Hi all,
I am interested in making some cnc parts myself.
The parts will be mostly rc related (helicopter parts).
I have a million questions, but would like to start with a few more important ones.

I read this forum and many other sites, until last week I didn't even know how to spell cnc, so please be patient with my uneducated and maybe stupid questions.

Here we go:

First I'm not sure if I should go with a mill or a lathe.
For example, I like to make a part like a washout base or a servo horn (take the original plastic one and make it aluminum). I know I could buy it much cheaper, but what would be the fun of that?
And then I would like to make a rod with a thread (like a flybar rod).
I understand, that for one part I need a mill and the other a lathe.

What is the more useful tool for a beginner? Lathe or mill?

Now, let's say I would go with a mill.
I'm still not clear if I should buy a mill and make it cnc, or if I should buy the finished product.
My budget is about $1200.00 and I like the mini mill from HF or homier to start with for about $400-$500.

There is someone on ebay who sells a mini mill:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=12584&item=3826385691&rd=1

but I guess this is misleading and he really sells the micro mill, is this right?

Or I could safe some more money and just buy the cnc from www.taigtools.com or something equivalent.

If I decide to build my own cnc, I will have to do a lot of research on the electronic - motor part, which I haven't started yet.

The next part is software.
I did some small c programming (many many moons ago) I still know html code and some java.

What program do I need o learn?
Something on the affordable side.
Would I have to learn to use maya or auto cad or something like that, or are there less complex programs out there?


Is there something like an adult evening course that I can take (I live in Fort Lauderdale) and first learn all that stuff about cnc and make some parts just to see how difficult this might be?
I'm not doing this to get a job, I want to have fun making my own parts, but at the same time I don't want to brake the bank.

All your help is greatly appreciated.

:) :) :)

Welcome to the zone Data, I think you will find a lot of users here with simialr interests in RC parts. A good site for building heli parts with cnc is Tauseef's site: http://www.cuttingedgecnc.com/
He has converted a small sherline mill and is making some nice stuff. Hope it helps;)

Originally posted by sendkeys
As for a controller to run the "g code" the other software makes;
turbocnc is the cheapest at i think 20 bucks. Mach1-2 at 150 is faster with more options.

Sendkeys gives lots of very good advice here for any beginner. Read and heed :)

For 3D surface machining, where the code is generally about a gazillion short linear moves, Mach2 is the only one of these two programs to consider. It can be run in either exact stop mode, where there's a slight pause between each move, or in a continuous contouring mode where the motion is non-stop from block to block. Tcnc has only exact stop, and some posts from the developers indicate continuous contouring is at least a couple versions down the road. In a surfacing program this can make hours of difference in the time it takes to cut the part, and each stop generates a small but noticable tool mark. It might also be worthwhile to check into some of the DeskCNC products as well to see if they offer continuous contouring. They can supply a software package that integrates motion control and cam into one package, and a multi-axis driver to work with it, all at what looks to be a very reasonable price.

Originally posted by metlmunchr
It might also be worthwhile to check into some of the DeskCNC products as well to see if they offer continuous contouring.


DeskCNC is in continuous contouring mode by default.

The DeskCNC controller software includes probing directly to an .STL surface, rotary or slaved 4th axis, and CAM programming all in one.

http://www.imsrv.com/deskcnc

Hardware options include a 4 axis stepper driver board ($50), 2 amps @ 35v, and step controlled closed loop servo drivers rated at 30V and 5 amps ($65 each axis).

An inexpensive contact probe/tool setter is available, and some inexpensive/discounted bundled kits with motors and control systems are at:

http://www.imsrv.com/deskcnc/bench_top_cnc_systems.htm

Fred Smith - IMService
http://www.cadcamcadcam.com

thanks for the advise.
I'm reading posts after posts and sites after sites, there is a wealth of information out there and a whole lot of people like you, willing to help.

I think the idea of a mini lathe and a mini mill sounds very appealing.
I will then convert the mill to cnc.

but first things first.

someone I know wanted to learn some 3d program, but never relay got into it.
since he's got more money than brains (I always tell him that too) he is willing to sell me one of his software.
he would sell me either maya 4.0 for $500.00 or autocad 2004 for $300.00.
I looked at rhino3d and that costs only 200.00 for a student license (I will take some classes to be a student again).
what would you do?
would the extra cost for maya or autocad be worth it?
after learning to design a part in 3D, I can then go to the next step and get a program that converts it to g-code etc.

so, what is your opinion for the 3d program?

