Tennis ball machine DIY - part 2
Вставка
- Опубліковано 25 лют 2014
- After several months of hard work ;) I hereby present an update on my home-made machine.
New features:
- construction is now stable, has rubber bands so it won't damage the floor
- significantly less vibrations
- added ball feed tube, now it won't accidentally tear off an arm
- electronic adjustment of rotation speed of each wheel (in a closed loop, PID controllers, opto-couplers and slot discs)
- electronic adjustment of vertical angle
- can be controlled with switches and buttons
- can be controlled remotely (currently with cellphone over bluetooth)
music:
"Cold Funk" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0
creativecommons.org/licenses/b...
"Repercussions" by JewelBeat.com - Наука та технологія
Very impressive, I look forward to seeing part 3 when you've added your improvements!
You are awesome...I am a Romanian strudent that just finished Industial maintenace Technology.. and last year i started to play tennis and i love it.. i would like to built a machine like yours as well BRAVO! I take my hat off!
Well done, I'm impressed. I'm also interested in building something like this and will follow: looking forward to seeing the "completed" unit (because nothing is ever really complete!)!
that is AMAZING!
Waiting for part #3
you displayed lot of hardwork and imagination for designing machine, Keep it up...
Great project! Will you also try to implement ball spin (top spin, back spin) maybe by varying the speed of one of the wheels?
Please can you provide specs of the motors as well as a guided break down of how you made this...very interesting project mate👌.Thanks for sharing
What are your wheels made out of and how much do they weigh? Much appreciated
Hi There
Great work on this project !
A quick question - is there any chance you plan to release a parts list, drawings, etc so we can all participate in building our own machine ?
Polak Potrafi :)) BRAWO!!:)) Zamawiam jedną sztukę tej maszyny :D
Fantastic project. Any news on the progress (and possible open-sourcing / instructions)?
Any chance of sharing your project as DIY? I want to build an ice-hockey puck shooting machine... Or at least the parameters of your motors?
awesome. great work.
What about the promised progress?
I really see a good ,and more important, feasible concept for a ball machine.
Maybe you could give us some infos about your Hardware, which motors did you use, which controller, i would really appreciate it as i am planning to make my own machine.
I've been looking into building my own tennis ball machine, and I'm just wondering what/how you chose to measure the RPM? I have most of my other ideas figured out, just locking down the measurement step for a fairly accurate input to the PID control.
Nice project! Do you have a link to the motors or some information about them? I'm wondering what wattage/rpm I'd need. And how are you reading the current speed of the motors? Thanks!
very very clever....congratulations, i struggle to open a can of coke...thats the extent of my mechanical ability...this is extremely impressive well done!
Thanks for sharing, good work
Hi there! Good machinne!!! I would like to know the caracteristics of the main DC motors. Thanks bro!
Amazing project. Coud you please send me a part list? Which h-brige and motor specification did you use? Tks
first of all congrats.and please could you inform me about the type of the electromechanical cylinder do you use and is there his cao design
amazing and inspiriting job. I am trying to make my own machine and I am not sure how to push and pull the engines estructure. You did it with a rotary engine but, how do you connect and link the engine support to the estructure? could you please help me? Thanks in advanced
Hi, great work! Is it possible to get some plans and software from you to build an own machine?
Looks good, did you consider hand truck wheels? I would think they could be balanced with normal wheel weights
Hi
0bo0, very impressive project!! Can I ask you which motor shield you've used to control this powerful motors from Arduino?
Thanks!
nice. i am less nervous watching you guys feed balls into this version :)
Is there open source porject for this work, can you share devices, equipment and codes ?
what type of wheel are you using and can you find tell me where I can find then. Also I love to machine!!!
Sir 0bo0 , Just asking if you sell this machine? thanks for the reply
nice work did you get patent for it or out in the market yet
Where can I get motors like the motors in your prototype? which are the specs? I need to build a tennis ball machine like yours for a college project and I have a few doubts yet with the motors
Yes I guessed as much so. Well that’s the world we are in. I have looked all over the world and even the Chinese ones are the same price. For me I just want to play tennis and want a machine to improve my tennis and as a means to keep a little fit. Not that I am any good but its gets me out most days when the weather’s OK. T
he best machine on the market today seems to me to be the spitfire without going into the professional level.
I would still love to get a start by seeing all your sketches and or notes. I am not looking at it from a profit making aspect.
I am green when it comes to the electronics but my gut tells me that they can be controlled a bit like a macro in Excel. I am in the dark as to how the spins are done. How the wheel spin spin should vary. If an additional angle would create a side spin. The demonstrations you did pitched the ball well. Would it be good for me even as it is now? Undoubtedly. I would lust love to have a crack at making it.
