Spoked wheels in CAD

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dnevil
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Spoked wheels in CAD

Post by dnevil »

Here is a nice step-by-step explanation for designing spoked wheels in CAD:

http://www.pacificlocomotive.com/process.php

These are the same essential steps I've used to design spoke wheels in Fusion360.
Driver with light counterweight for American locomotive 4-4-0 in Fusion360.
Driver with light counterweight for American locomotive 4-4-0 in Fusion360.
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Tsukunea
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Re: Spoked wheels in CAD

Post by Tsukunea »

To add to this discussion:
Another user-friendly alternative to Autodesk Fusion is Dassault SolidWorks. I have instructed classes on modelling in SolidWorks and can offer advice to any who need it.
2020-02-16 (1).png
7.5" Gauge 9" Driver
datman
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Re: Spoked wheels in CAD

Post by datman »

Hi Tsukunea,

I am drawing some wheels in Solidworks. Do you use the same method for creating the spokes as mention in the above web page?

Thanks
Ian
datman
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Re: Spoked wheels in CAD

Post by datman »

I have it sorted now, I forgot I had gone back over my wheel models and got a satisfactory result.
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BR55 Wheel.png
Tsukunea
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Re: Spoked wheels in CAD

Post by Tsukunea »

Hi datman,
Sorry for the delayed response. My method of spokes is basically the same as the method dnevil linked to. I draw on the top plane, extrude to the rim, and make a circular pattern around the base of the wheel.
2020-02-18 (1).png
datman
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Re: Spoked wheels in CAD

Post by datman »

Hi Tsukunea,

Thanks. I did similar on my second attempt, except I lofted from 2 sketches. My initial attempt was messy and I was using surfaces tools etc.

Ian
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ChipsAhoy
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Re: Spoked wheels in CAD

Post by ChipsAhoy »

Ohh, I am starting on a set of spoked wheels today....timely! I have switched to OnShape, but the sequence is the key here.
I just about missed this thread tho, perhaps see if Mods might place it in "All things Cad and Cam" section.
Scotty
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Harold_V
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Re: Spoked wheels in CAD

Post by Harold_V »

ChipsAhoy wrote: Wed Feb 19, 2020 9:37 am <snip> perhaps see if Mods might place it in "All things Cad and Cam" section.
Scotty
Because of the limited readership in that forum, moving this thread would not be a good idea, as it is related directly to the topic of live steaming.

In lieu of moving the thread, I have created a new thread in the All Things Cad & forum and provided a link to this thread, making it easy for those with an interest to navigate to the thread in question when reading the All Things Cad & forum.

H
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AnthonyDuarte
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Re: Spoked wheels in CAD

Post by AnthonyDuarte »

These methods are perfectly fine if you only need to create a representation of the driver in your CAD model, and will be purchasing a driver casting. However, if the intention is to make your own driver pattern, draft needs to be taken into consideration.

Below is an example of a driver drawn as a true scale model off of full-sized blueprints.

First, the outside of the casting (drawn here without stock for the tire) must have draft. The parting line is typically near the back of the driver, so the spokes, rim, and center boss are drafted in two directions. The inside edge of the outer rim (not sure what the proper terminology is) should be a curved surface, sometimes made up of more than one radius. The narrowest point, or smallest ID, should be at the point of the parting line.
Driver Rim Profile.jpg
I always draw the center as a loft so I have full control over the geometry. Two profiles are drawn for the loft operation, and a number of guide curves are drawn so the boss comes out correctly.
Driver Center Boss Side View.jpg
Driver Center Quarter View.jpg
Every drawing I've ever seen has the same basic spoke profile with differences only in size and severity of the taper.
They are defined by 2 profiles at two points along the spoke.
Driver Spoke Profiles.jpg
Driver Spoke Loft.jpg
When lofting the spoke, be sure that "merge solids" is not selected. This will leave the spoke as a free body that can be more easily patterned around the driver. Sometimes issues arise when patterning the spoke as a feature rather than a body. Patterning free bodies and then merging the solids afterwords has always proved successful.

Then fillet until your heart is content. Make the fillets as large as your CAD software will allow. They need to be bigger than you think. Sometimes this takes some fudging.
Driver Front.JPG
Tsukunea
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Re: Spoked wheels in CAD

Post by Tsukunea »

@AnthonyDuarte - Using a loft with that odd tangency on the back seems overly complicated and hard to dimension. I've always drafted outward from the outside face of the wheel. Are you using an IBLS standard profile for your drivers or are they blind?
2020-02-21 (2).png
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gwrdriver
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Re: Spoked wheels in CAD

Post by gwrdriver »

AnthonyDuarte wrote: Thu Feb 20, 2020 12:44 pmThen fillet until your heart is content. Make the fillets as large as your CAD software will allow. They need to be bigger than you think.
Anthony, that's more like it! And I'm glad you brought this up . . . I was keeping my mouth shut, to avoid being seen as critical of something I've not done myself or contributed to, but to my eye the examples so far could use quite a bit more filleting. Your photo example shows a considerably improved appearance. To be sure, there were probably drivers with very little fillet, but the vast majority tended to be generously filleted.
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jcbrock
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Re: Spoked wheels in CAD

Post by jcbrock »

Tsukunea wrote: Fri Feb 21, 2020 11:30 pm Are you using an IBLS standard profile for your drivers or are they blind?
I'd hazard a guess these are from Anthony's SP S-14 project, and he is using a tire.
John Brock
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