circulation fan status update and wiring question.

[DocZ]

First the wiring question. Of those with the fan retro-fit, how have you run juice to the motor? Obvious choices would be separate but equal, with a stand-alone plug, VS splicing into the smoker's electrical at one point or another. Would appreciate any feedback I can get on this one.
BTW, I've finally completed the fan installation with the help of all those that have contributed posts to this subject. My variation on this project used the recommended grainger motor (modified to run CCW) and two 2" fans. I chose to support the motor by tapping four 6-32 threaded holes into a leftover piece of 1.5x.25" steel stock cut to the width of the smoker. I mounted the motor to this bar by passing four screws through the available holes in the motor housing and using 3/4" spacers to stand off the motor from the supporting bar. I secured this horizontally to the back of the box via vertical edge-mounted sections of aluminum square channel(1+1+3/4"=2.75") to accommodate the motor dimensions. In retrospect, I realized I overbuilt this bracket when I found I could lift the smoker and carry it by this bracket!  Does this ever happen to you folks?
As far as the pass-thru for the motor driveshaft: I used lamp hardware (a 1" brass nipple and two cross bars). The relaxed dimension between the inner and outer walls was reduced by 1/8" net, while providing a rigid channel and sealing the insulation environment from smoke and moisture infiltration. One or two additional things that may be worthwhile to incorporate: I found that I could snuggly telescope a 1"length of thin-wall brass tubing (.25" ID) within the lamp nipple to reduce the dead air gap around the driveshaft ("gorilla" glued). Also, during the mounting process I slipped a three inch length of  thin-wall brass tubing (3/16" ID) over the driveshaft to help ensure that my final mounting position would not bind on the driveshaft. Once mounting was secured, I simply removed this sleeve and confirmed clearance was intact. I don't remember anyone addressing the idea of smoke or moisture infiltration thru the driveshaft hole and I could be completely off-base about this concern. I will try to add some pics later, if interested. Rich <`))>><[im



g][/img] Finally got the pic thing done, thanks to Acord coming to my rescue. This may be a good time to add that the setback on the frame to position the motor properly can also be modified by the spacers used for the four 6/32" screws threaded into the cross bar. I used 3/4", but 1/2" or 1" spacers would have worked too. Obviously, changing spacer length will change your choice of vertical supports (square channels or?) you decide to use. Also, I bent the cross bar just abit using a vise to improve the alignment (hopefully you won't need to do this),and over-sized the holes at each end of the cross bar to allow minor alignment changes before cinching this final fastening point.

[Habanero Smoker]

Looks like you have come up with some good ideas on installing the fan. Is there any way you can post pictures.

I haven't installed my fan yet, but I am using a separate cord to plug the fan into an outlet. I do a lot of smoking using the cold smoking method, and if I tie the fan into the wiring of the generator, that will limit my options on where I could locate the generator. I guess it may be possible to tie it into the wiring of the cabinet, prior to the current reaching the rheostat, but that may limit you options of turning off the fan if by chance you don't want to use it.

[winemakers]

I am not worthy.  I simply drilled a near diameter oversized hole for the motor shaft and let the smoke do as it will.  I find next to no outflow sufficent to either stain or heat the motor.  My shaft is long enough that I have a second fan blade mounted against the motor (outside the smoke chamber) and I suspect that I got it right by accident.  The motor I purchased had a classic 110v two prong pigtail, so I plug in with an 18 ga extension cord.

smoke on
mld

[Mr Walleye]

Hey Doc.... sounds like you did a fine job!  ;)

If you get a chance post some pictures. They will definitely be helpful for others.

Mike

[DocZ]

Please excuse the delay in getting the pic's loaded. Learning curve issues. In the mean time I wanted to add a postscript about using the bracket as a lifting handle---DON'T!!! With the narrow tolerances for the driveshaft I tweaked things abit by lifting the box and had to use a couple of aluminum shims to bring things back into spec. BTW Happy turkey day  to all! <`))>><

[Habanero Smoker]

Whenever you can post the pictures will be great. I will heed your warning and not pick up my smoker by the fan. :) The way you mounted your, does sound more secure then the way I was going to mount mine.

