Pizza Oven Catering Trailer

[KCStudly]

If you've been following my 'The Poet Creek Express' build (link in signature) then you know that I am building in the loft of my buddy Karl's metal fabrication shop.

Well, he has just started a spec job building a wood fired pizza oven trailer. Although this isn't a camper (mods feel free to redirect), he will be building the chassis and custom cargo doors from scratch (...along with an interesting mount for the oven), so I figure we can all learn from his experience as a master fabricator.

The oven weighs 3500 lbs and will be mounted on a pivot table (think Lazy Susan) so that the opening of the oven can be positioned right, left or to the rear depending on site conditions.

The main box frame will have a large 20 something inch deep enclosed storage compartment(s) under the oven platform, accessible from either side at the front and thru a tailgate at the rear. This area will be used to haul coolers with the food, firewood, the chimney for the oven, as well as other related catering supplies.

It will be a double axle trailer (two 3500 lb straight axles with elec. brakes). The main perimeter frame and xmbr’s are 2x3 x 3/16 wall. On top of 2x2 x 3/16 risers is a similar 2x2 x 3/16 upper frame. The tongue will be an A-frame with center rail. The 'A' sides will be 2x3 x 3/16 reaching back to the 2nd xmbr, and the center will be 4x3 x 3/16 reaching back to the 3rd xmbr.

The pivot table will have a flame (or laser) cut track of 3/8 thk steel like a big washer. Bearing wheels mounted around this ring will support a 1/4 inch thk disc that the oven base frame will bolt to. In the center of this disc there will be a stub shaft that extends down thru a flange bearing that will be bolted to the upper deck. The bearing will define the center of rotation, but the roller wheels will support the weight further out. Under the center bearing there will be a shaft collar and retaining ring clip to keep the shaft from lifting out.

Here're some pics. He started yesterday.

The box frame is fully welded here.


This is the mounting plate for the pivot bearing.


For food service legalities, it will have four sinks; wash/rinse/sanitize, and a smaller hand wash. These are basically bain-marie trays with holes cut in the bottom for drain fittings. These will get set into the deck at the front with potable and gray water tanks below.


Many of the trailer related parts will be sourced from this supplier (no affiliation). I believe they are out of NJ.


The sides and floor of the storage box will be clad with sheet steel, stainless steel on the top, stitch welded on then sealed with body seam sealer. There will likely be at least one large storage drawer at the rear, if not a pair, on 4 ft extension glides.

The cargo door face frames will have a ‘J’ shaped lip around the openings to act as a drip gutter, and the doors will have a similar formed edge with gasket that will seat on the face surrounding the gutters.

Lots of details have yet to be determined and the customer is still making decisions, so I’m sure there are more things to come.

Hope you get a kick out of this. It should be interesting.

[Greg M]

Man, Karl gets all the cool jobs.

[KCStudly]

Man, Karl gets all the cool jobs.

He's got skill and an eye for quality.

[Wobbly Wheels]

Thanks for starting this.
Since reading about it in the other thread, I'd like to see how it goes together...but I don't want to clutter that thread with the inevitable questions.

[KCStudly]

No problem. Karl had some other jobs to get done this weekend, but plans on getting back to the oven trailer on Monday. A bunch of the sink related parts showed up (Surflo pump and drain kit) as well as the axles.

Stay tuned.

[KCStudly]

Karl has made a bunch of progress. The basic trailer design, axles, suspension and all of the trailer related hardware were provided by the designer/job super, but the details were left for Karl to figure out. The suspension and tongue are now on and the main cargo area deck has been fit and stich welded down.

They stepped up on the aluminum wheels and nice Goodyear tires. The axles have easy lube spindles with zerk fittings under the rubber plugs in the bearing caps. Notice how the center pivot of the axle equalizer is centered under the center of the oven, well toward the rear. The departure angle is really good!


Despite using 5x10 ft sheets of steel, the deck required a seam, so Karl welded a strip of flat bar down the middle between the xmbrs for the seam to land on. The sheet stock on top is just lying there for now as a matter of convenience. As it sat right here we estimated the tongue weight at about 160 to 200 lbs; it took both of us to lift it.

The tongue. At first Karl thought there was a conflict with the center mount tongue jack and the center tongue tube, but he ended up blowing a hole thru the top and bottom of the tube so that the jack could pass thru w/o weakening how the coupling mounts or the tongue. The main tube was wide enough that the side walls of the tube remained intact.


A shot at the suspension.


The first 10/ct of the build looks like 90/ct complete, but as we all know, the devil is in the details!

[KCStudly]

The side and rear panels are being tack welded on.



The edges of the panels around the cargo door openings have a standing lip flange formed in them. This stiffens the panel at the door opening and creates a diverter for water that might roll in when the door is open. The vertical seams will be fully welded and sanded smooth.


This is a test bend for the cargo door panels. The corners of the panel were notched on a special corner notching die punch. The end flap will get another small notch so that it clears the first double bend.

[KCStudly]

The pizza oven trailer is rolling right along (bah-dump-bump!).

The tandem axle fenders that the contractor sent were not only too long for the spring length and spacing; they were nested together in shipping and had been bent with a crease to one side of the center drop. So Karl solved the problem by making his own fenders. Here is the flat pattern design.


… and the sheared blanks.


Here they have been formed and are sitting on some blocks for a test fit.


A day or two later the fender seams had been welded and they were bolted thru the frame risers. You can also see that Karl has welded the body corner seams, sanded, and added a touch of filler to smooth things out a bit. Good look at the tail light cutouts in the rear door, too.



Speaking of the doors, the forming was complete and the seams welded.




Latch hardware temporarily installed for fitting; will come out again for paint.



