By Boyan
MDF quality
Hi, Just doing some showroom test cuts on MDF today. I believe its good to add 2nd quality MDF as normally thats what i find here in Spain. Very good MDf and a Crap one. The good one is very dense, very smooth. And cuts excellently. The other one is more like paper like though it seems nice at first touch. On a very sturdy machine with brand new super sharp Kyocera fish tale 3mm 2 flute micro grain carbide bit that i use from years and is probably the best 1/8 3mm bit around, feed rate had to be lowered to 70% from original. I am saying that cause normally even the start cut on an absolutely new material for me using HSMAdviser is superb. So same like the normal MDf -30% slower. On photo below could be seen how clean is the cut with the adjustment, opposing the initial one. Another note also is for V engraving wood. Especially soft wood. Whatever the calculators say, raise the feed more than 60IPM or 1500mm and wood will start to ship even if the cut is perfect. So as i cut a lot of that, that my rule of a thumb. Its simply a quality of wood which has grain. Not talking about the woods without grain. So maybe there also some small change, say wood without grain all stay same,. Wood with grain- different material with max 1500mm/min for engraving. I am talking about 60 and 90 degree bits. 45 and 30 had be be even slower on wood grain. I cut thousands of pieces per year with quality tools, so i believe i have some reason. Same thing happens also with big CMT indexing cutters. they cut perectly but on every hundred pieces 5-9 will hack up if feed is not lowered. So i prefer 100% result, hence the notes. I believe if a person cuts a couple of pieces and sees a perfect cut he assumes all is right. Not so when you cut 500 pieces of same material. In short, HSMAdviser will be even more perfect if a separation between woods with grain and no grain is made and speeds for Grain are lowered accordingly
Eldar Gerfanov (Admin)
Hello, Since you are the expert on routing here (i have been a metal machinist), i am going to ponder some solutions and consult you via email when i have something concrete to suggest. In the mean time could you send me your cut library? Thank you for the feedback.
Boyan
HI Eldar, I will play a bit with the slider adjustments to see where they are leading me, before discussing further. At the moment my conclusions are based on all sliders at middle. What i was saying is not change the way it calculates things, but more of a safety feed limit to avoid chipping the grained wood. But maybe i am missing something, so let me double check what i am saying :-) Will be happy to do some test with photos if needed. But basically for safe cut on wood and one that always works 16k rpm depths same as diameter, 17k for hard woods and 18k for woods that have defects and variation of material. 1500mm/min feed rate. Not that i do not cut at 16000mm/min HSM wood https://youtu.be/6red66CDLxo?t=3m6s or at around 8000 mm/min normally but there is a risk of chipping and hacking about 7-8 pieces from 100
Eldar Gerfanov (Admin)
Hi, I know exactly what you mean. Calculations work perfectly in most cases except when they do not. You suggest adding grain/material quality parameter. I agree that we need something. This is why there are S/F overrides to fine-tune your settings. How I can improve that is perhaps by allowing users to create their custom materials based on the existing ones. (Because trust me. You don't want to create materials from scratch.) Where you would adjust 2 -3 sliders to get things just right for your particular batch of material...... Perhaps I can rework the already-existing Custom Tool Tables functionality for that too... Any way. Let us think things through to come up with a best way to tackle this. Best regards.