topic Re: Bicycle handlebars...help... in Fusion Design, Validate & Document Forum

Bicycle handlebars...help...

Anonymous — Wed, 31 Aug 2016 21:53:27 GMT

I'm trying to make a bike handlebar without a lot of progress.

I'm using the tube command...but I don't think this is wise.

The problem is the tubing is 7/8" OD with 1/8" thickness...except for where the stem grips it. How do I enlarge this section of about 2" (linearly). That diameter is 1.25"

Also, the bars have three sections:

the bottom bar (attached to stem)

the riser

the grip.

The bottom bar and riser are on the same plane, but the grip angles toward the rider 15d.

Any help?

Big Thanx!

-G

Re: Bicycle handlebars...help...

JamieGilchrist — Wed, 31 Aug 2016 23:19:39 GMT

Hi GPriv,

are you trying to create a road style drop bar or more of a mountain bike style flat bar?

something like this? https://gallery.autodesk.com/fusion360/projects/19939/bike-handlebars?searched=

Re: Bicycle handlebars...help...

Anonymous — Wed, 31 Aug 2016 23:35:14 GMT

I was in the process of adding a picture then I couldn't edit the message.

Here's one side. Was going to mirror it after completed.

Re: Bicycle handlebars...help...

Zephyr958 — Thu, 01 Sep 2016 00:16:48 GMT

Hello, GPriv,
Try this,
At end circular section exactly where you were about to mirror , Add an offset plane at zero distance, then sketch two circles on that plane 7/8 and 1.25" then extrude the area between the circles in two directions to your required distance, with conditions set to join. That should do it
Good luck

Re: Bicycle handlebars...help...

TrippyLighting — Thu, 01 Sep 2016 00:43:46 GMT

Use a loft on with profiles sketched on planes along a path.

File is attached for study.

Re: Bicycle handlebars...help...

Anonymous — Thu, 01 Sep 2016 06:37:26 GMT

I get this:

I created a 3D of the line because it has a 15d angle toward the rear.

Did I miss a step?

Re: Bicycle handlebars...help...

Anonymous — Thu, 01 Sep 2016 06:41:20 GMT

if I click the next in line, I get a window warning saying it cannot reverse direction.

I tried clicking the circles going the other way, starting at the center of the bars, and I get the same warning window upon clicking the last circle (at the top of the bar).

Re: Bicycle handlebars...help...

Zephyr958 — Thu, 01 Sep 2016 14:48:57 GMT

Hi, GPriv.
The beauty of Fusion 360 is that it allows room for unlimited solution to your design.

Here is how I did it;
In order to extrude this coupling over the extruded pipe, the last 2-3 inch section in your sketch and therefore the pipe, near the mirror plane must be of a straight line not a spline.

On a an offset plane draw two concentric center diameter circles if you want the section to be hollow.

Instead of extruding as Join, I used new body, mirror, Finish by converting the bodies to components, and then assemble with as built joints, fillets etc..

Re: Bicycle handlebars...help...

JamieGilchrist — Thu, 01 Sep 2016 17:10:11 GMT

Hi GPriv,

I took TrippyLighting's (thanks TL) model and made a quick screencast showing two different approaches to your modeling problem.

1. is using the loft command. This shows the picks through the loft command to get the result. In TrippyLighting's model he does a second loft to create the hollow of the tube (i did not show this in the video but the steps will be the same, just the profile selections are different and a cut operation to remove the material)

2. Using the pipe command to get the primary shape of the bar, then the loft command to get the swaged area for the stem clamp. I then use the shell command to get a consistent wall thickness.

happy to answer any other questions

Hope this helps.

Re: Bicycle handlebars...help...

Zephyr958 — Thu, 01 Sep 2016 18:59:28 GMT

Using the loft tool is a nice approach if you are making a virtual prototype, your design did not factoring in the 15 degree angle toward the rider. Approaching this from a practical stand point, if the entire length of the handlebar 7/8 OD will be made from 7/8" tubing using a bending machine, it would be impossible to expand the center section to a dia of 1.25 inches. In the shop this solution will work only if made in two pieces, then with a swagging tool expand the end of each section. However swagging the end will reduce this section thickness of the handle to about 1/16" making it weaker and harder to weld. Using a coupling then welding will make this section stronger. Just saying

Re: Bicycle handlebars...help...

JamieGilchrist — Thu, 01 Sep 2016 19:10:58 GMT

actually butting is a more typical process used to create the variable diameters throughout the bars without making half and welding. http://www.pinkbike.com/news/spank-handlebar-777-how-its-made.html

just saying 😉

Re: Bicycle handlebars...help...

Anonymous — Thu, 01 Sep 2016 19:15:38 GMT

Thanx, everyone.

Just jumping on now to read the replies--will get to the task a little later.

Just wanted to express thanx.

Also, this is for aesthetics purposes and training with this particular stem.

It is the only stem I have access to as a STEP file--and I didn't want to waste time building one in 3D.

The actual stem will have the 25.4mm standard (this one is the 31.8mm "new" standard).

Re: Bicycle handlebars...help...

Zephyr958 — Thu, 01 Sep 2016 19:35:33 GMT

The only part of the video playing are the commercials, the actual how its made video refuse to play Didn't know you guy are so thin skin. If how it's made videos, are the your best reference to explain your solution, I hope you are not designing handlebars. Run the two design through a stress and strain analysis, then show the failure results. That particular section of the design should be the strongest part of the handle. I rest.

Re: Bicycle handlebars...help...

TrippyLighting — Thu, 01 Sep 2016 20:38:45 GMT

@Zephyr958 wrote:

I rest.

That's not a bad idea!

Re: Bicycle handlebars...help...

Anonymous — Thu, 01 Sep 2016 22:36:27 GMT

I loved that video. Huge fan of "How Things Are Made" despite my gfriend's constant ribbing.

I don't understand the seemingly barbed retorts here, but whatever...

My way of solving my problem was a combination of what I had and the Pipe command. I added three circles in succession at the bottom tube and used the Loft command to join everything. Then mirror. Then rigid joint.

Thank you again.

-G

Re: Bicycle handlebars...help...

Zephyr958 — Fri, 02 Sep 2016 01:54:20 GMT

First let me say I respect you as a master, but as you must know one cannot be a master if you don't challenge the master. I normally don't follow. I was following your advice that the best idea is to rest. However, someone made a private request about fusion 360 ability to perform stress test, and I believe the answer is yes it can. If that person need a definitive answer they should ask a master with your credentials, or refer to the video in this link. https://www.youtube.com/watch?v=JdtkFheshB0

Re: Bicycle handlebars...help...

TrippyLighting — Fri, 02 Sep 2016 02:09:33 GMT

Please elaborate what the initial question by the original poster has to do with stress analysis ?

Re: Bicycle handlebars...help...

Zephyr958 — Fri, 02 Sep 2016 02:16:58 GMT

The request is for further info please see below

"You mentioned "stress analysis" on one of your posts-- is this offered in Fusion 360? I'd love to use it on my bike frame."

Re: Bicycle handlebars...help...

TrippyLighting — Fri, 02 Sep 2016 02:24:09 GMT

Ohh. Sorry! My bad!

Yes, you can do static stress analysis. In order to do so you'll have to change from the Model workspace into the Simulation Workspace and then others hopefully can help.

I've not used this aspect of Fusion 360 as I don't need it for my work. Thermal analysis is more interesting to me, but I've not used that yet either.

Re: Bicycle handlebars...help...

Anonymous — Tue, 06 Sep 2016 18:15:59 GMT

My solution was two-part (stated above).