Fan

[Raye Minor]

http://www.susanminor.org/images/smokers/sunsepa.gif
Circulation Fan
From Olds, Bubbagump & Others
http://www.susanminor.org/images/smokers/sunsepa.gif


John, (bubbagump)

These pictures are of the prototype I made for Chez. The one I made for myself is similar. However, because the two walls that make up the back of the box are so thin my mounting bracket now goes all the way to both sides of the outside walls of the box.

A couple of things I need to suggest and point out. First there is a high limit switch inside the back wall of the Bradley. It is higher then where I mounted my fan. So there are two wires that run to it. I suggest that before you drill the hole for the drive shaft of the motor you open up the back of the Bradley and see where they are located. Mine were to the left of center so I did not have to move them.
http://www.susanminor.org/Rayeimages/fan5.jpg

Next I suggest you drill the pilot hole from the inside of the unit and not from the back. The reason is simple. You don't have to take measurements to figure out where to drill the hole so you don't lose a rack. How I did mine was easy. I removed all racks except the V rack at the bottom. Next I placed the drill bit through fan blade's shift hole. By doing this the fan blade became my visual template. Thus I could eye-ball where to drill the hole and not lose a rack or the V pan. Plus the V pan gave me something to steady my hand on.
http://www.susanminor.org/Rayeimages/fan1.jpg

Because the walls in the back are so thin you will find that even with the longer full side to side mounting bracket that the motor's shaft can be knocked out of alignment with the shaft's hole. What I did to help eliminate the problem of the shaft rubbing up against the hole's side is on the inside of the box I drilled out that one inside-wall with a much larger drill bit.

At first I did not give much thought to the heat transfer from the aluminum fan blade via the shaft to the motor. It did not take long to realize that this had to be addressed.
http://www.susanminor.org/Rayeimages/fan10.jpg

What I did was to add a second aluminum fan blade but it was mounted on the outside of the box (self cooling heat sink.) I also added an aluminum hood at the back of the motor as another heat sink. This fixed the heat problem. I did two tests of over 40 hours each with my box ranging from 205 to 305 F.

These are the pictures of the prototype:

Without hood:
http://www.susanminor.org/Rayeimages/fanmotor.jpg

http://www.susanminor.org/Rayeimages/fan3.jpg

http://www.susanminor.org/Rayeimages/fan4.jpg

This is the fan I got from Granger Supply. This blade from the smoke I saw it blowing looks like it is blowing at a 45 degree angle and not straight out. Please note that Granger, like many sites will make changes which results in broken links. If a link does not work please notify us, in the mean time if the link does not work, search their site by using the parts number:
Fan Blade #2MXY4 (http://www.grainger.com/Grainger/DAYTON-Propeller-2MXY4)

This is the motor I'm now using:
C-frame motor #4M079 (http://www.grainger.com/Grainger/wwg/search.shtml?searchQuery=4M079&op=search&Ntt=4M079&N=0&sst=subset).

In this picture the door had been opened for about 1 minute. You can see the smoke is being pulled back towards the fan, and do note how well the smoke is mixed at the top of the chamber:
http://www.susanminor.org/Rayeimages/1smoke.jpg

Now no matter what fan motor you use, you will need to get one with at least a 2" long shaft. Even then it is a tight fit.

I have marked this posting so I will be notified if you have any questions. However, seeing how you are a trades person I doubt you will have too much to ask.

In closing as I said earlier I have about $40.00 or so into this. That is not much for we are getting back. Plus it will take about 2 hours with making the mounting bracket etc..

Good Luck!

Raye

[Bubbagump]

Hi Olds,

I noticed smoke residue on the outside fan in your one pic. Is there much smoke leakage out the back?

Bubbagump

[Raye Minor]

The original fan was Counter Clockwise Rotating. Next due to the weakness of the wall plus the mounting bracket on the first one did not go completely across the back I ended up drilling a larger hole for the shaft. Thus the fan on the inside was pushing smoke out to the fan on the outside. In the picture the fan blade that has smoke was on the outside. The new fan is just that..a new fan.

What I originally thought was I could get away with was placing the fan between the 3rd and 4th racks. The only problem was the more I looked at it after I installed the fan blade the more I saw that it was now sticking out further into a small part of the 4th rack area than I wanted. That is when I moved the fan down between the V pan and the 4th rack area. The original hole is now blocked.

