Section III – Part I |
Rear Vertical Supports
This is a good place to talk a bit about the build of the other two sections. Each section fits to other sections and those connection areas need to be dead on. This is where jigs to ensure that can be very helpful. Luckily, I have my Prusa I3 MK3 FDM printer which will allow creating such jigs. |
Front vertical Supports
The bottoms all lock into notches in the Jig tank frame and we can use the Top Caps/Stringers shown in yellow to keep them aligned (front to back) while the glue dries. Care needs to be taken with the side to side alignment – The Top Caps shown in green will help align everything a straight edge aligned with the jig tank will work for that. … and yes I moved the stringers and caps vertically a bit since the focus at this point are the support timbers. They (stringers and caps) would of course be locked to the supports (no glue) to act as jigs while the glued supports set up. |
 Once the glue dries this is where we will be at – I hid everything except for the parts glued up to this point.
Ha. This is where you have to be very careful and not be a klutz and knock these pieces loose before adding reinforcement from later pieces. |
Floor Supports
While butt joints would be much simpler here – the dapped joints are much stronger both in the model and full-size. |
Floor Boards
Note: There would have been sheet metal applied to surface this floor with metal. In “Mining Library … : Engineering and mining journal.” published in 1912 – “… and the inside is lined with sheet iron 3/16″ thick, in which the holes for the nails are countersunk.“ |
Let’s start with these. They are nicely locked in place by notches in the end of the Jig Tank stringer and about midway where they are notched to fit over the ends of upper stringers of the Jig Tank.
Next add the Front Vertical Supports.
This bit promises to be really, really “fiddly”. The notches are all cut at angles – notice that the notch in the rear vertical supports are horizontal at the top but cut at the slope angle on the bottom. The notches in the Jig stringer are the same. The notches in the lower sides of the Floor slope support beams are angled on both sides of the cut. This will simply require slow, careful notching of the beams to get everything to fit correctly.
The floorboards are 3″ x 12″ boards – in O scale that’s 0.250″ x 0.0625″ – except for where the boards have to be narrowed to fit. The 3″ thickness is much more important than whether the boards are 12″ wide – or 10″ etc.
