STOP Breaking Router Bits! - 391

In this video, I'm going to cover the three main reasons why router bits break. Now that's in a CNC machine, a handheld router or a router table. It doesn't matter. I'm going to refer to all of those bits as router bits. And if you implement these three things, then hopefully you should have a reduction in the amount of bits that you actually break. Before we get into that quick shout out to Bits and Bits for supporting this channel, Bits and Bits is a small family owned business in the Pacific Northwest that manufactures not only their own high quality router bits, but they distribute other high quality router bits, such as white side bits. Bits and Bits adds an Astra coating to their bits to reduce friction and therefore reduce heat buildup. You reduce the heat buildup, you prolong the life of the bit. If you're interested in checking out some high quality router bits, go to bitsbits.com, use a promo code Jbates to save 10% off at checkout. And now let's jump into the subject of this video. I've got some notes to go by for this video. So hopefully I stay on track with all of this. There's three reasons why you're breaking router bits. Number one is kind of silly, but I have to include it. Accidents that happen. Number two is incorrect feeds and speeds. And number three, the incorrect size. So first off with accidents, it's kind of silly to just say, well, stop having an accident, then you won't break any router bits. Well, uh, there's a little bit more to it than that. Ways that you can reduce the amount of accidents is establishing a routine. That's one specific way. Establish a routine. If there's a step that you have, if there's a series of steps that you have to complete every time you do something such as change the router bit, then if you, if you establish a routine that includes some checks to, to make sure everything is set up properly, then you're going to reduce the amount of router bit breakages. And I know this because it took me a while to really drill into my head, check this setup after it's set up, especially with the CNC machine. I would, I would be willing to bet that every single router bit that I've ever broke is not because I've reached the lifespan, uh, the end of the lifespan of the bit, not because I was using the bit improperly. It's because I did something stupid. I did something that I shouldn't have been doing. Or quite often on the CNC machine, I set the wrong Z-axis height. So for example, on a CNC machine, you typically set your Z-axis height, the height of the bit based upon the material surface or based upon the machine surface. And if I'm breaking a bit on the CNC machine, I guarantee you it's because in the software, I set the bit height to be on top of the material surface and on the actual physical machine, I set the bit to be on the material, uh, the machine bed surface. So that means it's going to plunge through the entire thickness of the material before it actually thinks that it's going to be cutting stuff. On a quarter inch bit, it's gone. It's broken no matter what. Uh, on a half inch bit, I have done that on a couple of half inch bits. And depending on the material, um, it just cuts through it. No problem. I don't think I've ever broke a half inch bit doing that, but you're going to find the weakest link. And most often that's material, uh, workholding, how you have the material secured to the bed of the machine. So something is going to shift, bind, break, get caught into something. You're going to have to smash the emergency stop as fast as you can. Um, all that to say, try your best to establish a routine that will reduce the likelihood of you doing something stupid to break a bit. Routines are so helpful. Number two, incorrect feeds and speeds. It's very, very important on a CNC machine to have the correct feeds and speeds. It's less as important on a router table or a handheld router because you, you kind of have that instant feedback. Uh, but for something that's a workhorse, like a CNC machine, it is extremely important to get the proper feeds and speeds for two reasons. If you, if you're too aggressive, then your bit is going to deflect much more. And the greater the amount of deflection, which is how, how much the bit is actually bending under stress, the greater the amount of deflection, the more likely you're going to, to just break the bit, right? So going back to step number, uh, problem number one is an accident. If you have, if you, if you're plunging through the entire material before you actually start to make the cut, that is a tremendous amount of bite. That is way too aggressive. And you're going to break the bit. Opposite of that is if you're too conservative. And that's something that happens a lot with people who just get into CNCs or just start using a router table. They think that if you're, well, common thought is if you're going slow, then it's going to be less load on the router bit and you're going to have the best results. That's not necessarily the case. In a router table, you can go too slow. And what you're going to see is you're going to see burning. Well, that burning happens because of rubbing. Rubbing is what you'll