My HM4 case & fan setup on WSM 22.5


 
J

John Case

TVWBB Member
I put the HM4/Rpi into a snapware kitchen storage case. I figured it would make it somewhat water tight.
I have an old salt/pepper shaker that has rubber plugs, I'm going to put the plug in the hole on the cover with an extension on the button for control to make it water proof from the top.
The hole where the wires exit I'm going to put plumbers putty there to help seal it.
Until I do that, the case fits nicely into a 1 gallon ziplock bag. I just zip it closed.

Below are pictures of the case and how I installed the fan on my WSM 22.5

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i-FjrDwjf-X2.jpg


Thanks,
John
 
Don't you think you need a way for heat to escape from your HM? I don't know. But, it seems like it would not be good for the components to not have a way to breathe.
 
Darren C. said:
Don't you think you need a way for heat to escape from your HM? I don't know. But, it seems like it would not be good for the components to not have a way to breathe.
Click to expand...

You could be right... but I have a ambient temperature sensor mounted on the HM4, during my cook yesterday I was able to monitor the temp of the HM4 in the case. See my other thread if you want to see the temp in the graph. It spiked at about 175 when it was in the sun. I put a towel over it and it went right down.

Thanks,
John
 
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Darren C. said:
Don't you think you need a way for heat to escape from your HM? I don't know. But, it seems like it would not be good for the components to not have a way to breathe.
Click to expand...
Ventilation may or may not be needed. My Model A Pi I can put in a tiny styrofoam box and let it run for a day and the temperatures don't get over 65C. All the parts are rated for 85C operating temperature. You can check the CPU temp under System -> RaspberryPi. If it is sitting in the sun then you either need to shade it or get some real good ventilation.
 
DO NOT leave your HM sit in the sun in a container like that. I have my HM in a 3D printed case, to protect it from rain I put a tupperware container upside down over the top of it (with no lid attached, there are spaces between the slats of the shelf below to allow ventilation). The other day I let it run in full sun and WOW did it get hot! So hot that the display became a solid block of color and I thought I had killed my HM. After it cooled the display looked right again and the HM came back to life, but I wouldn't want to subject it to too much of that kind of heat.

I had at one point been determined to create a water proof case for my HM, since then I have gotten comfortable with just putting the tupperware bowl upside down over the top of it when I am not there to attend to it. I have run it like this through some pretty serious rain and haven't had a problem (Sun has been my only problem). I guess if there was enough wind rain might get blown up there, or the tupperware might get blown off, but I haven't had that problem yet. I am using a disposable tupperware type of bowl, which has rounded edges under where the lid mates to it. When upside down these rounded edges fill with water in the rain and I think that weight should help to hold it down....
 
John,
If that is the way you had the fan attached for your first cook. You should seal the pan where it joins to the smoker for better temp. control.

dave
 
RalphTrimble said:
DO NOT leave your HM sit in the sun in a container like that. I have my HM in a 3D printed case, to protect it from rain I put a tupperware container upside down over the top of it (with no lid attached, there are spaces between the slats of the shelf below to allow ventilation). The other day I let it run in full sun and WOW did it get hot! So hot that the display became a solid block of color and I thought I had killed my HM. After it cooled the display looked right again and the HM came back to life, but I wouldn't want to subject it to too much of that kind of heat.

I had at one point been determined to create a water proof case for my HM, since then I have gotten comfortable with just putting the tupperware bowl upside down over the top of it when I am not there to attend to it. I have run it like this through some pretty serious rain and haven't had a problem (Sun has been my only problem). I guess if there was enough wind rain might get blown up there, or the tupperware might get blown off, but I haven't had that problem yet. I am using a disposable tupperware type of bowl, which has rounded edges under where the lid mates to it. When upside down these rounded edges fill with water in the rain and I think that weight should help to hold it down....
Click to expand...

Thanks for the info
 
John,
The goal is to make the HM (blower) be the ONLY source of air that your smoker gets. If there are other sources, then its effectiveness is reduced as is the lowerest temperature you can maintain. You will see on other threads where some of us build solenoid driven valve to control the air flow (we say it is for temp control, but I just do it for fun :) ).

It sounds like your smoker is pretty tight and if you can get control over the air flow you should be set. BTW without the blower, if you close all the vents on your smoker does the fire go out? If so that is where you want to be with the fan attached as well.

dave

dave
 
D Peart said:
John,
The goal is to make the HM (blower) be the ONLY source of air that your smoker gets. If there are other sources, then its effectiveness is reduced as is the lowerest temperature you can maintain. You will see on other threads where some of us build solenoid driven valve to control the air flow (we say it is for temp control, but I just do it for fun :) ).

It sounds like your smoker is pretty tight and if you can get control over the air flow you should be set. BTW without the blower, if you close all the vents on your smoker does the fire go out? If so that is where you want to be with the fan attached as well.

dave

dave
Click to expand...

Dave,
Thanks for the info, I will seal the bowl/blower where it attaches to the smoker. I was considering building a servo/blower combo as I have servo's from my model airplane days.

How beneficial do you think it would be to have the air enter under the coal grate instead of off to the side as it does now blowing into the stock bent holes?
 
I don't think it will make much difference. The only thing I could see is that it may be slightly hotter on the side that the air enters. It is pretty common for smokers to have air enter in a single controlled spot.

The advantage I feel you get with the air manifold, like Ralph built, is that it creates resistance for the air flow, cutting down on the amount of air that slips past the blower when it is stopped. I was looking into building one, but then his ping pong ball solution was just genius. I am going to make one of those because it is brain dead simple and not very error prone.

I still think the servo/fan combo will give the best solution but it does bring additional complexity and failure points.

dave

John Case said:
Dave,
How beneficial do you think it would be to have the air enter under the coal grate instead of off to the side as it does now blowing into the stock bent holes?
Click to expand...
 
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