Quieting the fan

Due to complaints in the office about the fan noise from the Ormerod (despite having reasonably sound absorbing screens around my work area), I sought something quieter rather than being banished to print away from my desk/bench. I changed the fan to RS part 758-8207. This is so quiet that at first switch-on I thought it was not receiving power (with the deflector fitted you cannot see the blades turning). The PSU fan completely drowns the new hotend fan noise. The problem of course is that the quieter fan does not shift as much air as the original - so would my Ormerod overheat?

I brought the hotend up to 250 deg and the bed to 110 deg (it struggles to get there so I started my time from the point where the bed reached 100 deg). I positioned the nozzle at zero height over the centre of the glass so the bed heat would cause the most damage. Then I took continuous temperature readings at various places. The temperatures appeared to pretty much settle to a steady state after about 30 minutes apart from the bed that was slowly passing 106 degrees at that time. The Ormerod has now been sitting in that state for a full hour (with plastic unfortunately cooking in the nozzle, hope it's not now blocked). Ambient around the machine is presently 23 degrees. The bed has reached its set point of 110 deg. I print with the bed at 90 degrees after the first layer, and of course the extruder & X axis will be further away from the bed as well, so this is definitely worse-case.

With Ray Hicks's fan cover mod, the exhaust air is expelled from the top of my heatsink cover and none onto the nozzle or bed. The exhaust air is steady at a temperature of 42 degrees. The heads of the bolts that attach the cooling block to the printed part became steady at 50 degrees exactly. The cooling block itself reads 55 degrees - though I think that may be higher than reality, because if the thermocouple I am using to measure is not in good contact with the aluminium block, the temperature goes up to 65 degrees as it is affected by the heat from the nearby bed and nozzle. The X-axis LU runner bearing is measuring 40 degrees at the top - but after an hour that is still slowly rising, though as said, a normal print would see it further from the bed most of the time, so I'm not that concerned (and the fan change would have made minimal difference to that temperature anyway)

As all my printed parts in the hot areas are now ABS, and assuming ABS remains strong enough at up to 60 deg or so, it looks as if the fan is good enough to work.

Dave
(#106)

Just replaced the hot end fan on my Ormerod.
I got a cheap Xilence fan from ebay.
Its much slimmer, only 11mm, so it now sits flush with the heatsink surround. Almost as if the original was designed for an 11mm thick fan.
This means you need to use shorter bolts to attach it to the alloy block. Luckily these were supplied in my kit.
New molex crimps needed fitting. I hate doing that with pliers, I really must get some proper Molex crimp tools.
Hardest part was removing the pins from the connector on the old fan.
But its on now and unless you looked at the blades turning you would not know its running, its so quiet.
Not sure whether its going to pull through enough air.
Spec on the new fan is 6.9CFM or 11m^3/h.
I can't find spec of original fan.
And I can't try it out yet as my bed is in pieces while I make a new bed support.

This is an issue I need to address too, that fan vibrates and can be heard through the floor to living room downstairs loudly!

It would be good if we could find the cfm and static pressure figures for the original unit??

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Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

I can't find link to exact fan, but here is one that seems very similar:
[dgyuguang.en.alibaba.com]
Which suggests the CFM between 7.1 and 8.6.
Static pressure between 3.98 and 5.58 mmH20
Noise between 29 and 33 dBA.

Unless anyone else can find the exact details, I think my new fan is pushing through about 6.9 CFM compared to up to 8.6 on old one.

I use this one ebay together with iamburny's duct which gives a more direct route. I think the fan is very similar to the model he used. Result: Fan noise insignificant.

This is the fan I use, quieter than the PSU fan and with decent flow rate.

[uk.farnell.com]

Matt

Edited 1 time(s). Last edit at 03/19/2014 07:19PM by iamburny.

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Limited Edition Red RS Ormerod 1 #144 of 200 - RRP 1.09fw
iamburnys Ormerod Upgrades Github
Follow me on ThingiVerse My Designs

Anyone with the quieter eBay fan notice any side effects?

