Hi guys I’m here for advice again, today I was trying a new kind of oak that a company dried and it’s a little bit expensive (15$ per small board like the one in the image below - I’m from Colombia so no idea if this is a rip-off in your country but I wanted to test it anyway)
I would like to create this beautiful carving that you can purchase here:
Right now I’m having problems with my speeds and feeds, the speeds and feeds that I’m using worked with a cheap piece of oak before so no idea why is not working now. I can smell the burning, I don’t like the sound and my bit gets black.
I’m using these settings with a Whiteside 1/4 up cut endmilll
And these are the settings that I plan to use with a Yonico 1mm tapered ball nose.
could you guys please recommend me some settings for this piece? I’m really concerned about the plunge rate since I couldn’t find details about this anywhere. Thank you very much
Still learning cnc but have a lot of experience woodworking.
When the wood burns while milling/routing/sawing the feed rate is too slow and or the bit/blade is dirty.
When you get burning the bit/blade starts accumulating carbon on it’s surfaces and it will then burn the wood even if the feed rate is otherwise appropriate, unless you increase the feed rate radically.
First clean the bit. Then try again with a faster feed rate and or slower rpm.
Is that bit still sharp? The corners and cutting edges do not look sharp at all.
For the 1/4" tool those settings should work (the feedrate could be bumped to 100 or so though), so I tend to agree with @kelaa that it may be the endmill that is now dull (from hours of previous use OR from using it at incorrect feeds and speeds before, it only takes of a few minutes of rubbing to make it dull)
Your best bet is to try with a fresh one I think.
Really? to be honest I have been using this up cut endmill for all my projects since 2 months ago so it makes sense. I’ll compare it with a new bit.
Also… I’m a super beginner so I used 220 sandpaper to clean it (to clean the burning marks and sticky stuff)… is that something I shouldn’t do? then how should I clean them? Thanks.
Endmills are consumables.
They can be sharpened, but it’s a skill, and to have it done professionally requires min. quantities which it is difficult for the typical hobbyist to reach.
For a bit, see:
They should be handled as any fine tool (wearing gloves is suggested), and the cutting surfaces touched as little as possible (carbide is easily chipped). Cleaning should be done w/ a suitable solvent and a lint free cloth in such a way as to not damage the cutting edges.
Hi WillAdams, what about cleaning them? how should a beginner clean the burning marks or accumulated sticky stuff that needs to be rubed away? only with the solvent and a lint free cloth aswell? What kind of solvent do you recommend? Thanks.
Simple Green is one recommendation I’ve seen made here.
I just use isopropyl alcohol.
There are dedicated cleaning solutions marketed to machinists — not sure if they’re worth it or no (I’ve got one spray bottle in my Amazon cart but haven’t pulled the trigger yet).
I have a relatively inexpensive ultra-sonic cleaner that I use in conjunction with an oven-cleaner type spray (like Simple green). Cleans the gunk off beautifully.
To be fair, the average university undergrad shared machine shop endmill and carbide tooling looks like that anyways. I think my worst was forgetting that the high-drive and low-drive on the vertical mill have different spindle directions, and then running a boring bar in reverse. I was wondering why it was smoking so much and cutting so little.
To be clear, do NOT do this.
You can use acetone, laquer thinner, or some other strong liquid solvent to clean off sticky stuff, with a paper towel.
Otherwise, new bit.
Thank you very much, to be honest I was thinking the sandpaper method was ok since nobody said anything about it
Just like cutting with a table saw, if you feed too slow you’ll burn the wood. With a three flute 1/4" bit, running at 18000 rpm, cutting hard wood, you should be running at 550inpm. Find a chip rate calculator.
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