Yep...GGaskill has his micro Tannenberg and his full size one, but I'm going to fill the niche of the mini scale! I've also got another project in mind (it's a secret, but you guys will like it
), but I want to secure some bronze for it (at least SAE660), and that will be harder to find than a trip to Home Depot.
Thanks to him for his plans, because I'm scaling them for mine, so if you want to picture what I'm doing,
click here. I'm not going to reinvent the wheel on this by redrawing it, but if any of you really want my numbers I'll be happy to give them to you, though you can use the formulas I give to calculate them off of the full scale plans linked in the link in this paragraph.
For starters, I wanted to determine that I could easily enough find raw material. A few calculations allowed me to determine that Home Depot could help, by supplying a 1/2-4.5" SS Bolt:
nominal 1/2-4.5" SS bolt:
.464 in thread
.492 outside thread
shank unmeasured, but larger than thread (I forgot to measure before I started working on it, but will measure the shank after I'm done with the first side - see pictures below.)
Max OD of material at muzzle for octogon shape:
.464*cos22.5=.428
Max OD of material at shank for octogon shape (this is actually a little smaller than actual - see note above):
.492*cos22.5=.455
3/16 bore = .1875 (SF calls for OD=.5625 if no chamber - not sure how I'm going to address this, since I don't know that I can do a chamber, or that I'd want to do one.)
.1875/.6690=.280 scale
OL = 13*.28=3.643
Max OD = 1.594*.28=.447
Max Side width (at Max OD)
.447*sin22.5=.171
Here's the start:
Filing the first side. Everything will be based on this side, so I stopped after getting tired of fighting off mosquitos.
Beginning work on BB Tannenberg - establishing first side
Fisrt side further along