For those of you who have not been following my blog for the past few weeks this entry will get you caught up with my Makerbot Semi build that I have been working on. I have completed the assembly of the Semi tractor and the UFO (see earlier posts) and am currently working on printing out the Lowboy trailer for the complete model using the Makerbot 3D printer. I have been compiling some interesting data on this build over the past couple of days. So far the number of hours I have spent just printing the UFO and the Semi tractor has exceeded 80+ hours. I have also gone over my computer model that I used to design the complete model and the grand total of parts in the model will be almost 500 pieces. The best calculation that I can make on the total amount of time it will take to print out the complete Lowboy trailer is another 60 hours. But all of it is fun so it is another labor of love.
In this image is the computer model of the Lowboy trailer by itself. It is 23.8 inches long with a triple rear axles made from aluminum rod. With this trailer the total length of the Semi/Lowboy trailer assembly will be 30.5 inches long.
These two images are of the rear chassis of the Lowboy trailer with the axles and wheels mounted. This will help you better understand the progression of photos to follow below.
The Lowboy chassis for the rear wheels is made up of three separate main sub-assemblies. Each section took a little over an hour to print and I was happy they turned out so well. In black they are perfect for the build.
These "U" shaped connector pieces are what will be used to hold the three main sub-assemblies of the frame together.
With two of the chassis sub-assemblies flipped upside down I slid the "U" connector over the two mating cross pieces and snapped it into place. The fit was nice and tight and no glue was needed to hold it all together. I designed mounting holes in the "U" connectors to run plastic filament through to hold this portion of the assembly together. It was so tight that the holes were not needed. You would break the parts if you tried to take them apart at this point so my design worked out better than I had hoped.
A very nice looking assembly and 3D print job at this point.
As before another chassis sub-assembly section is added to the build at this point with another "U" connector to make a nice clean looking rear chassis.
Very tight assembly with good stiffness. The rear chassis portion of the Lowboy is complete at this point. It is 2 inches wide by 5.5 inches long. As pictured it is only 1.5 inches tall. Not a big assembly but nice detail just the same.
Here I've added the axles that will be used in the trailer. They were made from polished 1/4 inch aluminum rod and cut to 4.5 inches in length. The tips of each rod were then drilled out to accept a cotter pin to hold the dual wheels on each side. With having to print the twelve wheels for the rear chassis assembly it will take roughly another 15 hours of printing on the Makerbot. I will hold off on that portion of the build until the very last of the assembly of the Lowboy. All the wheels will match on the Semi so it will look really good. Look back at some of my earlier posts to see the Semi tractor build and the completed photos of it with the completed UFO.