Part 5 - Time for a NEW Design! - Tennis Ball Machine - DIY Build 

Thank you!!

Thank you!

Wow, such a detailed comment, really appreciate you taking the time to write this down. I have seen the spiral tube mechanism on some other tennis ball machine and you are right, it is a lot simpler compared to the one I have built. But the simplicity comes with a few downsides, for starters, its got limited capacity, as all that inner space is not utilised. And the next one is the fabrication itself, its not going to be easy to source something like a spiral pipe from hardware store (may be it is, idk) I am assuming you are referring to a solenoid type of an actuator and not a linear actuator here. If that is the case, the actuator mechanism sounds simple but it may not be 100% jam proof. May be I am wrong but I can see ball travelling faster between actuations resulting in double drops or a ball getting caught when the actuator closes resulting in undesirable effects, may be ball gets puncture (unlikely), or the ball pipe gets damaged due to the pressure exerted or the actuator gets damaged (not sure how the electrical properties of an actuator works here). Not to forget the timing of the actuator has to be worked out. You could keep it simple and leave it at a constant frequency though. I hear you on the "keep it simple" approach, I definitely thought of that and if I wasnt making a video out this, I would have done that as my first machine. My aim was to make a machine that is feature rich so viewers and I know how to do it but absolutely trim it for one's purpose. May be I might make a simple design later or if I still fail to make this version of the machine a reality - you've given me some food for thought. Cheers 👍🏽

I hear you mate. It's hugely frustrating when something that's so simple in principle turns out to be a blocker. There's definitely ways to mount a motor to a wheel using a coupler and shaft but I couldn't get through the issue of inexperience and lack of tools. I had to go down the path of expensive parts in a hope that it solves the issue. Let's see My suggestion is if you are using genetic motors and wheels, try reaching out to a local metal worker. They'll be able to create a frame and mounting plates for motors and bearings that reduce vibrations. Having said that, balancing wheels is tricky but not impossible to overcome. But they'll give you some pointers. Heck maybe even do that for ya. Why didn't I go down that path? Well, I got excited about 3D printing the parts 😬! But I'll reach out if and when I have to. All the best.

Thanks for letting me know. I got that comment from my wife as well. I will do better next time. Cheers 👍🏽

Hey there, thanks for the comment, really appreciate it. It has been a wild journey so far and still a lot more to go. Hope I get to the end of it soon 🤞🏽 The motors mentioned in this video are from a company called Lobster. They are sold all over the globe by authorised resellers. Here is the link to the website I bought them from. They are based out of UK but I had it shipped to Australia where I live. www.racquetdepot.co.uk/lobster-server-throwing-wheel/ www.racquetdepot.co.uk/lobster-server-motor/ I could not find an equivalent motor in the Chinese direct to customer websites like Aliexpress. I did find one on Alibaba but they were asking similar price for a sample of two units as they usually deal with bulk orders being business to business sellers. Hope this helps, thanks for stopping by. 👍🏽

@@john.alisterThank you, John, for the quick reply. I'm excited about your machine and wish you much success.

Way to keep the project going! I use ASA filament for my printed wheels because I leave my machine in the car. You're definitely an inspiration. I love the idea of the gears and parts adjusting the height of the throwing arm. I'm so ready to take apart my revamped tennis machine for Pickleball for this project if possible. I would love to zoom/face time you on my machine sometime or my 3d printer setup for the ASA filament

Hey Chris, thanks for the encouraging comment. I'd love to connect sometime for sure. From what I gather pickle ball machines need less power than a tennis machine. I don't play pickle ball although it's gaining popularity here in Australia. I'll be using ABS for the high stress parts in this project, like the motor mount plates and the fixed arm it connects to. The rest is probably going to be PLA.

@@john.alister PLA is a good idea for the production of the parts, testing, and low cost.

Oh that is a very interesting question. I don’t play padel ball but I know that the courts are smaller than Tennis Courts. The gap between the wheels are usually going to influence the amount of spin and the distance of the throw. So the closer the wheels are, the greater the pressure on the ball when it is being thrown out. In my case I’ve got about 50mm gap between the two wheels. Please note that my wheels have a concave shaped edge that hugs the ball better as opposed to a flat edged wheel that has relatively less contact with the ball. I’d say try anywhere between 50 mm to 60 mm and see what works for you. Hope this helps mate. Thanks for your comment, really appreciate it.

@@john.alister grazie mille amico ho fatto 50mm e devo dire che va benissimo ho stampato le ruote concave con motori 775 12v 4000rpm e la forza è notevole...ma vedo che i 775 sono pochi adatti emettono tante vibrazioni. grazie ancora.

Wow, a working machine 👏🏽👏🏽👏🏽 Congrats mate. I see you've used 775 type motors. Can I ask what did you do for the wheels? And how you mounted it to the motors? Or fellow maker from Argentina has that issue and your experience will help him. As to the ball feeder, I'll answer to the best of my knowledge Balls not seating in the holes is just a fact of life. But it should not occur frequently. Looking at your video it seems the balls are dropping pretty consistently. But I also can see it in detail so I'm sorry if below doesn't help. To ensure balls are caught in every hole, the spinning disc needs to be made with curves and slopes similar to the store bought machines. My feeder disc is made of two 30mm high density foam sandwiching a 6mm plywood disc. I've sculpted the foam discs to stimulate that to a degree but even then not all holes catch the ball. Ive made my peace with it 🙂 Coming to jamming, this one is a pain. There are 3 things to look out for. 1. The ball getting caught below the disc just before it falls free 2. The ball getting caught above the disc. This usually happens when there are two balls in a hole and they are squeezing each other out when they are about to fall 3. Balls jamming randomly. I faced all these issues and resolved them as below. First issue. Make the hole on the bottom bigger than the ball giving it time to fall fast. But don't make the guiding hole too big. This will prevent two balls getting into the guiding holes. Second issue, you need to play with the finger projection above the dropping hole so that it only allows one ball to fall down but also not so rigid that it cause jams. I use a spring like projection that's used as a door stop for this. I placed it at a height thats just right for a single ball in the guiding hole. For the last issue, my observation is to have the balls mix up. So I used some side projections. Kind of like pushing the balls in as they go around the container. I'm not sure I've nailed this but it seems to work for me Oh lastly,user a strong motor. Sometimes brute force will solve it. Hope this helps and good luck. You've got a working machine! That's quite impressive 👏🏽👍🏽

I did mention I got a good starting point from designs I got off internet. But you're right, I probably could have mentioned the source. Thanks for your comment, I'll do that in my next video. I had to make a lot of updates to the 3D models to suit "my" design. You'll notice the differences if you have a closer look. For ex. The motors I use are different and therefor had to make changes to the models to suit them. But in general, yes, "my" design based off of that. And yes, I did buy them on cults3D website and not just one but two of the designs.