Newbie- Need some advice.

[Mk786]

I am a senior computer engineering major and in order to graduate I have to do a senior design project. For mine I decided to build a CNC Router with a friend. However, neither my friend nor I have much mechanical skill/knowledge.

Since we are Computer Engineers the focus of our project will be the software/control system. So we need a very simple(and hopefully inexpensive) design for the mechanical aspect of the project. I was thinking that the easiest way to do this would be to buy something like this:

http://www.lowes.com/lowes/lkn?actio...510&lpage=none

In order to turn it into a CNC router I was hoping to set up something that could move the wood on the x/y plane over the surface of the table. From my initial research it seems like stepper motors would be the way to go.

I have questions for those of you who are more knowledgeable about this subject than I am:

1. How feasible would it be to build something that could move a smallish block of wood over the table? I have 2-3 months to do this.

2.Would it be accurate enough? Keep in mind since this is for a project it only has to be accurate enough to demo when it is due. It doesn't need to be very high quality(I was thinking something that could rout blocky text or simple patterns would be good enough).

3. The motors need to be controllable with a microcontroller. Do you have any recommendations on what I should use for this?

4. Also is there anything out there that is premade - as in the mechanical parts are all there it would just need a control system/software? My professor said that if we could buy a premade one and just focus on the electrical and software side of it that would be ok.

If anyone here can help me or offer me advice I would be extremely grateful.

[jwillhite]

Originally Posted by Mk786 In order to turn it into a CNC router I was hoping to set up something that could move the wood on the x/y plane over the surface of the table. From my initial research it seems like stepper motors would be the way to go.

Sounds like a lot of fun, I did something similar a couple of months ago check it out http://www.cnc.draft-design.com. If the point of this project is to focus on the software and the electronics why not just forgo the z axis and create a simple plotter. If you can find a couple of old junk scanners they would have all the parts you need to build a simple 2-axis cnc machine a.k.a a plotter. The cost for this is essentially zero and demonstrates full cnc control without the added complexities of building a structure capable of cutting something. If you need to actually cut material I doubt you will be able to build anything for under 400$.

[Mk786]

Originally Posted by jwillhite Sounds like a lot of fun, I did something similar a couple of months ago check it out http://www.cnc.draft-design.com. If the point of this project is to focus on the software and the electronics why not just forgo the z axis and create a simple plotter. If you can find a couple of old junk scanners they would have all the parts you need to build a simple 2-axis cnc machine a.k.a a plotter. The cost for this is essentially zero and demonstrates full cnc control without the added complexities of building a structure capable of cutting something. If you need to actually cut material I doubt you will be able to build anything for under 400$.

Hmm, interesting. I'll definitely have to consider doing that. If possible, however, I'd prefer to attempt to make a simple CNC router. If $400 would be enough to make a simple one capable of at least routing block style text/simple geometric shapes into wood then I would be okay with that and I think my partner would be too. $400 was about the upper bound of what we were hoping we could complete the project with, since there are two of use we can split the cost and it isn't so bad.

If it looks like doing the router won't be possible in our time frame/too expensive then the plotter idea seems like it would be almost as fun to do(and the lower cost doesn't hurt either ). Thank you for the advice/idea.

[TOTALLYRC]

You could go real inexpensive and use black gas pipe and surplus steppers and such.
I have seen websites with such stuff but don't remeber any at the moment.
If you just need to be able to demonstrate cnc cutting with out any real power or accuracy, you could make it out of plywood,mdf or what have you. Could be done really cheap if a friend has some wood wroking tools. If the tracel needs to be a few inches in each axis, you could use drawer slides. Won't be able to do any real work but it should be ok for you.

Mike

[Crevice Reamer]

Maybe this will give you some ideas:

http://buildyourcnc.com/default.aspx

CR.

[Crevice Reamer]

Or this:

http://www.instructables.com/id/How-...-Cheaply-and-/

CR.

[Crevice Reamer]

And this:

http://forums.bit-tech.net/showthread.php?t=151605

CR.

[Crevice Reamer]

This too:

http://www.cnczone.com/forums/showth...002#post531002

CR.

[Crevice Reamer]

Plus this:

Another MDF CNC router.

CR.

[Mk786]

Originally Posted by TOTALLYRC You could go real inexpensive and use black gas pipe and surplus steppers and such. I have seen websites with such stuff but don't remeber any at the moment. If you just need to be able to demonstrate cnc cutting with out any real power or accuracy, you could make it out of plywood,mdf or what have you. Could be done really cheap if a friend has some wood wroking tools. If the tracel needs to be a few inches in each axis, you could use drawer slides. Won't be able to do any real work but it should be ok for you. Mike

Alright I'll see what I can find, thank you.

Also thanks for those links Crevice Reamer - I just woke up so I haven't had time to do more than glance at them yet but I'll read over them as soon as I have time.

[Crevice Reamer]

Here is a really cheap pipe frame mill, with video instruction:

http://www.instructables.com/id/SOEL9J8F5GE3DPE/

and here is another mdf model:

http://www.instructables.com/id/How-...-Cheaply-and-/

CR.