You did a wonderful job explaining this and showing how it’s done, I’m 25 and it’s my first time running a small job and i needed a little refresher just to be sure I did it right, you’re the man thank you
I couldn’t remember if OWL was correct haven’t done sheet metal in years thanks for the short simple reminder RU-vid needs more videos like this for those who just need a quick refresh to assure the memory lol
The problem with cutting a simple miter as you've done here is that your duct grows. Small offsets aren't usually a problem but when you get into bigger offsets it will. I always train people in 3 piece offsets so your makeup matches and never grows. To do that, you need to make an arbitrary travel length in the middle of the duct in which the length is never shorter than the offset itself. You use the OWL formula only in the travel piece then divide your OWL x2. Lay out both side of the travel piece (add one inch to your travel AFTER using OWL if you're using a slip and drive connection), cut it out, then flip the center over. Put the three pieces back together and you're done. This also allows you to get a more accurate length on your total piece as you can just trim a little off of one end of the makeup to get it to fit perfectly and looks much cleaner.
Thanks for this tutorial. I had to fabricate my own 90 short way elbows because I couldn’t find any at the local home centers. Took me a little bit but disgusted out two ways of doing it.
I used this app I developed to calculate square offsets on Android phones. Works fine on site instead of guess work or eyeballing it... play.google.com/store/apps/details?id=com.simpleoffsetpro&hl=en_IE
Nice video you can do this a few ways with measuring width using half the distance to make your second mark then that is your first cutting angle. from those two marks measure 4.5 more inches from the first angle you just created for your second marks. I would like to see you make a true 45-degree angle in any duct video. Would you use this method with that also? offset x width / length = cut? just wondering what a true 45 is so when you have a reducer in the middle of the next offset and the duct size changes. How do you correct the true 45 in that scene?
The best way to offset ducts is the the three Piece offset. I usually do it just like i bend conduit . If you have to offset over 10 inches you have to use a speed square and use a 30 degree angle so you mark it on 15 degrees then make the line . After that you use your tape to measure over 10”(offset)x 2(30 degrees multiplier)+2” for s&d connection. Witch will add up to 22” . Then from that point you use your speed square again just like the first step.. you will now have 3 pieces.
if your offset is originally 4.5 inches how did it shrink to 1.8...is the point of this method to be able to just tap some rectangle duct together then make the offset appear after its put together rather than to make like a 4 piece transition measuring out the offsets on the separate peices?
When plugging in your measurements into the O.W.l formula, will the width vary according to which way you are offsetting? Example ; let's say you have a 14"x8" and you want to offset to the side(left or right ), will then the 14" becomes the width since it will be getting cut?
Dumb question but if you were to cut on the longer side will the Width change? Like for example let’s say your duct shown in the video is 16x8 and I want to cut it the other side will the OWL be: 4.5x16/20 ?
ok I understand the offset part but I am lost bcuz u don't explain where u get ur width or ur length from? I read on one of the comments that ur 20 is the space u needed between ducts but where do u get width from ....i would appreciate u sharing that with it would help me a lot in my job....thanks for ur vid and time
I'm glad I saw this review bc 20 inches s slip look like 20" long too..now I understand offset × width which means at this video up and down offset..( the drive side)÷ the length of the connection of drive to drive length
where did you get your length from? If I want it for a wait that's 20in long how long my duct has to be before I cut it knowing that I will loose some length after the offset is cut off and what if you do it with TDC Joints you don't have to add the 2 in?
The width used in the OWL formula uses the width of the side of the duct that is in the same direction of the offset. If you need a up or down offset you will actually replace the width with height for the equation. But if you need a left or right offset you will use the ducts width. Hope that makes sense.
So when you want to do a offset with the owl formula you put your offset measurement times drive with means height.. then you divide length which I am confused the length of the duck or the length of the S Drive
Don't need to cut inch for the s just snip the corners so you can bend them down to level. Also you'll find if you cut them a inch depending on your cut you won't get your hooks close enough. Always go half inch
Ok. So this can be SOOOO MUCH EASIER! 1st, why did you put the duct together? It's a lot easier to cut when it's not together. B: why are you marking an inch for seams? They're implied. The length is what it is. Lastly, your bird method is nerdy. Go to a wall, measure the length of the offset off the wall and mark the floor. Place your cut length at that mark and tilt it to the wall and measure the the gap from the floor to the corner of your piece. That's the cut. None of this converting .8 to 3/4 math (which was wrong btw). I actually have to do this today so maybe I can be a you tube guy and show you how much quicker and easier the big boys do it. Funny how ya didn't show what a pain in the ass it was to cut that duct after it was knocked together. Rooky
