SHOP MATH (Ep. 1): Convert Angular to Linear Dimensions 

As a former sheet metal instructor, it's great to see others enjoying the power of math in the trades! There's a positive correlation between math knowledge & money you earn!!! Don't ever fear math!

As a retired (old) home hobbiest welder and somewhat of a machinist I had the opportunity of letting a large local fab shop let me watch over a welder for a few hours. It was an eye opener for me, as welding was the smallest part of what was going on. In addition to the math you presented, there was the creativity they used to figure out how to repair some dimension parts that did NOT come with any reasonable instructions. Lots of common sense reason had to be used by the folks there. Thanks for showing other aspects of welding.

This is what I want to see more of. Theory side of welding. The practical has been regurgitate so much but you don't see anyone going into theory.. brilliant! 👍🏼

welding is the easy part fabrication is where you actually have to use your head

These are great videos I hope that you continue to do more math related videos. I use these videos with my students and these are great ways that they can see how math is an important part of the welding field.

This has got to be the most informative video uploaded to RU-vid on the day it was posted!

To simplify the formula, Pi x Dia. x angle divided by 360. Gives you the same answer. Also you may need to account for material thickness as well. Great vid as always sir

I have been a structural fitter for a year and a half. High school math is 10+ years in the past. These videos serve as a great refresher and I enjoy your presentation. Very informative. Keep up the good work.

As always, a great video. One thing I would mention is the very last part of the equation when you converted 55.5" into feet, you rounded to 4.62' but leaving off that last decimal(55.5/12=4.625) can have consequences at bigger amounts. For this video it was only a 1/16th difference. Thanks for the video, I didn't know how to do this!

You are quite an educator sir! I did not know you could divide inches by degrees. Very helpful.

This is what i love about fabrication, solve the puzzle, then weld it together. Thank you bob!

ABSOLUTELY LOVE THIS VIDEO!! I’ve been stuck on this problem for days!Exactly what I needed for my my project!

You are very good at breaking the "complex math" into simpler terms. Thanks.

in school I quickly realized the value of math. many times I would read the bosses prints and would find he was wrong on some numbers he came up with. it's good to do that before you start cutting.

this is a great video for experienced and inexperienced welders love it

Really well done. I carry a fabric tape measure in my kit. Marked in inches and centimeters. The math you demonstrated is accurate and simple. I am a welding student at American River College, Sacramento. Math is stressed in the early classes.

Better than any Math teacher I had in high school!

thank you, I knew it was simple. But the process escaped me and made it feel more complex. It's funny that i actually learned all of this just 2 semester's ago.

I have been welding 28 years in the industry. I know the that all calculations should be done on the prints. Shop is to build and produce not to calculate, that for people drawing the prints. This video was awesome and your other Shop Math videos. I have a very strong CAD knowledge and this is one of my pet peeves. Back before CAD I could see this being a problem. We as welders have to execute our operations at 100%. Draftsmen and Engineers should do the same. Pride in your Craft.... Just my two cents... Love Your videos Bob!!

I love the applied math lessons. Thanks a mil!

Very interesting to see matg at practice again!!! Havent seen this in a while!! Not a tech whatsoever but thought I see what shop math is like at least for this equation.... awesome teacher!!!!

Explained very well,, I've done this very thing lots of times.

I went to school for fabrication and just now find your amazing helpful videos…. Dang

wow the metric system, i think is way easier, the last part of converting into feet, we dont need to, its all in millimeter, but great video, always nice to get it refreshed Thanks

While Not a Welding video in the usual way, this video is still a very useful and important video. Interpretation of drawings correctly is what makes the difference between a welder and a tradesman. You can claim to be the best damn "Gun" welder ever, laying down beads that make people drool, but if your welding of one component to another is done in the wrong place and/or at the wrong angle/orientation, then it dont matter for shit, because someone with better skills will have to come along and rework your botched up job. Trouble is Mr Gun Welder, you wont get to see just how much work is involved because you will have already been sent on your way down the road. Every trade and occupation has "Gun" operators who end up creating more work for "Real" tradesmen and women to fix up.

Now I can calculate it without asking my super ! I always hate having the super figure things out for me. Great lesson.

Great Job Teaching Shop-floor Math...Welding Layout is Awesome. T J (Tom) Vanderloop, Author, Teacher & Manufacturing Consultant; AWS & LSME Member

Aww man makes me laugh and he’s right on the money at same time. Good stuff!

Great Review and a Big Thanks! T J (Tom) Vanderloop, AWS Member and Layout-instructor

Cool video. I like this guys style.

Great vid! Do some more welding math problems!

Sure did help Bob... thanks

Wow that was awesome

Can you do more videos like this please this was so informative and helpful thank you so much

You could also simplify by converting the angle to radians and just multiply by the radius. The length of the arc becomes (37*pi/180)*86 = 55.54 inches

Awesome!! Thank you!

This is awesome. thank you

GOOD JOB !

I had a job that needed 90 degree bent roundstock with a certain radius length in addition to the leg lengths bent from a single straight piece cut to length as to not waste material. We did our best guess and then added a bit to get the correct length after a test piece, but knowing the correct way to do it would have been really useful. It was .25 * pi * dia + leg + leg. Also I need to relearn all that triangle BS from geometry.