Raye

[Raye Minor]

Car,

Do make note that the original fan was counter clockwise rotating. When bubba first put his on he did it as it is shown in the pictures above. Which was wrong as the motor he was using is clockwise rotation.

Next, this set up will only get you 35 CFM, so don't expect a windstorm.

This is the fan blade I used: Fan Blade (http://www.grainger.com/Grainger/wwg/itemDetailsRender.shtml?ItemId=1611631590)

This is the motor I used: Motor (http://www.grainger.com/Grainger/wwg/itemDetailsRender.shtml?ItemId=1611772183)

If you have add a second heating element this fan will not move enough air to balance out the box. Again please keep this information between us.

Olds

[ChefBill]

I got a friend in sheet metal shop. I may get him to duplicate the back of the BS in a heavier gage gal. sheetmetal to help take some of the flex out.

1. Also, add a thin PTFE washer to inside on the shaft to help cut leakage to zero.



I'm just full of it today. :) ChefBill

[Raye Minor]

At this point I really don't have a leak. The outside hole is only 1/16" larger than the shaft. ;)

[ChefBill]

Raye,
I got the fan mounting bracket made yesterday and then I pulled the back off of the BS. I made the bracket a little wider than the one in your pictures so I had to move the Hi-Limit wiring over about 2" toward the edge. Plenty of slack so easy to do.

I'm going to use your suggestion of using the fan as a template to drill from the inside above drip pan. I think I'll go up about 1/2" so as to give pan clearence to come out over the pins it rests on.

You guys did a great job engineering this project. Wade Bradley should take lessons from all the "Backyard Engineers" as to how to improve an already great product. He may have with the new larger version.

I really wish his new IT guy would convert the BS forum to VBulletin and get away from Snitz. I use VBulletin on 3 other forums and it's a lot more versatile and has more features.

[SMOKEHOUSE ROB]

will be installing my fan on Monday thats when the fan will be here, will take pics to post, have some ideas for a simply box/mount for the fan motor, but since don't have it yet i need the dimensions of the motor? can anyone help, thanks

[ChefBill]

will be installing my fan on Monday thats when the fan will be here, will take pics to post, have some ideas for a simply box/mount for the fan motor, but since don't have it yet i need the dimensions of the motor? can anyone help, thanks

Rob,
The fan motor measures about 2-1/2" wide X 3-1/4 high. One thing I discovered is that it'll need a lot of open area around it for air circulation. A 2" diameter fan's not going to move much air to cool the motor. I'm going to just make a shroud half way around mine to channel the air over the motor a little better. I made my mounting bracket just like Raye did but I made mine 3-1/2" wide where the motor mounts. By doing this I can mount up to a 3" fan between the motor and the back of the BS.
I Just made a run at 300º smoker temp and 55º outside and motor was (95º) plenty cool. Bradley heats up by the door thermometer a whole lot quicker with fan running.
I just found a piece of Lexan that'll cover the door opening, going to put a Bisquette on the burner and just for kicks watch the smoke to see how it flows. :D
Note: Rob, Make sure your mount is big enough to keep the fan from flexing and the shaft touching the edge of the hole thru the BS. The metal inside & outside is real thin and it flexes quite a bit... ChefBill

[SMOKEHOUSE ROB]

Rob,
The fan motor measures about 2-1/2" wide X 3-1/4 high. ChefBill thanks Bill , what does it measure from the back of motor to the front, or how much space is need from the back of motor to the first fan before it toches the back of the bradley?

[ChefBill]

Rob,
You'll need 2-1/2" from back of the BS to the rear of the fan motor mounts to get the first fan in and clear the BS back. Also, you'll have to take the OEM screws out and put them in from the shaft end. (Turn around 180 degrees) easy to do. Otherwise the fan hits them.

Take a close look at the 3rd & 4th picture down and you'll see where they were turned around when Raye remounted it with the bracket rather than thru the smoker back with no outside fan. Bill

[SMOKEHOUSE ROB]

http://i8.photobucket.com/albums/a30/smokehouserob/fan1.jpg
http://i8.photobucket.com/albums/a30/smokehouserob/fan2.jpg
http://i8.photobucket.com/albums/a30/smokehouserob/fan3.jpg
http://i8.photobucket.com/albums/a30/smokehouserob/fan4.jpg
ran for 3 hours at max temp, around the fan motor only saw a temp of 86,

[Raye Minor]

I will add at this point that the fan listed that I use is clockwise running. As such it blows air towards the door. One of the persons who added a fan (I don't remember who it was) was able to reverse that fan. If you can do that I strongly suggest you do. The reason why is this fan blade blows out at a 45 degree angle and can cause a problem when blowing towards the door and you are smoking a full box.

