To me, everything is NEW.

[hansa]

Hi.
Im building the structure for a CNC router, i have'nt realy investigated/understood what kind of motors i need but started building anyways.
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The structure will be made of MDF and/or simular.
pictures at my web-site http://snile.net/

The design is borrowed from whom ever google found for me and modified (No pictures of drawings, cause i realy suxx0r at it, and all i got are numbers in my head).

My main issue is understanding Controllers and motors.
How much power do i need? How big motors do i need?

The rigg will end up at something like 80x80cm work area (2,5'x2,5')
It will move with a threaded steal rod size M20 (0,8"). And it will primarly be for wood cutting.
How big steppers will i need?
Iv been looking at a kit with this: http://www.hobbycnc.com/steppers/23-200-DS.jpg : stepper. It looks so small. But as i said. I dont have a clue about the electrical part of this project.

Greats: HansA

[rboeser]

Based on what I've seen and read, the 200 oz-in stepper should work for your set up. If my calulations are correct, your travels are about 32" x 32".

If you are buying new, my personal opinion is to buy a step larger than what you think you need. In this case it would be around a 300-350 oz-in. Keep in mind that a stronger stepper will help with tight spots and binding that will show up in a hand made machine. The end result will be faster rapid ability with the stronger stepper.

Again, this is based on reading the many posts about this subject. Not based on math or formulas of any kind, just a gut feeling.

Best of luck with your project, it appears you have a good start. I would know more about it but I can't read whatever language it is at your forum.

[hansa]

Thanks.

I'll write a few articles in english to when i got some good progress and something to show

[hansa]

OH! yeah. People got tips on sites to buy kits, WITHOUT DC TRAFO, or 230volt option?

[rboeser]

Originally Posted by hansa OH! yeah. People got tips on sites to buy kits, WITHOUT DC TRAFO, or 230volt option?

Do you mean "without a DC transformer"? I am uncertain of what you are asking. All stepper motors require a DC power supply, or at least a controller with a power supply contained inside it. This power supply is normally taken from an AC power source as it the most common available.

As for as the 230v option, many transformers are available with a 110/120 or 220/230 VAC mains option. I am not even sure where Norway is, much less what suppliers are available to you, sorry.

[hansa]

Norway is up north in Skandinavia neighbour to sweden.
I see several controllers on the net with everything except the DC powersource. Thats what i need. Or, if i can get a complete package, then thats what i need.
Problem is Europe does'nt have a good CNC comunity so gotta buy most of the stuff from US and pay &#!% to get it to Norway.

[rboeser]

The DC power source is as simple as an AC transformer, a bridge recirfier and a large capacitor. All parts should be available to you through any electric supply house.

For example, if you take a 24vac transformer and rectify it, it will output around 34vdc. The formula is ACvolts x 1.4 = DCvolts. This will be the output after the bridge. A bridge is 4 simple power diodes and can be made from discrete components easily.

For your capacitor, use roughly 10,000uf per amp to keep ripple to an acceptable level. If you need a 10 amp DC supply, use 100,000 uf of capacitors. You can paralle capacitors to get to the capacity required. Use a volt rating of the caps at 1.5 times the volt output. IE: 34Vdc x 1.5 = 51volts. Use a 50 volt rated cap for safty sake, you don't want them blowing up. If you have 36,000uf caps, use 3 of them.

You can also use 3 (or 4 depending on the number of axis) transformers at a lower amp rating. If you want a 10 amp supply for 3 axis, use 3- 3 to 4 amp transformers, one for each axis. In this case, a 36,000uf cap for each transformer is perfect.

24Vac is a normal low voltage for household HVAC uses in the States. I'm uncertain if you can get a 24v HVAC transformer capable of 3 amps, but I would look at the local heating A/C repair business. CNC has little to do with finding a DC power supply, use your imagination, transformers and capacitors are everywhere in the industrial junk yards. And you likely have them at the local electrical supply store.

I think I read a post here on altering a transformer raped from a microwave oven. It's not to hard to calculate how many turns to remove to drop the voltage to what you want. Please use caution... working with mains power is dangerous.

[hansa]

The DC powersupply is NOT the problem. The problem is the controller and the steppers. Things i dont understand at the moment.

[rboeser]

Are items cheaper to get from Germany for you? I found a website one time that had kits for controllers. It was in German so I could not understand it, but the pictures and IC's used were certainly stepper controllers.

[ViperTX]

hansa...match the controllers to the motors......look at the specs on the controllers and then compare to the specs of the motors.

The power supply you need will have a 220 VAC input and whatever DC voltage output you require for your motors and the controllers.

[jerber]

Originally Posted by hansa Norway is up north in Skandinavia neighbour to sweden. I see several controllers on the net with everything except the DC powersource. Thats what i need. Or, if i can get a complete package, then thats what i need. Problem is Europe does'nt have a good CNC comunity so gotta buy most of the stuff from US and pay &#!% to get it to Norway.

Nanotec has some very nice steppers and controllers. I'm very pleased with the stl5709l1108 steppers for my XY table.
Steppers from the same range should be suitable for your machine.
I don't have any experience with the drivers from nanotec.

www.nanotec.com

btw CNCzone is THE cnc comunity for Europe (although there's a lot to find on german sites and I can read/write german I don't like to do it).

[hansa]

Originally Posted by rboeser Are items cheaper to get from Germany for you? I found a website one time that had kits for controllers. It was in German so I could not understand it, but the pictures and IC's used were certainly stepper controllers.

YES! germany is excellent! Its on the same continent so shipping is cheaper. (Trailer)
I'll go find out what 'CNC router', 'stepper' and such is in german. Thanks for the tip! greate!

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Match controller to motors? this is why i want a kit. I have'nt figured out the different steppers yet. i see so many different. So i "need" a kit for my first build