BBQ Hot Dog Roller

BBQ Hot Dog Roller

You know those 'hot dog roller' machines at the corner convenience store that keep those dogs hot and juicy... You can have one built into your barbecue. Just lay your dogs on the rollers, fire up the BBQ, and let the rollers spin your dogs as they cook to perfection.

Sounds kind of fun. I thought this couldn't be too difficult...

Well, first, what were the rollers going to be made out of? Stainless steel tubes? Chrome pipe? Way too expensive for my wallet. After some exploration I settled on copper water pipe. It was much more economical than the other two. I had also considered chrome towel rods, closet rods and even curtain rods, but I'm not so sure if the "chrome" on those was real chrome. Who knows what toxic chemicals could be leaching into my hot dogs. So I figured if the copper water pipe was suitable for potable water it was good enough for my hot dogs.

[Update: Note that MarcellS2 in the comments points out that using copper in cooking can cause potential life threatening issues. Therefore the copper tubes in this project need to be replaced with stainless steel.]

Next, am I going to provide some type of bearings for the tubes to allow them to spin freely? This might be a little overkill but I don't want the motor to bind. After some investigation I discovered that a 1/4" x 5/8" bearing fits perfectly into the sleeve of copper fittings designed to slip fit over 1/2" copper pipe. A perfect way to attach a bearing to my pipe.

The last big question to answer was how to transfer power to turn the pipes. I figured I could use a low RPM motor to drive the 'main' pipe. But how to transfer power to the other tubes? I didn't want anything too complicated mechanically and I didn't want to spend too much money. I always tend to default to what I have on hand. I had some two-part liquid silicone mold making compound for another project. I thought I could make some 'rubber bands' to transfer power from one roller to the next. This particular silicone was suitable for up to 450F. That would work in a barbecue! I would just have to cast my own high temperature 'silicone rubber bands'.

Well, with the major obstacles tentatively solved it was time to charge forward into the unknown.

6 ft of 3/4 in. copper water pipe

[Update: Note that MarcellS2 in the comments points out that using copper in cooking can cause potential life threatening issues. Therefore the copper tubes in this project need to be replaced with stainless steel.]

6 - 3/4 to 1/2 in. reducing fittings. (These fittings slip over the copper pipe on both ends - there are some that slip over pipe on one end and fit into a fitting on the other - you don't want those.)

6 - 1/4 in x 5/8 in ball bearing - all metal (No rubber or plastic sides or seals.)

3 - 36" long 1/4 in x 20 all-thread rod

Assorted 1/4" x 20 course nuts and 1/4" washers

2-Part Silicone molding compound. Food safe, high temperature.

3D printed mold (Optionally formed from sheet plastic or clay)

Cooking Spray as a mold release.

Low RPM motor

Barbecue

HOT DOGS!!!

I don't know if custom making my own silicone rubber bands is a bit extreme and over the top (Probably) - but I had the materials on hand and I would get to try out my vacuum pump on a real project. (It had just been sitting around since I got it for Christmas one year.)

I used the brute force method of determining the diameter of the rubber band: I took two pieces of 3/4" copper pipe, spaced them 1/4" apart and wrapped a strip of paper around them to determine the circumference of my silicone rubber band. I then used the formula below to determine what the diameter should be:

Diameter = Circumference / Pi .(3.14.59...)

With the diameter of my silicone band calculated I used Fusion 360 to create a mold that I would 3D print to cast the silicone in.

I created a band model with only 1mm wall thickness. I hindsight I should have made it at least 2mm thick, if not more. I took the Fusion 360 model and 3D printed it. I had added a funnel type feature to help get the liquid silicone into the mold.

I also figured I needed some mold-release so I used cooking spray.

Fearing that with the 1mm gap the cooking spray would not get all the way down into the mold, I placed the molds with cooking spray in them into the vacuum chamber and pulled out the air, which allowed the cooking spray to bubble and then fall down into the narrow mold when I released the vacuum.

I have included the stl file of the mold as an example. But as mentioned, I would make the band thicker.

This 2-part silicone was easy to use. Mix equal parts by volume. 50 minutes to work with it, 6 hours to cure.

I considered not using my vacuum to remove bubbles, but because the mold was so narrow (at a 1mm slot) I decided to use it. Even after using it I could see bubbles in the finished bands.

Note to self: Thicker wall (again!) and let silicone stay under vacuum LONGER!

Removing the bands was challenging, even with the cooking spray having been applied. I purposefully destroyed the 3D printed molds - and it was hard. The filament was much tougher than I anticipated. Being careful not to tear the bands I finally freed them from the molds!

I was originally going to cut off the 'funnel' portion of the band so it would end up being just a band, but I decided to keep it to add strength to the band. It didn't get in the way and just made it stronger.

As noted previously the rollers are 3/4 inch diameter copper water pipe.

The pipe was cleaned with SOS pads (Soap On Steel wool) under hot water. I needed to remove al the surface printing on the pipe; and who knows what germs live at Home Depot?

The pipe was cut into three 2 ft lengths. I allowed quite a bit of space between the copper pipe fitting and the wall of the barbecue in order to allow all-thread rod sticking out of each end of the pipe to be slid into the mounting holes in the sides of the BBQ.

It is amazing how perfectly the 1/4" x 5/8" all metal bearing [1/4" (hole in the center of the bearing) x 5/8" (overall diameter of the bearing)] fit into the 3/4" x 1/2" copper pipe reducer. The bearing slid into the 1/2" side. And he 1/4" all-thread rod slipped wonderfully through the bearing.

Going from one end of the roller to the other: a 1/4 x 20 course nut, followed by the bearing, then the 3/4" to 1/2" copper reducer, then the 3/4" copper pipe, then the other end's reducer, bearing and nut. No need to solder the copper pipe to the reducers or to anything else, it all fits snugly sandwiched all together on the all-thread rod with the nuts holding the assembly together.

The pipe in the center freewheels nicely on the bearings.

My BBQ already had 4 holes on each side of the BBQ.

I chose to increase the diameter of two of the existing lower holes with a 17/64" drill bit to accommodate the 1/4 in all-thread rod. I had to drill a third hole on each side to accommodate the third roller.

Don't forget to slip your Silicone Bands over the ends of the rollers before you mount the rollers into the sides of the BBQ.

Mount the all-thread into the mounting holes with nuts and washers.

I was fortunate to have purchased a surplus motor years ago that was designed for use in a moving promotional advertisement.

It had a crank mounted to its shaft and a very slow gearhead motor (about 6 rpm). It had a cardboard tube battery holder. It ran on 4 D cells.

I removed the crank and the arm that fastened with a set screw. I knew I had to interface the motor with the 1/4" all-thread rod so I drilled a 17/64" hole in the end of the arm.

I then bent the arm around so that the shaft hole and all-thread hole lined up.

The all-thread fit right into the arm and was secured to it with a nut on each side of the arm.

The motor was supported by the all-thread with the original motor mounting bracket keeping it from spinning.

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There you go - You have an honest to goodness BBQ Hot Dog Roller!

To make this more functional for larger gatherings just add more rollers!

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Now go cook some 'Dawgs' and ENJOY!