Great video ! I use this formula all the time , (dia. × π ÷ 360) × degrees = you measurable distance. That is a priceless lesson when working with round parts. Just make sure the engineer gives you the freaking diameter haha

55.536 inches is the Arc measurement. 54.576 inches is the Chord measurement ( straight line with steel rule ) for 37 degrees on a 172 inch Diameter.

More math fabricating videos like this would be awesome. Thank you so much, I learn so much from you. You rock!!!!

Great video Bob. I'd have to use a calculator though.

and now i know! thanks for the theory.... 😃👍

No, Thank you… Very well lecture. Instructor broke everything down to convey this problem.

Thank you.

Great explanation, you'd be good at core math. I would use a proportion to solve. And leave it in inches but that's just personal preference 540.35"/x = 360/37 X=55.53"

Helps alot

Thank you so much

This helps.....................Cheers

"how bout that" XD Great video, but that cracked me up.

Wonder if there are any good series for fabrication? Ive been welding 8 years now and I learn something I feel like I should have known within my first 2 years every few months. Every fabricator Ive ever been around that was worth a damn acts like its a secret recipe or something and when you catch a trick they use and start doing it, I can always tell somehow that theyre shocked in some kind of way.

Nice nobody has ever trained me on stuff like this but I figure this out by myself good to see the pros do the same but I need some help with triangles building some wine racks over here

I need to go back to first grade math🤪

Radius x degrees(37) x sine (.01745) would also do the trick

can you please cover how to change a decimal point into fractions of an inch as i only know millimeters and thats ok till i only have fractions for drill bits and need to drill and tap a thread

nice

holy heck the imperial system is inefficient AF example 7'-2" is 2184.4mm ... x 2 = 4368.8mm x 3.1416 = 13725mm / 360 = 38.125x37 = 1410.6mm. No need to convert from feet to inches and back again, just move the decimal point over!

If the nozzle is 37deg,from 180 deg,can it be subtracted (143deg)& worked out in the same manner from zero deg & equals the same? I know it would be a longer measuring but can it?

I wanna know how to convert 11/25 to 7/16

What was the formula to get the .62 to 7 and 11/16”?

Interesting and informative. Why didn't you leave it at 55 1/2 inches? was there a reason?

Can someone explain where the 12 came from

Okay I'm interested, but before I get started, I want to say, I didn't learn the unit circle with 270 over yonder. How can 270 & 0 be only 90 apart? Now I will watch.

I lost an 1/8" somewhere...ugh! Sure wouldn't try for a sixteenth.

Trust me it helped

Hmm. The video was published today 11/18/2016, but there are two comments from a month ago. How does that happen? That doesn't add up.

It’s very important to point out that this is NOT a “linear” measurement. This is an arc length which is a measurement wrapping along the circumference of the circle. You’d have to use a fabric tape measure or a string marked with the dimension to lay out the feature. Getting the straight linear dimension from point a to b requires trigonometry.

My boy is wicket smaat

I broke my own heart thinking I could be a fabricator, but I’m terribly behind in math, so now it just seems unrealistic. 😭

Learning this is really hard for me because I don't pay any attention

Is there a math book for welder you recommend?

oh they help , still don't understand it, it's just a fuzzy picture to me when it comes to math .

Fun fact my teacher got mad at me for doing the formula wrong. I did. Radius times 2 times pi. The book told me to do Radius2 divided by 2 times pi2 Smh

Just thought of something Bob..... a guy could use this math to draw a pentagon, octagon or whatever shape that would start with a circle.

Eu prefiro ver você soldando!!!

If only we had some scientific engineering calculator on a smartphone that everyone has on the job these days.

55.5 inches is actually 4'7-1/2".

Just to reiterate and continue the common-sense approach to doing fabrication math, one should realize rather quickly that 55.5" cannot be 4' 7-7/16. When one starts with X.5" then the conversion to feet must come out A' Y-1/2". The error here is in the rounding. Or, as a lab tech would say, an error in significant figures. 55.5 / 12 = 4.625, which would round to 4.63 rather than 4.62. However, in either case, the proper measurement would be 4' 7-1/2". To do the calculation more accurately: 1) divide the decimal inches by 12, then keep only the whole number, dropping the decimal remainder. In this case that is 4, which is the number of whole feet in the final answer. 2) subtract the number of whole feet x 12 (in the example 48) from the original number: 55.5 - 48 = 7.5. Again keep only the whole number (7) which represents the whole inches in the final answer. 3) Take the decimal remainder from the inches calculation (0.5) convert it to a fraction (1/2) which represents the fractional inches in the final answer: 4' 7-1/2" However, I fail to see the need to convert to feet and inches from inches because 55-1/2" would be way easier to work with than 4' 7-1/2" on every tape measure I own. Interesting, but irrelevant, side note: The actual length of that arc is going to be just a shade over 55-17/32" and can be calculated even easier by multiplying the radius of the circle by the central angle in radians. To convert degrees to radians simply multiply the degrees by a constant of 0.0174533.

do it in metric and it's way easier

These is like learning Chinese for me. This bums me out that I cant be a welder because I’m terrible absolutely awful at math. Numbers are my enemy

What even is inches lol

Lost me. How did you go from 4.62 to over 4.7? The onscreen math doesn't add up. It doesn't help your standing in front of the math on the white board.

That was painful to watch. So many inaccuracies in the measurements! I don't understand how anyone could use those units of measurement.

Why not use mm like the rest of the world!😉

imperial measurements because fuck logic.