The available factory made aluminum diamond plate boxes run $1200. I'm far too cheap to buy one. Time for a Macgyver moment. After reading the specs on the factory model, I went to Home depot and found this tool storage box for $60. It's a little longer, but the genny still fits in. To attach the box to the truck and prevent / deter theft, I elected to use the hole in the middle of the bed of the truck meant for the 5th wheel attachment. It is a 2 3/8" diameter hole, 4 inches deep, through a heavy steel frame which is bolted to the truck. Strong enough for a 5er, strong enough for this job.

The 2x2 metal frame was removed from the bottom of the generator. This made it low enough to add a 3/4" thick piece of BC plywood bolted into the bottom of the generator using the factory supplied 6 threaded bolt holes. The plywood has a cut out to accommodate the pan on the bottom of the genny.A hole was drilled in the center to allow for a 1/2" galvanized carriage bold to be dropped through the plywood. This bolt is what attaches the plywood to the truck frame. The plywood is attached to the genny. The box is sammiched in between.

The genny was set into the box, with the bolt sticking through the hole about one inch.To get fresh air in, the factory specs a 665 CFM 12v fan. I found one on Ebay for $20. A 9 inch hole was cut in the side of the box. That hole was covered with a roofing vent cover from Home Depot $31.The gaps were filled with backer rod, and everything was sealed with a silane caulking which is waterproof.

The exhaust is another roof vent from home depot $20The cord to the trailer was bought from Amazon, $92 which included the inlet box for the trailer. This shouldn't figure into the cost as I would have had to buy them anyway but thought to include them so y'all have an idea of the total cost.The cord was notched into the side, just below the water tight lid. 8 holes were drilled in the bottom to let any rain water or spilled gasoline or oil escape.

The lid needed to be notched a little to accommodate the gas cap on the genny. I used an inside pipe cutter to remove the box lid ribs. The bolt sticking through the box feeds into a wooden plug, the width of the hole in the bed of the truck. To keep this plug in place, a 1/2" female union nut was let into the bottom and screwed onto the carriage bolt about half way. The whole thing is tightened to the bottom of the job box, letting the plug and female union nut stick out about 1/2" as the hole in the truck sets about 1/4" below the bed of the truck. This gives me a little room to feel when the plug hits the hole and centers itself.A 3.5 inch galvanized steel bolt is threaded through a locking washer, a piece of flat steel* with a hole in it, then another 1 1/2 inch wooden plug to center the whole unit from the bottom. The bolt assembly is threaded up through the 5th wheel hole into the female union nut, then tightened with the same impact driver and socket as the stabilizer legs. * The steel is 2 inches wide, 8 inches long and 1/4 inch thick to act as a giant washer. The genny is now bolted to the truck, can be used in the rain, and while traveling. The total cost was $169, saving around $1130, and enjoyed the experience.

upper wood plug detail The bottom 1.5" has the full sized hole for the female nut. The upper section has room for only the carriage bolt. The sections are screwed together to allow everything to be taken apart when the genny goes in for repair.

DIY generator box for a honda 3000 | Good Sam Community

Houston_Remodel
Explorer
Sep 20, 2020
We've been running the exact same box since the original post. We used it Labor day weekend at the beach. Still going strong
rickv3
Explorer
Sep 07, 2020
Hi Houston Remodeler, just found you're post today, have the same honda generator, wondering how the box is functioning, is the generator staying cool or overheating, this is a great design and would like to make one for my generator, how do you open the picture image in the instruction how to construct. Thanks in advance

Rickv3

____________________________________________
2014 jayco eagle 5th wheel 27.5 rlts
2008 ford lariat 450 dually
Houston_Remodel
Explorer
Jun 06, 2016
Spent several days driving through Arizona in 110ºF heat, the generator powering the air conditioning in the TT as we rolled along. No problems.
Community Alumni
May 10, 2016
I got them from eBay. I got the pair from a seller named Speed Daddy, but there's lots of people that sell the same fans. They come in sizes from 6" to 16". According to the info online each one of my 12" fans push out 1700+ CFM.

http://stores.ebay.com/Speed-Daddy-Com/Cooling-Fans-/_i.html?_fsub=3489166018&_sid=841766438&_trksid=p4634.c0.m322
samhain7
Explorer
May 10, 2016
Proxim2020. Where did you get the fans?
azrving
Explorer
May 10, 2016
Nice job. I agree with the idea of being as quiet as possible with our generators. I built a 12 gauge steel cabinet with a similar 120 v fan and vent. I also made the cord long enough that I can park the back of the truck away from our rig. Only problem is forgetting to shut it off. At times, depending on where we are I will keep the lid propped about 2/3 of the way open.
Houston_Remodel
Explorer
May 10, 2016
We had a chance to use the generator in the box for an overnight boondocking stay. It purred along, barely audible, for 17 hours using half a tank of fuel.
Houston_Remodel
Explorer
Apr 26, 2016
Thanks ! since my readings were higher, I'll keep an eye on the temps.

Really appreciate your effort.
Community Alumni
Apr 26, 2016
I had an opportunity to take some temperature readings. I took the temps after the generator had ran for a couple of hours. We had a pretty good load on it the entire time. We had the 15k AC going along with the TV and the converter charging the battery. I used a wireless indoor - outdoor thermometer to take the temps and all are internal.

Outdoor Ambient: 85 degrees

Location #1 - 97 Degrees: This is the location in front of the left fan. Also where my kill switch is located.

Location #2 - 110 Degrees: This is the location in front of the fan on the right. The exhaust blows into this fan.

Location #3 - 86 Degrees: This is the air intake side of the generator.

Location #4 - 89 Degrees: This is the temp on top of the gas tank.

Here are a few pictures of the box.
Houston_Remodel
Explorer
Apr 23, 2016
Temperature readings on an 85 degree day

Click here