The work about for this is simple. You create a collard that is 2 inches wide. Mount it around the fan blade. Make sure you leave enough room behind the collard so the fan can have an area to pull the air from. Or if you are like me I generally only smoke an item or two at a time so what I've done is to place foil on the bottom rack and this deflects the air to the door and not directly on a item being smoked.

One day when I have nothing else to do I'm going to pull my motor and reverse it so it will then blow towards the back of the box and that will end this problem.

[KosherSmokin]

Thanks Raye for making this post public, it's a real service to the whole Bradley community.

I want to install a fan in my bradley right above the drip shield, like the previous designs.
My presumption about desired airflow is that I would like to pull air (perhaps from below)? and distribute it to the rest of the cabinet.

I gathered a couple things from previous posts about the fan specs:
1. Clockwise Fans (CW) will push air towards the door, and Counter-Clockwise Fans (CCW) will pull air towards the back.
Question:
Has there been much airflow through the shaft hole in the Bradley, ie. cold air will you be blowing in with a CW motor, and vice versa smoky air leaking and blowing on the motor with a CCW motor? I would think that especially with a CCW motor you should be careful to make the shaft hole small.

2. The fan blades blow at a 45deg angle, but is it down or up?
If I guess up, that means that I have the correct airflow pitch (down to up) with a CW motor, but it also means I might turn my chickens on the bottom rack into jerky with hot air blowing on them. I like your idea of making a collard, but I'd rather be pulling air than pushing air. With a CCW motor I think the same blades (assuming a 45 deg. UP pitch) would work.

3. On the Grainger website it appears that this particular motor may not be reversible (Ball bearing, not sleeve bearing), although ball bearing it says is more suited for temp. sensitive applications. Have you found a CCW version of this motor, or is there something I'm missing?

Thanks for your input!
Sam AKA KosherSmokin

[Raye Minor]

Question:
Has there been much airflow through the shaft hole in the Bradley, ie. cold air will you be blowing in with a CW motor, and vice versa smoky air leaking and blowing on the motor with a CCW motor? I would think that especially with a CCW motor you should be careful to make the shaft hole small.
In my original prototype the hole was to large for the reason I have already stated. My current outside hole is larger but not enough to worry with.


The fan blades blow at a 45deg angle, but is it down or up?
360 degrees.


On the Grainger website it appears that this particular motor may not be reversible (Ball bearing, not sleeve bearing), although ball bearing it says is more suited for temp. sensitive applications. Have you found a CCW version of this motor, or is there something I'm missing?
One of the members that used that motor reverse it. E-mailed to me that he was able to tap on the shaft enough to get it to slide out. Someone else talked about the box not been even in heat. From what I remember that member added another heating element and it was touching the bottom of the V-pan. At that point the V-pan became an extention of the element and it would read hotter there than at the top of the box.

[IKnowWood]

Rob

Looking at your Mod, did you use the same 4M079 CFrame motor? And for the fans, did you use a 2" on the outside cooling part?

Did you invert the fan or pin to get it moving counter-clockwise. How did you do that.

I see you used a large swaure conduit box, did you need to add more material for attaching the motor or was it a simple drill and screw motor on?

This will be my next mod over the summer as I have time.

Thanks so much all.

[pfowl01]

Hello all,

I just installed a circulation fan in my unit following the guidance from this site. I was able to reverse my motor by removing the rotor with a screwdriver and then flipping it 180. Just pry between the casing holing in the rotor and the metal bands, it pops apart fairly easily. Then flip 180 and squeese the ends back on with a channel locks.

[Raye Minor]

pfowl01,

Thanks for the information.
Olds

[nodak]

I just installed my fan.

I reversed my motor, I left the fan blades as is and it seems to be blowing in the correct direction. Is this correct????

[Raye Minor]

If reversed the fan must be blowing towards the back of the unit. If not then it will not put out any air.

