# Thread: A question for the Gurus

1. ## A question for the Gurus

I have been asked by a friend to help him out with his RG500 motorcycle project.

He is looking to make performance exhausts. Yes they are available to buy but that is not the point of the exercise!

The bike is a 4 cylinder with a different routing for for each exhaust. But the basic straight line form of each can is identical.

Can I please get some ideas form those in the know on a process to follow to create a single straight can with variable dimensions(diameters at positions along a line from a zero point).
And then from that be able to "bend" the centre line to create 4 different configurations.
See the attached pic(borrowed of the internet) of what the final product would look like.

Once we have the final designs, each segment will then need to be flattened into a flat pattern for laser cutting, rolling and welding.

All ideas would be appreciated

2. I would draw a 3D sketch of strait lines inline. Each line being the length of each section you need.
Then create a plane on the end of each line and draw the cross section at that length point.
Then loft from one sketch to the next.
The 3D line can then be adjusted to the path for each pipe.

3. Hey "Bro"

I an perfect world yes, your idea works, but how do I manufacture it then?
The attached jpeg shows the exhaust in a straight line.
As you can see it is made up of 7 rolled sections and a pipe on the end.
I am going to have to driving line(3D sketch) and split it up into say 20mm a piece, straight lengths with a maximum deviation of 10°-15° between neighbouring lines.
The individual pieces would then be cut off where they intersect with the next piece of pipe.

One of the problems I have is that the driving(centre) line needs to a be a projected line dependent on 2 sketches(top and side view) Easy enough yes, but the projected line is what needs to be constrained to specific lengths.
Is this even possible in SW? I've never tried. I've created projected lines before but it has been the resultant of the 2 views and never constrained to a length. I will have to play a bit.

The second problem I have so far is...
The file I have created is a multi (sheetmetal)body part.
Is it possible to make a drawing of the flat pattern of each part for laser cutting? I have tried but you can only unsuppress 1 flat pattern at a time. And the drawing updates with the currently unsuppressed part every time I change(frustrating!) I'm obviously missing something!
Do I have to build it as an assembly?

I'm sure there are going to be more frustrations and questions but hopefully some one can help me with these 2 so far

Cheers
Craig

4. Originally Posted by Aquatic
...but the projected line is what needs to be constrained to specific lengths..... Is this even possible in SW? ......
Add the specific length dimension (end point to end point) to your sketch line after you have adjusted its angle.