hear a lot on a CNC machine and sometimes see it in, in burned edges and such. But if you're going too slow and establishing rubbing, what that means is every time that router spins or the bit spins, it's not taking a bite. It's only taking a bite sometimes. And those other times where it's not taking a bite, it's simply the shaft of the bit or the cutting edge of the bit is sliding up against the material and rubbing, not cutting, but rubbing. And if you're not cutting, you're just rubbing two things together and do that. You'll feel heat buildup. It's a much faster process on a spindle that's spinning 18, 24,000 RPM, something like that. So you're going to immediately increase heat and dull the bit or increase heat so much that it can't handle the deflection and then break the bit. On a router table, the easiest way to, to avoid burning is to slow down the RPM of the, uh, of the actual bit. If you slow down the RPM, well, you're not going to be spinning as fast and therefore you're going to have a more, more, um, you're gonna be more likely to have an opportunity where the bit actually removes material. You want to make chips and not dust. So there are some chip load calculators that are really, really handy with CNC stuff. Uh, I'll leave links down in the description where you can reference this type of stuff. I have, uh, I'll have a link to a great video that Corey from Avid CNC did on, uh, feeds and speeds. If I'm not mistaken, it was a live stream. So it's, um, not the shortest of videos, but it's packed full of information. There's a program out there called G wizard and it's made by CNC cookbook.com. Now this is, if I'm not mistaken, a paid version, but it's a lifetime fee. It's not like a subscription service. And I bought this a long time ago and I've referenced it a few times. I, uh, I thought I would use it more than what I did. Um, but it was very informative if you will, if you will. Another video is from cutting it close. And, uh, that references chip load as well. I'll have links to those three references down below. Achieving a proper chip load is, is basically achieving the right size chip that is being ejected. Now it's not just RPM though. The other side of that coin is your feed rate. I always recommend on router tables and handheld routers to adjust your RPM first, and that is because we all have our own comfort level working with machinery. So if, if somebody is comfortable going a little bit slower with the machines, you don't want to tell them, Hey, speed up. If you speed up your workflow and you're not used to that, you could potentially introduce some safety issues. So number one, router table, handheld router, adjust your RPM. Number two, if that's not doing the job, then you will have to adjust your feed rate, and if you are using a router table or a router, a handheld router, then, uh, you are the feed rate. You have to change how fast you move the material through. If you're burning, that basically means you need to go a little bit faster. Now don't just go all out and make things unsafe. That's, that's not what I'm saying, but understand that you're a slow feed rate and a high RPM are where you will get, uh, burning rather than actual chip ejection. So on a CNC machine, it's just changing values. And that's something that you can figure out with, with, um, chip load calculators or just figure out with trial and error. The third reason why you are probably breaking router bits unnecessarily is the size of the bit you're using. Try to use a larger diameter shank router bit. So think about this, just the shanks, right? I'll use dowels to talk about this. We have half inch, three eighths of an inch and quarter of an inch. Which one is going to be easier to break? Obviously the quarter inch is going to be easier to break. Okay. You remove that from the equation. Half inch, three eighths. What's going to be easier to break? Obviously the three eighths will break easier than the half inch. Assuming it's all the same material, which, you know, carbide shanked or high speed steel shank router bits, whatever it is, apples to apples comparison. It's going to be easier to break a smaller diameter. So therefore, if you have two bits that have the exact same cutting edge, like this first example right here, the cutting edge or the geometry is different on this particular example, but both of these are three eighths of an inch spirals. One of them is a three eighths of an inch spiral on a three eighths of an inch shank. The other is a three eighths of an inch spiral on a half inch shank. Which one do you think will hold up better long-term? It's probably the half inch shank. Now in this particular example, the three eighths of an inch cutting edge and cutting length are basically the same. So maybe the, the stress weak point is going to be down there and you're going to have the most, the greatest opportunity for breakage. However, I'm going to lean towards the half inch being stronger because the flex from all of the material sticking out of the collet, you're going to have half inch material sticking out of the collet. So it's flex point is going to be a little bit further towards the tip compared to the three eighths