I got the Tennis Ball Charger 150 from Set US Tennis. I have been very happy with the result. The unit is equipped with a air valve on top so you can charge it with a compressor instead of the hand pump. It also comes with a special tool that allows you to tighten the cap so that it doesn't lose pressure over time. When I bought the device I had 144 Penn heavy duty balls about 2 weeks old which I use with a ball machine. I put the balls into the device and left them for 5 days and when I removed them they bounced just like new ones. There are only a couple of small negatives. The unit only holds about 140 balls, and you have to remove them manually rather than just dumping them out. It still only takes a couple of minutes. A little pricey at $300 but worth it in not having to fabricate something myself that may or may not work right. The benefit is saving money on balls and always having the correct bounce when I practice.
How To Pressurize / Revive Old Tennis Balls...
- Thread starter SeasonedNovice
- Start date
Chotobaka
Hall of Fame
Looks like you could make hash-oil with that, too.
ignacvucko
New User
Schrader valve?
Hey retrograde,
Can you give me the size and/or partnumber for the schrader valve you are used? Also, what size tubing are you using for the valve? (I have tubing that's 5/16" x 9/16" OD)
Thanks!
Ignac
Hey retrograde,
Can you give me the size and/or partnumber for the schrader valve you are used? Also, what size tubing are you using for the valve? (I have tubing that's 5/16" x 9/16" OD)
Thanks!
Ignac
retrograde
Rookie
You'll want 1/4" ID tubing. Mine is 1/4" ID x 3/8" OD. The thicker the wall on the tubing, the trickier it will be to fit the tubing over the air valve and the tank's disconnects. Heating the tubing with something like a hair dryer will make the tubing pliable enough where you can slip it over the barbed end of the disconnect and the tank side of the air valve.
Just go to your local auto parts store and ask for an air tank valve that has a 1/4" threaded end (got mine at O'Reilly). They cost around $2. Google "air tank valve" if you want to see pictures.
tacotanium
Professional
I've been wanting to do this for a long time. Do you guys think one of those big glass pickle jar can handle 28psi of pressure daily?
Ronaldo
Bionic Poster
Only when you leave the pickles in the jar
MaconTennisClub
New User
Just found this thread and thought I'd share what I've been working on... comments/suggestions welcome.
I just started playing again recreationally after a 20 year hiatus and find that the felt on the balls far outlasts the balls going "dead". My local county tennis center has ball machines for rent, and includes practice balls to be used in the machines. However, all of the balls are totally dead which makes practicing with them tedious and impractical.
My thoughts are to use a "paint pot" as mentioned here earlier in the thread. I bought one at HF for $80 ($100 less the 20% off coupon). I removed all the fittings (including the safety pressure release valve) and added a male inlet and a pressure gauge. The pot is steel, 2.5 gallons, and hold about 30 tennis balls.
So far, I've observed that the balls start to crush (you can hear them deforming inside the pot) at about 40psi. The pot from HF is relatively cheap and so the seal doesn't work very well. An easy solution for this is to just set your regulator for the desired pressure from your air compressor, and let it run and maintain the pressure in the pot as it leaks.
My plan is to chart out different pressures/durations to determine the most efficient pressure/duration for reviving a "dead" ball. For instance, I plan to take known dead balls (exposed to the atmosphere for at least 6 months), measure their rebound (using a rig I set up), then "pressurize" them at 15psi, 20psi, 30psi, etc. for 24 hours, 48 hours, 72 hours, etc. After each round in the pot, I'll retest their rebound to determine how much "bounce" is gained. It will probably take a few weeks to come up with the right blend of pressure/duration, but it seems like it'd be the most empirical way of doing this.
The commercial product that goes for several thousand dollars (and perhaps can only be leased) doesn't give much information other than 50psi and 4-5 days. Since there's no easy way to test the internal pressure of the balls, my thought is that the simplest solution is to measure the rebound when dropped from a specific height. My rig drops balls straight down from 100" as specified by the USTA. I plan to use my hi-speed camera to capture rebound height.
