Poly pulleys vs steel pulleys

[ynneb]

I have noticed that most who have made cnc routers have chosen steel pulleys over poly/plastic pulleys. Is this because they really are superior, or is just a steel is better mentality, not based on anything else.

I am highly considering buying the poly pulleys. Does any one have any thing to say about my purchase choice before I buy them?

[InventIt]

Are you referring to timing belt pulleys?

If your on a tight budget it may be worth saving a few $ to get the poly. Problem I noticed is 2 fold. One, the circumference is not true to the shaft. Two, the way there mounted to the hub looks weak. I wouldn't think you could put much of a load on the poly like you could on the alum/steel. I guess that depends on you design requirements

Probably worth a few extra $$ to go with alum. And they look nicer

[pack rat]

I replied earlier but something happened, don't know what. There is a site that uses plastic pulleys, look under reduction gearshttp://www.axxustech.com/Axxus4x8/axxus_4x8.htm