new guy questions on types of homebuilt cnc's

[Goldhunter_2]

First let me say hello!! I love to build things mostly becuase I don't have the funds to buy them I happen to see a guy on one of the metal cast sites I go to say somthing about this site and said he built a cnc machine, I'm thinking ya right I have been looking around this site all afternoon there is lots of info to take in. I build lots of wood stuff of course, but also do Aluminum and steel most the time just cut out with a torch.
I admit when I think of CNC machine I think of a water pressure system that cuts metal to computer design (never considered a router or wire setup) and since we are admitting stuff I am not that great with the computers (my son is) but I have used Cad systems for drafting and I use a 3D hull program for the alum boats I build . Since the main thing I would want to cut is metal the water pressure would be what I want, now on to the questions
Honesty how hard is it to build a water presure CNC machine ? and what are the best drawings to get? and what do you honestly spend to build it? how thick of metal can these systems cut?

[DieGuy]

You might consider a plasma system too. That would be a bit easier to build.

The cost can be pretty darn cheap by salvaging printer parts for a dremel type router to thousands. You need to condsider what you want for accuracy, size and how much you are willing to be inovative with aquistions to build your dream machine.

[Goldhunter_2]

heck any metal cutting machine would quilafy right now for dream machince i would like to be fairly accurate say within 1/8 or maybe 1/16th of a inch??? is that to unreasonable? I have used plasma cutters once or twice but the ones I have used could only handle very thin metal and I know they have thicker cutting one but always considered plasma as way to expensive, I also was thinking water cleans at the same time making a neater part and would be much cheaper.
would be interested in looking at what your talking about as I have lots of old printers, dermalsetc...but agian may main thing would be metal (steel and alum) would love to do boat props and gear reduction parts

I have still been looking around the site and it seems as most guys are talking about router cnc but can't find anything on a waterjet system for metal. I have been trying to take in all the info I have been reading and my head feels like this now

[abasir]

May be this site may offer some info
http://www.waterjets.org/index.html

[mvaughn]

I seem to recall a few threads that were posted some time ago about building a waterjet style machine. I think the conclusion that everyone came to at the time was that is was cost prohibitive to build the components required to generate the extremely high water pressure required to cut metal.

I'll see if I can find that thread for you.

[mvaughn]

Here is some info

High pressure low volume water pump


CNC Waterjet

[ger21]

Originally Posted by Goldhunter_2 but always considered plasma as way to expensive, I also was thinking water cleans at the same time making a neater part and would be much cheaper.

A waterjet would probably cost 10-20 times more than a plasma, and they can be a lot more dangerous. You need the water pressurized to 20,000 - 40,000 psi. I've never seen a homebuilt version.

[Goldhunter_2]

ger21,
I agree anything is dangerous if your not care full, and the tools to do metal are more so then wood tools. I saw a oxygen bottle that fell one time and broke the value off it went through 4 block walls and was part way through the 5th and last wall of the building.

mvaughn,
those are some interesting threads thank you. I admit that is more presure then I had imaged 60K is a bunch. course i would not cut anything more then 4-5" thick and that would be very few and far between. most my stuff is like 1/8 and 1/4 alum and maybe 1/4,1/2, 3/4 inch steel and surely not 10" thick stuff

absair,
interesting site thanks

[ViperTX]

can you really cut aluminum with a plasma jet? I would expect it to blow holes every so often. Depending on the overall size of the aluminum you expect to cut....I would select a CNC mill or router over just about anything except having someone cut it for you inexpensively.

[Goldhunter_2]

well unfortunatly have someone cut it cheaply doesn't seem to happen and when your makinging lots of cuts well thats $+$+$+$$$$ I have ways to cut alum but nothing like what I could do with a CNC I don't do as much steel anymore but want that to be able to. If I could see a plasma cutter cnc up close or even a good set of plans that would give me a better idea if it is that much more finacial feasiable then a waterjet system, I may just have to stay with old fashion methods
yes you can cut alum with plasma use the shops on my last boat bt it was not as neat/clean cut as a waterjet would be

[Goldhunter_2]

PS. I can't see a ruoter cutting three postion alum object, maybe it has been done but seems like a hard thing to make work