Society of Robots - Robot Forum
Mechanics and Construction => Mechanics and Construction => Topic started by: Thomas Countz on December 22, 2008, 08:32:52 AM
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I am just about ready to begin my next robot project, when a silly little question popped up. As the title implies, I am finding it difficult to determine which building material to use for my robot chassis. Expanded Polyvinyl Chloride (Sintra) or High Density Polyethylene (HDPE). Through my research I was able to find that both materials seem to fit my needs; they are both thermoplastics, they can be easily remanufactured into the required dimensions, they are inexpensive, they both have similar tensile strength characteristics, ect. Within my research, I find that the two are both applicable to my project, and therefore I am unable to decide which material to use.
Based on your experience with either of the materials, which do you suggest?
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Based on my experience... your robot isn't going to be crashing into stuff at 30mph, and probably won't be something designed for a minimum possible weight (i.e. won't be trying to use material as efficiently as possible)
Thus, use whichever's cheapest.
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Well, you're asking a subjective question. ;)
You need to determine exactly how strong you need the material to be (an actual number). You also need to tell us what machine shop tools you have and your budget ;D
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I lack the ability to calculate the stresses that my robot will go through, however, with that knowledge that I lack knowledge, I will be able to seek out knowledge ??? I have access to a machine shop (my father's) so I'm not to worried about that. My budget is small for this project (what else is new) Overall I'd say I have an unfixed budget of $125, not including the previous purchases I've made so far (servos & mcu)
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to me sintra is easier to work with
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It's PVC (sintra) toxic? That's one of the reasons I switched to polyethylene. ;)
I mean, for most uses it's okay. But if you have a baby family member or a pet and they try to chew on it...it's not so good. Or if you heat it up, the emissions are toxic.
Just thought I'd cut that in...
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Yeah I decided to go with HDPE because of it's ecoFriendlyness ... aka recyclability ;D ;D
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I lack the ability to calculate the stresses that my robot will go through
If you can't calculate, get some sample materials and run a few experiments. Or just guess and go overkill . . .