Reducing Peek Fan Speed

[RocketMagnet]

Looking to replace my Peek Fan with a desk based blower unit..
So I got a Squirrel blower wired it into the Rambo peek fan connection, piped it up using Tygon Tubing and Support coil to prevent it kinking, made a new peek fan mount etc.. works really well.. too well in fact as its a pretty large blower and it's serious overkill so I'm looking to reduce the Squirrel fan speed a bit. Considered a POT but I presume the output is PWM from the Rambo even on the Peek Fan supply so I should be able to simply add control for the fan speed there?

Presume this mod has been done before so looking for some advice of where in the code its turning the peek fan on/off.. and if I can slow it down there please.
It's not blowing air onto the part but it's a bit too much.. yeah I could add a bleed but I'm really looking at the noise aspect

Any help much appreciated..

[geneb]

I'm not quite sure why you're doing what you're doing.

The PEEK fan is specifically there to cool the PEEK cold section of the stock hot end. It prevents heat creep from causing jamming problems. The fan should run at 100% while the hot end is at 50C or above.

g.

[RocketMagnet]

Yes I fully understand how the standard peek fan works. I've replaced it with a large blower unit which is too big to mount at the hot end so its piped to a Nozzle replacing completely the Peek fan/fan mount. This gives you significantly more cooling capacity without any vibrating fans at the hot end..

So considering the Blower is rated significantly higher than the standard fan (depending on pressure drop ~7-12X CFM) I'm looking for an easy way to control the speed potentially based on a temp sensor mounted just above the peek. So the most logical way to perform this task is the same way the layer fan speed is controlled.
Also with such a large blower I should be able to drop the RPM significantly making it very quiet and still get as much cooling as is required.

Ultimately you could argue against the point of many mods... I've personally had fun and overall learned a fair bit in doing so.. I had the parts except the blower which was only a few pounds ordered with some other items and thought TBH why not remove the fans from the hot end, isolate fan vibration and take some weight off...

So I'm asking if the peek fan supply from the Rambo is controllable... the Layer fan is so I'm hoping that the Peek supply (Heat1) is also.

[rpress]

In Configuration.h I believe the right setting is EXT0_EXTRUDER_COOLER_SPEED. 255 is full, 0 is off.
https://github.com/seemecnc/Repetier-09 ... ion.h#L275

[RocketMagnet]

Cool Thanks will look tomorrow. I'd found it elsewhere in the code but it was checking various states were not 255 and not actually setting it.
appreciate the pointer and will test it tomorrow... cheers.

[RocketMagnet]

Thanks it looks like it's EXT1_EXTRUDER_COOLER_SPEED but it doesn't make any difference what you set it to the Eeprom still retains 255..

As far as I can tell in Eeprom.cpp it references e->coolerSpeed to EXT1_EXTRUDER_COOLER_SPEED which is defined as 0-255
and I can see where it reads and writes the value to and from the Eeprom but still not sure why it's not updating the value if I define it anything else other than 255

I'm also not sure what -> means in say e->coolerSpeed

[teoman]

Same as e.coolerSpeed

But if e is a pointer then you use e-> instead of (*e).

[rpress]

If you are using the EEPROM, then the values in Configuration.h will be used as default when the EEPROM is cleared with "M502", "M500".

In the EEPROM Extr.1 xxx is the same as EXT0_xxx in the code. Did you change the EEPROM value in Repetier-Host? That should work, or you can use the "M206" gcode. For example "M206 T0 P254 S128".

[RocketMagnet]

Thanks rpess, yes you can just change it as you like by directly updating the Eeprom from Repetier as it's running. So that's it working and controllable.
I think I know what was happening, essentially I think I was changing the value(s) on the Orion Firmware but I was being lazy and just using manual controls from Repetier to turn the extruder heater and fan on.. so it was irrelevant what I'd set it in the Firmware as it never ran the code to update the Eeprom and write back to Repetier. So starting it from Repetier would always set the value to 255

Seems like i'm looking at a speed of somewhere between 50-100 to match/exceed the stock mounted fan. Probably a bit lower when I seal the blower around it's body as it leaks badly though the body case snap fits all around it's circumference. Still playing with various designs to replace the stock fan mount, I've got a working one but looking to refine it. I also only had some pretty large bore tygon tubing (9.5mm internal bore), yeah it works but with so much overcapacity I can balance it rpm vs bore.. so looking at 5mm to replace and run at ~100 so about 40% fan speed. Will be really good for long prints with option of higher cooling rates... especially at higher hot end temps also if i'm after really good detail by minimising hot end vibrations. It's a only 30 second task to change between the two cooling systems If I need to, changed the hot end cooler mounts so I don't need to undo any bolts they just clip in and out.

So thanks rpress/teoman/geneb really appreciate the help.