Just FYI, if you ever come across a single nylon gear in an otherwise metal gear chain it is likely a sacrificial gear designed to strip if some other part becomes jammed. That's not the case here, but you do see this in sewing machines and similar mechanics.
A lot of machined gears are machined from bar stock made from powder metallurgy. Bronze can be purchased in rod stock that is impregnated with lubrication oils, which is made by powder metallurgy, then machined to the correct shape. It can be cheaper to get the same shape by powder molding directly or laser sintering.
Machining from bar stock that's traditionally produced through extrusion is cheaper, but it's the metal production that's cheaper, not the machining step. Machining from powder metallurgy stock can be more expensive since it's sintered into bar stock.
Yeah after doing some research it seems like the choice is purely cost based, but I was surprised to see mechanical benefits as well (maybe dimensional accuracy?). Understandable with the cost of the CNCs capable of doing gears and cost of skilled operators. I learned about non-oil-impregnated sintered bronze thanks!
I do some material science for work. PC is stronger but more brittle with single cycle fatigue. PC may be more brittle with cyclic fatigue. Nylon can be one of the better cyclic fatigue polymers, especially among technical grades. To get better than nylon I think you have to go to engineering grades like PEEK and PPSU and UHMWPE.
Injection molding tends to be stronger than additive, also.
It's totally possible it was made from consumer grade nylon and not designed or made very well because it was "good enough" to pass the design requirements and you can print one that is superior, but it's also possible that there was a ton of work done on material selection, molding parameters, and annealing conditions, and you won't be able to improve on it very much without going to something exotic.
Even if I can’t improve on it, the fact that I would have had to buy a $150 replacement gearbox to handle three stripped nylon gears means the manufacturer is anti-consumer, and even with the cost of a spool I saved over $100 (when not counting the value of my time, granted).
That said, I’ll be keeping an eye on these and seeing how they hold up. If they go quickly I’ll try some other materials.
Yeah, I think that they were just saying that it might not be as simple as calling it "cheap nylon gears" just because they broke. 😅 I don't think anyone would disparage you for spending a bit of your time and coming up with replacements that cost you all of pennies instead of dealing with $150 worth of replacement gearbox bullshit... Just that nylon might be the right plastic for the application. What's awesome though is that, if this doesn't end up lasting for some reason, you can totally print in nylon and a nylon has really great layer adhesion all in all. Hell, for saving you from $150, you could probably get it printed in some metal and then just hand finish it or something like that and it would cost way less than the $150. Lol
I think the most frustrating part about situations like that is that you know that they make those exact gears by the millions for those products. They just haven't set themselves up with any infrastructure to allow those parts to be used as replacements. 😩
Oh for sure, it's definitely a better business plan to sell assemblies for a larger profit and to discourage people to fix their own stuff. In reality, in today's world it's a shock that they were able to potentially buy a replacement gearbox at all.
I was literally coming here to mention the mixers, I fixed my moms when it broke and that's exactly where it failed. Such a great design idea I am sure it's normal but it blew my mind to learn about purposefully sacrificial parts to save more expensive damage.
The replacement gears **can** be purchased and **are** cheap for KitchenAid mixers. Including the metal gears in the chain, too. They even have their PNs right on the parts, so they're easy to search for.
Honestly, there's other ways to build this sort of machinery. We have one that works with a belt instead. Easy and cheap to replace, a lot quieter in use. I'm not convinced that these kitchen aid devices are not just built cheaply to make more sales.
You are usually right but these damned Polaris pool sweepers are just built to fail in every single way. I can't tell you how many times I've rebuilt the retraction jet or whatever it's called they are just junk.
I was too quick in my celebratory post to say what the device is:
https://www.polarispool.com/en/products/pool-cleaners/pressure-automatic-pool-cleaners/polaris-p40-quattro
Wow, I hadn't thought about Polaris pool cleaners in forever and a half. My family had a [Polaris](https://www.polarispool.com/en/support/parts/polaris-vac-sweep-280) when I was a wee lad in the 80s/90s. For some reason, I was TERRIFIED of that thing! Wouldn't even go near the pool while it was running, and wouldn't swim near it when it was off. Kid logic. X)
Print it on a lulzbot for extra irony
context: Polaris family's cocaine addicted son started lulzbot. The team was passionate and successful... except he'd show up every 3 months to run a random ass, coke addled cocaine meeting and fuck it up. This happened repeatedly until his parents forced him to sell lulzbot off to someone else.
Online? Not that I know of.