:) :) :)

Data, unless your mate is pulling your leg and is really trying to sell you a cracked version of Maya or Autocad, then those prices are a bargain. I dont know their exact prices, but they are worth many thousands of dollars the last time I looked. I always thought that maya was more for doing cartoon type things, like in "Bugs life" etc. ( I could be wrong ) But autocad 2004 was probably a better program for doing 3D design work. I havent used either though. Although I have seen both been used by others.
Expect a very steep learning curve for these programs. It is one thing to own good software but another to be able to use it.

It is interesting to see how many approach CNC. Most build their machine first, and then scramble to find software to run it ( As I did ). Then there are others who have software and think, How can I produce something tangible from it.

You could start by downloading all sorts of trialware and experimenting with it to see what program is the one you like to use.

Since 3D animation is a previous (somewhat current?) hobby of mine, perhaps I can give you some advice. Stay far away from Maya. Especially if you have no 3D experience. Not that it won't do what you need it to do. First, I can't believe your friend paid full price and is going to sell it to you for $500. Second, the learning curve will be incredibly steep. And you'll never use 90-95% of the program.

A little general information about high end animation software. You can model pretty much anything you want in them. From realistic faces to machine parts. They have very few limits, but each works a little differently. (I'm talking generally about Maya, Softimage, 3DS MAX, Lightwave 3D...). For very precise mechanical type parts, go for a CAD system. You can generally model precise parts faster and easier in a CAD package. If you know what you're doing, you can do a lot of things you could never do ina Cad package, but you'll find that Cad packages can do things animation software can't do as well. Most animation packages (the modeling portions, anyway) are much easier to learn with prior 3D experience, as generally 3D is 3D, and is similar in all packages.

AutoCAD. First thing you should now is that Autodesk will not let you transfer AutoCAD licenses. Not sure of the legality of buying it, but you'd never be able to upgrade it. AutoCad is extremely powerful in the 2D department, but you'll find that the 3D is a bit limited. It would be no problem to do your RC parts, but complex 3D parts can be difficult.

If I were you, I'd go the Rhino route for $200. Rhino should do all the 2D stuff you need, as well as more complex 3D stuff than AutoCAD can do.

Remeber, though. You don't always need a 3D model to mill 3D parts.

you know the saying: "if it sounds to good to be true - it is"

I spoke with him this morning and he said he made a mistake and he couldn't sell maya that cheap.
oh well.
anyways, he still would sell autocad.
I guess I have to find out about the AC license thingy.

I also found out about solidworks, you can get a student version for $179.00.

now it's between SW, AC or R3D :D

Data: It might be an idea to DL a demo of the programs you're interested in as a few of them have a very steep learning curve and may not be able to do what you need...

Data,

The downside of the student version of Solidworks is that it stops working after 24 months (that's what it indicates on the website), so you would need to re-purchase the current version at that time and still need to be student/faculty to qualify.

I am a newbie as well, and I think IJ has the good idea to download some of the demos and try to draw something. Some of them are more intuitive than others (I found I could draw something in Solidworks easier than AutoCad, at least without instruction).

If you do not have much machining background (like me) I would also recommend taking some classes on manual/CNC machining if available at your local community college.

Regards,
Rick

to keep you all updated.
I had the opportunity to try some different cad programs over the past few days.
I didn't like autocad.
I was able to draw some squares and circle's etc. but found it difficult to progress into 3D drawings within a couple of hours.
it also seems to be geared more toward architectural drawings.

I then was able to try solidworks from a student at the school I checked for classes.

wow, within the first 1 hour I was drawing a nice box with extrusions etc, and it was so easy to make changes to anything.
that's what I want.
I will now sign up for some classes to learn solidworks and or cnc machining etc.
as soon as I'm qualifying I will order the solidworks student edition.
I figure if I work with this software for 2 years (until it expires) I will know if it is worth it to buy the full version or if I just become a student again to get the next student version.

what do you all think about this decision?

Data,

Sounds to me like you're off to a good start.

