sup fabrication nation welcome to the channel today i think i’m going to spend a little bit of time and go over pie cutting so the popular thing these days is to pie cut tubing to make bends not necessarily my preferred method of welding or making bends but that doesn’t mean that it’s not a good way of doing it and I get a lot of questions about how to do it so without going into great detail I’m going to spend a little bit of time show you how…. give you some pointers give you some guidelines to go by when doing pie cut bends and maybe show you something that you didn’t already know all right so pie cutting creating bends with pie cuts is for you for anybody out there that doesn’t know it’s basically taking sections of straight tubing cutting them out of pie shape and then when you stack them together you can actually create nice smooth bends… okay now obviously you could just go start cutting all kinds of pie shaped pieces of tubing and weld them together and you have a pie cut but there is kind of a proper way to do this a professional way to do this I don’t really prefer pie cuts myself so im not necessarily an expert on this I usually just go with a mandrel bent tube I buy mandrel bends and then put those bends together to achieve what it is that I want to achieve just because I don’t prefer it doesn’t mean it’s not a good method there are some pros and some cons to pie cutting and mandrel bends both there’s also a place for pie cutting there’s certain instances where you can’t necessarily Bend tube mandrel bent tube to the radius that you need or the material itself is not very bendable and in those cases pie cutting is a must there are actually several companies already out there that do pre-cut pie cutting for you most of its laser cut it’s very precise and exact one of those companies is called ticon ticon basically does titanium tubing of all sorts you can see mandrel bent stuff to being exhaust anything you basically need they can do for you the reason I bring them up is because they do offer a sample kit so they offer sample pieces of titanium that are already pie cut it’s a very well priced kit they’re not very expensive and in those kits they’ll send you some filler rod some pieces of pie cut tubing and different sizes and some pieces of titanium plate so if titanium is something that you wanted to experiment with you can go get one of these sample kits from them all this is unpackaged but when you get it it will be nice and sealed package them pretty ticon ticon industries com actually sent me this kit plan to experiment with it at some point never really tried my hand at titanium I’m going to give it a try and maybe use it for like wastegate tube on the bid stir something where it’s nice and clean and cool as long as I can pull it off alright so let’s talk about some of the pros and some of the cons to pie cutting some of the pros would be you can get tighter radiuses then you might be able to get with mandrel bending you can use materials that maybe aren’t very good at bending like the material itself might be too brittle to bend it so if you pie cut it you can actually achieve what you’re looking for in some instances it might be cheaper to buy straight tubing and pie cut and creates your bends versus buying a mandrel bent tube alright so now let’s get into some of the basic theories of pie cutting and kind of the right way to do it so pretty much what the standard is is either a 9 degree pie cut so four and a half degrees off either side of center so if this is a tube and you mark a center line you want to go four and a half degrees one way four and a half degrees the other way and you have a 9 degree pie cut the other way is an 18-degree pie cut so this was a straight tube you’d have a 9 degree cut in a 9 degree cut equaling a total of an 18-degree pie cut the reason that these are pretty standard is because you can achieve the angles as you want the easy angles very simply so if you have a 9 degree pie cut 10 of these makes 90 degrees it’s easy for you to do that five of them would make a 45 degree and then basically the same thing when you have an 18-degree pie cut it only takes five of these to make a 90 degree angle and you can see when you use a 9 degree pie cut when you stack several of these together you can actually make a very nice smooth radius on the inside some of the other pros are you don’t get any shrinkage through the bend so even in mandrel bent tubing you do get some shrinkage through the bend itself and pie cuts you don’t get that these are all straight tube so if this is a you know two and a half inch tube you’re going to get a true two and a half inches of your radius through the bend some of the downfalls to pie cutting obviously the labor you have to cut and weld so many little pieces it’s kind of a disadvantage another pro to pie cutting is you really kind of have unlimited access to clocking of angles so as you are doing a band you can start to rotate these and create all kinds of complex curves and bends it wouldn’t necessarily be as easy to do with mandrel bends you could you could chop them out and basically pie cut the mandrel bends themselves but wouldn’t be as easy to do a need that’s enough about these let’s go over here to the bench and I’ll kind of show you how you want to lay these out in a fashion that give you a give me the same cut repeatability and allow you to make really nice lobster or pie cuts all right let’s play something out here to scribble on alright so we’re going to do is I’m just going to give you the very basics to the proper way or at least a good starting point to lay out tube for pie cuts so the first thing that you need to do is you need to figure out the distance around your tube alright so what you want to do so the first thing you want to do is going to measure the diameter of the tube which is obviously the distance across the tube itself so from one side to the other a diameter and on this one we’re going to say it’s four and a half so 4.5 is the diameter and you want to multiply that by pi which is a 3.14 that is going to give us 14.1 three so 14.1 three is the circumference around this tube alright we want to find out is we want to find the halfway mark perfectly half way through this tube here so we’re going to do is we’re going to take 14.1 three we’re going to split that in half and divide that in half it’s going to give 7.065 okay so we know that 7.065 inches around this tube from this point here is going to be perfectly half way around so it’s going to give you basically your perfect halfway through this tube now the reason that you want to know this is because this is going to be critical as far as cutting and lining up the tubes themselves because we’re going to mark the to you halfway so you can see these marks on this tube here that is the halfway mark when you mark the tube halfway before you cut it it allows you to cut those angles perfectly square ok every time and once they’re cut it’s going to allow you once you line these up you know that you’re going to have a perfect 90-degree Bend it’s not going to waver any as it as it bends as long as those line up it’ll also allow you to clock these things purposely alright so these are these here at hand mark before they were cut if you get them from ticon or a company like that a lot of times they’ll have a weld seam on the inside have a weld seam on the inside here as long as you line up that well team you know that it’s going to be exactly the same throughout that bend alright so using this formula you take a long straight piece of tube which essentially would look like that right so essentially that’s what that tube looked like before it was cut there’s a straight tube I’ve got a line drawn down this side got another line drawing the other side’s achieve that is perfectly opposite of this line and all you have to do is Chuck that thing up in your bandsaw or whatever you’re going to use to cut it make sure that this side is perfectly the highest point up and then to start cutting for half degrees four and a half degrees for a half degrees four and a half degrees in perfect world you kind of want these inside pieces here to match so you want all the inside distances to match or be very close if you take that straight tube and cut it up into a bunch of pie cuts that are exactly the same you will then be able to put these together and make nice pie cut bends so you can see how that works once again measure the diameter of the tube times it by pi 3.14 that’s going to give you the circumference split that in half that’s going to give you your perfect halfway point once you figure that out draw lines down the entire length of the tube that are opposite of each other you want them to be perfectly opposite of each other and then just go down and cut once you’ve done that you’ve got all your pie cuts then you can kind of put those together as needed usually you’ll just want to tack it together as you create it and then once you have what you want then you can go back and weld it all up all right guys there you go a very easy introduction to pie cutting and making pie cut bends that’s so what you want to do it those are the basics of it the rest of it you can kind of figure out on your own there are some very in-depth videos on YouTube about pie cutting if you kind of want to look into it more I know the fabrication series does one I’ll put maybe a link to that video in the description if you’re not familiar with that channel you can go check it out like I said that’s the basics there that’s all you really need to know to get started and make nice professional clean looking pie cut bends I hope you guys enjoyed that as always thank you for joining me and uh I’ll see you guys tomorrow go do work son