TFS: Pie & Lobster Cuts Part 1
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- čas přidán 4. 06. 2016
- The unique method to create a bend in a tube without bending it. Pie cutting a tube at a particular angle will allow you to create a bend radius when calculated and mated properly. There are even some really unique features of using pie and lobster cuts which can not be achieved with a typical bend. Part 1 of Pie & Lobster Cuts on The Fabrication Series covers the design, angles, calculation, manipulation, and creation of pie cut tubing.
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there are people that know more than you, but if some can't transfer that knowledge to other people so they can understand it.
YOU Sir make all this so easy to understand and seem as easy as it is!!! i am learning a lot.
thank you from everyone that enjoys your videos!!! keep up the awesome work
Thank you!
Still love the old videos!🤝🏼
Great information, I have learned a lot from the “pie cut” videos. I’m currently building a rat rod and getting closer to the time that I will have to modify the headers to make them work. I feel sure after watching these that I can do it. Maybe not with the ease you do, but I think I can get it done regardless.
Thanks for the info.
Very well explained. This method makes the job of making a pipe go to whatever direction you need very easy to do. Simple even. Takes the guess work out of it. Thank you so much.
Thanks for watching!
Thank you for making this video. I have been trying to ins a video explaining how pie cuts work for months so I can make custom pipes for my dads Harley for Father's Day. You have no idea how much this is gonna help me. Great explanation.
Thanks for watching! Good luck on the build!
Dope video man!! Keep up the good work!!👍
Here's a brief explanation why you can't weld different angled cuts:
Let's take a right triangle with a 3" height and top angle of (your example) 9 deg...this gives a base of 0.475" and a hypotenuse of 3.037"
Now, let's look at a right triangle with a 3" height and a 45 deg top angle...this gives us a base of 3" and a hypotenuse of 4.243"
You cannot weld a 3.037 dia pipe to a 4.23 dia pipe. I realize the pipe diameter is 3", but when you cut it at anything other than a 90, it becomes an ellipse and the diameter increases with the angle of the cut!
Hope this helps a few people
Excellent explanation.
what it's the best way to cut the pay cuts if I want to try to make something with pay cuts but I don't have bench saw ore disk saw for metal to cut it? please pm
Mindaugas Berteska There really isn't an easy way to do it without something that cuts straight. If the cuts aren't straight, you end up with mis-matched angles and gaps.
that's suck's because I have 3 ore 4 meters 304 SS and planing to make induction tubing, and I want to try for my self
Mindaugas Berteska You could always have a go at it. It's just difficult to get the pies to line up if the cut angle isn't perfectly straight.
This is great! Can't wait to see the fitting/tacking/welding!
I'll have it up soon. Thanks for watching!
This is really really helpful, looking forward to the follow up
Should be up soon.
Well done I like how you did this I wish I would have seen this when I did my 3" stainless exhaust for my big block suburban with headers to 3" cats to twin 3" inlet flowmaster muffler with 4" exit I was using seat of the pants engineering . I don't have cad it sure would have helped thou ! Thanks for explaining what normally used for cut angles .
Great video! I'm working on a completely unrelated problem but this lesson helped me brain storm a fairly elegant solution using this technique. THANKS!
Thanks for watching!
Outstanding video, very informative. I'm really looking forward to the practical application video as I am going to have to use this technique to build the exhaust and intake for a custom TL1000R project I'm working on.
I'll have it up as soon as possible. Thanks for watching!
I looked everywhere for an explanation on how to find the angles you need holy pie thank you !!
Awesome. More coming soon!
Remember that if your entry and exit is straight, you will have one additional pie cut piece because you are losing the entry and exit angles.
Thank you so much! I've been wanting to know how to do this. love your videos get up the great work.
Thanks for watching!
Good video!
Looking forward to your demonstration of how you actually cut and weld together these crazy lobsters :)
I'll have it up as soon as possible. Thanks for watching!
Great explanation! Thanks!👍
man, great info. love your channel. I always learn so much from you.. really man, thankyou!
You're welcome. Thanks for watching!
love the vid! looking forward to part 2!!
I'll have it as soon as possible.
Lobster backing as I call it is a big no, when it comes to a performance situation. In an every day car it's accepted. However It creates a lot of drag and pressure increase, especially with cars that have many bends In the exhaust system. I use pre fabricated radius bends (which means the pipe diameter does not change throughout the bend) for performance applications. It doesn't impact peak power a lot, but allows the engine to get there much much faster.
