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Hi all, We are working on a swing-arm upgrade for a trailer we are building out of aluminum. As seen in the photo below we have two identical pieces of pipe. Each piece of pipe has a 30 degree bend to them. As seen in the photos, both right hand ends of the tube were notched with a whole saw bit This is because there will be a vertical piece of pipe welded at this end where the 2 pieces of tubing will meet the vertical piece of tube. We then worked on hand filing the joint together. While it looks good in the photo below we are looking for a simpler/faster solution that can still provide a good tight joint. We realize the whole saw notch is good but in order for the two pieces of pipe to join the single vertical piece of pipe(piece with the black X) we need to cut the bottom/top of the corresponding tubes in order for them to mate properly. Are we correct in thinking that we need to cut a 60 degree piece off of each tube? and if that is correct, is there a measurement we can use to figure out where to start the 60 degree cut in the notch area? (in the fish mouth). For instance, how far from the center of the pipe should the 60 degree line start etc? Look forward to the tips, hopefully I explained it well enough.Cheers
Reply:I can't tell from your description what orientation things are in. I'd like to see a photo of a similar part complete, or a CAD drawing of what you are trying to achieve. I think you are talking about a two legged exhaust style collector, but its just not clear to me. (Collector: # of feeder tubes = 2) If you are talking about a collector, try this software... Its free, written by me. Those templates include the tube centerline intersections on them, so you can get lengths cut perfect. Take a look at the help/info buttons on 1) the simple tab 2) the collector tab and 3) the airframe cluster tab. Does your assembly look like any of the images pasted there?--ZipLast edited by zipzit; 10-25-2016 at 02:14 AM.
Reply:I understand what you are trying to do. Is this for production or simply for making a few pieces? If it's for production I think that I would make a couple of fixtures to guide the cuts.As far as the 60 degree cut, although that angle sounds about right it is impossible for any responders to calculate without knowing the amount of degrees in the tubing bends.Miller Trailblazer Pro 350DMiller Suitcase MIGMiller Spectrum 2050Miller Syncrowave 250DXLincoln 210MP
Reply:you can get a pipefitters blue book and it will tell you how much to cut off and where to start...There are a few videos on youtube that can explain the layout process
Reply:
Originally Posted by zipzit
I can't tell from your description what orientation things are in. I'd like to see a photo of a similar part complete, or a CAD drawing of what you are trying to achieve. I think you are talking about a two legged exhaust style collector, but its just not clear to me. (Collector: # of feeder tubes = 2) If you are talking about a collector, try this software... Its free, written by me. Those templates include the tube centerline intersections on them, so you can get lengths cut perfect. Take a look at the help/info buttons on 1) the simple tab 2) the collector tab and 3) the airframe cluster tab. Does your assembly look like any of the images pasted there?--Zip
Reply:
Originally Posted by zipzit
I can't tell from your description what orientation things are in. I'd like to see a photo of a similar part complete, or a CAD drawing of what you are trying to achieve. I think you are talking about a two legged exhaust style collector, but its just not clear to me. (Collector: # of feeder tubes = 2) If you are talking about a collector, try this software... Its free, written by me. Those templates include the tube centerline intersections on them, so you can get lengths cut perfect. Take a look at the help/info buttons on 1) the simple tab 2) the collector tab and 3) the airframe cluster tab. Does your assembly look like any of the images pasted there?--Zip
Reply:Er, no. I'm more confused than ever. I was hoping to see a COMPLETE ASSEMBLY, not just a CAD drawing of components that aren't arranged. I have no clue what is horizontal or vertical to you. I'm sure its clear in your head, but I don't understand at all where you want to go. Do you have a photo of what a completed "aluminum trailer swing arm" looks like? I'm looking for the big picture here. I don't understand what you mean by "2 pipes need to join the vertical pipe" I don't understand what you mean by "These ends just sit on each other" I want to verify.. we're talking about a trailer suspension swing arm, right? One of these:
Terminology (based on 30 years of design experience in an Detroit based Car Manufacturer): Best practice when discussing parts is to refer to their orientation in FINAL 'TRAILER' POSITION. (We actually used the words "in car position" whenever discussing parts.) Horizontal means parallel to the ground when installed in the trailer, not how it sits on a table when you are building it. Vertical means it sticks up straight in the air when installed in the trailer. Hence my confusion. I cant see how you'd have anything vertical in a trailer swing arm. I will say, I'm hoping you are making this for a bicycle trailer, something with minimal loads, right? As you know Aluminum doesn't have the best properties for repeated loading/unloading cycles. It gets brittle, and cracks and fails without giving a lot of warning.
