Directly powered case and hotend fans both died

[akovar]

I have a couple FT-5 R2s that run fairly often. So, I've had my share of parts that just need to be replaced, including both the case/stepper-motor cooling fan and the hot-end cooling fan. Both of these fans are directly connected to the same terminals on the 24V DC power supply, as the build instructions describe. Today, it was noted that both of these fans no longer run on one of the FT-5s, though all motors and heaters appear to work correctly, and I've verified 24V at the power supply and end of the cable run for the fans.

My first instinct would be that the fans just died, but I'd just replaced the hot-end fan (about 2 weeks ago), and they both died at the same time. It just feels odd.

So, does anyone have experience with this? Just a fluke occurrence of two parts going bad at the same time? Or is it possibly some other error, i.e. the power supply is going bad?

[Tin_Falcon]

This does seem a bit odd.
Are these fans 24 volt or 12 a 12volt fan will run on 24 but not for long.

In this age of mass production a 5% -10% out of box failure rate is considered acceptable that is 5-10 for every 100 coming off the line.
You should be able to test the fans either with a meter set for ohms or on an independent power source.

As far as the power supply if you are getting 24 volts . and everything else works you should be fine.
that said You can upgrade your power supply to something like a Meanwell 350-24 for $ 30-$35 from amazon and the like.
In my experience having built 2 ft kits and helping with a third the power supply's are a weak link in FTs supply chain. as Ft replaced two of the three.
The other ting that does not make sense is that the fans that keep critical parts cool are often the cheapest on the market.

Hope this insight helps.

[Ron]

I have an R1, which is barely an R1 any more, but for what it may be worth I replaced both those fans almost from day one.
There are known problems with them.
Most likely they failed at different times and you just happened to notice them at the same time.
The one in the electronics enclosure is pretty easy to miss.

The original electronics enclosure fan is far too small for its intended purpose.
The way it is mounted (the "grille" through the enclosure material) and its airflow capacity are inadequate, as is the dinky exhaust port near the PSU.
As a result everything inside runs hot.
I installed an 80mm fan and exhaust port grille into the back cover of mine.
Now everything inside runs nice and cool.
Others on the forum have done similar things, I am hardly alone.
It is a known issue with the FT-5 enclosures and their fans.
You really should consider doing this.

As for the cooling fan on the hot end, it almost certainly is a sleeve bearing type if it came from FT.
Being thrashed around on the hot end it won't last long just because of that.
Sleeve bearings have one benefit only- they are cheap.
That's all folks.
They will start to make ugly noises as the bearings wear out and eventually they just won't start up.
Buy ball bearing replacements if you possibly can, and double ball bearing types if at all possible.
Do not buy "wave" or "vapor" bearing versions for hot end usage either.

Two thumbs up on the MeanWell 350-24 PSU.
I have been running a 240-24 in my printer for a long time now but I am also running an AC mains-heated print surface so my PSU load is much lower.
I have used MeanWell supplies in a number of designs at home and at work and I have very rarely had any issues with them.

FWIW... I hope it helps you..

[akovar]

Both of the fans that died were 24V replacements I had picked up (Amazon, I think) - the original ones that came with the kit didn't last all that long... They are labeled as 24V-DC, Hydraulic Bearings.

@Ron, you may be correct that the case fan had died some time ago and had just gone unnoticed. I guess I'll wait to see if the new fans last. And I'll look into making an upgrade on that case fan as suggested.

Thanks for the insights!

[Tin_Falcon]

Hydraulic Bearings.

Fluid dynamic bearing (FDB) and hydro dynamic bearing (HDB) fans are in essence highly modified versions of the sleeve bearing fans, where the design of the bearing is different and also the lubricant fluid is kept intact with the use of seals (some good-quality sleeve bearing fans also feature seals to keep the oil intact). This means friction is kept at very low levels even after prolonged usage, which can easily exceed 50,000 hours and in some cases reach up to 300,000 hours.

IMHO double ball bearings are likely a better bet.
sound like your manufacturer used this term for marketing not actual manufacturing.

[Ron]

I agree with &Tin_Falcon, the "hydraulic" bearings are probably marketing hype for sleeve bearings.
Even a single ball bearing fan will likely be better because the sealed fluid ones are not cheap.
And they are being thrashed around with very high acceleration rates on the hot end during printing.
The 80mm fan I am running in the electronics case is a double ball bearing unit and I expect it to easily last the life of the printer.

The 30mm square one on my E3D hot end is another matter.
It is too small for double ball bearings but is ball bearing, and is only available in 6 or 12 volt versions (no 24 volt offerings, sadly).
So I just added a small adjustable step down regulator off the 24 volt rails and it works great.
I actually run it on about 10.5 volts and it cools the hot end very nicely.
I used this one specifically- https://www.digikey.com/product-detail/en/orion-fans/OD3010-12HB/1053-1199-ND/2621104
It is cute, not all that loud despite its high speed, and was cheap enough that I purchased a spare.

If you have the original extruder with a 40mm fan though, you can definitely get 24 volt ball bearing units in that size.
.

[csorrows]

The PSU issues are due to them being driven far too close to the rated capacity. These are cheap Chinese units and don't always live up to the claimed rating. I pushed for a long time to move to AC bed heaters. I finally won with the FT-6. Have you heard any issues with FT-6 PSUs dying? No. Same supplier also.

For what it's worth, I have AC bed heaters on both of my FT-5s and have had zero PSU issues. I highly suggest this.

[Ron]

I totally agree on all counts.

I have had an AC bed heater for a long, long time and would not consider returning to a DC heater even if for no other reason than the timing.
I can go from room temperature to printing at 80C on the bed within 5-7 minutes without any problems.
With the original DC heater it was more like 20-25 minutes and I had to have an external MOSFET "relay" to keep the motherboard and its connectors from burning itself up.
AC heaters are the only way to go.

I now have repurposed the external MOSFET for the hot end heater.
So the motherboard is loafing along and with an 80mm fan blowing right onto it, it stays nice and cool.