This entire comment has so much misinformation in it I don't even know where to start 🤣
WOW!!! This video really opened up my eyes about how to do this right instead of just working by eyeball approximation I usually do. Lol
Thank you VERY much!
You're welcome. Thanks for watching!
Ok, I am 70 years old and have never thought about this. However, I could easily follow everything you demonstrated. You are a great teacher!
I also read some of the comments and I had no problem with the sound or video, I am on a mac it that matters?
Thanks, Tom
Thanks, Tom!
The audio crackle and sync issue is a CZcams thing. It is messed up on some of my devises, but fine on others. It's really a hit or miss.
Thanks for watching!
I have watched this video 5 times and I finally get center line radius....... I was only thinking about drawing the angles from the bottom of the tube center line to the top, which would make a sliver at the inside of the bend. No more watching videos like this half asleep, last a few hours sleep over it....
tyler krenik clr is the one thing I'm still trying to grasp/how to figure out on an actual job correctly. Don't know how to come up with it measuring a job from scratch.
a ton of great information. keep it up man!
Thank you!
This is an excellent explanation....thanks!
Thanks for watching!
nice work ! you help a lot
Great info and how you explained it. Thankyou
Thanks for watching!
Awesome vid finally understand the angles of cuts!
Excellent! Thanks for watching!
Forgot - when doing this sort of fabrication, folks, don't forget to check to see what sort of mandrel bends and 'doughnuts' are available in the material, diameter and radius are available from the various suppliers. It can save a shedload of time, hassle and money (welding supplies) and can be neater - but the aesthetics comes down to personal preference.
Makes me want to weld up some pie, lol. Great video!
Haven't had enough by now? haha. Thanks for watching!
Very well explained!
Thank you!
Life is all about the test of our own skills. I have watched several youtube videos, probably too many videos. I am a perfectionist and so are you. At the next fabtech in Chicago I would love to see a throwdown of the best of the best in welding and fabrication. Will you be there, or will you crawl into some deep dark whole.
Really enjoy your content and was surprised how much I understood. I've been shown this a couple times and "got it" but it still felt like witchcraft.
Great video!
If I can answer some questions to make it feel less like witchcraft, let me know. That's what I'm here for.
Thanks for watching!
@The Fabrication Series Mate thanks for sharing, I have a question regarding clocking, how many degrees can you clock each piece before they start to become out of round? Or what is the degrees you go by?
great video! keep up the good work. nice shop too!
Thanks!
Small suggestion: Put a whiteboard on the desk to kick some light on your face at the computer. Great content. Great lesson. Thanks.
Great video! After watching it my sidebar suggestions were half car videos half cooking videos...took me a second, then I realized it...Pie & Lobster.
Haha... makes sense!
thank you
Hey Justin first off awesome videos! Now i've been trying to make a merge collector from pvc pipe first and put my bandsaw on 60 degrees ive marked my pipe and my bandsaw so after the first cut i clock the pipe 180 degrees and make the second cut.. now when i put them all together it doesnt fit.. is this a mistake im making or is it because im using a 200 dollar bandsaw? am i maybe better off with a decent miter saw? regards from The Netherlands
Nice video man,you explained it so clearly.Now all i need is a way to measure the degree when clocking the peaces.maybe a 3" wraparound degree ring peace of tubing with 1 degree incroments scribed into it.
You can use a wrap around, or make a single mark on the same place on each piece to note where your zero degree reference is compared to the other. Try a few methods and see which one works best for you.
That's what iam talking about finally somebody can touch topic on this
Thanks for watching!
Yup can't wait for the next part
Can you make a pie cut circle? I would like to see that
this will help me do a custom turbo kit for my tiburon V6
Awesome!
I love your videos and learn alot from them. but how do you make that layout onto the pipe itself or do you just put it into the chop saw?
I'll have the layout techniques in the next pie cut episode. It's really pretty simple.
Mine went from straight out of my extractors then a few lobster backes to get it running straight along the chassis rails, then into my 4" hotdogs, them 90• down then a left or right angle went under and up back into str8 then up ans yeah 5mm out of whack which wasn't to bad I think...... was gr8 fun doin it though. Hadn't used a tig for nearly 15 to 20 yrs...... was wikked fun though
what computer program are you using for your design phase of your engineering process?