of an inch shank and three eighths of an inch cutting edge. This is all the same exact diameter. So that the pivot point is going to be closer to the collet whenever possible, try and get a larger diameter shank bit. Here's another example with 60 degree V bits. Both of these have the exact same 60 degree V bit cutting geometry. However, one of them is a half inch shank. One of them is a quarter inch shank. It's just obvious looking at these, which one's going to break faster, which one will have, which one will hold up longer with the same amount of wear and tear on it and the occasional accidental abuse. That's the thing. It's, it's most often not the routine wear and tear. It's the accidental abuse that you add to it. Try to find a half inch shank versus a quarter inch shank whenever possible. And of course throw the same rules in there for three eighths of an inch bits as well. Can my spindle or router table handle a larger diameter bit? Well, a blanket answer to that is most often if it came with a larger diameter collet, then you can use a larger diameter bit. The shank size. Anyway, you still have to take precautions. If you're using a, a half inch shank router bit in your router table with a two inch diameter, you know, panel raising bit, you still have to take precautions there. Don't forget about chip load, but generally speaking, if it comes with a larger collet, you can use a larger diameter bit. Here's an example. This particular CNC machine, this I'm in the wrong way, wrong spot. This spindle right here is a pretty darn powerful spindle. It's eight and some change horsepower on three phase. I have it hooked up to single phase 240. So it's around a six and some change horsepower if I'm not mistaken. It's a pretty darn powerful spindle. It's not the one that I had on here since day one. I had a lesser powerful spindle on it previously, and I could still use the same router bits that are the same bits that I use now. Prior to this machine, I had an Axiom CNC machine. By the way, this is an Avid CNC. Really great. Love it. My previous CNC machine was an, it was an, did I say Axiom? Got them confused. This is an Avid CNC machine. Love it. My previous one was an Axiom CNC machine. Names are very similar. And I love that machine too, as well. That one had a 2.2 kilowatt spindle, if I'm not mistaken. And that one, I still handled the half inch and three eighths of an inch router bits whenever, whenever possible. That was my default one to put into the machine. And on that particular machine, I don't have my test around here. I try to keep all of my little testing blocks and put them in a pile so I can refer to them later. Couldn't find it preparing for this video, but I had a block of Babinga, super hard, dense wood, and I was using a three eighths of an inch diameter, three eighths of an inch cutting diameter router bit. It was a spiral bit. And I was taking a three eighths of an inch depth per pass. That is huge. Making full width slots. And I was able to get up to 157 inches per minute with good results while still being in an optimal chip load range. That's the key thing. You can plow through some stuff and just check the box and say you did it, but did you do it with the optimal chip load? That's a different story. I was able to do that on a much smaller spindle. So I don't want you to have the misconception that in order to use these larger diameter shank bits, just like a regular half inch spiral up cut bit, you don't necessarily have to have a super high powerful spindle or router to actually turn them with good results. So with what you have, experiment with a larger diameter, but most of the time you're going to find out that you can handle it just fine. The machine can handle it just fine. And it does take a little bit more time. It'll interrupt your workflow to swap out to a larger bit whenever possible, especially on a CNC machine. A lot of people don't like to change bits, but you're most often going to make that time up in the faster amount of time it takes or the reduced amount of time it takes to accomplish the same amount of work for CNC machine. That's a big thing with pocketing. If you can get a larger diameter bit to pocket out and remove more material faster, you're going to save time, even with swapping the router bits. That's it for this video. If you have any questions or if you have any input to add to the discussion, leave it down in the description as a comment. The comment section on these types of videos is oftentimes more valuable than the video itself, because there's a tremendous amount of user feedback that people provide. So if you have something to provide, you have something to add to the discussion, I encourage you to leave a comment in the description, check out my friends at BitsBits, use the code JBates to save 10% off your order. That's not an affiliate code. I just, I work with that company and that's the best discount that we can negotiate and provide to pass along to all of you guys. So I make nothing on their sales, the volume of their sales. Just, just use the coupon code and save some money. Um, that's it. You guys take care, have a great day and I'll talk to you in the next video.