I was looking at a second hand 15-20 year old Tennis Tutor 4p which was the best they did at the time. I spoke to the manufacturers in the states. Extremely helpful. They said based on the diagnosis that the battery was dead as that model was not designed to run off the mains and did not come with a smart charger. The chap had examined on a big screen the frame, control panel, remote and even the wheels. His opinion was that all was well. But this sold as broken for repairs for £350. The world has gone mad.
All the best and thanks for such a quick reply. Oh and I am getting into the music.
Jacky
What kind of wheels are you using? And however woul you say that this is ping to cost overall when it's done?
I wish i had this kind of machine when i was kid playing tennis. But right now my son plays. so i will try to build that kind of machine.
One question which motor did you use at 1:33? can you please share the link where to buy it? did you use the same motors for vertical and horizontal move?
What kind of wheels are you using? And what would ou say the overall cost will be?
Hi Nice job, what kind of battery did you use?
Hey man, I'm building this at home, I already have those exact motors and i have them running but I'm having some trouble with designing the frame. is there a way I could get in touch with you and ask for some advice?
Hello! At the end, which rotation speed was the best to play in court?
hai obo0 i want to make tenis ball machine , what part do use ?
blok diagram
how the tools work ?
thank you
Do you have a parts listing for this awesome project?
First of all I must commend you on the work you have put into this machine, well done sir! I am curious about the size motor used for the elevation of the ball launcher, is it stepper/servo? Also how did you connect the threaded bar to the motor shaft?
Thank you.
Thank you. It's a DC motor, several tens of watts power + potentiometer on axis of rotation (for absolute positioning). Motor shaft is connected to screw by a cylindrical coupling part which has a two holes on both sides, one that matches shaft and the other one has the same thread as a rod. Screws perpendicular to the axis secure the connection.
After the tests I found that this mechanism works pretty well but it is not very precise and I don't recommend it. I'm going to replace it with something else, probably a motor with gearbox.
Hello!! First of all: great work!! Very interesting!!
And thank you very much for sharing these 2 videos.
I'm trying to build a similar tennis ball machine.
I've put togheter all the data you posted in the comments:
electric motor: FIRST CIM 12V 5280 RPM
(12v - 5280 rpm - stall torque 2424 mN-m)
wheel weight: 750 g each (ideally less than that)
distance between wheels: 3.5 / 4 cm
In a past comment you suggested to use a less powerful motor with approximately these specs (100-200W, 3500-5000 rpm under load and long shaft).
My concern is that the power of the motor you really used is approximately 8 times higher!! I'm definitely an amateur when it comes to electonics so maybe I'm wrong, but here are the numbers:
P (watt) = torque * 2*pi*rpm/60 = 2,424* 6,28* 5280 / 60 = 1340 watt (= 1,3 KW)
As you see, it's 1340 W versus 100-200 W.... Which is right?
Moreover, at the same amount of rpm, with 150 W, the torque woul be 8 times lower.
I hope you can point me in the right direction ;)
Anyway... GREAT WORK!! Bye
Hi! Your calculation is wrong. Stall torque means 0RPM. There's a datasheet for this motor on the Internet, it contains rpm/torque curve. According to the document maximum that the motor can deliver is ~343 watts of output power at 49% efficiency. But much less is needed to keep the wheel spinning at a constant rpm.
hello there, did you finish this one? Can you provide instructions to build one?
hi, so you can control the speed of these motors ? they are not "fixed" like with most of CC motors
Very amazing. I am technologically "brain dead" so this is quite interesting to watch. Great job.
Thank you.
What is the maximum speed with this specs?
hi, can i know what kind of batteries you used? and the duration of the game? thank you.
Hi Bo,
well done on the great work. I'm pretty familiar with most aspects of what you are doing electronically but I just have a couple of questions on the app development and remote comms.
For someone who is not experienced in developing apps, what is the easiest way to create an android or Iphone app like what you have with simple buttons for increasing/decreasing speed of motors and tile angle?
I presume the Bluetooth comms you are using is equivalent to doing a serial read/write on an RS232 port once the Bluetooth channel is setup?
I notice you are using an RC controller at the end of your video to control the tilt angle. What is the RF transceiver module, which is connected directly to the H-Bridge module, that you are using to communicate with the remote RC controller (Turnigy)?
Thanks,
Paul
Hi Paul, thanks.
I don't want to recommend anything for mobile development because I'm not feeling competent in this matter, but my app was created with Xamarin and it wasn't difficult at all.
Bluetooth module is transparent to the microcontroller, works as a simple serial (RX,TX,GND).
RC RX component on the video is "eleres" - it's a polish 433MHz transceiver based on RFM22b module.