Outside and inside circs are a series of straight lines. Digital pipe.
Welcome back
Thank you!
12:31 RIP headphone users
Haha, Yeah, sorry about that. The downside of not turning my notifications off before shooting an episode.
The Fabrication Series actually this is my only problem with your videos, and it's not the notifications. it's the huge differences in audio volume throughout. please even things out so we don't have to turn up the volume to hear you and then get blasted by power tools etc.
fuck that ! that
is for pussies
Hahahahaahhahaahhahahahahhaahhhahhaa.. Know how that feels
Unfortunately a COMMON problem for a lot of you tube efforts...
I know, you probably already know this, But your mic sensitivity ( on the pc at your desk ) is popping like crazy..
Thanks for bringing this fabrication knowledge to the free world!!
Jersdunz That's actually a CZcams processing byproduct. It's total hit or miss whether it does it or not, and I really wish I could do something about it.
Still waiting on part two Jastin. 😜
There is an excel spreadsheet calculator, that does all the maths for you. You just populate what CLR, diameter tube, degree of bend, & how many cuts and it will give you the angle you need to set your saw and the length of the short side. I have used this calculator for 7 years with great success. Just google pie cut calculator.
If it works - use it
Pie cuts or lobster cuts are fun but lots of labour though. Did my exhaust manifold and dual exhaust and my intake all by eye and angle grinder on my XJ. I'm actually itching to do my car now even though the job will be worth more than the car lol. Buying a few UJ bends saves a ton of time.
CanadaBud23 Buying mandrel bends is ideal in cost cutting, but they don't always fit in the same spaces where pie/lobster cuts can.
Most of the time they never fit quite right. So I end up pie cutting those up to fine tune the directions of them. I mixed it up a bit, the collectors required sections that were very small. I'd say roughly 2 degrees because of the space between the block, pan and driveshaft and angling because of the vband clamps. It was a nightmare but I got 2 3" pipes through there :D
Learning pie cuts saved my exhaust idea so I'm glad to have learned them when I did. This vid is good solid information.
i read in a cylinder head porting book somewhere that a change of 15 degrees or less in angle has no change vs a smooth radius although this was for cutting the seats
i assume that it would still stand for intake or exhaust tubing
There is almost always a measurable change. It's just a matter if it makes a negligible difference. The data I have viewed over the years suggests that pie cutting has no major adverse affect on flow at either 4.5 or 9 degrees.
cool video man.
Thank you!
I can barely make my chop saw hold a true 45... 9 is going to be fun!
Just let the saw do the work. let it cut on its own and don't force it. It should cut just fine.
Great info - did notice your lip-sync is out a bit.
Must try this in my CAD.
Yes, about mid way through the audio processing issue so it's off a bit. Something I can't control since youtube is what processed it.
Cool video man!
Wish someone had put something like this together when i was starting out.
Did you notice that odd crackle on the vid when you speak or is it just my computer?
Keep up the good work
The audio does have a crackle. Some vids process just fine while others do not. It's a CZcams editor problem.
May seem stupid or i didnt grasp and i did watch a few times. Is there a way to mark a center line on a piece of strait stubing..measuring in (x") off the center line..this disregarding the center cut radius. This is just a question about making the common 4.5° and 9° angles i know im derrrppp with this but an exaple of the question or a guess of the answer possibly?..**For a 4.5° pie cut, using a piece of 2"o.d. strait stainless tubing. I will mark a centerline and draw a line around the tubing. What would the top of the piece be cut too amd same with the bottom? 2" on top a minimum (i would think) of a 1/4 on the bottom of the pie. Sorry in advance for the drawn out way of asking a lrety simple question. Amy advise would help
360 degrees of pie = donut
the snack fabrication series ;)
Haha
Actually it’s a Torus.
Can you have an exhaust that is made with pie cuts, extrude honed?
Have you ever heard or seen of welding pie cuts in a positioner or rotator?
Bro you look like a kid in this video lol I can't believe it's already been this long
Have you considered doing a video on conical pie cut bends?
You're the first person to ask. I suppose I could make it happen if the job comes up. If not, I can likely put something together.
it's basic apprentice level 2 development work not really used on small stuff nowadays except show bits. Mainly used in heavy plate ducting work like on power stations then allow for the thickness.😂
We use it all the time in the auto industry
Ding!! Sweet man,this finally made light of how I've been doing it wrong on all my attempts. I didn't know you matched angle to angle. Well I do now, and clearly understand how awful mating angle to straight piece turns out. Great video!
