Right on the money!!
Dimond ball cleaner RPM
- Thread starter northshoremb
- Start date
If you expect to get a rotational change in the spin of the balls, you have to reduce the speed way more than what you're running. Faster spin produces less friction, and increases the centrifical force if the balls spinning.
If you have access to AC single phase Variable Speed Drive you can change to speed of the motor easily. You can run the motor at low RPM with out loosing any torque. Now depending on who you are and where you purchase this it can be pricey. I am in automation and my company is a distributor of these products. I have a free sample sitting on my desk that I am planning to use for a Lathe project in the near future.
Here’s an additional photo, i couldn’t upload.
I agree, problem is i can’t find low speed AC motors that I can mount sideways. I even tried a 30degree cone shaped bottom disk , it helped but not enough. Sorry I can’t send pics, thanks for your info.
You must be using a 220v 50hz motor, or a gear drive 120v motor, 1025rpm is not a normal AC motor
Please send info I need to solve this problem.
No 120v AC direct drive motor.
Sure thing, if you're looking for an 120v motor gear reduced output rpms because you want to hook it up to the rotisserie on your BBQ.
What you're looking for is a 120v worm drive gear reduction motor. Those you can buy from about 20rpm output and upward from there.
Look up a 1/6hp worm drive motor.
I live in Canada and I am a distributor for Rockwell Automation. I can only sell in my select Area. If I were you I would look at ordering a drive from Automation Direct which is a online company that sell automation product a a cost effective price. Make sure it comes with an external potentiometer so you can adjust the speed of the motor by hand. You will be able to adjust your motor to any speed you would like with out loosing Torque. This drive adjusts frequency and not voltage so you will not damage the motor. You will also set your motor overload in the drive so it will trip on amperage overload. If you do not have electrical knowledge it may be a stretch.
A VFD can make a motor run slower than rated speed, however a major point of consideration at low speed is cooling. A typical electric motor is cooled by a fan on its shaft; at low speed the fan moves less air and at some point the motor will over heat. This is generally not a problem with centrifugal loads such as fans, pumps, and blowers because the torque required by the load drops drastically with decreasing speed. In this case, the motor is doing less work, and there is less waste heat to dispose of.
A VFD can drive a motor faster than its nameplate speed, however, above the rated speed, the motor looses torque (twisting force). At higher speeds, less and less torque is possible. The maximum continuous power (speed times torque) is limited by the motor design, therefore a VFD cannot deliver more power than which the motor is thermally capable.
A VFD can also make a motor more efficient, but only at reduced load and/or reduced speed. A drive system will not use less power when the motor is running at rated speed and rated load. In fact, it uses slightly more due to the losses within the drive.
A VFD can make a motor reverse without the use of contactors, but it can’t make the reversal faster than the combination of the motor’s max torque and the load’s inertia allows.
A VFD can make a motor produce more than its rated torque but only briefly. The amount of time is limited by either the drive’s overload capacity or the motor’s thermal capacity. A drive cannot make a motor produce more than its maximum torque. Max torque or Stall Torque is generally not shown on the motor’s nameplate. The iron in the motor can only sustain a certain amount of magnetic flux density, even if iron is driven harder, the flux density will not go up. The amount of torque a motor creates at the flux limit is the most torque that can be achieved.
This is all correct.
If the we are trying to reduce the speed of the motor and retain torque this solution will work. It also has it own overload built in so will protect the motor. The problem here is not if it will work, it is the cost of the drive and having the lability to be able to wire and incorporate the drive in the space of the ball cleaner.
Torque is an issue with a ball polisher, which is why reducing the rpms of a an AC motor just simply to slow down the buffing platter won't work. When you reduce the rpms, yet maintain the same resistance in the torque needed, you've also reduced the motors ability to cool itself in that application, there by heading to burnt out windings in the motor.
This is the exact reason why I used the 1 1/2" pulley on the motor to drive the 6" pulley on the main drive platter, motor still spins at 1725 rpms, but the output is 431 rpms, and the final torque has been increased 4X to that of a 1 1/3hp motor, and no additional cooling of the motor is required.
When I analyzed every kind of ball polisher ever built and sold on the market, I determined they all shared to common problems, 1) they spin the balls to fast, and 2) they didn't do anything to offset the centrifical force of the spinning balls to insure a 100% uniformity in the polishing of the balls.
Heating can be an issue but I sell thousands of these drive a year to OEM's that make Boilers, gasification machines and furnaces and as long as you not running at very low speed no problem for the drive. Drive and motor mounted were heating is a concern and they preform well. I do not see a ball cleaner have anymore heat than these applications. Now if you buy a cheap drive with small heat sink you may have problem with the drives failing in some applications. Electronics and heat do not work well together. For this application you will not harm your motor.
But you're overlooking one vital part of your equation, load resistance. Spinning a fan only has a load resistance of the air its pushing, and how fast you want to push that air.
Its a whole different load resistance to mount a 3/4" x12" platter on the motor shaft, then create resistance to that platter from spinning freely, by placing 8 balls, or even 16 balls on the platter, with a wax cleaner solution on them, separate the balls creating even more friction by placing barriers to which the balls rub against, and even more friction if you're using a belt drive system, that if the belt is to tight, will alone stop the motor from starting up.