Hi, Bro
How to get more information for this machine, pls send me the web link......., What was the finishing product.
Hi, congratulations!! I liked very much.
Would you tell me?, what kind and model are the motor's dc for pitch and roll.
Thanks very much!
Banebots FIRST CIM 12V 5280 RPM 345 oz-in Brushed DC Motor you find them on www.Robotshop.com or on Andymark.com with a 8 mm shaft check for specifications on the two sites.. i found it less expensive on www.Andimark.com
It looks awesome now!! Are you going to use servo motors for horizontal movements??!!
Thanks. Haven't decided yet but I think about low rpm/high torque dc motor+gearbox+potentiometer. So basically a DIY servo :)
Hi Bo, still waiting for PART 3
:D
Are there news?
0bo0 Nice work. I like it. Beach Tennis is like tennis but on the sand. I would like to make a practice court with home made machines like yours. I wonder if you have a way I can use your idea to build this court. The machine must be at about 8 to 9 feet high, some times lower and should be able to shoot balls straight or straight up for lob shots and should be able to carry a basket with 50 or a 100 balls with automatic feeder. Do you have a part list that you would share. Do you sale the complete package??Would you help me build this machines??.I would like to build a Training Beach Tennis Court with 4 or 5 of these machines that can be programmed to shoot balls in a specific sequences simulating a real game, if you know what I mean. Maybe it is crazy but I know it can happen. Let me know please. Thanks. ezio.
I am a part of research team at a university. We would be interested in using your machine for testing golf balls? Is it robust and repeatable enough to test a golf ball?
You said that you use driver BTS7960B 40A, it means based on first cim motor dc datasheet your torque less than 173.4. it is correct?
Hi very impressive too. Any chance you give us you code and material list? Regards
Hi, Did you finished the Project? Are you selling it? I would like do make a machine like that for my personal use...
Hello! Could you please tell me what is the distance between wheels?
hi,good job,im from iran,i want too make a machine like you,plz say all information about youre motor,like:ac or dc/power/spin/torque/speed and other info.tnx
Can you share project details ?
what kind of PID controllers are you using?
Anyone try this project with brushless motors yet? Just wondering if the efficiency increase would give longer run times or faster shots. I'm primarily looking at doing this for pickleball, which is much lighter weight ball and may not need quite the torque required for tennis balls. Also doesn't need to compress the ball as much, so wheel spacing and placement will be different. Just curious if anyone has done this.
Hi 0bo0, Meaning do you provide instructions to build one? thanks..
You effort is impressive, any idea from where to get the commercial bowling machine wheels ?
Thank you. I would ask machine distributors/shops, maybe they sell replacement parts.
Hi Bogden, do you have any interest in documenting the assembly of your tennis ball launcher? do usłyszenia z canadé.
i like this music!!!
Any chance for making this for customers? I'm looking for a cheap tennis machine
How far the ball can go on max/speed of wheels?
Hi! How's your tennis ball machine after those years?
Hey brother, did you ever complete the machine? Would you share the plan? Cheers :))
also how much rpm does the motor have?
I'm a tennis player and a student in mecatronic, I really like this project, machines like that are way too expensive on the market now. I'm building one too but with a microchip PIC24 and prefabricated wheel from a tennis ball machine company(But it cost me 120$ for 2 wheels...). When do you think you will have part 3? Continue great work, thanks for sharing!!!
Thank you. I think sometime during the winter, when I have more time to work on it. The original wheels are a bit pricey, but they will be much better than custom made.
Can't find the part 3; that final phase never materialized? Anyway, great work!
Also where did you get that wood?
Hi OboO
Wow what you are doing is so professional and well thought out. I have been looking for a tennis ball machine on Ebay etc. I simply can't understand why they are so expensive. So you can understand my interest in your work. It is so professional. Having lost out on a bid to buy a "for repair" tennis ball machine I am very keen to make my own.
I notice that you drew your plans in Autocad or Revit. I have both on my machine as well was Solid Works. My use has been Autocad to sketch buildings but with help from friends, I could get up to speed with whatever program you have used.
I would be over the moon if you would share your research with me. I desperately want a tennis ball machine as I love tennis, want to improve at it and well as keeping fit. I can see that working with you I would not only have a tennis ball machine but it would be the best available on the market. I am anxious to understand how the spins can be created using the two wheels. I notice that you have a piston solution for the vertical oscillation which is much more responsive to the systems used in the sample I was looking at.
I also note it's been a couple of years since this video so it may not be on the top of you list anymore.
I look forward to hearing from you.
+Jacky Kenna Hi Jacky, thanks for your comment. The answer to why they are so expensive is: because they are patented. And that's also the reason why you can't replicate the design and sold it cheaper.
