Creating parts

[Lefteris]

Hello all,

Continuing a question that formed in another topic I would like to ask people here how do they actually make the parts for their robots. In the other topic and in some articles in the Robot Magazine I saw guides on how to make plastic molds from a material called polyurethane. All the guides used a part which they called "the positive" the thing that will create the mold to make many negatives(copies) in the future. That's for plastic.


So the question is .. how do you go from designing it to a CAD program to cutting/making/manufacturing it in reality? The only thing that can come to my mind is using a CNC router. But since I am not that much into making my own robot parts YET , I can be very wrong   So if you have any advice and tips to add please do so.

Thanks in advance,

        -Lefteris

[Razor Concepts]

Drill press, rotary tool, and hand saw are all that I need 

[ArcMan]

A very good start.  Also about what I started with.  I now also have a mini-lathe (which I use for all my robot projects) and a MIG welder for the big steel robot (my yard robot).  I'm currently using my drill press with an X-Y vise as a poor man's mini-mill.  The chatter is horrific - I really want a proper mini-mill.

[galannthegreat]

well personally i use a dremel with a drill press set up and a flex shaft, and i surprise myself in how good things come out. A milling machne and a lathe would probably be the tools of choice IMO, but they can cost a bundle, not including all of those expensive and necessary add-ons.

[Admin]

A low tech method would be to buy a block of soft wood, and carefully carve it with a carving knife and sand paper.

This is what I did for my first vacuum forming projects.

Expect to mess up if you are new to carving, so buy several blocks of wood just in case.

[galannthegreat]

I personally got my dad to ask a favour at a local machine shop and they cut two aluminum discs for me on the plasma cutter, and lil bit of sanding and filing it's perfectly smooth.

[dellagd]

go to e-machineshop.com
that might help

[gfscustoms]

I usually do my design in a cad program such as Autodesk Inventor or even just plain autocad. You can then find a shop who does laser cutting of plastic and send them your part files.

It works great as long as you don't mind only flat pieces. The tolerance is very tight and you can choose from a wide range of plastics.

Online places such as pololu.com have a pretty good selection of materials, but I found the best way is to find a local shop to do the cutting. I found a local engraving shop to do all of my cutting for significantly less than online, got it in 2 days with no shipping.

I usually create all of my parts in Inventor with all nuts/bolts, spacers, washers, bearings etc. in the model, then just export the faces of the parts you need cut. When you get the parts back, as long as you were carefull with building the model, the real thing will bolt together perfectly.

Good luck

[MaltiK]

for  your metal robotic needs, bigbluesaw.com is a cheap, easy, effective choice
polou.com also has a good laser cutting service

but probably the easiest and cheapest, as others have said is buying materials from your local Home Depot and manually cutting/carving etc.