Bought some motors. Now what?

[Zeno]

Recently happened across cnczone. Saw a message where someone posted http://www.automec-direct.netfirms.c..._dc_motor.html . Want to build cnc machine, so I went there and ordered three of them.

Why three? Because I want a 3d cnc machine!

I haven't the slightest idea what I am doing, but I think I will need more than just these motors. There is so much information in these pages, that I become confused and bewildered. (That's not actually very hard for me to do.)

I am a currently unemployed cabinetmaker, who would like to make a really cheap cnc machine. What can I make with these motors? What else do I need?

Any help will be appreciated!

Thank you,
- Zeno

[Zeno]

Oh, by the way, I have an old 90mz computer I can use in the shop, and a laptop on which I run AutoCAD 2000 inside. I have woodworking tools and know how to use them. I can arc weld, but it ain't too gracefull and the results ain't pretty!!!

[teilhardo]

If you bought dc motors, you're going to have to learn a lot about electronics and encoders to turn them into servo motors. It gets pretty complicated. If anyone else viewing this forum knows how to turn those *cheap* dc motors into a DIY closed loop system, feel free to give us some direction.
-Tei

[Zeno]

Uh-oh! I found the thread. Guess I should have read the whole thing first! Apparently I must get encoders at $36 for each motor, and machining tools and skills too!!!

my new cheap servos

I think I am also learning that I need either four or five motors. Why, I haven't the slightest idea!

-- Zeno

[Zeno]

Thanks for the info, teilhardo. I think I avoided stepper motors because homecnc.com said stepper motors were either not powerful or fast enough, or powerful when fast, or something like that!

As for turning these into servo motors, I thought they were! The page didn't say 'stepper', and I didn't know there were more than two kinds :-! As you can tell, if I need to know much about electronics, I have a lot to learn!

-- Zeno

[balsaman]

You need 3 motors. The problem is you will need 3 drives too, plus the encoders. The drives are $114 each. What you are trying to build is a servo system. Most people spend around $600-1000 for a working system, and you still don't have any of the mechanical parts for the machine yet. There are much cheaper drives out there. It depends what you want.

My suggestion is to sell the motors on ebay, then spend a few weeks at least reading about all the home made machines here. Decide what you want, and what you want to spend, then build a machine. Buy the motors and electronics last. By then you will understand a lot more and know what you need and want.

Ask questions, we will help you along.

Another suggestion I have is start small. Simple means you might actually succeed.

Eric

[Zeno]

Thanks for the help. I had figured I needed the electronics first, so I would know how strong I must build the other parts to hold the weight of the motors and to rout whatever was possible with those motors.

I have now read "Three Dimensional Trimming and Machining" by Susnjara. I now know the common cnc router configurations, however am totally confused as to which axis is which due to a misprint between text and images on page 31, which caused me to skip the head configuration info since I have no idea to which axis he refers in those descriptions (and I know I'm building a 3 axis machine now, and I get the X,Y,Z part). I know much more than I did about stepping motors and servo motors, although the paper is more overview and theory than actual implementation instructions for the oblivious. I have read but don't really understand from the sparse pictures about the different tracks used on cnc machines. Read about holding the work and tooling, but got completely lost on determining accuracy.

After all is said and done about this paper, I now realize that there is much more I don't know than I ever imagined I didn't know. For any other newbies who have not read it, it is at http://www.thermwood.com/ in the Books & Multimedia section. Reading it provides great insight and, I'm sure, saves years of head scratching, and it is free for the download (ain't the internet [and Mr. Susnjara] wonderful!).

I now know that I cannot afford servo motors, and am currently reading "Jones on Stepping Motor Types" at http://www.cs.uiowa.edu/%7Ejones/step/ .

It is truly wonderful to have these resources online, both the papers for learning and the experienced people here on cnczone.com to answer questions and volunteer their expertise to walk the uninitiated through this experience.

Thank you for your help, Eric the Balsaman.

-- Zeno

PS. How the heck does this machine cost $25 euro? --> http://www.cnczone.com/gallery/showp.../cat/505/page/

[ynneb]

Good on you Zeno, I like your hap-hazard approach. Youll get there in a round about fashion.

It wont be as quick as you first imagined, but youll arrive there.

It wont be as cheap as you imagined but it will be worth the effort.

You wont get any sleep, coz of all the thinking youll be doing.

Welcome to the CNC Zone ( Not that dissimilar to the Twilight zone )

EDIT: I guess 25 euro if you already have all the parts and dont need to buy anything alse except for a few nuts and bolts. I bet he didnt include the cost of the driver cards, his software, his computer, the cableing etc. Maybe he was refering to the actual steel work.

[balsaman]

Your welcome.

I am guessing it's made for 25 euro because, as ynneb said, he had all the parts before he started, and didn't include any of the electronics, which would typically add another $250.00.

Eric

[samualt]

Zeno:
You get three gold stars from me for enthusiasm! I had that kind of feeling about $3000 ago, LOL. But, I'm building a big 4'x8' machine and knew it would cost that much.

If I might make a suggestion, check out the following:
1. www.crankorgan.com - Plans for small, cheap, fun machines. Good for the beginner.
2. www.cheapcnc.com - Kits that are cheap for the beginner. Nice for the price. Put together in one weekend.
3. www.machinetoolcamp.com - Kits in the mid to upper range. Best to buy all parts from them. The instructions are like connect-the-dots.

There are lots of other plans and some kits. CadCut is probably the most professional machine plans (See forum here). It all depends on what you want to do. Some spend only $100 and build a pretty neat little cnc router. Others like me want a goliath which is much more expensive. Just keep that enthusiasm boiling-over, choose what you can afford, and go for it!