Regarding vertical oscillation. Mechanism shown on this video is not precise enough, due to two things: 1) potentiometer (+ADC) as an absolute encoder has a very low "resolution" 2) it's difficult to make small corrections of angle using DC motor with ordinary screw and nut - if a current impulse is short the motor won't move because of friction, when the current is increased, it starts to move and overshoots. So in order to achieve precise angle control this mechanism has to be redesigned.
I devoted quite a lot of time to this machine and when I realized that it would require twice that much time to finish it and there's no way to monetize it, I decided to focus on other projects.
Since this video was recorded I've slightly improved electronics though. The machine can now be controlled with a builtin LCD touchscreen. I've also found cheap components for absolute angle sensing (hall-effect sensors).
if you were using a steppermotor wouldnt you solve those problems?
any idea of where I could find those wheels?
Well done. It looks awesome.
Is it possible that you can put together a part list and instructions??
Thanks
Thank you. I may release plans and/or source code, but not before the machine is finished.
Thanks
+0bo0 Hello, congratulations for the project. There have part 3?
Could you show the code? thanks
@@0bo0 When
Hi
Excellent video and great engineering skills!
I have started work on my own version and have got the exact same 12V CIM motors as you and will be using an Arduino for control. The only thing I am having trouble with is the H-bridges. I cant seem to find anything on E-bay that can drive more than 2amps. Could you please give me some details on the H-bridges you are using as I cant quite see them in detail from the video. Thanks and I'm looking forward to the next video you post! Chris
Westy_cpw Hi, thank you. Try this on ebay: BTS7960B
0bo0 Hi, thanks for the information. I have found them now.
I am building a cricket bowling machine so my machine will be horizontal instead of vertical like yours. I have a test system set up on the bench with two motors and two optical encoders that allows me to read the rpm of each motor and display it on an LCD screen that is all controlled by an Arduino Uno. At the moment each motor is controlled by a variable resistor but I cant work out how to set the rpm I require via and input to the PC or even a blutooth app like yours. Would you be able to give me some help and advice based on your code? If you can help I will send my email address. Thanks a lot Chris
Hi Chris. I used a PID algorithm to control rpm. It compares current and set values of rpm and makes the motor spin slower or faster using PWM signal on H-Bridge. There are several free libraries for Arduino on the Internet. You need to tune PID parameters to get fast response without overshoot, this is the most difficult part. Once you have it, create a simple command parser that reads input from serial port and passes required rpm value to PID algo. HTH
Hello oboo, please only tell us what are the specifications of the motors...... please please it is an excellent proyect congratulatios you are smart
+Etiel Natan Hi, the motor spec is about 5300 rpm at 12v, free running current 2.7A, stall current 130A
how much weight is your wood wheel?
hi, can you please tell me where did you get the frames. Specially the "U" shaped stand. I tried making myself, and they are not of precise measurement, so there is lot of vibrations
Metal support parts were laser cut. High precission of rotating parts is very important. Took me quite a lot of time to balance the wheels
Hi! is there a part 3?
Hello 0bo0..Fantastic work...Whether it is possible for you to share DC motor specification for vertical Inclination along with rpm ..Thank you very much
Hello. NB4056A@12v. But that motor choice was a mistake. Couldnt achieve good precision with it. I think a similar size stepper motor should work much better
would you provide instructions to make one of these ball machines. Can pay you for your effort.
what motors did you use?
Hi , Great job man (y) . can I know how to reduce motor's vibration?
Thanks. Dynamic balancing - spin the wheels up (one at a time) and check vibrations (a phone with an accelerometer can help here). Then add some mass on a rim and check again. Move the mass around until vibrations are smaller. Once you figure out what's the optimal place try bigger or smaller mass. I used small coins and a duct tape.
hello Bo
have you got some SolidWorks files to share ?
Fantastico
Do you have one for sale?
hello
I have the same model reconstructed and would like to know which battery you use it.
battery make/model?
Thanks for the tip
Hi. Two 12v 7Ah ups batteries.
is the machine ready? where can we purchase it?
How do you call this concept?
which motor you are using
Where can I get those wheels??
Hi!!! Did you finish it? :)
hello, by any chance could you explain how you mounted the motors to the wheels, ?
Hello. imgur.com/POTDarx it isn't the best way probably
Hello, what is the diameter on the wheels?
que motor tiene?
Hello,
Whats the name of the motor by time: 1:33 ?
I would appreciate an answer
Thanks!
Linear actuator
Hi OboO,
I am trying to build a same type of machine.I am considering a 12v 2A 5Ncm DC motor and L298N motor driver.I am expecting your suggestions....
Na it won't work the torque is very less they had used 25 kgcm torque
Interested in your ball machine where can I find you to talk privately