I'd love to know everyone's thoughts -- especially if you've attempted something like this already.
thanks!
I just started playing again recreationally after a 20 year hiatus and find that the felt on the balls far outlasts the balls going "dead". My local county tennis center has ball machines for rent, and includes practice balls to be used in the machines. However, all of the balls are totally dead which makes practicing with them tedious and impractical.
My thoughts are to use a "paint pot" as mentioned here earlier in the thread. I bought one at HF for $80 ($100 less the 20% off coupon). I removed all the fittings (including the safety pressure release valve) and added a male inlet and a pressure gauge. The pot is steel, 2.5 gallons, and hold about 30 tennis balls.
So far, I've observed that the balls start to crush (you can hear them deforming inside the pot) at about 40psi. The pot from HF is relatively cheap and so the seal doesn't work very well. An easy solution for this is to just set your regulator for the desired pressure from your air compressor, and let it run and maintain the pressure in the pot as it leaks.
My plan is to chart out different pressures/durations to determine the most efficient pressure/duration for reviving a "dead" ball. For instance, I plan to take known dead balls (exposed to the atmosphere for at least 6 months), measure their rebound (using a rig I set up), then "pressurize" them at 15psi, 20psi, 30psi, etc. for 24 hours, 48 hours, 72 hours, etc. After each round in the pot, I'll retest their rebound to determine how much "bounce" is gained. It will probably take a few weeks to come up with the right blend of pressure/duration, but it seems like it'd be the most empirical way of doing this.
The commercial product that goes for several thousand dollars (and perhaps can only be leased) doesn't give much information other than 50psi and 4-5 days. Since there's no easy way to test the internal pressure of the balls, my thought is that the simplest solution is to measure the rebound when dropped from a specific height. My rig drops balls straight down from 100" as specified by the USTA. I plan to use my hi-speed camera to capture rebound height.
I'd love to know everyone's thoughts -- especially if you've attempted something like this already.
thanks!
IdrinkYourMilkshake
Rookie
Sounds great. Just make sure to keep track of ball brands along the way. Two balls equally dead do bounce different heights if they are from different companies.
My experience is anything 25,30,40 etc doesn't work as well as 18-20 over a couple weeks. It will be interesting to see what results you get. Keep us posted, thanks!
MaconTennisClub
New User
Here's a picture of the "setup".
I've been thinking about testing the "rebound" of the balls, and have decided that rather than spend the time and energy reviewing film, I'll likely just use the "thud" sound on the first and second bounces and compute the height by taking the time interval between bounces. I think this approach will be more practical, consistent, and faster.
Here's a picture of the "setup".
I've been thinking about testing the "rebound" of the balls, and have decided that rather than spend the time and energy reviewing film, I'll likely just use the "thud" sound on the first and second bounces and compute the height by taking the time interval between bounces. I think this approach will be more practical, consistent, and faster.
Here's a picture of the "setup".
v-verb
Hall of Fame
I'm going to do this - I got a ball machine and it's hell hitting dead balls
MaconTennisClub
New User
Thanks for the info v-verb!
It looks like the canner version is aimed at maintaining the pressure of new balls -- but could certainly work with re-pressurizing also.
I'm most curious about the finding the "optimal" pressure/duration to recharge balls the fastest. I'm also curious about how much speed could come from "overcharging" balls beyond regulation pressures. Obviously, you couldn't use these balls in tournaments, but they could certainly be fun to play with if there's a significant difference.
From my observations so far, I calculated a fresh set of Penn Championship balls as rebounding between 60-61 inches. This measurement does not factor in drag (as my rig isn't in a vacuum). My height might also not be EXACTLY 100" (although it's very very close if it isn't). Ultimately, it doesn't really matter though. My standard for comparison is my calculated rebound height of brand new balls. "Dead" balls rebound 50-53 inches per my calculations.
Thanks again for the post -- let us know your progress!
