I’m pretty new to this. I have done multiple cuts now, and seem to be getting the hang of it, except when it comes to cutting all the way through the wood. It has worked a few times, ok, but others I always seem to have problems with bit/router shaking, and today it tore into the side wall on the final pass. I have tabs in place, everything is secured well. I have tried various speeds, and various bits. Does anyone have suggestions for cutting through hard wood as far as what depth per pass, feed rate, plunge rate, etc…? Upper right side in pic is what happened today. I don’t wanna be scared to keep working on projects that require full cut through.
Is this red oak?
Its pretty notorious for not carving easily. It can be carved but the settings require a more narrow selection versus other hard woods that are more accepting to a variety of settings.
However the first thing i suggest is ensuring the belt tensions and eccentric nuts are adjusted correctly before anything else because if those are off than nothing will fix the issue…
I honestly don’t know what type of wood it is. It’s an old stained piece that was in our bathroom. I was using it to experiment on. I had everything calibrated not too far back, maybe I should check again.
Is it better to use an 1/8 bit or something bigger like a 1/4 to cut through?
Id use the smaller 1/8" bit. Less forces placed into the cnc frame cnc motors using the smaller bit.
What type of endmill are you using?
I’ve tried a few different ones. I wanna say the last one I used was a 1/4 upcut bit. I’m about to head out in my shop now and recalibrate. I notice the bottom wheels aren’t even touching the bottom track on the Y axis. Maybe that’s causing it.
Hey Jason, congrats on the purchase! I can confirm that that is definitely oak. I’ve had my machine for about 1 year and I started out trying to do things just like this. I was using all kinds of very hard woods, before I understood feeds and speeds- and what the machine can handle.
Your machine can do this- but probably much more slowly than you were going at it. For whatever reason, I found the stock settings to be far to aggressive for some hardwood/bit combinations. The 1/32" bits are for decoration. If you can find ANY feed or speed that allows them to cut wood- let me know.
What feed and speed were you using? The type of bit (upcut/downcut/compression) also makes a huge difference as well.
Once you get a feel for the controls, I would begin by cranking everything down. I like to use the upcut bits when I can because of what they do. They draw the material up the bit and out of the pocket where it’s out of the way. You will probably have to use a milling bit to achieve your 1"+ depth on the through cut though.
For a lot of reasons, you want to use the largest bit you can for the particular application. You could cut that round with either an 1/8" or a 1/4" so I’d load up the 1/4" single or double flute mill.
The rule of thumb I would follow is: set your depth per pass to NO MORE THAN HALF THE DIAMETER OF THE BIT. Ask yourself, “how big is my bit?” Then cut that number in half. .25" bit becomes more more than a .125" dpp. If you’re using an 1/8" bit, your dpp should be .0625.
For feed rate, start slow. You may leave burn marks or wear the bits slightly faster- but that is better than firing your work piece across the room, or getting hurt. Both of these things can happen. Go with like 40 inches per minute. Then watch and listen.
Listening is as important as watching. The sounds wont mean much to you at first, but you will learn to understand feed and speed by sound alone.
I wouldn’t start with hardwood by the way! Find a nice piece of pine, or old plywood. Run some tests to plunge a particular depth into the wasteboard at different points on the wasteboard- them check with a caliper. There are lots of fun and low impact ways to learn the machine- but I don’t blame you for going deep on some oak round 1.
Thanks for the feedback, much appreciated. I’ve made a decent amount of cuts on various types of wood. Starting to understand the speeds pretty well, and multiple bit changes took a bit, but I figured it out. I went to school for Graphic Design, so it’s nice to be able to create a lot of things in Illustrator and save them as svg files to open in Easel. I probably am going to fast on the cut through. I did notice a few loose wheels, and I have to tighten my belts a bit more. Here are a few things I made.
As you can see with the cassette tape, the cut through worked fine. It’s also pine, so a lot softer.
Those are cool man! Sorry- I didn’t mean to peg you as a first-time user. Hardwood is definitely the variable. The bits eat the pine and ply nicely (try cutting PVC- its like butter!) but oak is a different beast. If you inspect the cuts you can see where the bit struggles and the quality of the cut slips- at 90 degree angles to long grain. Because the bit spins in 1 direction, but travels in both- you will see the effect is more pronounced on one side of the hole than the other. (A circle is the perfect cut to demonstrate this- because it cuts and crosses the grain in all directions.) Specifically this is at about 1:00 and 7:00 on the hole you cut as pictured. Basically, as your bit is traveling with the grain of the wood- the motion across the x axis is either ADDING TO or RELIEVING the chip load that the bit is dealing with. The deeper and faster you go- the more this applies. This applies to hard and softwoods- but it’s much more important with hardwood.
You mentioned you’re in graphic design. I’ve been a carpenter for 15 years, and I’m sitting on like 12 STL files that I can’t use because they are too big and I can’t find a way to shrink them to under 100mb. Any suggestions?
There’s a few methods for shrinking the STL file and I discuss them and show the method I use in this livestream from a few weeks back…
I didn’t mean to contradict you on the 1/8" vs 1/4"- I should have read your post more closely before starting to ramble. Gantry flex didn’t occur to me- and checking to make sure everything is tight and true is much better advice than going slow with a big bit. Just slap me if I get to carried away. I’m 1/2 through your livestream and I’ve already formated my first few STLs. Thanks again man
I love this group!
Seth, is there a way to convert files to STL?
Well, there’s a basic method to convert a photo to STL but it usually doesn’t produce useful results.
This site uses the contrast of light and dark areas of the image to make high and lows of the STL as a lithopane.
The other option is to manually contour a 3d model based off of the image as a reference. Carveco Maker Plus , Vectric Aspire, and ZBrush can do this more manual method but it can often take hours or rather days to achieve the desired outcome…
Or pay someone else where the cost of living is much less to do that manual creation of the 3d model for you, like on fiverr for example.
Thank you!! Looks like I’ll just be sticking to 2D. Is there a site where STLs are already created where I can just download/import them?
This is great! Thank you so much, Seth.