Another spoked wheels tutorial

[airportkid]

This is such an outstanding tutorial I got into Excel and applied its principles to create a general purpose template graphic so as to avoid all the tedium of plotting by hand with protractor and straightedge. The graphic has two inputs: total number of spokes (integers evenly divisible by 4 from 12 to 44) and hub radius as a pct of inner wheelrim radius. You can very quickly establish all the correct proportioning using a "slider" to set the hub radius.

I have one quibble that perhaps only those pedants who add valvestems would care about: the spokes should be plotted to the INNER wheelrim radius, not to the outside edge of the wheel. Plotting to the outer edge makes the spokes' intersections at the wheelrim unequally spaced. At the scales we deal with the differences are so minute it's practically negligible, but if you take the trouble to build a spoked wheel designed to be faithful to what spoked wheels actually look like, it's a point to keep in mind.

Many thanks for the superb tutorial.

I'd've attached the Excel spreadhseet with the graphic but don't know how - if interested in it PM me & I'll email it to you.

[Mirco]

Thank you.
Graphics in Excel? Interesting, I didn't know it is possible. I used a CAD for the drawing.
Files can be attached by that paperclip () button on the toolbar above (hope we both have the same configuration).

Of course, the INNER rim side. I wrote that, but in lowercase .

Originally Posted by Mirco

...Draw the lines from points on the inner side of the rim (40° spacing), tangentially to the hub:...

[airportkid]

See if the attachment works, for those with Excel - I'm getting snowed with requests! The attachment engine only allows this as a zip.

Some notes on the spreadsheet:

It's NOT protected in any way, so be careful if you start mucking around not to trample cell formulas. The input boxes are FORMULAS set by the slider switches. If you want to type values in directly instead of use the sliders, type them into the slider value cells to the right side of the sheet.

You'll have to manually tweak the aspect ratio of the plot area as WYSWYG does not apply to all printers. It may look circular on the screen but will print as an ellipse until you make adjustments. Similarly, the plot has to be manually sized as well to the scale desired.

The checkboxes control visibility of each of the 4 CW/CCW spoke "splays". For the template you only need the top 2 turned on (or the bottom 2).

You can use the plotter for any number of spokes (evenly divisible by 4) but it will only plot complete spoke sets up to 44 spokes. I can't imagine any wheel needing more than that but it is fun to crowd up the plot with high spoke densities just to see what they look like. If inputting high spoke values DO NOT put them into the obvious box, which is a formula, but over to the right as 1/4 the total spoke count.

TABLE 1 provides hub dimensions for wheels that have parallel spoke pairs which can be built without using a center jigpost (the nail in the tutorial).

TABLE 2 is just there for mathematical interest - its parallel spoke pairs only go from wheelrim to hub, so would need a center jigpost to build just like any other wheel.

Hope this works and helps out.

[B-Manic]

Thanks this is an excellent tool.

[rmks2000]

Very cool.

[Mirco]

Wow.
Nice piece of math. Thank you.

[adyokehpunya]

how many thanks for the tutorial, so helpful bro..

[leclerc]

Very Nice Tutorial on the spoke !!!
I know my fellow modeller in Indonesia would really appreciate this.

[rbeach84]

Originally Posted by airportkid

See if the attachment works, for those with Excel - I'm getting snowed with requests! The attachment engine only allows this as a zip.

Some notes on the spreadsheet:

It's NOT protected in any way, so be careful if you start mucking around not to trample cell formulas. The input boxes are FORMULAS set by the slider switches. If you want to type values in directly instead of use the sliders, type them into the slider value cells to the right side of the sheet.

You'll have to manually tweak the aspect ratio of the plot area as WYSWYG does not apply to all printers. It may look circular on the screen but will print as an ellipse until you make adjustments. Similarly, the plot has to be manually sized as well to the scale desired.

The checkboxes control visibility of each of the 4 CW/CCW spoke "splays". For the template you only need the top 2 turned on (or the bottom 2).

You can use the plotter for any number of spokes (evenly divisible by 4) but it will only plot complete spoke sets up to 44 spokes. I can't imagine any wheel needing more than that but it is fun to crowd up the plot with high spoke densities just to see what they look like. If inputting high spoke values DO NOT put them into the obvious box, which is a formula, but over to the right as 1/4 the total spoke count.

TABLE 1 provides hub dimensions for wheels that have parallel spoke pairs which can be built without using a center jigpost (the nail in the tutorial).

TABLE 2 is just there for mathematical interest - its parallel spoke pairs only go from wheelrim to hub, so would need a center jigpost to build just like any other wheel.

Hope this works and helps out.

Airport, you can apply protection to the formula cells if you wish - a password isn't required to do so - and it would prevent the kind of "trampling" you mention.

I might attempt to convert this into an OpenOffice spreadsheet if you're okay with that - as open source, OOo (shorthand for OpenOffice) is available to anyone - just make sure and download it from openoffice.org ONLY (there are a lot of spoof sites out there!)

[dobeedu]

how 2build a war tanks chain wheel?