[bfamily]

Hello all, anyone know of a good replacement for the stock stepper motors that come with the 6040 Chinese CNC. These are listed as two phase hybrid stepping motor 3A/phase, 150N.cm on one page of the manual and 57type/1.5A on another page. I am having a hard time finding a replacement in kind.

[awerby]

What makes you think your stepper needs replacement? It's rare for them to go bad; usually it's the drivers that blow up.

[bfamily]

Hey Awerby, At the moment there isn't anything wrong with them, I have had this machine for less than a year and already I have had to replace the flex coupling between the stepper and the screw as well as the bearings on the X axis screw. it was at this point I decided to start buying replacement parts for a quick change over as I have projects backing up. I haven't had too much trouble finding parts for this machine (like in kind) until I got to the steppers and there drivers. I was thinking that if I couldn't find a like in kind replacement I would upgrade but I don't know enough about them to make an intelligent decisions.

[awerby]

If the parts are poorly-made enough to fail shortly after putting them into service, perhaps you should look beyond "like in kind" replacements and shop for better ones. If that flex coupling that broke, for instance, was an aluminum helical type, the new one isn't likely to last much longer if it's made the same way. Instead, think about getting a stainless helical or a Lovejoy type coupler. If you're thinking of replacing the drivers and motors that came with your machine, see if you can find higher-quality ones that will give you better performance, rather than more of the same crappy ones. I'd say go for a Gecko G540, paired with a 48v power supply and motors that have about 2.3 mH inductance, but there are cheaper alternatives, if you're strapped for cash, that will still out-perform the original equipment.

[bfamily]

Hey Awerby, first off, thank you for answering my post. I have done quite a bit of research and saw some really cool stuff but wast sure if I could use it or no. I did look at the love joy couplers and almost bought them but I believe the I had my settings wrong in mach3 that caused the coupling to break. I got a really good deal for 3 of them on eBay so thought if they break I will definently upgrade. Not sure why the bearings failed however. I did look at the Gecko 540 but being uneducated on this I wasent sure if I could use it with the existing motors or if I had to upgrade them as well.

[awerby]

You can probably use it with the existing motors, but you might get better performance if you switched them out. It depends on how much inductance they've got, and whether they have enough torque when they're running. What size power supply has this machine got? How many volts DC does it put out? Usually those machines use low-power drives because they're cheap, then put in a low-voltage power supply so as not to burn them up. But then they use high-inductance steppers (because they're cheap) that really need more power to perform at their best.

[bfamily]

Wow, This machine is so generic that the only thing on the power supply is the 110/220 Volt input. No output voltage and no amperage rating. If did decide to change them out what steppers would you recommend. Also does the G540 come with a power supply. Sorry for all the questions but I'm the only one I know with a machine and have no one else to ask.

[awerby]

If your existing power supply doesn't have any information on it, you can detach it from your system (before applying power), turn it on, and measure the voltage it puts out using a multimeter set to DC voltage in the 10-100 range. My guess would be somewhere between 24 and 36. The G-540 doesn't come with a power supply, but you can give it one that puts out up to 50 volts. You'd probably get better performance out of your motors if you did this, but without knowing more about the motors you've got it's difficult to say what would work better.