It looks like the canner version is aimed at maintaining the pressure of new balls -- but could certainly work with re-pressurizing also.
I'm most curious about the finding the "optimal" pressure/duration to recharge balls the fastest. I'm also curious about how much speed could come from "overcharging" balls beyond regulation pressures. Obviously, you couldn't use these balls in tournaments, but they could certainly be fun to play with if there's a significant difference.
From my observations so far, I calculated a fresh set of Penn Championship balls as rebounding between 60-61 inches. This measurement does not factor in drag (as my rig isn't in a vacuum). My height might also not be EXACTLY 100" (although it's very very close if it isn't). Ultimately, it doesn't really matter though. My standard for comparison is my calculated rebound height of brand new balls. "Dead" balls rebound 50-53 inches per my calculations.
Thanks again for the post -- let us know your progress!
Nostradamus
Bionic Poster
this is nice, but if the ball loses all its fur, then it just flies thru the air too fast and is very hard to control still
MaconTennisClub
New User
True -- the re-pressurization process only makes sense under the assumption that the "fuzz" is still intact and that the ball is otherwise still playable. This comes into play more often with balls used for a ball machine rather than match play.
Balls used in match play are struck by rackets and against the ground hundreds of times in the course of a few sets. Generally, people only use a few (3-6 balls) during a match. However, with a ball machine, you may have 100 balls and only strike each a few times depending on how many times you reload the machine.
If you don't have the chance to make it to the court to practice with the ball machine very often, then you could go months without wearing down the fuzz on perhaps hundreds of otherwise "good" balls that go "dead" in a few days/weeks...
Tennis facilities and country clubs also have hoppers and hoppers full of gently used balls (often played once during tournaments) that coaches/pros use for teaching/practice. These balls often end up "dead" way before the fuzz is gone... It's literally thousands and thousands of dollars that go to waste...
Looking forward to your results! By the way, one good way to precisely find the bounce height is to take a high-frame-rate video of the ball against a white background and measuring tape. Then, you can play back the video and freeze it as the height of the bounce. The MythBusters used this technique many times for measurements of fast moving objects.
MaconTennisClub
New User
Thanks! I actually tried that approach at first, but it involves a considerable amount of setup time and review. Camera angles, frame rate, shadows, zoom, lighting, human error, and a million other factors make that approach much less reliable than simply computing the theoretical height using the time differential between bounce 1 and bounce 2.
In reality, for what I'm trying to accomplish, the actual numerical rebound height is irrelevant. What matters is having a fast, easy, consistent method of comparing the relative bounce differences between "new" and "flat" balls.
Ronaldo
Bionic Poster
NE has adopted a new policy using the above Ballicek app.
I do not understand what you have said.
Ronaldo
Bionic Poster
The Belichick app to check ball pressure. Btw, new problem with used balls. Carts are filled with used balls then pushed behind curtains where it is cold. Rarely find a ball that bounces.
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I bought a Corny keg a few months ago and filled it with 50 balls. Not getting the results that everyone else is getting.
First tried at 25 psi for 2 weeks - 3 balls had recharged out of 50
Put 47 back in at 30 psi for 4 weeks - 2 balls had recharged, the rest were still flat
I've noticed Head Radical balls and Wilson Extra Duty are the only ones that have recharged so far. I have a lot of Dunlop Fort All Court in there and they don't seem to want to recharge at all.
What's the deal? Does it only work on balls that are slightly flat? I admit that some of the balls I am using have been in the back of my closet for a year (extra squishy).
First tried at 25 psi for 2 weeks - 3 balls had recharged out of 50
Put 47 back in at 30 psi for 4 weeks - 2 balls had recharged, the rest were still flat
I've noticed Head Radical balls and Wilson Extra Duty are the only ones that have recharged so far. I have a lot of Dunlop Fort All Court in there and they don't seem to want to recharge at all.
