Wich Stepper Motor you will choice?

[samsagaz]

hi guys, i want to start buying the products to start my own CNC machine i want an big machine at least 2 meters for 1 meter (hope that is possible to do that)

i want to route wood and foam, and maybe sometimes drill PCBs.

dont know if will be possible to do that in just one machine, btw, for the pcb can i build and small machine.

well, abt the motors....

i found an store in my city that are selling some stepper motors but dont know which to choice

i read that i need 1.8 Step Angle but i found that this store sell 0.9 Step Angle too!

will be getter to buy an 0.9 intead 1.8?


for example ill show you some of the specs that i found

Angle Length Current Resistance Inductance Holding Torque Detent Torque Rotor Intertia Lead Wire Weight

Model 1 | 0.9 76 3.0 0.5 1.8 170 6.0 440 4 1050
Model 2 | 1.8 76 1.5 4.2 9.2 150 6.0 440 6 1050
Model 3 | 1.8 112 3.0 1.6 3.5 250 12 800 4 1400
Model 4 | 1.8 76 2.5 1.8 6.0 98 9.5 230 4 1000
Model 5 | 1.8 150 3.0 3.8 20 750 28 2.5 8 5000 big motor

The Torques are in N.cm Min

well to choice an motor i just need to see the Holding Torque?

if i want to have no problems with my motor wich torque i need to choice?

for example for Hobby Projects, Mass projects, Industrial Process how much torque on each one?

i dont want to buy an **** machine i want at least something to create 4-5 cuts/day its not industrial but not hobby either

hope some of you understand my english

[jeffs555]

The size of stepper you use would depend on what leadscrews you use, and how fast you want to cut. You need to decide this before you can pick out stepper motors.

Those are all small motors. Most of them do not have enough torque for a 2m x 1m table. The largest one, has only 750 N-cm (ie 106 oz-in) of torque. The 750 N-cm motors might barely work, but most people would consider even 1500 N-cm to be marginal for a table that size.

[samsagaz]

ok, so is an brutality 2mt for 1..... i can use an small table at least for my first try, and i can made each pcs in 3-4 steps....

well lets decreace the table size to an quarter of that, 100cm x 50cm (so i can made the same pcs in 4 times)

i searched google and i see that 750 N-cm = 1062 oz-in instead 106, maybe the table that i found is wrong....

1500N-cm = 2124 oz-in

im wrong?

[jeffs555]

You are right. I normally work in oz-in. I missplaced the decimal point in doing the conversion. The 750 N-cm is 1062 oz-in, and should be plenty strong for a 2 meter table. The 250 N-cm (ie 354 oz-in) might even work. I know that some people drive tables that size with motors that small.

[samsagaz]

the only problem that i found is that all this motors work at 24-40v

Voltage: DC24-40V
Current: 3A (max)

they sell drivers too with this options Micro Step Option：1/2，1/5，1/10，1/20，1/40; total 5 options

and all these drivers work at 20-45V output
its not good, right?

[jeffs555]

As long as the drivers are rated at 3A or higher, they should work. Any voltage within the range of the drivers and the motor would work. A 36 volt power supply would work with the drivers, and also be within the ratings of the motors.

[samsagaz]

Thanks a lot! i found nice prices for the motors (less than 30 dollars each one) but the Driver a little expensive (115 dollars)

[samsagaz]

is that possible? ill send you some pics about the motor and driver.




(i need 3 drivers for an CNC machine)

[samsagaz]

and latest question....

how much torque i need for 3 diferents machines

Machine 1 (small 40x40)
Machine 2 (medium 80x80)
Machine 5 (big 100 x 200)


i will order the motors today and ask the factory about the drivers, dont know why are too expensive i will need 3 drivers for each motor.... the motor is like 30 dollars and the driver 115)

[whateg01]

Forgive my ignorance, but what does the size of the work area have to do with the torque necessary? As long as a person is willing to live with the amount of time it takes, I wouldn't think the work area would be a deciding factor.

Just wondering.

Dave