This something I do quite often yet I always struggle with. The bends always come out looking funny. Does anyone have a tried and true method for doing this? I'm getting sick of trial and error.
What problem are you having? A standard elbow is 1.5 times the nominal diameter, so the centerline radius of a 6" pipe is 9", then oftset that centerline by half the actual pipe diameter (6.625 / 2 = 3.3125), connect the ends and that's an elbow.
There are several third party piping products out there, among them are :
See if this helps...
Draw two 10' long, 4.5" OD conduits intersecting at 90° at the southwest point (imagine the capital letter "L").
- Construct the first conduit ("horizontal" rectangle) from #0,0 to @120,4.5
- Construct the second conduit ("vertical" rectangle) from #0,4.5 to @-4.5,120
- Create centerlines along the longer axis for each conduit. You will have a horizontal xline through #0,2.25 and a vertical xline through #-2.25,4.5
- Since pipe bends are calculated from the middle of the pipe, the intersection of those two xlines will be the point to offset. This point should be #-2.25,2.25 (FOR BOTH FILLETS !!)
- You will need to know the proper bend radius of the conduit, pipe or tube material. In this example, we'll use 4 times the outside diameter or 18 (4×4.5)
- Create a point from #-2.25,2.25 offset @18,18. This should be at #15.75,20.25
- Explode the two rectangles (you won't be able to fillet the rectangles correctly if you skip this)
- Create the inside fillet. Start the FILLET command, specify RADIUS and select the point at #15.75,20.25 then select the point <270° to the horizontal conduit (this should be #15.75,4.5. The radius length will be 15.75). Select the two inner lines to fillet. End the FILLET command.
- Create the outside fillet. Start the FILLET command, specify RADIUS and select the point at #15.75,20.25 then select the point <270° to the horizontal conduit (this should be #15.75,0. The radius length will be 20.25). Select the two outer lines to fillet.
- Trim and/or erase any temporary and construction lines.
Once you get the hang of it, you can easily consolidate this process to about 3-4 steps. HTH !