The Oukei TW-2700-E1 Table Tennis Training Machine is a consumer grade serving machine. It stopped working due to an out of aligned spring. Photo 1 by Don Tai
My neighbour is hard working and has few hobbies. She loves table tennis but has no partner, so she bought a table tennis machine, which shoots balls at her. This machine, an Oukei TW-2700-E1, she loves, allows her to return balls without help from the family. It was unfortunate when the machine began jamming. I opted to fix the machine, and she was grateful to have it back in service. It turned out the fix was very simple, but rendered the machine unusable.
The Oukei 奥奇 （ao qi) TW-2700-E1 Table Tennis Training machine, Made in China, is consumer grade, meaning that there is a lot of plastic. Though the wheels and motor seems like metal, I would not be surprised if there were plastic gears inside. The housing is plastic, and easily broken with rough handling. The rotating platter wheel is plastic, the motor’s metal spindle, with a key cutout, is held on with a plastic nut, held fast with a metal screw. These indicators show it is not made to last. The power supply, 12v 3A, is small for the voltage required. If used significantly you should expect this power supply to burn out.
The Oukei TW-2700-E1 Table Tennis Training Machine is a consumer grade serving machine. It stopped working due to an out of aligned spring. Photo 2 by Don Tai
Partial Disassembly
Take off the top plastic collar with a clockwise rotation. Be very careful, as there are 4 small tabs that could break. Note the black plastic rotating platter wheel. On the underside of the wheel at the spindle is a small Philips head screw. You will need to loosen this almost all the way out. The spindle has a keyway, so that it rotates through the motor but does not slip on the platter. Pull the black rotating wheel straight up, exposing the spindle and keyway.
The Small Fix
Note the spring, dangling down the middle of the ball hole. The fix is to loosen this spring and rotate it to the left so that the ball has easy access through the hole, but will block the ball from going to the left of the hole. The top platter rotates clockwise. A ball falls down to the hole. The spring should block the ball from going too far to the left and therefore under the platter. This would cause a jam between the motor and the spinning platter. The spring should not block the ball from going in the hole.
The Oukei TW-2700-E1 Table Tennis Training Machine is a consumer grade serving machine. It stopped working due to an out of aligned spring. Photo 3 by Don Tai
The Oukei TW-2700-E1 Table Tennis Training Machine is a consumer grade serving machine. Top platter has a philips screw underneath. Photo 4 by Don Tai
The Oukei TW-2700-E1 Table Tennis Training Machine is a consumer grade serving machine. Metal motor spindle with a keyway attaches to the platter over the keyway. The screw goes through the platter nut and the metal keyway. Photo 5 by Don Tai
This spring will move over time and will need to be adjusted. A better design would be to block the spring with a piece of plastic so that it will not move.
The Oukei TW-2700-E1 Table Tennis Training Machine is a consumer grade serving machine. Ensure that the spring is to the left of the hole, allowing the ball to drop into the ball hole. Photo 6 by Don Tai
The Oukei TW-2700-E1 Table Tennis Training Machine is a consumer grade serving machine. Ensure that the spring is to the left of the hole, allowing the ball to drop into the ball hole. Photo 7 by Don Tai
Reassembly
Tighten down the spring, but don’t break the plastic. This machine is somewhat delicate. Insert the platter back onto the spindle, properly lining up the keyway, ensuring the platter is all the way down. The platter’s philips screw goes through the platter nur and through the hole in the spindle. Do not over tighten. There are no threads in the spindle keyway, so it will not lock. Reattach the top plastic collar and you are done.
Conclusion
This minor repair will be required periodically as with use the spring will move. As this is a consumer machine I do not expect it to last for years, maybe a year. I could not find the user manual online.