I haven't tried it yet as I need to get more 3mm bits, lol!
I also notice that it never seems to use more than about 0.2KW of cutting power which seems a little odd, do most tasks really need so little? Additionally it seems to love TiALN coated cutters but I thought that only really made a difference for really hot milling applications, not cutting plastic for example.
I think G-Wizard is pretty good, but a bit of common sense always helps.
Thanks for the reply Jonathan. I thought it said 8000RPM in your video showing a 6mm flute at 600mm/min but I was wrong it doesn't say about the cutter speed.
I'm no expert either , snapped plenty of bits myself, I use 3mm (2 flute) to cut my 4.5mm acrylic as well. Here's the settings gwizard gives me @ 2.25mm per pass its: 20428rpm & 1052 mm per min. (this gives me a nice finished edge hardly needs cleaning up) I have read before that you should only cut at half the depth of cutter width ie: 1.5 with 3mm bit. Here's gwizards settings for 1.5 per pass : 21005rpm & 1273.8 mm per min. These settings are with gwizard set at conservative low.
Hope this helps, good luck , I know how it feels too keep breaking bits, still do while trying too cut 3mm 5005 aluminum sheet it's like bubble gum :-)
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Thanks, I just tried some cutting again with the suggested feeds and speeds of G-Wizard and it doesn't melt the plastic as I thought it might. I guess the key is getting enough chip-load not to cause rubbing.
I'm cutting 8mm sheet, so I did multiple 3mm pass' at first with a 6mm cutter and then did a finishing pass at full depth removing 0.5mm of material. The end result is very good but there are still some very slight snipe marks. I need to sand and buff it afterwards for a real smooth finish. I tried flame polishing it with a butane pen torch but I think the flame is not hot enough as it looks a little patchy.