What's the deal? Does it only work on balls that are slightly flat? I admit that some of the balls I am using have been in the back of my closet for a year (extra squishy).
wolfinsignia
New User
dunlop balls usually last me a long time. its probably the rubber prevents air flow at a better rate.
also i don't know about the steel vessel, but with almost all other not mechanize ball pressurizer you will need to adjust the psi every couple of days.
anyways i plan on getting a 2 gallon pump spray sometime this month. attach a psi gauge and see how that does. should hold about 10-20 balls .
also i don't know about the steel vessel, but with almost all other not mechanize ball pressurizer you will need to adjust the psi every couple of days.
anyways i plan on getting a 2 gallon pump spray sometime this month. attach a psi gauge and see how that does. should hold about 10-20 balls .
Nostradamus
Bionic Poster
Can they EVER invent a tennis ball that Never loses its pressure ever ? is this even possible ? I am not talking about the pressureless balls, those are too heavy and too harsh on the arms.
Nostradamus
Bionic Poster
and Dead balls are really bad for your shoulder and back as well. it Causes injuries.......
jumping out of a moving car is also bad for your shoulder and back, but no one in this thread is suggesting doing that either.
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I'm finally seeing some results with my corny keg. I'm unsure if this is scientifically accurate but I microwaved some of the balls first and then quickly threw them in the keg and ramped the pressure to 40 psi. This seemed to help with the repressurizing when I took them out a couple of weeks later, but it could have been a fluke. I'll try it with some of the "stubborn" balls next week.
sundaypunch
Hall of Fame
If you are looking to revive old balls that is probably the best. If you have a ball machine, keeping them pressurized at 15psi will make them last almost indefinitely. The balls eventually start losing their fuzz and bounce too much.
parasailing
Legend
Only problem I see with pressurizing balls is that you would have to do it with balls that still have a good amount of felt on them. Having ones that don't have much felt would be like playing with pressure less ones which offer bounce but don't play like regular tennis balls because they don't have a good amount of felt on them.
I think you hit the nail on the head there about it only working with balls being slightly flat.
The problem is that very flat balls under higher pressure on the outside tend to get squished in and lose their round shape easily if the outside pressure is too much for the inside pressure plus the rubber to hold up its round shape. Once the very flat ball caves in with a dent, it cannot get repressurized properly due to its odd shape now.
I have the clear Pressureball tube with 8 balls inside stored at 20 psi and I've seen first hand how easy it is for several very flat balls to cave in under 20 psi, thanks to the transparency of the clear tube. When you release the pressure those flat caved in balls pop back out to the round shape. So you wouldn't know if you can't see the balls inside your container when stored.
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Guys and Gals,
We need to revive this thread. The problem with all the suggested solutions are they are extremely expensive, hard to load balls in and out etc. I am thinking about buying a 5 gal metal bucket with a level and rubber seal and just pumping until it explodes to see what the max pressure it can take. If the thing can hold 20 PSI its "good enough". I have a feeling it will fail with a leak before it actually explodes. You could add a clamping system to the top and bottom to make the lid better handle the pressure. Has anyone tried pumping one of these up until it fails?
http://www.yankeecontainers.com/c/do-your-buckets-pails-come-with-lids/img_4693/
Of course safety etc. will be considered blah blah blah.
Nick
We need to revive this thread. The problem with all the suggested solutions are they are extremely expensive, hard to load balls in and out etc. I am thinking about buying a 5 gal metal bucket with a level and rubber seal and just pumping until it explodes to see what the max pressure it can take. If the thing can hold 20 PSI its "good enough". I have a feeling it will fail with a leak before it actually explodes. You could add a clamping system to the top and bottom to make the lid better handle the pressure. Has anyone tried pumping one of these up until it fails?
http://www.yankeecontainers.com/c/do-your-buckets-pails-come-with-lids/img_4693/
Of course safety etc. will be considered blah blah blah.
