Trying to make a Bilby tower
I have kicked the idea around for a while now of making an HO Bilby tower. It posses extreme challenges to additive manufacturing (3D printing), as at 1/87 scale it is wispy to say the least. The tower I have modeled is correct to the diagram posted by Richard Leu here:
Rich Leu, post: 297759, member: 38 wrote: Since Most Model Railroads Are Of An Earlier Era
Page 9 in this PDF (not page 9 in the book) has a detailed dimensioned drawing of a Bilby tower that would give you enough information to construct a scale model.
I??m afraid an accurate HO scale model (1:87.1) would be pretty flimsy. For example, the 1 3/4? x 1 3/4? angle iron that makes up the bulk of the outer tower would only be 20 thousandths in HO scale. I don??t know if you can even buy material that small. And it sure wouldn??t survive the first time the cat decided the layout was a good place for a nap.
His link appears to be broken now. The link to my model is in the “Surveying 3D model” thread located here https://surveyorconnect.com/community/computers-tech/surveying-3d-models/paged/3/.
The issue with this print is its very nature. The towers were built multiple ways I am sure, but, the one in the pdf was with “L” metal that wasn’t very big. I have made the tower with 1mm braces throughout, which in real scale would be 87 times bigger or 87mm square. That is obviously way to big to be true, so, I will fudge there. The other area I just don’t know what to do is the legs and the instrument at the top of the tower. I do have models for both a T3 and GST-30 legs, but, to get them printable at 1/87 would be a lot of work and they would end up being blobs. I am doing the tower now in draft resin which limits me currently to a 300 micron layer height. I may try the instrument and legs separately in a resin capable of 25 micron layers, which will allow for some detail tests. I am very confident of success of the tower without the instrument and I will post regardless of success. More over, it is a welcome break from printing baby Yoda’s for my wife. If this works I will display it at my office for a bit and then send it to someone with an HO train set diorama as it really is nothing more than a challenge to trainless me.
I have broken the inner tower into 9 parts and the bottom three are printing now. With the supports they weigh in at 46ml of resin. Wish me luck!
This is one of the aforesaid baby Yoda’s to show printer accuracy. He is 2″ tall and is a slippery little bastard as just before the picture he jump from my hands ran under some furniture and covered himself in dust bunnies
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