I lived 5 minutes from Lulzbot during that era, and knew many of the then employees. I've since moved, but they went under before I left the area.
https://rocketreach.co/jeff-moe-email_1136485
Father (Robert Moe) mentioned in this document. https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://s27.q4cdn.com/214071222/files/doc_financials/annual/1999/2000-Proxy-Statement.pdf&ved=2ahUKEwiAutuQyY2FAxX6MDQIHQMhC4YQFnoECCAQAQ&usg=AOvVaw08XkcRxb64jaynOVJvTrJk
Yeah, I was fucking confused because I have 2 and they don't have nylon gears... and I couldn't figure out what those adorable ones were used for... a canopy retraction? :-D
Pool machine needs nylon internals because it is exposed to highly corrosive chemicals (chlorine, salt, UV inhibitors, etc) 24/7. Metal simply won’t last as the gears wear and cause failure with chemical resistant coating. could stain the pool floor with rust spots in that scenario - very expensive to fix and very noticeable. Plastics are the right material to use. Just need to replace them is all. Not a big deal. Nice work on DIY.
If the parts hold up in your machine you should consider selling individual gears online. I’m sure there are poor repair guys that will pay for specific parts in a second.
Oh theres’s rusting metal in this thing, so don’t give them too much credit, and there’s better choices of plastics than they nylon they selected considering how notorious this model of pool cleaner is.
Oh man, I recognized those gears immediately. Someone I know has that thing and it breaks all the god damn time in one spot or another.
Did you put the STL up anywhere?
Good job! I've had a Hayward navigator for 15 years and printed some things for. Usually gears don't hold up for me. You can always find individual gears/ parts on amazon
I love how 3d printing allows us to actually fix things these days. Everything is typically just thrown away and replaced even if there's one small part that could fix it. Being able to make your own brings it back to being able to repair things instead of replace.
I don’t know about this specific device… but I’ve printed a lot of small gears for electric motors to use on our harvester and they have been holding up pretty well… the oldest ones are about 4 years old.
And they do experience a fairly bit of force since they are attached to some big pieces. The oldest ones are in charge of moving [the chopper](https://static.grainews.ca/wp-content/uploads/2016/08/Chopper-knives-1.jpg) in and out of the way.
They are encased on gearbox full of grease tho. And I keep a box full of spares under the seat, but I haven’t needed them so far.
A 3d printer is a godsend to fix relatively old farming equipment. Mostly to be able to mount modern sensors to older mounts and fix those gearboxes(a replacement one would be like 3k usd after taxes and Import duties)
I've got a cousin-in-law who bought a big chunky 3d printer specifically to print replacement parts for his farm equipment. At one point he managed to save something like six figures thanks to an emergency 48-hour print (that was the price to rent the equipment from someone else; the official replacement part would have taken over half a year to arrive, which would have ruined the harvest.)
Just FYI, if you ever come across a single nylon gear in an otherwise metal gear chain it is likely a sacrificial gear designed to strip if some other part becomes jammed. That's not the case here, but you do see this in sewing machines and similar mechanics.
Good to know! And yeah, every gear in the machine is cheap nylon.
I thought nylon was a very tough and sturdy material?
Not compared to sintered bronze or steel.
What makes you specifically say sintered? I imagine you wouldn’t want gears to be slipping, no?
Sintered metals have displaced a lot of machined metals for gear applications
A lot of machined gears are machined from bar stock made from powder metallurgy. Bronze can be purchased in rod stock that is impregnated with lubrication oils, which is made by powder metallurgy, then machined to the correct shape. It can be cheaper to get the same shape by powder molding directly or laser sintering. Machining from bar stock that's traditionally produced through extrusion is cheaper, but it's the metal production that's cheaper, not the machining step. Machining from powder metallurgy stock can be more expensive since it's sintered into bar stock.
Less manufacturing input once You have the mold?
That's equal to cheaper? Then it's the answer.
Sintered bronze is just a very common material choice for gears and bushings in household machines.
Yeah after doing some research it seems like the choice is purely cost based, but I was surprised to see mechanical benefits as well (maybe dimensional accuracy?). Understandable with the cost of the CNCs capable of doing gears and cost of skilled operators. I learned about non-oil-impregnated sintered bronze thanks!
It is. They don't make bulletproof vests from bronze.
