Can anyone tell me how to draw this wheel.

rob_white

mahir

I see this being done in 4 features and 3 sketches.

1. Sketch the cross-section without ribs.
2. Revolve to make the base wheel.
3. On the same plane as the first sketch, sketch the rib.
4. Extrude the rib symmetrically.
5. Sketch the triangular cut.
6. Extrude cut the triangle.
7. Create a circular pattern of the rib and triangle extrudes.

Steps 1 and 3 can be combined into a single multi-profile sketch if you like.

rob_white

Thanks to both of you, yes I am new to CAD. I am about to start the construction of a steam truck which has imperial plans. I am converting the design to metric.

rob_white

I can revolve the spoke section bu can not work out how to remove the cutout sections as they are not on a plain but a cone.
Also can not work out how to apply the webs.

Thanks in advance

jason_bennett190

Have you tried drawing sections of A-A and revolving however many degrees are required to make a cutting tool, then do a boolean subtraction?.

mahir

I see this being done in 4 features and 3 sketches.

1. Sketch the cross-section without ribs.
2. Revolve to make the base wheel.
3. On the same plane as the first sketch, sketch the rib.
4. Extrude the rib symmetrically.
5. Sketch the triangular cut.
6. Extrude cut the triangle.
7. Create a circular pattern of the rib and triangle extrudes.

Steps 1 and 3 can be combined into a single multi-profile sketch if you like.

rob_white

Thanks Mahir,

I have got this far, see link

I can not see how to draw the "triangle" (extrude cut) as the disk is actually a cone.

Thanks for your help so far.

NeilCooke

There's always a number of ways to model everything - here's one way:

https://cad.onshape.com/documents/939a97756eb249052a46905d/w/e9abac8a47150b24bf08c1d8/e/a1585b740f333719febb3b0f

rob_white

I have now managed to draw the extrude remove but can not do a circular pattern on the feature! 
Anyone know a work around? Other than draw it 8 times!

mahir

@rob_white, the main body is conical, but the triangular hole is just a simple linear extrude. Draw the triangle sketch on either a plane perpendicular to the center axis or on the flat upper/lower edge of the wheel. Once that's done you should be able to circular pattern the extruded cut around the center axis. You can select the outer surface of the wheel as the pattern axis. 

Seems like you're new to 3D CAD. OS has some good tutorials. I would go through those. They're much more explicit. 

mahir

Here's another model to look at. Although, Neil's looks better since the rib radii would be cut on a lath, not thickened linearly.

https://cad.onshape.com/documents/57acdfaae4b005c413ed9b6f/w/3fd585a46d3af1b3ba413c53/e/900941813cb19e709ef9c759

rob_white

Thanks to both of you, yes I am new to CAD. I am about to start the construction of a steam truck which has imperial plans. I am converting the design to metric.

rob_white

Here's the finished articles, The larger grey one thanks to Paul.

My main problem was with the circular pattern tool! I did not see the top drop down to change from replicating a part or feature it being above the New, Add remove .... options and also I had not realized that you could specify the axis from a circle (the rim).

Hope this helps someone.

srbh

Dear Rob,

I'm building a 2" scale Steam Traction Engine from imperial plans as well.

What are you building?

Regards

rob_white

Atkinson 3" scale 'Standard' 6 ton truck

owen_sparks

rob_white said:

 I am converting the design to metric.

Hi @rob_white, you're probably well aware of this but if not OS is perfectly happy to work in metric / imperial or both units at the same time and do all the conversions for you.

For example if you have your default units set metric, you can still enter "1/8 inch" into a dimension field and OS will work out the conversion.  It can also use expressions so you could enter "(3 * 7/8 inch) + 10mm" as a dimension.

I imagine NASA may have found this useful when designing Mars landers...

Regards,
Owen S.

rob_white

Yes thanks I was aware. I have opted to do all conversions/roundings in a spreadsheet for various reasons.