Main fan not permanent

[jonatanrullman 17]

Hi,

 

I bought myself a third UM2 yesterday. What can I say, with a couple of upgrades to make it a sort of 2+ I simply love these machines.

 

This particular one was bought several years ago but the guy wasn't much interested in 3D printing, just 3D prints. He never got it working properly. So it has run 221 hours. Got eight spools of plastic into the deal as well. Paid €1100 so I'm happy. Though regretfully I suspect that the seller isn't as he originally wanted €1500 and he was a really nice guy. Buyers market though, there was two nearly identical for sale about 1,5 drive from each other and the other guy told me later that he would have taken €800 if i had offered it.

 

Anyway. This one has a weird feature compared to my other two. The main fan only activates when the extruder hits 50 degrees C. I know about this feature from Marlin of course, I just thought the UM2 wasn't able to use it.
Was this an experimental feature somewhere along the line or is it a hidden feature you have to activate in the firmware or something? I would love to have this on my other two machines as well.

 

Cheers

[tinkergnome 702]

1 hour ago, jonatanrullman said:

Anyway. This one has a weird feature compared to my other two. The main fan only activates when the extruder hits 50 degrees C. I know about this feature from Marlin of course, I just thought the UM2 wasn't able to use it.

 

This depends only on the revision of the main board. On the older boards (Rev. 2.1.1) the 5 Volt supply for the small fan is hard wired and not switchable. This has changed for newer boards, that are used for the UM2+ (Rev. 2.1.4).

A cheaper option for older machines would be a bimetallic temperature switch and a bit of tinkering, see here:

UM2-RearFan-Automatic

Edited January 13, 2018 by tinkergnome

[gr5 1,270]

So if you go back even older, the first few thousand UM2s had a very very quiet 3rd fan.  You really can't hear it.  And it works just fine.  So consider just buying 2 for your older UM2s:

http://www.digikey.com/product-detail/en/MC25060V2-000U-A99/259-1573-ND/2757803

[jonatanrullman 17]

I see. My newest one is probably a later batch then. I was hoping I had just missed something.

 

My other two are fairly quiet. My very first one was very loud but I didn't notice until I got my second one and realised how quiet it should be. I think the second one was pretty early because it had the very low light encased led strips. Anyway, I ordered a new fan for the loud printer and they are all just fine. Would have been even more quiet with it off though.

I might get one of those switches and mount on the side I guess. It won't fit on the top because I use Alexander Leisentritts modified print head. It's not a really big deal, just very nice that the fan shuts off when not in use.

 

Cheers

[gr5 1,270]

The fan I linked to is silent from 2 meters away.