I began this project earlier this summer and part of it sat around for quite some time. I had been using a 15 gallon spot sprayer and a homemade 6' boom mounted on an old Snapper riding mower to spray for weeds in the yard. So, I decided to build a tow-behind sprayer to pull with the newer Deere 155C lawnmower we have. Of course, if it was going to be new, it had to be bigger and better...
The new sprayer will have a 25 gallon tank (obtained for free of course) and a boom of approx 10'. Although probably over-the-top, the sprayer is also going to have walking tandems so it rides more smoothly over our rough lawn...
I had welded up the majority of the frame earlier in the year but had stalled out while starting on the tandem walking beams. The original steel design was not working out with the steel that I had readily available. So, this weekend I decided cast aluminum would come to te rescue!
The new trick in this portion of the project was embedding the "axles" for the wheels in the casting. To do this, blind holes were milled into the foam pattern that were slightly smaller than the bolt to be used, in this case 5/8". The heads of the bolts were cut off and grooves ground in the shanks to anchor them into the aluminum casting. The bolts were pressed by hand into the foam and the tight fit held them mostly square. It worked just like it was planned, those puppies are in there for good.
I also poured a few of the hinge pieces needed for the folding boom.
