[nofx]

I'm Jon
I don't have any pics but I have been buy peices for the last 2 weeks. I have questions about some things.
I'm trying to decide between steppers and servos still because the similar price of gecko stepper and servo drives. I bought a 48v 20amp power supply. If I got 6amp stepper motors will that power supply enough amperage and if I wanted to add a 4th for a 4th axis is there enough overhead to add one?

I also got my racks for my xaxis from moore gear. I'm trying to work out the math for sure with that.
It's 20pa 20 degree rack .5by.5 fairly standard rack for this application.
The 203 driver has 10 step micro stepping
A regular stepper motor has 200 step per full turn so therefore the math is
1inch pitch diameter pinion on a stepper should yield 0.005 then micro step it to 0.0005 resoltion correct? The reason I ask this is because I don't understand the for cncrouterparts 3:1 reduction system unless you ned more torque in your system?
Is there such thing as to much stepper power? It's not much more for the 906oz vs a about 600oz stepper.

[hemsworthlad]

Hi jon,

Yes you should be ok with that supply regards Amp, from what i've read they say about 68% of total motor amps, but were it may leave you short is the volts.
Depends on your motor specs really, if you roughly work on 20X the rated motor voltage it will give the voltage for the best performance. . . Or the a more accurate way is 32x the Sq/root of the inductance of the motor, the specs on the motor will give it as say 6.5mh.

Regards to much Stepper power.!! Yes n No
Really you need to be sizing the steppers according to your build size and style, a lot of variables come into play that have to be taken into consideration to work it out properly. . . Things like drive system being used IE R+P or Ballscrew etc and weight of gantry etc being moved all these make a differance and it can be large. IE a ballscrew is a lot more efficient than a threaded rod so less force is required to turn it. . . . . I believe thats why the reduction with R+P, more torque is required due to the higher friction involved.
It could also be for resolution.? I'm rubbish with math, but i think you didnt take Pie into account with your calc's.
A 1" Dia gear will rotate 3.141" per rotation so resolution will be 0.015" per 200s and .0015" 10Xmicro. .? (Be gentle with me if i got it wrong did say i was rubbish at math. . Lol)

There are loads of threads giving the science of the forces involved if you want to work it out that way or just do what a lot of people do and look at similar machines to what you have in mind and use that as a guide.
One thing to bear in mind with a stepper, generally the bigger the motor the slower they spin, Ie most Nema23 will spin faster than Nema34's.

I,m no expert and i,m sure far wiser bods will be along soon to give there expertise but thats my 10cents worth, hope it helps.?

[nofx]

1" Dia gear will rotate 3.141" per rotation so resolution will be 0.015" per 200s and .0015" 10Xmicro. .?


I,m no expert and i,m sure far wiser bods will be along soon to give there expertise but thats my 10cents worth, hope it helps.?

Thanks alot, that makes more since now that i see it. so im using rack for x and ballscrew for x and y axis. so now i have to figure out my gearing for x but thats okay. its a 0.2lead ballscrew is the math 0.2 divide by 200 by 10?
0.0001

jon

[ger21]

The reason I ask this is because I don't understand the for cncrouterparts 3:1 reduction system unless you need more torque in your system?

With a 1" pinion and direct drive, the force is the torque/ pinion radius. With a 600 oz motor, you'll have 75 lbs of force, when the motor is not spinning. At higher speeds, that force will quickly drop to 1/3 or less. The problem is that you need a lot of force to accelerate quickly. Gearing 3:1 triples your force.

[nofx]

ThANKs ger for the info.
Well heres my ideas on paper.
done out of 1inch square tube, 1.5 inch square tube and colded rolled steel.
Theres a couple parts left out for view but if anyone can see a flex point that would be helpful to let me know.
Moving xaxis table with ballscrew
yaxis moves on a moore gear rack.
zaxis on a 4inch by .375 plate with ballscrew.

[nofx]

found the render button. heres some renders