Regards,
Rick

OneCNC XR is an excellent cadcam program for someone who wants to make parts. Even though it is not cheap when you buy the versions capable of doing solid modelling, it is cheaper than buying something like Solidworks, and then turning and buying OneCNC later on to cut the parts.

There is no such thing as a 3d convertor to turn a solid model into gcode. There are lots of decisions to be made about machining a part. Fully automated "conversion" (as I imagine it) is impractical, because it still takes a human mind to make a few choices about what, where, when and how the cuts are going to be done. :)

Originally posted by HuFlungDung

There is no such thing as a 3d convertor to turn a solid model into gcode.
now I'm confused :confused:
please excuse my ignorance, but if I would design a part in solidworks, there would be no way to translate it into g-code?

couldn't I use something much less expensive like meshcam to convert from SW to g-code or some plugin that would do this?

the price of SW as I mentioned is $179.00 and meshcam is about $150.00.
that's why I thought I can get started on the software side with under $400.00 and be using a fantastic program like SW that would otherwise cost $5000.00.

How do design engineers that use only SW get their parts done on a CNC mill etc.?

now I'm really confused :confused: and I thought I did my homework. :(

You can even use StlWork for $75 as your CAM program, but you are still going to have to
know what you are doing to get decent results.

Converter indicates that you think you can "push a button and get a part".
Cam programs at any cost don't work that way as there are too many variables when making parts.

Design Engineers pay a very high price to machinists and programmers to turn their ideas into a real part.


FredSmith - IMService
http://www.cadcamcadcam.com

There is a fundamental difference in CAM software like ONECNC and programs like MeshCAM and STLWork.

To get your models into MeshCAm or STLWork, you have to export as an .stl This turns your solid model into a model composed of lots of small triangles. To get really smooth models, you need lots of triangles. Then basically a grid is created which basically corresponds to those triangles. Then MeshCAM will send the tool along that grid, making sure to hit every point.

Real (expensive, high end) CAM software, on the other hand, can actually break a solid model into discreet surfaces if needed and machine those surfaces the best posssible way, even actually following curves if needed. Machining time can be a fraction of what it takes for the MeshCAM type, with better finishes possible as well. This is a very simplified explanation. Needless to say, these types of CAM software are much more complex and the price is much higher.

Data,

That's why you're going to take the classes. The software program doesn't know the size and shape of the material you're making the part from and how you're going to hold on to it while you're machining it. You will have to figure out what machining process you want to do in the proper sequence, to end up with the finished part.

As I've said, I'm still a beginner. To be a real machinist it will take alot of experience in looking at parts and figuring out how to actually make them. The CAM software will help write the g code once you figure out what order to do things, but you can't just open a 3D part file and expect it to figure out all of the variables. At least this is my understanding of things, as I still have alot of classes to take :)

Regards,
Rick

:) :) :)

Data: A good example I found (remember I'm a total newbie) was a simple file I'd saved as an STL, DeskCNC converted it to G Code and it was around the 28.000 lines the same part as a 2d DXF converted to one pass of 26 lines and one of about 30 :)!

There are times when you'd use 3d cutting but in a lot of cases 2d+ depth (2.5d I believe is the term for this type of pass) works very well!

I can't imagine running an STL mesh as machine code. It would be very hard on the machine, and would probably look like hell. I've never done it of course, so I could be quite out to lunch.

BTW, since we are talking about expensive software here, and future purchases (after the student priviledge has expired), then I wouldn't go blowing a wad on Solidworks, and trying to skimp on the CAM software. That is why I say OneCNC is a good balance (pricewise) for both modelling and CAM together. This is only one choice of many possibilities out there, so I don't mean to be tramping on anyone's favourite software combo.

HuFlungDung, I completely understand your point, but onecnc is completely out of my budget and wouldn't fit into my plans.

you see, I don't worry about SW expiring in two years from now, maybe I'm not even in this hobby anymore by then (remember it's just for my hobby).

I figured to get my feed wet in cnc and related activities, I will start taking classes at local schools (very little money)
then I want to buy a mini lathe (about $500.00) and a mini mill (about $500.00), some tooling over time and practice making some simple parts.
after doing that for awhile, I can determine if I want to go all the way to cnc and convert my mill for maybe another $500.00.

