kjetilhansen Posted December 15, 2015 Posted December 15, 2015 Hello all I have for a while now encountered a big problem for me drawing a helix in Autocad in 2D. This also include the calculations What I am trying to do is bend som acrylic plastic in a helix, but to do this I need to draw it and print out a 2D drawing of the helix, wrap it around a rod that is the ID of the helix... Is there somone that could spare 2 minutes to help me with this drawing? The helix rod is 4.8mm thick the helix should be 95mm high (+ - 5mm) the ID for the cylinder is 24mm and I am hoping for 4 turns... If anyone wounders, I am making a replica of a movie prop from the movie Resident Evil, and need to bend the acrylic that is seen inside of the cylinder, Ill attatch a picture of my progress this far. Quote
lrm Posted December 15, 2015 Posted December 15, 2015 Do you want something like this? If so add a helix with the following parameters- Base radius 14.4 Top radius 14.4 Turns 4 turn Height 95 ~Lee Quote
RobDraw Posted December 15, 2015 Posted December 15, 2015 Why struggle with doing it in 2D? Making it in 3D is so much faster and is easily converted to 2D, if it is necessary. Quote
TheCADnoob Posted December 15, 2015 Posted December 15, 2015 Hello all I have for a while now encountered a big problem for me drawing a helix in Autocad in 2D. This also include the calculations What I am trying to do is bend som acrylic plastic in a helix, but to do this I need to draw it and print out a 2D drawing of the helix, wrap it around a rod that is the ID of the helix... Is there somone that could spare 2 minutes to help me with this drawing? The helix rod is 4.8mm thick the helix should be 95mm high (+ - 5mm) the ID for the cylinder is 24mm and I am hoping for 4 turns... If anyone wounders, I am making a replica of a movie prop from the movie Resident Evil, and need to bend the acrylic that is seen inside of the cylinder, Ill attatch a picture of my progress this far. Im not sure a printed 2D helix is what you need. if you wrap a 2D print of a helix around a rod as a template, it wont be a helix.. unless i'm just really missing something. you would wrap a straight line around a rod to get a helix so you don't need a drawing of a helix but a straight line. If you don't know the size of the rod you need to bend around i believe you can subtract twice the diameter of the helix rod from the ID of the tube which is 14.4 (I might go a little smaller to ensure it actually fits with in it) You can just mark even spaced points on the face of your bending rod to get the number of turns you need. THe only complicated thing that would require drawing is if you are limited by the length of your acrylic. If this is the case you can solve this by considering each turn as the length of a hypotenuse of a triangle made up of the height/n (n= number of turns) and width (width is the circumference of the ID) once you figure out the hypotenuse you multiply that by n and if your acrylic isn't as long as n times the hypotenuse the you acrylic isnt long enough you have to reduce your n or turns EDIT: rough calculation is something like 318 mm of acrylic rod around a 14.4 OD rod... unless i totaly noob it up lol Quote
ReMark Posted December 15, 2015 Posted December 15, 2015 The object you are trying to create is real (3D) so why not design (as Rob mentioned) and print the helix in 3D? Quote
kjetilhansen Posted December 16, 2015 Author Posted December 16, 2015 I just drawed the helix in 3D and projected it to 2D, and then read the post to mr. TheCADnoob, and he is right, I need to make a 2D drawing that I can glue on a rod, and heat and bend acrylic around. I remember I tried to draw this abot a year ago, but failed, I can't remember what I did wrong, but I belive I had some problem with the calculation of PI... Quote
steven-g Posted December 16, 2015 Posted December 16, 2015 (edited) When you flatten it out, you will just have a straight line, the only thing you need to find is the circumference on the inside of the helix. This will depend on the diameter of the rod you have to bend around, just alter the width of the flat drawing to suit the circumference. Edited December 16, 2015 by steven-g Quote
kjetilhansen Posted December 16, 2015 Author Posted December 16, 2015 Thank you all for the help The helix was not perfect, but good enough for what I was doing It does need some tweaking, but this is a quick fix. Quote
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