I do have a request however, do you think you could demonstrate the process of making a merge collector? 3-1 or 4-1 or any other than 2-1. Clocking the tube rotation for the consistent angle cuts hasn't worked out. I haven't figured out how to accurately repeat those angles. I recently saw on trick-tools website they have a tube rotation gauge. That may very well be what I'm looking for. Thanks in advance, and will be looking forward to your reply, Adam.
Thanks, Adam. I will have info on merge collectors in upcoming episodes.
If there are n segments to make up 180 degrees, just use n-1 segments and the start and end cut' straight sections. Need more? Just put a single cut in a straight offcut/length for another couple of transitions. Simpler and neater, IMO, than your suggestion ;-)
when will we see some more..... great video
As soon as I can get it made. I'm pretty backed up at the shop right now.
How do you actually cut the tubing in say a chopsaw? Set it at 45 then rotate the pipe 180 each cut ?
I'll show it in an upcoming episode.
Hey dude! When do you come out with the next video on pie cutting you sad very soon i has been 3 mounts
I know it's been forever, but I'm working on it. Just have to find the right time to get it uploaded.
Okey! Love youre videos buy the way very Good information att good teatching Love IT !!! Keep the Good work up!
Question. Saw your vid on making X-Y-Z etc. pipes but there was no link to your Top Band Saw choice. Like to know. Thanks.
Earl Cousins Its in the "Tools and Gear We Recommend" link found on every video description.
Awesome video mate!! Started my welding education to learn this. Dropped out though and ended up as a tattooer haha. But the flare isn't gone and this video put my motivation back to life ! Can you tell me what wall thickness you'd use for an exhaust system? Or does it depend? Could you also explain what to do if you for example would do a lobster tail bend that also expands diameter and radius (and angle) all at the same time ? Like a compression chamber for a two stroke for example? Thanks a lot for this explanation video!! Another subscriber to the collection!
Exhaust wall thickness depends on the metal. I usually use 16ga for steel and stainless. Aluminum exhaust jumps up to 14ga, and titanium drops down to 18ga. Building the other exhaust style you mentioned has been requested, but I have to have a vehicle or project here to do it. I'm always on the lookout.
okay mate thanks a lot for your reply!!! really appreciate it ! cant wait for the video to come up at some point ! best educational channel on youtube by far !! peace !
Great vid, You should give us a tour of the new shop.
I will soon. You can head to the Facebook page and check out the most recent live stream which I gave a quick shop tour at the end.
Ok sweet. I will check that out. Do you use Mastercam for any cnc work or just drawing things up before welding? You seemed very comfortable with the software.
+draperb1 Mastercam is for all of my CNC work primarily. I also use it for drafting parts and checking dimensions on some things, but mostly used for tool pathing parts for the CNC.
what gas do u use to tig titanium? just normal argon?
Im having trouble making marks for my bandsaw !!
Nice vid. A++++
Thank you!
that can be done with Flux core wire welder Merrill?
It can but there will be a lot of cleanup work involved.
Neat info. We did this in my geometry class. I forgot how to do that. I’m making a new set of pipes for my snowmobile.
Blurry and sound crackles. You should preview your videos to put out better quality videos.
Daniel Swift Watch the new ones. This was 2 seasons ago.
How does each piece mate properly when changing bend direction? do you only rotate a few degree at a time or do you need a straight cut on one side of pie cut so you can rotate as much as you want?
If you are transitioning you will usually create a transition piece which will have the angles clocked to the bend direction on each end. If that doesn't make sense, I'll try to better explain.
The Fabrication Series makes sense thanks for explaining
I am currently developing a pie cut tool that will slip over a 3" OD tube with the 9deg angle that will be 3d printed, basically a ring that slips over tube and trace both sides with maker for the user to cut along
Look up VPG exhaust systems. They have what you're trying to do
@@blue32nu engineering to not pay someone and already made them, (year ago)
What is the length of a single pie cut?
Do you have the measurement of the long side lets say if you are going to cut the pipe on a chop saw you can cut one side than measure make a mark and rotate the pipe than cut the other side
Half the diameter is the measurement.
How would you go about figuring out what shape the pipe needs to be? Also, do you know of any software that allows airflow simulations within a model like the one in the video?
