Cheapest and easiest Desktop CNC

[MStef]

My first CNC build.

I'm going to build a desktop CNC mill but as my country (Iceland) has collapsed financially i find my self not being able to order things online without paying an arm and a leg. I have about 1 month to do this.

My plan:
A 3 axis, 4 would be a +, mill with a milling-area of about 300x450mm (A3).

I got some motors from 2 old Okidata dot-matrix printers, don't know if they will do the trick so i got a large HP laser printer/copier that i have yet to take apart.
I got axes to a metal shop.
Timeline:
week 1 - Gather information and free parts. Do a lot of price checks.
week 2 - modeling and design. Spend money :'(
week 3 - General build / Partial assembly.
week 4 - Assembly and testing.
week 5 - Make something and drink beer (in that oder)

If you guys have any ideas or tips or designs you think would be good please let me know.

[MStef]

I'll take some photos of the motors and write down there specs so you can tell me if they might work or not.

[MStef]

So i riped apart the small laser printer and it has a lot of good parts that may be utilized. The only thing i am not shore of is the electronics.
The electronics i'm not that good at. Here is what i got from the printer.


photo 0: Power supply
Pinnout (1-10) - (1,4,7,8)=GND. (2,3)=+5V. (5,6)=+24V. 9=NC. 10=HEAT_ON

photo (1): power inlet on/off switch.
photo (2): LED's and button.
photo (3): The motor
Type BH55FT15-04,
DC 24V, 15W, 1500r/min,
no.2202, L001 5411,
Japan Servo Co.LTD made in china
has a 5pin input.

photo (4): Motor underside
photo (5): Control board i guess
pinnout from closest to sticker clockwise
8pin=PSV, 2pin=cover, 2pin=THM, 8pin=HVPS, 6pin=sensor, 2pin=smart,
2pin=fan, 5pin=motor, 3pin=toner, 2pin=SOL, 2x12pin=?? something from the usb or paralellport.
photo (6): metal casing whats inside.
photo (7): Input signal board in a metal casing.
has the 12pin out, 6pin= sensor's, 2pin=single sensor

The question is: Can i use this stuff in any way.
Is the motor any good.

[FandZ]

Take a look in my thread. The rails I built are very cheap and very sturdy. I'd say around $8 to $10 per rail and roller assembly. I have video of the Y axis up rolling smoothly with over 100lbs on them. I should have video of the X this weekend. I'll be putting the gantry through some paces this weekend too. I'm sorry I can't be of more assistance on the electronics and such. I'm still learning.

Also if you do look at my build thread don't try to make the table portion. That was a lot of work. If was to start again I'd go in a different direction for the table. Not that I regret it, it is very strong, but I could have gotten just as sturdy of design avoiding aluminum angles. That was a pain.

http://www.cnczone.com/forums/showthread.php?t=71949

[MStef]

Exelent idea with the rails i was trying to find some way to overlap one square profile with another but yours is a lot better.
I see what you mean with the table top might just use wood at first.

[FandZ]

People do wood with a lot of success but I don't see the point. If I'm going to invest the time, I'd want it to be the strongest it could be. I'm probably going to put a wood top over my table for dry cutting and make an aluminum table top for wet cutting. That is, If I don't immediately start on my second one as soon as this one is finished.

Originally Posted by MStef Exelent idea with the rails i was trying to find some way to overlap one square profile with another but yours is a lot better. I see what you mean with the table top might just use wood at first.

[MStef]

Thars y i am goint to start out with a crude solid frame and so there will be plenty of roome for improvement. As for the table top I'll just slapp some wood on to but later i would make on efrom galvanised steel.

[MStef]

I need help. now i have gathered a a bunch of electronics and motors from different printers, scanners and other stuff.

because i have a lot of small rods i changed the scale of the cnc mill to just the size of an A4 paper so that i could use the stuff.

But i have no clue if i could just slap together any motor control board and use it with any of the motors.

I'm not a very electrically inclined person, i can solder perfectly but to design a circuit board not anytime soon.

here are the motors i have on my desk and i remind you about the photos below that i already posted.

Please if you have some advise for the electrical noob i'll take it all.

[steve323]

Those stepper motors look really tiny. They probably do not have a lot of torque. Let us know how they work out.

Steve

[MStef]

The one in pic 1-2 is very small came out of a scanner but the other one is about +4cm across and it spins to smothly to be a steppermotor may be a servo i dont know.

[steve323]

Pic 1-2 is obviously a stepper motor because it says so on the label. It is barely large enough to move a light weight scanner head. It looks way too small to power a CNC router where there will be heavier components and cutting forces to contend with.

The other pics look like DC motors. They might have circuitry to maintain approximately constant speed, but they would not be accurate or strong enough for CNC.

It looks like you might need to spend some money for real motors. I have never had much luck finding surplus stepper motors with enough torque to run a CNC router. Really good ones can be purchased here for around US$50. Not sure what is available in Iceland.

Good luck on your search and don't be too discouraged if everything takes longer than your original 4 week plan. I have been working on my machine part time for 2-3 years and it has just recently started being useful.

Steve

[ckm]

Hey there,

You can get pretty cheap small steppers (e.g. $30) from Keling. You can also get pretty cheap complete kits from Probotix.

CNC4PC also has cheap electronics, and the new Gecko G540 is pretty cheap as well.

HTH,

Chris.