[Oldman]

Nice job,

I've enjoyed my fan and I hope yours will bring you much joy. While I have not done jerky in a long time I do believe that after the smokin' the fan will aid much in drying out the jerky.

[Habanero Smoker]

Thanks for the pictures. I will probably use your ideas for mounting. I'm sure I will be asking a few questions when or if I ever get around to installing my fan.

[RandalfTheRed]

  I don't have one yet, but I do have a hint into Santa for the DBS 6R.  I just had a couple of questions regarding a circulation fan mod.

  Any thoughts about attaching the fan to the side rather than the back to eliminate the flex problems?  I just thought the support from the rack supports might help minimize flex.  I suppose the side opposite the smoke generator would provide more room?

  Also, would there be any advantage to mount the fan below the level of the V-drip pan?  I was thinking, perhaps, the fan could be mounted off center, closer to the back of the cabinet and closer to the heating element.  Perhaps this would result in a better distribution of heat/smoke/humidity diffusing through the V pan?  Probably would not require reversing the motor?  A potential problem might be causing the pucks to burn faster though?

  Thanks all for this discussion!

[Stickbowcrafter]

Very interesting.

-Brian

[Habanero Smoker]

  I don't have one yet, but I do have a hint into Santa for the DBS 6R.  I just had a couple of questions regarding a circulation fan mod.

  Any thoughts about attaching the fan to the side rather than the back to eliminate the flex problems?  I just thought the support from the rack supports might help minimize flex.  I suppose the side opposite the smoke generator would provide more room?

  Also, would there be any advantage to mount the fan below the level of the V-drip pan?  I was thinking, perhaps, the fan could be mounted off center, closer to the back of the cabinet and closer to the heating element.  Perhaps this would result in a better distribution of heat/smoke/humidity diffusing through the V pan?  Probably would not require reversing the motor?  A potential problem might be causing the pucks to burn faster though?

  Thanks all for this discussion!

RandalfTheRed;

Welcome to the forum.

I believe Winemaker mounted his on the side under the drip ("V") pan. There have been discussions on whether or not mounting the fan under the pan would make the bisquettes burn faster, and or cause smoke and moisture to back into the generator. I believe that smoke and moisture backup was not an issue. I don't remember how the fan performed under the pan, as to maintaining equal temperatures.
under.

[NePaSmoKer]

Hey Doc

Do ya think you could get some pics of your fan working and pulling smoke. I like your setup.

nepas

[DocZ]

I'll work on that. I guess I just have the door open? I'll see if I have some scrap plexiglass around. Is there a technique that demonstrates that better?

[winemakers]

Sorry if I gave the wrong impression Habs, my fan is mounted above the v-pan blowing back against the back wall.  From a flow perspective it is all wrong, from a whiskey and smoking perspective, it is all right.  To clarify, technically, it may not be the best solution, but from a low, slow and sipp'in perspective, the darn thing works pretty good.

I end up with roughly 4 degrees max between differential between the top rack and bottom, and I dont see any pale spots when 20 lbs of keilbasa are arranged on the racks or hanging from sticks.

The engineer geek in me screams that the fan should blow away from the rear wall, however, after several ounces of Knob Creek bourbon this evening, I believe the fan helps to accelerate the natural convective currents in the BS.  Seems the rear mounted element would encourage flow up the back, across the top, and down the door convection currents, and a rear mounted fan may either accelerate that sufficiently to make it more uniform, or it may just muddy the thermal waters enough low in the box that the 'average' temperature and smoke flow even out in the end. 

Regardless of the final outcome, for me it was another excuse to spend time with some of my favorites, Granger catalog, the garage fridge, power tools, and the old Bradley smoker.

mld

[Habanero Smoker]

Winemaker;

You probably didn't give the wrong impression, it's me trying to read someone's post too fast and coming up with the wrong understanding :)

I have all the part to install my fan, so eventually I am going to bite the bullet and install mine.