Nick
Why do you need to pump a metal bucket up until it explodes or until it fails? What's the point of doing that? It's already been said that even at only 20 psi, flat balls can easily implode and can't hold their round shape anymore. And once this happens, there's no way to recharge them. So you can only charge slightly flat balls without imploding them at a lower pressure like 20 lbs. At a higher pressure, at some point even only slightly flat balls will also implode. And if you don't have a transparent container, you won't see whether the balls will implode or not. Even if a transparent container, if it's a big container, you can only observe the outer balls and you won't see the inside balls and be able to tell whether they implode or not.
So in my opinion, the best option is to only go up to 20psi and recharge only slightly flat balls and not completely flat balls.
Rebounces dot com accept completely flat balls, however. So maybe they have a way to workaround the problem of ball implosion. The only obvious way I see is to sort them (by hand?) to different degrees of flat balls, and use the appropriate pressure to recharge each group separately until eventually at some point they will get fully recharged. This manual sorting can be pretty labor intensive, though.
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You may not know this, but the clear Pressureball tube I was referring to earlier is merely a flexible soft PLASTIC tube held together by either glue or heat seams around the edges. and as you pressurize the tube, it actually starts expanding when filled with air. At around 15 to 20 psi it stops expanding and becomes firm. But if you continue to pressurize it further, it can expand even more. But it's not recommended to be pressurized at over 20 lbs.
So if a soft plastic tube like the Pressureball can hold pressure just fine at 20 psi, I'm sure a hard metal or plastic bucket won't blow up on your face at 20 psi.
Now whether it'll leak eventually or not is a different story. But then leaking is not a safety issue. It's a reliability issue.
I had the Pressureball tubes (3 of them) for 6 months before all 3 started leaking. I contact Barry Mulder (of Pressureball) and he asked me to pour some boiling water over the seal at the opening to tighten up the seal. It didn't really help so he sent me 3 replacement tubes (and an extra to cover my return shipping cost of the 3 defective tubes back to him to investigate). Time will tell if the new replacement tubes will hold up any longer or not. These tubes have a 1 year warranty but he said they should last easily for a couple of years. Apparently my first 3 lasted only 6 months. But at least he's honoring his warranty and was very nice and easy to work with.
So if a soft plastic tube like the Pressureball can hold pressure just fine at 20 psi, I'm sure a hard metal or plastic bucket won't blow up on your face at 20 psi.
Now whether it'll leak eventually or not is a different story. But then leaking is not a safety issue. It's a reliability issue.
I had the Pressureball tubes (3 of them) for 6 months before all 3 started leaking. I contact Barry Mulder (of Pressureball) and he asked me to pour some boiling water over the seal at the opening to tighten up the seal. It didn't really help so he sent me 3 replacement tubes (and an extra to cover my return shipping cost of the 3 defective tubes back to him to investigate). Time will tell if the new replacement tubes will hold up any longer or not. These tubes have a 1 year warranty but he said they should last easily for a couple of years. Apparently my first 3 lasted only 6 months. But at least he's honoring his warranty and was very nice and easy to work with.
The conclusion is that repressurizing flat balls work as long as you're careful to match the ball flatness with the pressure level used. Too high a pressure on too flat a ball will cause the ball to become squished and it can't be recharged under that condition. This means you don't need to concoct a setup that can hold very high pressure. Around 20 psi is good enough for slightly flat balls. And that means even less (15 psi or less) for flatter balls.
The conclusion on what setup works is pretty much any setup you can buy or build that will hold up to about 20 psi and not leak.
The conclusion on what setup works is pretty much any setup you can buy or build that will hold up to about 20 psi and not leak.
Thanks. Got it. Has anyone here tried the Zombie tube ? I feel like that's the one I want to try first.
Booger
Hall of Fame
I guess I'll be the guinea pig.
+ Works as advertised, mine is currently at ~35 psi
+ Big rubber seal actually holds pressure, which is what none of the others do
+ Gauge on mine works nicely, same w/ hand pump
+ Can be used on a 4 ball can
- 6 small wing nuts are a little tedious (but not sure what would be better)
- Unsure how it will hold up being tossed around in my tennis bag
- Doesn't seem to fit over thicker ball cans like tretorn
- Took about 2 weeks to arrive
Ronaldo
Bionic Poster
I guess I'll be the guinea pig.
