upload a CAD profile or drawing & get it CNC'd...

upload a CAD profile or drawing & get it CNC\'d...

i'm thinking of doing something like this. I figured many prototypers might be interested in small runs of 1-5 or so. I want to find a good place to get stuff HAIII anodized but i do have access to CNC lathes and mills and all types of aluminum and such, hopefully sterling silver 10ga sheet soon. i might even do custom engraving on bodies. i've aways wondered how i can use that fourth axis... In fact i can probably engrave basically anything that can be put into a 4 jaw chuck.

this is sort of a feeler. Just throwing ideas out there.

Leon

Re: upload a CAD profile or drawing & get it CNC\'d

I would be very interested at a later time when I have finalized my ideas (just loose ideas in my head and on paper right now). Any recommondations for a good (maybe free) CAD program.

I don't know squat about how a CNC or milling machine works, so how does the CAD drawing control the machine? Do you just use the drawing as basis for programming the machines?

What would the price be for doing a prototype? I guess there will be a difference in price depending on size, number of parts and complexity of the parts.

If I were going to create a custom reflector, how would I get it reflectorized?

Sigbjoern

Re: upload a CAD profile or drawing & get it CNC\'d

cnc machines basically work on coordinates. you specify a 0 for your part. and then a tool walks around the part by reading a list of consecutive coordinates to go to. in layman's terms.

you can program by hand, but thats quite lengthy. cause you have to tell it how much to remove for every pass and there are special commands for cutting profiles on a lathe for example. the machine basically makes one coordinate path to follow at maximum depth, and then initiates a loop and step down command. so it takes your initial starting point, and given a constant amount of material to remove, will cut your profile in several passes by figuring out the intermediate steps.

toolpaths for a mill cycle can typically look like this
http://www.hitachi.co.jp/HAND/SOFTPAGES/p1725.gif

the veritcal lines are tool retracts and step downs, and you can see the uniform spacing between the flowlines.

the computer figures out how to complex surfaces you select, you just have to specify a ton of parameters, like tools used, stepover amounts, and depth cut increments, how fast to move through material (feed), how fast the tool should spin (speed), other "check surfaces" so the tools doesnt crash into holders..etc.

awr an i will be testing cutom drill bits to drill out parabolic aluminum reflectors from cones. so that may e an option as well in the future.

Leon

Re: upload a CAD profile or drawing & get it CNC\'d

That's very generous. Thanks for offering your services. I'm sure that will be useful to many.

Re: upload a CAD profile or drawing & get it CNC\'d

Thanks for your explanation Leon! As I thought, it appears to be much work involved in setting up the CNC machine, but probably interesting/fun as well. Maybe it is better to use CNC when you have more than one item to make because of the setup cost? That would of course require an alternative. I saw that Edisoncorp is offering prototyping services (they are redesigning their web site right now so the relevant page is not there yet), one of the services is a machine you just feed with a 3D model and it will spit out the complete part after a while. This is done by using some kind of powder which is melted together by a high power laser, layer by layer (I don't know how thick each layer is, but I think they are very thin). This is perfect for creating moulds for creating plastic parts. Different kinds of powder could be used, you could create everything from plastic to gold parts. I also saw this machine in action on TV some years ago, it was located at a research institute here in Norway and was at that time (if I recollect correctly) almost one of a kind in the world, but now it is probably more common so I guess several places will offer this service.

Sigbjoern

Re: upload a CAD profile or drawing & get it CNC\'d

they're called rapid prototyping machines. pretty cool. it's like an inkjet printer that prints onto a powder layer by layer. after it is done the whole thing is heated and the powder absorbs into the ink material and hardens it. you can print crazy things like interlinked chain links, mobius strips, spheres inside of spheres, anything 3d really. I'm not sure how much accuracy can be acheived tho. and the drawback...you can't magially turn it into aluminum.

Leon.

Re: upload a CAD profile or drawing & get it CNC\'d

Actually if you have the Selective Laser Sintering you can use sinter powders to make a aluminium flashlight, solid about 90+% density. And if you want to do it even better, you can go for the Selective Laser Melting which uses solid powder(no special outer layer needed for sintering) to melt them together, the mechanical properties will be as good as the real thing. These are also Rapid prototyping, but they are way more expensive than the Inkjet Printer Leon is talking about.

Re: upload a CAD profile or drawing & get it CNC\'d

I've got some sketches for a light that would benefit from treatment on a 3+ axis mill, and the tubestock to make it from.

I guess I need to finish them. Too bad I only have 2D CAD software.

Re: upload a CAD profile or drawing & get it CNC\'d

Pokkuhlag, thanks for the names, didn't remember what it was called myself. These were the ones I was thinking of.

Sigbjoern

Re: upload a CAD profile or drawing & get it CNC\'d

Here is an interisting article about yet another type of rapid prototyping technology called MPP:
http://www.mpp.no/intro/intro.htm

It is specially designed for making metal parts. Realy interesting the part of creating parts of metal too hard to be machined.

Sigbjoern