In this image you will see the collar / set screw are facing the motor. On a reverse motor make sure the collar / set screw are facing the motor as shown here.

http://www.susanminor.org/Rayeimages/fan4.jpg

Cya~!

[Habanero Smoker]

I'll post this on the Bradley site also. I'm getting ready to install my fan; hopefully this weekend. Since most of the heat transfer problems are at the rear of the smoker, I prefer installing the fan to blow in a CW direction (moving air towards the door). I understand the concept of placing a collar on the fan to prevent the air from blowing directly on the food, but is it a full collar, or half collar. If it is not a full collar would I mount the collar on the top, side (if so which side), or the bottom. My convection oven has a covering that pulls air from the front and expels it through several openings in the side of the covering, but if I set it up that way, I would have to set the fan to run CCW, which defeats what I wan to accomplish. At the fan's rated speed, would it make that much of a difference to have a small draft that will move across the food?

There may be pictures that show the collar, but my browser is not downloading all the pictures, and some pictures will only partially download.

[Mr Walleye]

I added a circulation fan sometime ago now. I used Smokehouse Rob's idea if using an electrical box to mount the motor in. I think by mounting it in an electrical box it keeps it somewhat enclosed, especially with the exterior cooling fan running. I removed all the plugs in the box to allow more air flow. No problems to date and it's been running a little over 2 years.

In the first photo you can see the "L" brackets that I bent out of aluminium. They are heavy enough that the only place they are mounted is to the outside edge with 2 #10 screws on each side. Lots for them to bit into out there. I did pre-drill the holes. Where the "L" bracket mounts to the electrical box I slightly slotted the holes in the box so I could make any adjustment that I had to in order to align the shaft in the centre of the hole through the back of the cabinet.

When I first installed it I changed the motor so it was running CCW. By doing this the back of my cabinet was always consistently hotter than the front of the cabinet. So I decided to reverse the motor back to CW, build a shield to deflect the air away from the lowest rack and run some tests to see how it works in this configuration. Here are some pictures.

This is a picture showing the mounting method and brackets I made when I installed the circulation fan.
http://www.susanminor.org/users/Hab/Misc_Files/Other/Walleye_Fan/CirculationfanRear.jpg


This is a picture of the 1 ¼ inch stainless steel I used for the shield material. It originally was a stick on stainless steel molding for a GM truck.
http://www.susanminor.org/users/Hab/Misc_Files/Other/Walleye_Fan/Stainlessmolding.jpg

This picture shows the 2 pieces I cut. I cut a piece 3 ½ inches long, then cut a piece 3/8 inch off of that.
http://www.susanminor.org/users/Hab/Misc_Files/Other/Walleye_Fan/Stainlessmoldingcut.jpg

Here are a few pictures of the shield completed and installed. I left an air space of about 1/4 inch between the back wall and the bracket to allow for air intake for the fan.
http://www.susanminor.org/users/Hab/Misc_Files/Other/Walleye_Fan/Circfanshield1.jpg

http://www.susanminor.org/users/Hab/Misc_Files/Other/Walleye_Fan/Circfanshield2.jpg

http://www.susanminor.org/users/Hab/Misc_Files/Other/Walleye_Fan/Circfanshield3.jpg

http://www.susanminor.org/users/Hab/Misc_Files/Other/Walleye_Fan/Circfanshield4.jpg


So far in my testing, on the 2nd rack from the bottom, with a temp probe near the back and one near the front I have a 1 degree difference. It varies from being warmer at the front or at the back by one degree, dependant on if the heater is cycling on or off.

Mike

[Raye Minor]

Thanks Mike,

Nice job!
Raye

[Starship]

One post said a single fan might not move enought air for dual heater elements. Has anyone considered dual fans, side by side?

Why not, other than added cost?

Also, there is a site http://www.onlinemetals.com/ where you can order 18G cold rolled steel, 17x30 for about $30.00 to make a stiffer back.

They have different gages and materials cut to size, and small orders are fine.

[Raye Minor]

One post said a single fan might not move enought air for dual heater elements. Has anyone considered dual fans, side by side?
I don't see why one fan would not move enough air.

Thanks for the link.
Raye

[Starship]

http://samshuford.com/sam/?cat=8

Pictures and information on my blog.

[Raye Minor]

Very nice.