View Single Post
  #20   Spotlight this post!  
Unread 27-09-2013, 09:23
JamesCH95's Avatar
JamesCH95 JamesCH95 is online now
Hardcore Dork
AKA: JCH
FRC #0095 (The Grasshoppers)
Team Role: Engineer
 
Join Date: Dec 2004
Rookie Year: 2001
Location: Enfield, NH
Posts: 1,811
JamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond repute
Re: pic: Team 359 Flow WaterJet Installation

waialua359, that fund raising is quite impressive! How does one even go about securing that level of funding?

Quote:
Originally Posted by Cory View Post
I can't speak for 359 but you can't hold anywhere near the tolerance of a water jet with plasma.
That depends on your definition of "anywhere near" I suppose, and the particular machine being used. I see CNC Plasma vendors citing tolerances at least as low as +/- 0.004in (I assume for higher-end systems) and up to +/- 0.030in for 'entry level' systems. I believe water jets fall somewhere on the better end of that scale, generally.

Certainly low-end plasma cutters can't reach the tolerances of a waterjet, but that's comparing a $10k machine to a $100k machine.

Quote:
Originally Posted by mman1506 View Post
We have a cnc plasma cam. It's really disappointing for anything other than outline cuts for welding or decorative pieces. It has a hard time making round concentric holes and requires a lot of set-up and calibration. The heat also warps the metal and heat treats it. Our CNC mill/router is much more useful for robotics purposes.
It's funny you should say that. Our CNC table requires little or no setup and calibration and doesn't warp metal when we cut it. At least it hasn't warped anything since we started using the proper current/cut rate calculators.

The the plasma arc doesn't 'heat treat' the edge of the cut, it nitride hardens it (and only 0.005-0.006in). A small distinction perhaps, but an important one. The HAZ will certainly degrade any heat-treatment in the parent material though.

We're going to use our CNC plasma table to build more and more parts this pre-season and figure out exactly how close to a finished part it can make. I imagine holes will be cut undersized and drilled to a final dimension.
__________________
Theory is a nice place, I'd like to go there one day, I hear everything works there.

Maturity is knowing you were an idiot, common sense is trying to not be an idiot, wisdom is knowing that you will still be an idiot.
Reply With Quote