[p3t3rv]

Hi for years i have been intersted in cnc but never dabbled now i look at it things seem a lot simpler than they did years ago, basicaly i want to make a pcb router/ light miller i have a a machien design in mind i have the software kcam4 and solidworks all i need to do is hook 3 size 23 unipolar steppers to 12 BDX53A connect them to a pic via 12 120R resistors and monitor the xstep,ystep,zstep,xdir,ydir,zdir maybe even streach it to opto couplers.

am i insane or is it that easy in a blaxbox kinda way ? i only want basic functionality first job would be routing some decent driver boards. i have 3 year old twins so masty chemicals are a no no its bread board or router

please feel free to comment

[mcpltd]

Why are you thinking of going Uni Polar?
Bi polar will give you so much better performance, and you can get a
Microstepping 2.5A driver off the shelf for as little as £30 so why make one?

[p3t3rv]

Hi unipolar mainly because i just got 5 new Astrosyn X173H Size 23 motors for less than £30, why diy ? mainly because i want to and have the resourses/equpment and intelligence but lack the deeper pockets needed for the "kit form" i agree £30 is a reasonable price but you need 3 for xyz so its allready £90 then you still needs motors £20 each ? we're up to £150 and my 3 year old twins have just grown out of their shoes by the time i've saved that up, im running out of hiding places with my wife and kids keep finding my cash stash !!! :drowning:

but seriously i want to do it myself just for kicks, because i feel i can and now i got my teath into it its do or die, death before dishonour!

[mcpltd]

Cool
good luck.

Hi unipolar mainly because i just got 5 new Astrosyn X173H Size 23 motors for less than £30, why diy ? mainly because i want to and have the resourses/equpment and intelligence but lack the deeper pockets needed for the "kit form" i agree £30 is a reasonable price but you need 3 for xyz so its allready £90 then you still needs motors £20 each ? we're up to £150 and my 3 year old twins have just grown out of their shoes by the time i've saved that up, im running out of hiding places with my wife and kids keep finding my cash stash !!! :drowning:

but seriously i want to do it myself just for kicks, because i feel i can and now i got my teath into it its do or die, death before dishonour!

[jeffs555]

all i need to do is hook 3 size 23 unipolar steppers to 12 BDX53A connect them to a pic via 12 120R resistors

That could be done, but you would be limited to driving the motors with a supply equal to their rated voltage. To get any kind of speed at all out of the steppers, the supply voltage needs to be 8 or 10 times the rated voltage of the motors, with current limiting to keep from overheating the motors. You could use series power resistors to limit the current, or you might want to check out this design which uses a PIC. It uses only a few more resistors and small signal transistors than what you describe. It operates the output transistors in linear mode to limit the current, and does microstepping. http://www.piclist.com/techref/io/st...step/index.htm

You also might want to check out http://www.pminmo.com/ which has a lot of good info on homebuilt drives.

Jeff

PS I don't have any experience with the linistepper, and wouldn't recommend it to just anyone, but it appears to fit your specs and experience.

[pminmo]

p3t...
Unipolars are the easiest to drive. Looks like the motors are 6 wire motors so they can be run bipolar or unipolar. What parts do you have available to use? You're going to have to switch 1A 4 wires each motor if you run them unipolar.
The other thing you need to consider is the software is expecting a PC parallel port.

[p3t3rv]

thanks for the help guys

great site pminmo lots of good info i had a few hours of educational reading

any advice on leadscrews ? m6 @ 1mm pitch seems a popular novice choice for a small pcb router

the motors i got from this guy
http://www.astrosyn.com/

they allso list surplus for sale below
http://search.ebay.co.uk/_W0QQsassZa..._excessQQhtZ-1

i likethe look of the linstep setup shouldnt be to hard to breadboard and get me started