Im not sure I understand your question about the shape. Could you elaborate?
The Fabrication Series I'm talking about the complete shape of the piping, after tacking the pie cuts and straight pieces together, how could you figure out the shape of that so you can fit it in the engine bay? Do you have any easy mockup methods for this like cardboard or something else?
Raio Lively Cardboard is common if you want to figure out what CLR you are after and how many cuts of an angle you are looking to do. most of the time you can simply look or measure the angle and the space you have to work in and calculate the pie cut angles by dividing the transition angle by hoe many pie cuts you want to weld, or divide by the angle of the pie cut.
I'll get further into this in a future episode.
can't wait to learn how to cut each piece:(
Soon.
so this never happens?
+Shinji “MrHirako” Hirako We're shooting the episode now, but no release date yet. It takes weeks to schedule and create an episode. Rest assured it's getting done because it's the #1 requested episode right now.
Where did you get your MasterCam Training? How Spendy was it?
Papa Wheelie It was free. I trained in a program called Workshop for Warriors.
why can't you mate a 4.5* bend to a straight cut? seems like it would save a cut no?
Just started watching your videos. Very helpful.
But this dude has a rigid frame, and you didn’t make him a springer seat?? Does this guy even have a spine anymore?
so for a 3 inch tube like that what would me the top and bottom widths for a 9 degree?
The width of the top and bottom is based on the Center Line Radius (CLR). The angle of the cut and diameter of the tube will not change the CLR. the CLR is only changed by the length (or width of top and bottom as shown in the video) of the pie cut itself. That length is based on whatever CLR you calculate.
how do i get this software?
Hi! I'm Q. I do love to make my own charge pipe for my projects and currently I am struggling to find some welder who can matches my standards!
I have arc welding machine but everyone keeps saying I can't use it for any piping related to the vehicles; but they do not provide me with an explanation! I tried to google it but I didn't manage to get my answer, so I ended up here, asking for your kind advice. 😇
this "pie cut" fabrication should only be used when there are no other options available, and for this particular application, there are pre-bent sections available off the shelf, and if you plan to do a lot of work or use some custom diameter tube, find a pipe bending shop and order those U bends yourself, the more you order, the cheaper will it be compared to off-the-shelf pre bent tubes, then cut required sections out for your particular bend in the pipe, and get a much MUCH better product than this method, which not only creates a turbulent flow in the pipe, but also takes a lot more time to weld
Welding the pipe like this looks awesome though and they don't have any turbulence issues that you are talking of
I am _very_ sure about what I wrote there, are you?
he will be back once he has looked up turbulence in the dictionary
The biggest reason for doing pie cuts is for creating a CLR that can not be bent, or changing the direction of the bend multiple times in a tight space. Turbulence is actually very low, and anything cut up the same way in a mandrel bend would produce the same issues. The only big killer to flow is too sharp of an angle.
I did not use the correct word - turbulance, it doesn't quite explain the problem, the issue with pie cut tubing is the repeated change in the cross section of the tube where your weld is, the gas flow will repeatedly have to expand/contract to flow through this tube - this is creating back pressure and messes up the flow, as I said earlier and you yourself mentioned - there are times when there is no other cost effective way - usually for large very thin wall tubing (65-80mm range), though this part usually is oversized anyway and the negative effect isn't noticeable
this is however important for headers, because you don't want to mess with the pulses before they hit resonator or a turbo, and there is no problem whatsoever to change bend direction - you do a perpendicular cut and rotate the next section as needed - perpendicular cuts in a bend are always round, this is a bad practice though too, it is highly recommended that after each bend there is some amount of straight - it isn't always possible, but good thing to keep in mind while designing the thing
so what is the best tool to use for achieving a small angle pie cut for home hobbyist. bench top band saw? my chop saw is not ideal..
I typically use the band saw for pie cutting. You can use a chop saw as long as you take your time and let the blade do the work - not your muscles.
+The Fabrication Series maybe I need to invest in some better blades then the cut off wheel type (waffle discs) any recommendations
I did my dual exhaust, straight out, had to go back to my book from my apprentership to work it out. I purchased 3" extractors, and then did my lobsterback cuts on my 4" pipes, and after 2 dayd on the tig I got it done, the two sides were within 5mm from eachother and it was lout as fuck on my 351 f100 truck.....