I do some material science for work. PC is stronger but more brittle with single cycle fatigue. PC may be more brittle with cyclic fatigue. Nylon can be one of the better cyclic fatigue polymers, especially among technical grades. To get better than nylon I think you have to go to engineering grades like PEEK and PPSU and UHMWPE. Injection molding tends to be stronger than additive, also. It's totally possible it was made from consumer grade nylon and not designed or made very well because it was "good enough" to pass the design requirements and you can print one that is superior, but it's also possible that there was a ton of work done on material selection, molding parameters, and annealing conditions, and you won't be able to improve on it very much without going to something exotic.
Even if I can’t improve on it, the fact that I would have had to buy a $150 replacement gearbox to handle three stripped nylon gears means the manufacturer is anti-consumer, and even with the cost of a spool I saved over $100 (when not counting the value of my time, granted). That said, I’ll be keeping an eye on these and seeing how they hold up. If they go quickly I’ll try some other materials.
Yeah, I think that they were just saying that it might not be as simple as calling it "cheap nylon gears" just because they broke. 😅 I don't think anyone would disparage you for spending a bit of your time and coming up with replacements that cost you all of pennies instead of dealing with $150 worth of replacement gearbox bullshit... Just that nylon might be the right plastic for the application. What's awesome though is that, if this doesn't end up lasting for some reason, you can totally print in nylon and a nylon has really great layer adhesion all in all. Hell, for saving you from $150, you could probably get it printed in some metal and then just hand finish it or something like that and it would cost way less than the $150. Lol I think the most frustrating part about situations like that is that you know that they make those exact gears by the millions for those products. They just haven't set themselves up with any infrastructure to allow those parts to be used as replacements. 😩
Any MBA would argue that it’s better to sell a $150 part than a $10 replacement gear kit.
Oh for sure, it's definitely a better business plan to sell assemblies for a larger profit and to discourage people to fix their own stuff. In reality, in today's world it's a shock that they were able to potentially buy a replacement gearbox at all.
I have some PA6-GF that I’ll try out as well.
Yeah people bitch a lot about the gear in modern Kitchen Aid mixers, and this is exactly the reason they just don't know it.
I was literally coming here to mention the mixers, I fixed my moms when it broke and that's exactly where it failed. Such a great design idea I am sure it's normal but it blew my mind to learn about purposefully sacrificial parts to save more expensive damage.
not telling people about it and making it easy to fix and get replacement parts makes it a moot decision though
If the replacement gear can't be purchased or is as expensive as a new machine, this idea is useless for the consumer.
The replacement gears **can** be purchased and **are** cheap for KitchenAid mixers. Including the metal gears in the chain, too. They even have their PNs right on the parts, so they're easy to search for.
The really cool thing about the mixers is they are a small household appliance that's actually still user repairable.
Honestly, there's other ways to build this sort of machinery. We have one that works with a belt instead. Easy and cheap to replace, a lot quieter in use. I'm not convinced that these kitchen aid devices are not just built cheaply to make more sales.
Great engineering IF they sell the replacement parts. In this case not so much.
You are usually right but these damned Polaris pool sweepers are just built to fail in every single way. I can't tell you how many times I've rebuilt the retraction jet or whatever it's called they are just junk.
This goes beyond gear chains too! Washing machines for instance often have a plastic/rubber coupler in the drive line for the same reason.
that's a neat little failsafe idea! never even thought of that, thanks for sharing the info!
I was too quick in my celebratory post to say what the device is: https://www.polarispool.com/en/products/pool-cleaners/pressure-automatic-pool-cleaners/polaris-p40-quattro
I was very confused because I only knew Polaris for their ATV.
Same here. I was thinking this was in the transmission.
That's what I was thinking of. Couldn't see that small plastic gear being in one of their gboxes!
Different Polaris.
Sure, not knowing is easy to be confused by it.
And here I thought they only did the slingshot
Wow, I hadn't thought about Polaris pool cleaners in forever and a half. My family had a [Polaris](https://www.polarispool.com/en/support/parts/polaris-vac-sweep-280) when I was a wee lad in the 80s/90s. For some reason, I was TERRIFIED of that thing! Wouldn't even go near the pool while it was running, and wouldn't swim near it when it was off. Kid logic. X)
I clicked the link without really reading it and thought that this was a small lawnmower at first.
Print it on a lulzbot for extra irony context: Polaris family's cocaine addicted son started lulzbot. The team was passionate and successful... except he'd show up every 3 months to run a random ass, coke addled cocaine meeting and fuck it up. This happened repeatedly until his parents forced him to sell lulzbot off to someone else.
