I have a 2013 DK40 that has already suffered a few blows to the lower grill in the woods. Don't really like the idea of adding expanded metal to the factory GG due to lack of coverage of the factory GG down low. So decided to build a GG with better coverage.
I could try and describe it but will just post some photos instead.
Yes the bottom bracket started out as a C-channel.
This C-channel is a little odd compared to what is available in the USA.
It is a piece of Metric Channel that was used as a crate for large Japanese CNC machines.
It measures 3"x6" with a center of the web thickness of .350"
The metal was just slightly to small for the Kioti GG/weight rack bolt pattern. I had to mill reliefs where the bolts meet the contours of the metal. And yes the bottom angle was milled off.
The rest of the grocery list.
all square tube is 3/16" and all rectangle is 1/8"
-2x2" square
-1.5x1.5" square
-1x2" rectangle (technically 11gauge .120")
-1.5"x1/2"x1/8" c-channel for grill
-3x3"x3/8" angle
-The bottom inner bolt mounts on the GG are modified 2"x2"x1/4" square with one of the sided cut out of the square.
-5/16-18x3/4" SS button screws with HD SS washers, all 18-8 grade.
-1/2"-13x1" grade 8 HHCS LE stamped (Lake Erie made in Indiana)
-M14 grade 10.9 flat washers.
-factory M14x1.5x40mm grade 9 HHCS
All welded with .035" MIG wire. Millermatic 212.
All bolts Blue locktited.
The Grill slats are spaced 10mm apart. To make this easy. I used a bunch of M10 x 12" long keystock to use as spacers during fabrication.
The reason I don't like expanded metal. It is to easy to bend and hard to bend back once it bends/stretches. Nearly impossible to paint properly. Hard to eliminate sharp edges.
Biggest issue is the paint problem. If you go to a trailer lot, all the rear drop gates on new trailers have rust bleeding out of where the expanded metal meets the tube. How can you get paint between the expanded and the square tube. Even the powdercoated trailers suffer from this.
I bolted the slats so that they would be replaceable and paintable on all sides. If the slats were welded. They would need to be welded all the way around on all sides or rust would creep out. That would be a lot of welding.
I changed my oil and air filter today. Decided to install a inner air filter along with the outer.
Anyhow I snapped a photo with the front grill off. It wasn't necessary to remove the front but I had both sides off for the maintenance anyway. I am at 76 hours.
While you have that open (or next time) you might thing about putting your favorite battery grease on the battery terminals to keep the fumes from starting corrosion there. I use NO-OX-ID. made by Sanchem. I have used it for years with good success. While I am at it I put some on the screw threads of the battery retainer bolts too. How many times have you seen bolts near a battery that are always rusty and or corroded to the point they just break off? I believe in coating them to protect them.. YMMV..but that is what I do.