If my decision is no, then no harm is done, I will know a lot more about cnc then I knew when I started, I will own a couple machines that will always have some use and I will know about a cad program that I might use for a long time to design parts for fun or not.

now, if I decide to go all the way.
I will then learn how to convert a mill to cnc, buy some additional software (like meshcam) for a couple hundred bucks and start making my own parts in cnc.
if it is within my budget at that point in time, I will then buy a cam software like onecnc that is well known at that time.

if my budget is to small for a good cad/cam program at that time, I'm sure there will be other options available.

you see, the last thing I want to do is:
buy a cnc ready machine for $6000.00, buy a software package for another $4000.00, brake my bank and charge my cc up to the limit and make a couple of parts just to find out that this hobby is not for me and sell it all for half the price.

the other way (the way I'm going to do it), I have time enough to find out each step involved to make a part without braking the bank and I can back of at any time without really losing anything.
every $$$$ I spend until then will have been worth it just for the experience gained.

if I don't like the design part and I don't want to spend the time on a cad program, I will have paid $179.00 to find out.
If I don't like the lathe and/or mill work, I will sell it again, might lose $200-$300 and will have paid for another experience.
if I go all the way to cnc, I did the machine work and cad program long enough to know that I want to stick with it and there is a high probability that I will use it for a long time.

This is my plan to approach the cnc thingy.

Data, I'm kinda in the same shoes as you. I'll offer some knowledge I'm getting on my quest. First, you can get into CNC real cheaply by picking up one of the many controller boards/kits on the market. I got a 4 axis controller for $120 and some steppers for $100. My plan was to build a simple 3 axis demo machine but now I'm planning on converting my mini-mill. I have acces to a Bridgeport Seris II CNC mill in a maching class that I've enrolled in. Anyway, what you may want to do is build one of the inexpensive CNC router setups. Not nearly as labor intensive as converting the mini-mill; along with adapting the motors to the mill, you'll have to adapt ball screws & improve the gibs in most cases. Your hardware will still be usable for the mill if/when you get bored making sawdust.

As for software, you can do the basics with turboCNC driving your controller, it's shareware and worth the $20 registration. You can hand write the code in a word processor and dump it directly to turboCNC and make chips. At least you'll get a good understanding on how NC maching works.

As for the 3D software and CAM software, I'm struggling with that right now, both with cost issues, and finding the right package. The OneCNC XR Express is $1500. The more I look into it, this really isn't that bad. I can save my coins and wait until I can afford it (a little tough since a need a TIG welder right now as well). If you can find a 2D CAD program that dumps a dxf file, you can use the free ACE converter to convert the file to G-code and run your mill. Keep In mind too, that there is a lot to learn as it pertains to doing the setup and jigging in the mill. A friend of mine who runs a Fadal VMC says the worst part of it all is making the fixtures. I can tell you first hand, from using the mini-mill manually, that you have to do a lot of adaptation and creative setup to make parts, even average size 3"x3" parts since the x-y movement of the mill is so limited. I'm trying to advance my machining knowledge into CNC for the purpose of making multiple pieces of the same part. AS for one-of's, it can be a waste of time to do things with CNC, not counting complex curves and profiles & engraving whcih just can't be done easily with manual methods.

So, my suggestion is to get a low cost quality controller board, I just posted a review of one I like. Get some motors in the 200oz/in range, and pick up the plans for one of the router systems and go to it. you'll be in the game cheap. If you find it is driving you nuts trying to make anything, you won't have alot invested. If you get the hang of it, you'll be able to make some awesome signs and engravings and perhaps sell enough to fund the jump into metal CNC.

I've got a few product/accessory ideas that if I can make them happen, I'll have funding for a real VMC and trimmings to go with it. (BIG Dream!)

You can do a lot with 2.5D CAM as well. Download Sheetcam while it's free, at http://www.sheetcam.com , and get a cheap CAD program like TurboCAD or DesignCAD, and you'll be on your way. You can add MeshCAM if you need it for the parts you want to make.

There is a neat free software package at emachineshop.com as well. It will dump a dxf file but won't retain the 3D info. Pretty nice 3D design software for a beginner.

For 3D modeling buy SolidWorks. You won't be sorry. :D

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