+ Works as advertised, mine is currently at ~35 psi
+ Big rubber seal actually holds pressure, which is what none of the others do
+ Gauge on mine works nicely, same w/ hand pump
+ Can be used on a 4 ball can
- 6 small wing nuts are a little tedious (but not sure what would be better)
- Unsure how it will hold up being tossed around in my tennis bag
- Doesn't seem to fit over thicker ball cans like tretorn
- Took about 2 weeks to arrive
Arrive or Revive?
Booger
Hall of Fame
It took two weeks from my order date for my zombie tube to arrive at my mailbox
Ronaldo
Bionic Poster
Ty, how long till the balls revived?
Booger
Hall of Fame
Depends on pressure and how dead the ball is. Day or two for fresh balls, maybe up to a week for totally dead ones? I just want to play 2-3 times per can, so I never really let them go dead.
Ronaldo
Bionic Poster
Heard that. BITD could revive nearly 30 balls with a ball charger. Now, those soda keg pressurizers are a memory.
Rebounces are coming out with Mini Green Tennis Machines in 2 version, 30 balls and 60 balls cans. You must use a special gas to re-pressuring the balls, though. So it's not free air. They claim the cost for local refilling of the gas should cost you about 1 cent per ball. But those machines are $270 for the 30 and $360 (or something like that, don't remember exactly) for the 60, not cheap. The idea of using a special gas kinda turns me off, though. Too much hassle, unless you want to revive a lot of balls at once. The advantage with the gas I think is that you don't have to worry about the balls collapsing so you don't have to sort them out to be of similar flatness and adjust the pressure accordingly.
I like these Zombie Tubes' design. I think I'm going to order me some. At $25 it's too much but at $17 (sale price) it's much more reasonable.
I like these Zombie Tubes' design. I think I'm going to order me some. At $25 it's too much but at $17 (sale price) it's much more reasonable.
Booger
Hall of Fame
I think CO2 makes sense if you are trying to charge balls fast since it passes through rubber easier (though that means the balls will also go flat faster). I can swap a 20 gallon CO2 tank for $15 at the local welding supply, which is a lot of gas. I'd be curious to see how long it lasts.
Yep, that's what Bill Dirst from Rebounces told me, too (about $20 for a 20lbs tank). But the tank will cost $144 up front as well, in addition to his Mini GTM.
I asked him the exact same question -> doesn't the CO2 (assuming that it's CO2, he didn't say exactly) passes through rubber easier, wouldn't it also mean the balls will go flat faster? So you'd need to use more gas to recharge more often. Didn't hear back from him on that yet.
Also, with a big container using gas, you can't just take out a few balls at a time to play with them without letting all the gas escape each time. So I can see the value of going for a Mini GTM if you're a coach or use a ball machine and need a bucket of balls available each time. But for individual players needing only a few balls at a time, the Mini GTM may not be a good use model.
I asked him the exact same question -> doesn't the CO2 (assuming that it's CO2, he didn't say exactly) passes through rubber easier, wouldn't it also mean the balls will go flat faster? So you'd need to use more gas to recharge more often. Didn't hear back from him on that yet.
Also, with a big container using gas, you can't just take out a few balls at a time to play with them without letting all the gas escape each time. So I can see the value of going for a Mini GTM if you're a coach or use a ball machine and need a bucket of balls available each time. But for individual players needing only a few balls at a time, the Mini GTM may not be a good use model.
Mine lasted longer, but suffered the same fate.
I'd never stumbled across these! Do report back. I'm an international customer, so it would be handy to see at least one review before taking a punt.
I've just checked the site. In case you didn't spot it, there's a 'Bundle deals' option where you can get two for a further discount. I suspect it would be worth contacting them if you wanted even more. Again, looking forward to any review... particularly if you buy the version without the pressure gauge and whether there are any regrets.