..
gosto de trabalhar com solda .é ví seu canal muito interessante que vc manja muito de soldas mig é tig é outro equipamento de soldas eu tou tendo aulas com vc amigo.obrigado por vc me aceita no seu canal. .!!!!
getting my miller soon can't wait to try pie cutting
dude you set up a shop now? followed my advise?
I was retired when I started this series in my garage. It was mostly to keep myself busy since I really can't stop working. 3 years of doing little to nothing was kinda boring. This series, my boredom, and many of my clients decided that retirement was not the way to go, so I opened up shop again.
9 degrees and then hydro
I live like 5 miles from the shop and I have a decent video camera and some lights. I should give you my number.
Right on Nick. The content has improved since the early videos. Audio has improved. But lighting could use some work. With a bit of production assistance, this could be the best "how to" on facebook. I hope he takes you up on the offer.
I almost made an investment into some better equipment. The only problem is expensive equipment combined with this environment (the shop) will almost certainly destroy it. If you would like to swing by and offer some input, I'd love to hear it. I am very serious about getting a small camera crew here at some point to help me bang out these vids a lot faster, but I really can't afford to replace damaged equipment continuously.
Metal dust destroys microphones, sparks and other dust will fade lenses, and soft boxes are almost always getting knocked over and/or can't get the right lighting in the space I am working in. Again, I'm open to suggestions. You're more than welcome to swing by and check it out.
Joanne Hart i
Rip fauxhawk
Do you do this fabrication as a living or your business? Your doing very well with your channel too!
Yes. I've been building custom cars, parts, furniture, and just about everything else for over 15 years professionally. I did retire once which is when I started this series in my garage to keep myself busy. Then I decided to get back into the shop since a lot of people seemed to really want more fab work and instruction (both clients and viewers). I have a shop again now in Vegas which is open to the public.
+The Fabrication Series I wish you the best of luck for your future! You have inspired me to try a lot of new fabrication techniques!
+The Fabrication Series I'm interested in entering welding or fabrication as a career. I know fab will be a hobby regardless, as I enjoy welding in my truck. how does this career treat you financially?
Financial success in this industry is largely based on you and your abilities. While I do earn a living by building very high end vehicles among other things, I'm not a millionaire. My early years were extremely difficult financially since my skills were limited. I still had to work a full time job while running my first shop. Your investment in tools and time to reach the point of financial stability in the industry is by far your greatest hurdle. You must continuously dedicate your time to achieve your success.
The other part of this is the people you see around you. There are tons of people that pick up a welder and call themselves Builder/Fabricators/Engineers while very publicly bragging about what they are doing. While there is nothing wrong with taking pride in your work, these people are often seen building for less than a year before they disappear. They essentially get ahead of themselves and their abilities which resulted in their financial and professional failure.
This industry takes time and dedication to continually achieve a greater ability. You MUST remember that there is ALWAYS something that you have to learn how to do, and someone ALWAYS knows more than you. You MUST remain dedicated to learning and be honest about your abilities. If you fail to do so, you will not achieve success in any portion of the industry.
I hope this information helps you a bit, and I wish you the best of luck!
The Fabrication Series Thanks a lot for the response; no surprise that i continue to gain knowledge from this channel. Keep up the good work!
CL +/- 1/2diameter X1.57 divided by # of segments.
I'm not sure I follow your formula. It doesn't seem to make sense as written.
The Fabrication Series let me see if I can explain it well enough. CL= center line, you need to know the size of pipe let say 2" and the actual OD of the pipe let's say 2.25"
The center line would be determined by the radius of the bend 2"X1=2 for short radius, 2"X1.5=3 for long radius or 2"Xany number just making the radius longer. I use Long Radius the most in my profession. So here is the example for 2" long radius. So CL=3 and half the OD =1.125
CL+ 1/2 OD X1.57 divided #of segments =heel
CL- 1/2 OD X1.57 divided by # of segments =throat
3+1.25=4.25(1.57)= 6.47÷4=1.67" heel
6.47÷8=.8" heel etc..
3-1.25=1.875(1.57)= 2.94÷4=.73" throat
2.94÷8=.36" throat
For a 45° or 22.5° bend figure out the 90 formula and use half the segments for a 45 or a quarter of them for a 22.5°. I wish I had the computer program to do this but I had to do it manually for my project. Thanks for the video it helps me see what the numbers represent.