Reply:
Originally Posted by zipzit
Er, no. I'm more confused than ever. I was hoping to see a COMPLETE ASSEMBLY, not just a CAD drawing of components that aren't arranged. I have no clue what is horizontal or vertical to you. I'm sure its clear in your head, but I don't understand at all where you want to go. Do you have a photo of what a completed "aluminum trailer swing arm" looks like? I'm looking for the big picture here. I don't understand what you mean by "2 pipes need to join the vertical pipe" I don't understand what you mean by "These ends just sit on each other" I want to verify.. we're talking about a trailer suspension swing arm, right? One of these:Terminology (based on 30 years of design experience in an Detroit based Car Manufacturer): Best practice when discussing parts is to refer to their orientation in FINAL 'TRAILER' POSITION. (We actually used the words "in car position" whenever discussing parts.) Horizontal means parallel to the ground when installed in the trailer, not how it sits on a table when you are building it. Vertical means it sticks up straight in the air when installed in the trailer. Hence my confusion. I cant see how you'd have anything vertical in a trailer swing arm. I will say, I'm hoping you are making this for a bicycle trailer, something with minimal loads, right? As you know Aluminum doesn't have the best properties for repeated loading/unloading cycles. It gets brittle, and cracks and fails without giving a lot of warning.
Reply:Lay it out how you want it and you can mark where the holesaw needs to be
Reply:
Originally Posted by roythayer
Lay it out how you want it and you can mark where the holesaw needs to be
Reply:Isn't that just a straight 90 deg fish mouth joint?ahh- I see what yer trying to do- you need to make 2 pieces fit together with an inside angle of 60 degrees?I think you want the saw set to 30 degree.Last edited by Broccoli1; 10-26-2016 at 06:05 PM.Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:
Originally Posted by Broccoli1
Isn't that just a straight 90 deg fish mouth joint?
Reply:i see...I would cut some from each a little at a time until it fits. Or experiment with scrap if you have some
Reply:This is a wee bit tougher with tubing because you need to make sure BOTH pieces are set up in the saw exactly the same.Square stock is easy peasy.Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:
Originally Posted by roythayer
i see...I would cut some from each a little at a time until it fits. Or experiment with scrap if you have some
Reply:30 degree on a chop saw to cut the tubing. You could then weld the 2 pieces of tubing together and then use the hole saw.example 45 deg gets you a 90 degree joint.Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:
Originally Posted by Broccoli1
30 degree on a chop saw to cut the tubing. You could then weld the 2 pieces of tubing together and then use the hole saw.example 45 deg gets you a 90 degree joint.
Reply:
Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:You can test up yer cuts with the cheap metal electrical conduit found at the box stores.Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:Chris, Lets talk first about tools. For this project, using aluminum, less is more. Save money. Work less, have fun. And its good to know this is a trailer for a bicycle and not one for a car. You will need access to:a printer (attached to your computer)a few sheets of papera pair of scissorsa roll of scotch tapea permanent ink marker / felt tip penThese are for making quick paper models of the joint.Chris for a start, use the software Its pretty obvious from your responses you didn't take much time to see what is available there. Oh, and did I mention, its free. No ads. Free. You have to use your mouse to click on the link. Nothing extra to download, works in your browser. For the vertical brace that runs from inside bend to inside bend there is no template that I'm aware of that will do EXACTLY what you want. You can get VERY close using the Airframe tab. Another choice is to mount the vertical 'brace' just to one side or the other of the bend. Choose the "Bracing" tab of the software, then create a "Bisector Bridge". Way easy. For the two ends that run into the horizontal "pivot" axis tube, I'd use the collector tab in the software. Select 5 legs (which gets you to exactly 72 degrees between the two tubes) or 6 legs (which gets you to 60 degrees) for "The Number of Feeder Tubes" Obviously you are only going to use two of those legs, so you will have to experiment on how to finish the joint a little bit. Use 90 degrees for angle between collector feeder and output tube ("Angle between feeder tube and centerline axis"). Print out the template on paper, full scale, cut on the lines. roll the paper up, use scotch tape and create a paper model. Play around with it, paper is pretty cheap. A whole lot cheaper then 3d printing feeder plastic. Play around with the paper models first so you have a good understanding of generally what things look like.Next series of tools you will need are:A hacksawa wooden block tube holder (so you can hold tube in the vise for hand filing, without damaging the tube) I make these out of 2x4" wood on the drill press.A few different lengths of half round files. Remember that in half round files, the length of the file determines the radius of the half round part. Try to find a file that has a radius equal or just a bit smaller than the radius of your tubing. (Ooops.. I don't need to tell you that.. you did read the suggestions on the Intro tab on that software link, right? All the file lengths and tube radii are listed there... )Access to a solidly mounted bench vise.Here's a sample of a tube holder. This is a pretty nice one, made of aluminum. Again, I just use scrap wood 2x4" and use one size of tubing per set of blocks.
