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Unread 31-12-2009, 15:33
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Re: pic: Chassis Idea

Quote:
Originally Posted by Formerly Famous View Post
I myself have been questioning the weight. I don't know exactly how much it will weigh. And honestly. There is no easy way to find out. (Without building it) The main thing that has me questioning is that is says this weighs 43.54 pounds...

The reason I went with live axles is simply because I have designed a live axle wheel. I will be making a dead axle of the same wheel and making a dead axle version of this.

Thank you for the notes. I will be taking all of them into account as I go over this design again, and again, and again.

-Rion
Okay, that is definitely not 43 lbs.

What you need to do is make sure every component is set correctly. If it's a machined part or metal piece that is a uniform material set it's material in SW, that will make apply the proper density and weight. For everything else go to tools > mass properties > check the box for assigned mass properties, and manually assign a mass. CIMs are 2.75 lbs, compressor ~5, etc... Someone posted a spreadsheet a while back that had most of the electronic's weights. You can do assigned mass properties for an assembly, and ignore the properties of it's components; for example, set the shifters to 3.4 lbs + 2.75 lbs (the weight of a CIM plus the gearbox).

As for trusting parts that have been imported or given to you from others; just don't. If a goal of yours is to use your CAD model to provide accurate weight estimates, get in the habit of making sure all parts are set correctly as they are made and/or inserted into the assembly. It is a horrible experience trying to figure out later on why the robot is 20 lbs lighter/heavier than you think it should be and you have 1000+ parts in the assembly.

Last edited by AdamHeard : 31-12-2009 at 15:35.
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