Guys, also just want to make sure I haven't just walked rather stupidly into an unusable motor:
Thanks.
As augie says, you're good with that motor.
You can get away with something smaller than a 50A/1000V bridge, but at $2.09, just go with it (assuming your Chinese part will be reliable).
Williams still has the same photo, so I don't know if they've made a change, but they used to advertise this as 180 Hz when they first released it.
Good to hear it's working reliably for you. There's no overheating in the diode bridge because the load current is only ~3A max. Even without that heatsink, that huge bridge could easily dissipate the few Watts. The heat issue (assuming the variable pot controlling the voltage is dropping the voltage as the speed is reduced) would be in the pot, not the bridge. I expect that the motor's torque is high only when it 1st starts up with grain in the hopper. After that, the torque is fairly low; therefore, the motor current, which is linearly proportional to torque, and in turn the power in the pot, will be low most of the time.
Don't feel stupid or bad. I've been doing this stuff for 36 years, so I have a slight advantage. What augie has suggested is basically what you're asking about, except it's even simpler than your example. It's just a light dimmer (variable resistor or potentiometer/pot) to vary/reduce the input voltage, the diode bridge, and a large capacitor to smooth out the ripple (turning AC to DC). You just have to be very careful, because you don't have a transformer to isolate (protect) you from the 120V AC line (but neither do most of the speed controllers).
I absolutely understand. To go that route, you need a little patience and luck. While it would be nice (and best) to have an enclosed controller, you could certainly use one of the open frame ones; you jut need a "safe" place to mount it out of the way to your mill stand. I think this is the motor you have. You may be able to use any of the controllers under Model 4182 Matching Controls. There are also some options that would work for you from KB Electronics:
Nothing wrong with using L090s; they're just bigger and bulkier than necessary. As long as the set screw is long enough, I don't see any problem using a keyway hub when you don't have one. If you can take your motor and mill into the local dealer and check them, then you should be good.
It would actually be easier for you to build an ac to dc powersupply because your motor runs on 130v you would just use the bridge rectifier like I linked and no transformer or smoothing capacitor needed.. thats for stepping the voltage to say 12 or 24v and smoothing the wave which isnt needed for driving a motor you would then be running it on 120v dc which will power the motor fine. If you wanted speed control you just wire a dimmer in the 120v AC line going to the rectifier.. the whole thing with a $6 plastic enclosure could be picked up at the home depot for under $20 with power cord and such..(minus the rectifier)
No, the smoothing capacitor is needed. Without it, you don't have DC, but rectified AC, as shown in the AC Power Rectified Graph in your referenced tutorial. You want the AC Power Smoothed Graph. A DC motor can operate from the rectified AC, but will perform better and be more efficient with a lower ripple input voltage.
Ok The articles I read when setting up my power supply said it's not needed for a DC motor and it's not caused any problems in the three years I've used my power supply to drive my Mills motor so your mileage may vary. If this was some sort of device that was being used for long periods of time or used a lot of electricity I guess it might make sense to invest the extra time and money to try to make the power supply as efficient as possible but for me I've hit the point of diminishing returns. Honestly at the time I was building the power supply I was going to add capacitors because I have plenty but I could not find any information on what value or voltage to use
I meant personal safety, but giving the motor its longest life is a secondary factor as well. A project box is probably recommended, to keep the 120VAC wiring safe and to minimize exposure to grain dust.
I think the answer is 'no' on that unit, as I think the -240 units are 240V, which you don't need and I doubt you want. I think KB just makes you buy a fuse and HP resistor separately since their controllers are somewhat universal so that a single model can be used for a wide range of HP motors.
The Williams unit will probably work, but it's a much lower power AC motor that they have imported from China. Maybe less hassle and learning curve, but not nearly as good as what you'll eventually end up with if you stick it out. That red button is just an on/off switch - no control I think.
Yes again on the project box. The 5K pot performs the variable speed; I hope that comes with the controller, so you'd mount it protruding through your project box. Functionally, it's similar to the dimmer, except the dimmer is dissipating a lot of power in Augie's build, whereas this one isn't.
You should be fine with that motor even though it's very old. Mine is the same vintage, and I called and talked to Bodine tech support to ask similar questions. The motor should be sealed and has a place to add oil if ever necessary (like you hear it). Closed housing is definitely preferred, but if it came down to a closed model for $200 vs an open one for $50 and a cheap project box, I know which way I'd go (and augie has already made it clear what he'd do
)I think they're identical, except the 13 is rated for ~3A and the 16 for 6A. The motor pulls only 1.8A, so either will work. Therefore, buy the cheaper one.
I know this was directed at augie, but the answer should be 'yes'.
Like I said above, I think KB just makes the fuse an add-on because the value depends on the motor HP. If you decide to go with one of those, they have a lot of info on their website, so you should be able to determine what you need. It may just be a standard fuse you can buy anywhere. And yes, there are 2 wires or terminals to add wire to that will connect to the motor terminals.
Variable speed is not a necessity; it's just a nice feature that is fairly easy to achieve once you opt for a DC motor. The other nice thing about a DC motor is that you reverse it by reversing the polarity of the wires (which is what you also do with AC but can do with a small inexpensive switch). I installed this small On/Off/On switch on my motor leads for reverse operation (which I rarely have used). You'd just mount the switch to the project box next to the speed pot. But Stealth is right, reverse can be helpful if the motor jams and can't handle the torque.
After checking in on this thread occasionally, I sure do feel inferior powering my mills with a slow speed 1/2" corded drill mounted on the mill table. Motor, controller, and coupling all in one box for $45. Probably won't last 30-40 years like a nice gear motor
Hey, I used my drill for several years. I t worked fine, but I had to hold it during the whole milling process, and I had to control the speed by "feel". It's not a necessity, but it's nice to just dump the grains and come back later after doing other things.After checking in on this thread occasionally, I sure do feel inferior powering my mills with a slow speed 1/2" corded drill mounted on the mill table. Motor, controller, and coupling all in one box for $45. Probably won't last 30-40 years like a nice gear motor
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But gives some sniffing to do. Thanks again. Very cool solution.