Need to get one in ready for a major rebuild this week

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Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

Main side effect is eardrums don't ring any more.

I've been using mine for about 5 weeks now with iamburny fan duct which gives smoother airflow anyway which I think more than compensates for the slightly lower fan throughput. Not noticed any problems with printing that I would attribute to the fan.

I notice there is some discussion about directing the output of that duct more towards the nozzle as that might be beneficial in more difficult bridges, which sounds interesting.

Ok thanks

I'm still using the two part air housings but might fit a backwash eliminator thingy after the rebuild.

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Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

I bought a quieter fan, but now that I have thermostatic fan control, I have reverted to the original one. I don't find the fan noise a problem when printing, and the fan turns off when the hot end is cold.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I have not noticed any difference in print quality.
Fan noise has gone completely. Infact when we turn on the PSU we have to look at the fan to make sure its on.
In an office environment its made a real difference.
We are not using any fan shrouds or ducts.
Best £4 I spent on the printer.

Got one coming, maybe my one is just a bit duff but it really vibrates when running, will try the quiet version and see how it goes.

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Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

Perhaps Ian from RRP could give us some info about the original fan specs? I'd hate to replace it with something that turns out wasn't good enough.

Would it be futile to think to replace with a 60x60mm fan instead? The mounting and duct would have to be redone but maybe it's worth it? Unnecessary?

No need in my opinion. A sub £4 40x40x10mm fan is all thats needed.
Sure, if you want to model and print new fan mounts etc, go for it. But a quiet spec fan is such a simple change, nothing else is needed.

Quote
balidey
No need in my opinion. A sub £4 40x40x10mm fan is all thats needed.
Sure, if you want to model and print new fan mounts etc, go for it. But a quiet spec fan is such a simple change, nothing else is needed.

You don't think that a potentially weaker blower would be unable to do the job? I'm asking since I don't know how much air is actually needed..

Hmm, considering the design of the original duct, what is it supposed to cool anyway? The heatsink is screwed tightly to the horizontal block the bowden tube is attached to, so perhaps the end of the bowden tube is supposed to be cooled? Is there a risk the filament starts melting "upwards" otherwise?

Quote
michaelljunggren
Hmm, considering the design of the original duct, what is it supposed to cool anyway? The heatsink is screwed tightly to the horizontal block the bowden tube is attached to, so perhaps the end of the bowden tube is supposed to be cooled? Is there a risk the filament starts melting "upwards" otherwise?

exactly that, there needs to be a sharp transition from cold to hot.

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Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

Quote
Davek0974

Quote
michaelljunggren
Hmm, considering the design of the original duct, what is it supposed to cool anyway? The heatsink is screwed tightly to the horizontal block the bowden tube is attached to, so perhaps the end of the bowden tube is supposed to be cooled? Is there a risk the filament starts melting "upwards" otherwise?

exactly that, there needs to be a sharp transition from cold to hot.

Then, how important is the cooling of the extruded filament?

I use this one:-
Ebay

As for side affects... My bank Balance didn't go down to much...... lol

My Big Blue cuts the noise down to....

Kim..

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Please send me a PM if you have suggestions, or problems with Big Blue 360.
I won't see comments in threads, as I move around to much.
Working Link to Big Blue 360 Complete

Quote
michaelljunggren

Quote
Davek0974

Quote
michaelljunggren
Hmm, considering the design of the original duct, what is it supposed to cool anyway? The heatsink is screwed tightly to the horizontal block the bowden tube is attached to, so perhaps the end of the bowden tube is supposed to be cooled? Is there a risk the filament starts melting "upwards" otherwise?

exactly that, there needs to be a sharp transition from cold to hot.

Then, how important is the cooling of the extruded filament?

Quite important, sometimes

I think bridging gaps needs more accurate cooling than straight printing, but I'm not sure about the differences PLA vs ABS as I only run PLA at present.