You will use the paper templates to get things close, but cut the tube a bit longer than necessary. You will be hand filing the notches to fit, nirvana perfect. don't worry, with aluminum this won't take but a few minutes. Be careful, file, test fit, file test fit. When all done, you are ready to weld up. Good luck, let us know how this works out.--Zip.Last edited by zipzit; 10-26-2016 at 08:55 PM.
Reply:
Originally Posted by zipzit
Chris, Lets talk first about tools. For this project, using aluminum, less is more. Save money. Work less, have fun. And its good to know this is a trailer for a bicycle and not one for a car. You will need access to:a printer (attached to your computer)a few sheets of papera pair of scissorsa roll of scotch tapea permanent ink marker / felt tip penThese are for making quick paper models of the joint.Chris for a start, use the software Its pretty obvious from your responses you didn't take much time to see what is available there. Oh, and did I mention, its free. No ads. Free. You have to use your mouse to click on the link. Nothing extra to download, works in your browser. For the vertical brace that runs from inside bend to inside bend there is no template that I'm aware of that will do EXACTLY what you want. You can get VERY close using the Airframe tab. Another choice is to mount the vertical 'brace' just to one side or the other of the bend. Choose the "Bracing" tab of the software, then create a "Bisector Bridge". Way easy. For the two ends that run into the horizontal "pivot" axis tube, I'd use the collector tab in the software. Select 5 legs (which gets you to exactly 72 degrees between the two tubes) or 6 legs (which gets you to 60 degrees) for "The Number of Feeder Tubes" Obviously you are only going to use two of those legs, so you will have to experiment on how to finish the joint a little bit. Use 90 degrees for angle between collector feeder and output tube ("Angle between feeder tube and centerline axis"). Print out the template on paper, full scale, cut on the lines. roll the paper up, use scotch tape and create a paper model. Play around with it, paper is pretty cheap. A whole lot cheaper then 3d printing feeder plastic. Play around with the paper models first so you have a good understanding of generally what things look like.Next series of tools you will need are:A hacksawa wooden block tube holder (so you can hold tube in the vise for hand filing, without damaging the tube) I make these out of 2x4" wood on the drill press.A few different lengths of half round files. Remember that in half round files, the length of the file determines the radius of the half round part. Try to find a file that has a radius equal or just a bit smaller than the radius of your tubing. (Ooops.. I don't need to tell you that.. you did read the suggestions on the Intro tab on that software link, right? All the file lengths and tube radii are listed there... )Access to a solidly mounted bench vise.Here's a sample of a tube holder. This is a pretty nice one, made of aluminum. Again, I just use scrap wood 2x4" and use one size of tubing per set of blocks.
You will use the paper templates to get things close, but cut the tube a bit longer than necessary. You will be hand filing the notches to fit, nirvana perfect. don't worry, with aluminum this won't take but a few minutes. Be careful, file, test fit, file test fit. When all done, you are ready to weld up. Good luck, let us know how this works out.--Zip.
Reply:Port-a-band style.
Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:welded and then hole saw.
Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:Fit.
Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge |
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发表于 2021-9-1 23:16:30