Re: Show off Your Machining! 2014
 

Looks like it was water jetted.

Re: Show off Your Machining! 2014
 

Nothing crazy machining wise but this assembly was designed and machined in just over 2 hours. The delrin bushing was machined in that time too. I was pretty proud of how fast we were able to iterate our design in 2015.
https://scontent-lga3-1.xx.fbcdn.net...94&oe=56F1DEB7

Re: Show off Your Machining! 2014
 

I can't tell anymore. I remember when waterjet produced distinctive edges but it seems like that's not the case anymore.

I'm eager to see where we end up in a year since we've added a CNC mill and lathe to our shop this year. Trying to get students to start using them this year and get shop supervisor more involved with the team.

Re: Show off Your Machining! 2014
 

It still produces a very distinctive edge. It's matte and speckled. Almost "frosty" looking

Re: Show off Your Machining! 2014
 

Here are a few pictures some neat parts/assemblies on our 15 bot.



https://goo.gl/photos/3S7NUVqLZMdKgeDZ9
https://goo.gl/photos/SVonUkqnnNMD18Py9

The second picture is of our elevator drive transmission, which was designed to be easy to swap out. The entire assembly is mounted on a 1/4" aluminum plate and drops out of the robot with three bolts. Then, the two pieces of square tubing can be unscrewed from the plate. The box on the left has a shaft coupler to allow the versaplanetary to be swapped quickly and the box on the right has a 10:1 worm reduction.

Re: Show off Your Machining! 2014
 

This plate was in fact cut on a Haas CNC mill. Machining credit goes to wafertech, our generous sponsor.

Its possible that the white paper background of this photo is making the shiny edges seem dull.

As I was not the machinist on this project, I can't give you the exact numbers. But I was there while this was being made and I can tell you what I remember the machinist saying. Something like 5000 rpm spindle speed with 12 ipm feed rate. The bit was .25" two flute end mill, and I'm pretty sure it was HSS. They did the thickness of the .25" plate in a few separate passes.

Oh! I just thought the metal our waterjet sponsor used had a weird composition. He did supply us with free 7075 aluminum parts once though so it didn't seem that far off.

Why does it do that?

Re: Show off Your Machining! 2014
 

It's because water jetting doesn't rely on the water to cut, but rather the abrasive that is mixed in with the water. This means you'll get a more dull and speckled edge instead of the shiny edge like you would from an endmill or chop saw blade that relies on a sharp cutting edge.

Re: Show off Your Machining! 2014
 

The water jet has very very tiny Sand particles in the water. If you go into a place with a water jet you will see pallets of sand. It uses a very high pressure (approx 60 000psi) to push the sand and water through a very small hole in a nozzle. The water/sand creates that weird edge because it is essentially sanding it's way through the metal.

Here's a video explaining it

Thanks.

Re: Show off Your Machining! 2014
 

Our CNC machining and work isn't high tier complexity. We're working on a metric gearbox and shifter option. (Normal ballshifter and/or swerve shifter)

Here is some machining work from last season:

Re: Show off Your Machining! 2014
 

Just use the other side of the ruler. ;)

Nice parts though! I still maintain that you guys make gorgeous robots.

Re: Show off Your Machining! 2014
 

We asked for a 3" hole. Everyone was pretty excited when this happened.

-Hugh

Re: Show off Your Machining! 2014
 

That sure is pretty. Is the last part steel/stainless?

Re: Show off Your Machining! 2014
 

:D
It's aluminum with brass IIRC, where the 2 vertical axles are stainless.