I still have the original jet engine fitted I have bought another from ebay, went to fit it but needs longer bolts as the holes are not counterbored for the screw heads.

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Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

I'll insert a Type K termocoupler in a few places and see how much the fan actually matter. Is there a recommended max temperature in the cold end?

The fan serves 2 purposes:

1. Keeping the top end of the nozzle cool, via the heatsink and aluminium heatsink block, to stop the filament melting too far up it (and to stop the nozzle mount from melting). IMO a smaller fan can do this quite adequately.

2. Cooling the print, especially when printing bridges in PLA. This is where a less powerful fan might not work as well.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
2. Cooling the print, especially when printing bridges in PLA. This is where a less powerful fan might not work as well.

I assume that there has to be some sort of focused airflow so the nozzle itself isn't cooled unnecessarily. If the flow were to be increased I also assume one has to be more careful not blowing air just about anywhere.

BTW, there are 2 slits at the top and bottom of the heatsink. I can't figure out the purpose of those slits. Anyone? The original fan duct even make allowances for those slits but splitting the duct in 3, with these slits blowing downwards between the air flow. Do anyone know why this is so?

Quote
michaelljunggren
I assume that there has to be some sort of focused airflow so the nozzle itself isn't cooled unnecessarily. If the flow were to be increased I also assume one has to be more careful not blowing air just about anywhere.

BTW, there are 2 slits at the top and bottom of the heatsink. I can't figure out the purpose of those slits. Anyone? The original fan duct even make allowances for those slits but splitting the duct in 3, with these slits blowing downwards between the air flow. Do anyone know why this is so?

There are 3 slots to accommodate a planned upgrade to have 3 extruders and nozzles. With only 1 nozzle fitted you can therefore safely block off the two outer ducts if the airflow is insufficient with a quieter fan, which will increase the flow to the duct you need. See my original post at the start of this topic for my findings regarding temperatures using a quieter fan - the cold block appears to be cooled perfectly adequately. I have blocked off all the lower ducts because they were cooling my ABS too much, though I really need some cooling when printing bridges.

Dave
(#106)

Quote
dmould
There are 3 slots to accommodate a planned upgrade to have 3 extruders and nozzles. With only 1 nozzle fitted you can therefore safely block off the two outer ducts if the airflow is insufficient with a quieter fan, which will increase the flow to the duct you need.

That's interesting! Just for fun, I'm going to measure everything with the original gear and do some experiments. Supposedly it should be fine but I'd also like to know how much margin there is.

Do you have any insight on the slits? They seem to be... a source of leakage...?

My fan has got really noisy when cold, and is not much better when warm. I had a search through some all boxes and found some 40mm fans that were left over from my old PC repair shop, they are Rasurbo 4010M-S, allegedly these are the specs...

40mm x 40mm
4300 rpm
8 CFM
19 dB

I just hooked one up and it's very quiet, might give one a try along with Matt's one piece later.

Regards,

Les

The bearings are going in my RRP fan, not very impressive for a relatively new machine, it noisy one minute then really noisy the next!

I have a spare fan from eBay but need longer screws.

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Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

The Rasurbo 4010M-S fan is so much quieter, and combined with Matt's one piece duct,seems to be printing great.

Regards,

Les

Here's something I've just tried which helps. I thought of the idea for my Big Blue twin fan, which even with quiet fans was making a bit my noise than I liked so....

I have rubber mounted the fans using rubber 'O' rings...
Each screw for the fan (in this case my twin fan), I put:-
'O'ring,fan,'O'ring,fan,'O'ring....

I found it helps alot on my fan designs... It might work with the other fan designs, but I suspect you might be better off with either a rubber gasket, or a foam pad (like that thin expanded foam packaging cloth, or anything soft and springy) under the fan.

Kim

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Please send me a PM if you have suggestions, or problems with Big Blue 360.
I won't see comments in threads, as I move around to much.
Working Link to Big Blue 360 Complete