Mecanum wear and dirt resistance

[tsaksa]

Originally Posted by flameout

Let's assume that team labor is free

I'm really looking into casting hot glue right now. We could make a mold using a pristine roller (we'd order an extra set of 12 to replace rollers that we mess up beyond repair) -- I believe there are commercial products for building reusable molds for stuff like this.


Thanks for all the advice.

I have used hot glue to cast a lot of things, but usually things that do not need much strength or abrasion resistance. If you have built many robots, or similar devices, you probably realize the importance of selecting rugged materials for wheel surfaces and the amount of wear even tough materials experience. And that is just with normal wheels. Mecanum wheels place even more demands on these surfaces. I expect you will find any rollers cast from hot glue to be a poor substitute for more conventional plastics.

If you do plan to try to fabricate your own rollers, try to think about all of the properties that will be important in the finished roller. How much weight will each roller need to support? Can you calculate the PSI at critical load bearing locations? Do you plan to lubricate each roller regularly or do you require some material that is mostly self lubricating such as Nylon or UHMW?

While I admire the desire to save money and try unique fabrication techniques, hot glue does have some significant drawbacks in a number of material properties. It may have good applicability if developing a rapid prototype, model, or even as a finished part if it is being used in a low stress application. But I doubt you will have much luck in this very demanding application.