Hello again guys!
I decided to have a crack at whatever that object is near the top of the SD Radar mast that appears to support a lot of antennas. It was quite a challenge, and once again the design was based on pictures kindly sent by Tom and Scott without the benefit of any dimensions. The main pictures I used are shown below. The first two gave me the overall shape, the third provided the approximate height of the structure, and the last showed me how it attaches to the mast.
Ass I said before there are numerous ways to do things in AutoCad and there may be an easier way to create this object, but here is how I chose to do it. The first step, as usual, was to draw the outline of the object, which in this case was difficult, as I had little to go on, and took a few tries before I was able to make a shape that I was happy with.
In trying to make the right shape, I would draw it in plan view, extrude it, and rotate my view to compare it to the photos. I think the shape I ended up with compares favorably to the pix.
The platform is thicker at the base, and tapers to the break point, so I created this by drawing a triangle, mirroring it, and lofting between the two.
This object was once again made out of sheet steel, so scaling was an issue. I shelled the platform to 0.5’ (which is between 1/32” and 1/16” at 1/144 scale).
Next, I added the center brace.
I then rounded the top edges and prepared to do the support end (although I later changed this.)
I made a rectangular plate extruded 0.06’ from the surface and bolts, which were extruded hexagons that had been inscribed inside 0.06” radius circles, but then scaled to 0.9 to fit. This will push the limits of the SLA. After doing one plate and bolt set I copied it to make the other one.
Note the red circles in the image above. They were made in preparation for the next step which was creating the brackets, which were made by lofting between the circles.
The bolts and plates were mirrored to the other side and everything was joined together.
I next focused on the support struts, and after a couple of attempts came up with the configuration shown below. The most difficult part was drawing the line in the correct location. After that I just lofted a circle down it and mirrored it to the other side.
The pictures show plates around the strut contact points to the mast, so I made these much as I did the access plates. The most difficult part of this step was finding the exact locations for the plates on the surface.
At this point, I switched focus to the top of the mast. For this I had a really good picture provided by Scott…
…So I started drawing and lofting circles…
…Until I got to the section that is cross sheet steel, where I lofted between two different size rectangles and rotate/copied it then made a bolt as described before and copied it. I then mirrored the two bolts, and then mirrored all four of them to get 8 total.
Then it was back to circles. The narrow section is worrisome. Even though it has twice the radius of the SLA minimum of 0.005” (0.06’ real size), I think it will be too thin to support itself. We’ll see.
I next worked on another unknown object and the bracket that supports it. I suspect it is some sort of directional sensor because there are similar sensors on the sides of the support platform positioned seemingly for this purpose. Maybe?
Anyway the bracket was made using lofted traingles, rectangles and a subtracted circle. These plates are only 0.03” thick so I think they will print, but they will be delicate. I left them unattached because it may be better not to print them and add them during the build.
Next I made the conduit and connecting hardware for the sensor, starting with the lower one, which is a combination of lofted circles and hexagons…
…Followed by the ones on the underside of the sensor bracket…
This was followed by the hardware on the top side of the bracket…
…And rounding the bracket edges.
Last, I made the sensor itself. I left it red and unattached too, because I again think that it may be best to make these pieces during the build.
Even though I made this piece complete, it may be best to make the whole assembly with PE, but for now I am going to go with what I have.