Quest M3 fan not working? - Page 3

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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FotonDrv

#21: Post by FotonDrv »

If I understand it correctly the resistor is there to keep the fan running. Once the fan is spinning the potentiometer is trying to carry/deliver the power to the fan but I cannot help but think that some of the available power is still being sucked up by that resistor.

If someone is going to cut that resistor please measure the fan power BEFORE you cut it and then afterwards. Another way to measure would be to put a CFM meter on the max output of the fan.
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Beanz

#22: Post by Beanz »

EspressoForge wrote: Has anyone seen a circuit diagram around for the M3? Would be handy if someone has made one already, maybe looking at that I could figure something out. :)
The only circuit I have seen for the original wiring was in this link but I cannot comment on the accuracy of the information , the model or year it was done. There appear to be some variations over time. Unfortunately this was only the heater circuit and there is no specific fan control circuit
The article also contains an application note for controllers for those wanting to dig a little deeper
https://nselabs.wordpress.com/projects/ ... -controls/

I was considering rewiring my Quest to try and tidy up the wiring by using some readily available modules mounted in a separate box to control the heater and fan. The modules I was considering at the time were from Cebek such as the I-16 for the heater http://fadisel.com/cebek-electronic/dim ... 3_290.aspx
and an R-8 for the fan http://fadisel.com/cebek-electronic/dim ... 3_296.aspx
Note these were for the 240V model, not sure on availability for other voltages but something similar may be available in other markets

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FotonDrv

#23: Post by FotonDrv »

Before I cut that resistor connection I thought it might be relevant to know what the fan was doing before AND after the excision.

I used a wind meter to measure the wind speed being sucked into the roaster into that small aperture at the back/bottom of the drum.

When the fan started to spin at about a setting of 4 the wind speed measured .9mph and at maximum speed it was 6mph.

I placed a cardboard tube over the impeller of the Kestrel weather tool (fit perfect just over the impeller blades without touching) and then stuck it on the hole in the Quest. I was surprised at how well it worked, but since it is all relative, the same method for getting numbers AFTER excision of resistor will mean something. Stay tuned, since it requires stripping down the roaster to clean fan and then the cut.
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TomC
Team HB

#24: Post by TomC »

Am I misreading this or did you not isolate the fan cleanliness on the prior test? That would be important if it changed pre/post.

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FotonDrv

#25: Post by FotonDrv » replying to TomC »

That would be a separate test to just see if cleaning made the fan more efficient. Then you might have to rate the degree of crude on the fan.

I would have to clean, reassemble, test, disassemble, cut resistor, test again. Seems like a days worth of work. A terribly cruddy fan I do not have and because of my rather fastidious nature I like clean things and do not ever let the fan get to the point of being sluggish to react to input. And then I have my fan system ducted outside so the additional resistance provided by that ducting would have something to do with the results and just be specific to my situation.


If I have absolutely nothing to do I will do the clean, test, cut and retest, It depends on how tough a time I have with the reassembly.

That Light at the End of the Tunnel is actually a train

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FotonDrv

#26: Post by FotonDrv »

Well, I cleaned the fan, which was not very dirty, and removed the ducting going through the window.
Before cleaning:


The fan did start to move at a lower setting of 3.5 on the rheostat and produced .75mph windspeed through the intake of the system. The biggest jump was the top speed which went to 9mph. After seeing crud in the duct and manifold I cannot help but think that system impeded the air flow.

So next mod will be to bend the openings/slats in the case so the fan can work more freely.

While I was at it I insulated the drum shell and it made 210g roasts pretty easy but one must pay attention to to high a heat causing scorching.

When I saw how that resistor was mounted/placed in the wiring section of Quest I decided it was not worth the hassle to try to cut it out just for a test. These guys at Quest sure would not make it in the NASA Spec wiring/engineering... Glad it works as well as it does :)
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whattodo

#27: Post by whattodo »

My Quest is newer model. Yesterday, I removed the resistor. It was Orange, Black , Yellow , Gold. Now, the fan starts to rotate at 1. Thanks to everybody for sharing the mod.

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Nunas
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#28: Post by Nunas »

When I saw how that resistor was mounted/placed in the wiring section of Quest I decided it was not worth the hassle to try to cut it out just for a test. These guys at Quest sure would not make it in the NASA Spec wiring/engineering... Glad it works as well as it does :)
One does not have to 'remove' the resistor to try out the mod. Simply cut the wire at either end and bend the resistor away slightly to ensure that the free wire does not touch anything. If the mod does not work out, just twist the wires together and re-solder. Agree on the NASA spec thing, although I'm old enough to remember when this style of discrete component point-to-point wiring was fairly commonplace in home electronics.

Maurice