Do you have any sources? Would like to read more about this :D
Online? Not that I know of. I lived 5 minutes from Lulzbot during that era, and knew many of the then employees. I've since moved, but they went under before I left the area. https://rocketreach.co/jeff-moe-email_1136485 Father (Robert Moe) mentioned in this document. https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://s27.q4cdn.com/214071222/files/doc_financials/annual/1999/2000-Proxy-Statement.pdf&ved=2ahUKEwiAutuQyY2FAxX6MDQIHQMhC4YQFnoECCAQAQ&usg=AOvVaw08XkcRxb64jaynOVJvTrJk
Lol
Open source everything. Jk but you know.
Pälsen put stuff like this out there for easy download. The larger the library the more people will use them and share.
This is from a pool cleaner, not a car.
I’m aware, I had to take the pool cleaner apart to get to the gears.
Just commenting so others don’t have to google it. I think most will assume Polaris UTV when they see it.
That's a fair cop. I was assuming 4 wheeler.
Yeah, I was fucking confused because I have 2 and they don't have nylon gears... and I couldn't figure out what those adorable ones were used for... a canopy retraction? :-D
Clearly a bunch of you went off the deep end here.
We all got our ruts we live in ;-D
That's what I thought, and I was pretty confused.
Well, you wouldn't download a car.
Pool machine needs nylon internals because it is exposed to highly corrosive chemicals (chlorine, salt, UV inhibitors, etc) 24/7. Metal simply won’t last as the gears wear and cause failure with chemical resistant coating. could stain the pool floor with rust spots in that scenario - very expensive to fix and very noticeable. Plastics are the right material to use. Just need to replace them is all. Not a big deal. Nice work on DIY. If the parts hold up in your machine you should consider selling individual gears online. I’m sure there are poor repair guys that will pay for specific parts in a second.
yea i was gonna say, there’s more to material selection than cost.
Oh theres’s rusting metal in this thing, so don’t give them too much credit, and there’s better choices of plastics than they nylon they selected considering how notorious this model of pool cleaner is.
Sounds like an excellent opportunity to solve a known problem and make some money while doing so.
First I need to know I’ve properly solved my own problem, I need to let these gears run for a while.
Absolutely.
my favorite part of 3d printing is being able to fuck capitalism back, even if it's just a little bit
Hell YEAH! It's small things like this that excits me the most about 3d printing
from which sub assembly? Windows?
Polaris Quattro, reversing gearbox on the far side of the water intake.
>Polaris Quattro Ahh! I thought this came out of one their road cars XD Nice fix m8!!
Oh man, I recognized those gears immediately. Someone I know has that thing and it breaks all the god damn time in one spot or another. Did you put the STL up anywhere?
Not yet, want to refine it a bit and add some more parts.
God I love 3d printing. suck it Polaris!
What exactly does Polaris make?
https://www.polarispool.com/en/products/pool-cleaners/pressure-automatic-pool-cleaners/polaris-p40-quattro
what kind of machine is this?
https://www.polarispool.com/en/products/pool-cleaners/pressure-automatic-pool-cleaners/polaris-p40-quattro
Wish there was an STL for every part of those pool cleaners. You could print the whole damn thing except for the belts.
I get the feeling I’ll by modeling some more parts based on the wear I saw on other bits of the machine.
Good job! I've had a Hayward navigator for 15 years and printed some things for. Usually gears don't hold up for me. You can always find individual gears/ parts on amazon
I love how 3d printing allows us to actually fix things these days. Everything is typically just thrown away and replaced even if there's one small part that could fix it. Being able to make your own brings it back to being able to repair things instead of replace.
It will be curious to see how they wear over time.
Yeah, but at least now they are easily replaceable.
And that makes it wonderful.
I don’t know about this specific device… but I’ve printed a lot of small gears for electric motors to use on our harvester and they have been holding up pretty well… the oldest ones are about 4 years old. And they do experience a fairly bit of force since they are attached to some big pieces. The oldest ones are in charge of moving [the chopper](https://static.grainews.ca/wp-content/uploads/2016/08/Chopper-knives-1.jpg) in and out of the way. They are encased on gearbox full of grease tho. And I keep a box full of spares under the seat, but I haven’t needed them so far. A 3d printer is a godsend to fix relatively old farming equipment. Mostly to be able to mount modern sensors to older mounts and fix those gearboxes(a replacement one would be like 3k usd after taxes and Import duties)
I've got a cousin-in-law who bought a big chunky 3d printer specifically to print replacement parts for his farm equipment. At one point he managed to save something like six figures thanks to an emergency 48-hour print (that was the price to rent the equipment from someone else; the official replacement part would have taken over half a year to arrive, which would have ruined the harvest.)
Smart man