The small pieces of 1/4 inch rubber were just there to check for fit with the hinges and latches. 3/8 thick weather stripping will be applied after paint.



I helped Karl bring in the stainless steel decking blanks fresh off the truck from laser cutting. The edges will be folded down and the pieces will be welded together at the seams.


At the front are the cutouts for the sinks.


The wood box and glide supports are in.



They are 4 ft glides with a nifty built in latch.


Here you can see the ring that will support the roller assemblies that will support the rotisserie. There will be a standing curb or lip of rolled strip stock around the ring and a rubber skirt hanging down from the oven rotisserie. You can also see that the edges of the deck have been formed, but not welded yet.




Karl used the same die forming tool that we used for the safety chain stays on TPCE, but used a larger size round bar for the heavier load chains.


I helped Karl work out the details of how this hitch pin will be mounted and used to lock the rotisserie from turning. The pin will be able to be pulled down and turned slightly to disengage it from the detent hole, then once the oven is rotated, turned back so that it springs into the next detent when the oven gets to the desired location.


Should have more progress to show tomorrow.

[aggie79]

Beautiful work! Keep the pictures coming.

[Vedette]

I agree with Tom.....beautiful job.
Awesome fabricating!
But man is thing going to be heavy?????
Keep up the great work and Thanks for the pictures.
Brian

[KCStudly]

Thanks guys. I'll let Karl know you are enjoying his work.
... and yes, it is going to be very heavy. The oven alone weighs 3500 lbs. Takes two to lift the empty wood box.

They are worried about weight creep, too, but it's hard to convert iron workers to thinking light!

[KCStudly]

This may very well be the last entry for the pizza oven trailer. After finishing up some details, priming and painting the inside, and installing the SS deck, Karl is scheduled to deliver it to the GC’s shop to do the exterior paint. They will work together to do the final assembly at that location, so unless Karl takes a few more pics of the completion, this will be it.

Since the cargo hatches open downward, they needed stays to hold them when open. The hinges are the slide off type so that the hatches can be removed, so Karl selected lanyard cables that made it easy to adapt for a quick disconnection.


The door end has these little anchor tabs that connect to the bolt from the latch, but will get tack welded to prevent them from spinning (live and learn).


For the upper removable end, weld studs (round bar with a fat button on the end, like a big nail head) were welded inside the door jambs for the cable loop to slip on/off.


Stabilizers mounted to all four corners. Also visible is the socket head cap screw tapped thru the skin and frame tube that keep the hinge from separating. To remove the hatches you remove one bolt, open the hatch, lift the cables off of the studs and slide the hatch off of the hinge pins.
Rear stabilizer.


Front stabilizer.



Close up of hinge and keeper bolt with door open (still needs a little clean up after welding).


From right to left inside the front compartment against the front wall are: two vertical straps with loops for a strap and angle cleats on the floor to secure a 25 lb propane bottle (yes, I told Karl that enclosing a propane bottle in a sealed lockable compartment was against reg’s, and using a bungee strap to secure the bottle was unacceptable, but it is what the customer wanted… unfortunately, it will probably skate thru the inspection); and two vertical straps for the hot water heater to mount to.


RV water heater.


Karl has really been pushed for time on this project, so has been unable to put his usual high level of detail into it. Also, the concern about overall weight has been growing constantly, so Karl decided to mount the rotisserie support rollers directly to the upper deck xmbr’s and eliminate the lower ring of 1/4 inch steel. The standing ring of SS sheet, yet to come, will be welded directly to the deck skin in lieu of the ring.



Here is the rotisserie frame and upper ring. The pizza oven is built on a thin sheet of steel with two square tube xmbr’s that will nestle down next to and bolt thru the longer of the two square tubes seen here. Also note the 4 large holes in the ring.


Once the oven is installed on the rotisserie (after lifting with two fork trucks) this stub shaft drops into the flange bearing mounted under the upper deck frame (seen here sideways because it was leaning against the bench).


Once the oven and rotisserie assembly has been installed on the trailer, this shaft collar will be clamped on under the flange bearing and a safety bolt will be installed thru the hole in the shaft to prevent the oven from separating from the trailer, yet still allowing it to rotate.


You can see the blue flange bearing mounted under the heavy center plate here.


The spring loaded hatch pin shown previously has been mounted into this (heavy) plate and fabricated steel guide bushings. The smaller bail handle slides into a smaller hole to allow the big pin to extend up into those holes in the bottom of the rotisserie and lock it into place. When you want to rotate the oven to face a different side, you reach in under the rear hatch, pull the bail down and rotate it a bit so that it doesn’t go in its little hole, which holds the big pin down out of the way of the rotisserie. When you get the oven to where you want it, or close, you turn the bail back, it springs up into the small hole allowing the big pin to go up. When the big pin and hole line up the spring does the rest.
Pin up.

Pin down.


The marker plate and 3 clearance light mounting brackets were installed under the rear cargo doors. I had recommended that the plate be mounted to the left rear door, but the customer wanted as much surface as possible for signage, so it got mounted low. The departure angle is steep enough with the axles set so far reward that it probably won’t be an issue.


I hope that we can get a pic or two of the finished project; we will see.

[tony.latham]

[Wobbly Wheels]

Wow, that was quite a job - it'll be good to see a pic of it 'in action'

[KCStudly]

It will be going to a start up business, I think, so I will see if I can find out the name and post a link to whatever might be out there on the inter-webs.

Karl said he might take some more pics (with his cell) and send them to me, but let's not hold our breath. I'm sure the finish will be just as hectic as what we've seen so far, so it wouldn't surprise me if the pics don't happen.

I am also interested to hear what the weight ended up being. They were going to hang it on a dynamometer and see.

We'll see.