SP Jawbone Branch (Part 48) - Continuing Owenyo 3rd Module Construction

While I've not done a "huge" progress, but at least I should document what's changed since the last post in Part 47.  I made some progress since the last post, which I didn't get to photograph, so I'll start by catching up.

Doesn't look like much, but there's more to this post than it looks!

One of the problems of getting this module started was even getting "something"... anything there to start working from.  I used a couple scraps to build the front frame during the last post, just so that I can now start building the complicated front frame and not have the rest of the frame flopping around.

Let There Be Gussets!

Gussets were glued into the end-plate joints with Owenyo #2 Module.

This gusset ended up getting a bit more glue that expanded out than I expected.  This was a repair after the bonding of the front doubler frame clamps twisted and popped this joint. - Oops.  So now it's bonded back with some extra glue.  I'll do a little filing work on the front to ensure the front fascia curved piece will fit flush with the inner frame piece seen here.

The rear end-plate gusset in place.

I also built one of these small gussets for the rear frame joint too.

Notes from the CAD Computer...

One of the nice things about drawing the whole layout in the computer, at least as a rough plan, is that in the complicated areas, I can go measure the computer's drawing for specific measurements that I need to build the modules.  

Notes from my CAD file on this module.

In this case, I was measuring out where the notches would need to be for the future main track spline to go across the front frame strips, and also where the skin of MDF sheet would form the road bed for the Owenyo Trestle to sit.  The 26.44" measurement was for the centerline of the track, which I'll be needing soon enough as I layout the spline.

I also made some notes about other dimensions I'll be needing, such as the 6" note on the left end of the main track.  That's to note the distance of flat track work before the vertical transition to the grade starts.  The depth of the spline should be adjustable, but I made notes of the height at the front frame, where it crosses over and also the height of the bottom of the top skin at the same place (about 1/16" below the datum plan of the left end-plate's top).

Do That Carpentry Stuff Again!

Right wall frame stripe inner doubler in place and lap-joint for end-plate.

 Notes were also made for vertical alignment off the underside of the top skin at the left end of the Owenyo #3 Module, which I'm taking as my vertical datum zero point.  The main track will loose 0.65" by the far end of the module along the right wall.  So I built into the final extension of the right wall frame strip that it will drop 0.65".

End Plate for the door-crossing module was bonded in place.

The end-plate of 1/2" MDF was also bonded in place with the corner squares on top and bottom while I was also bonding the inner doubler strip in place.  Many clamps were used in the bonding of that strip.  I ended up doing this outside and just at dusk, so I didn't get any good photos of the process. - So these after the fact in-place photos will have to do.

I'm using the spare scrap of MDF as a spacer for the future sky backdrop.

Also since the last post, I attached a bracket to the right wall, just in front of the window.  This allows me to work on the module framework in-place and add pieces without the whole module twisting or flexing, like I have been dreading for 9+ months on this module.  I took special care to be sure that the module will sit level on the bracket, so that as I lay in the grade transition and spline work the grade will be the correct 1.25% when its in place.

Notes on the rough front frame.

So from left to right my notes are as follows: ~2" of straight strip, which will be doubled by the front curved fascia strip for the first ~2".  Then until 6.75" the temporary front strip will be the only piece there.  Past the 6.75" point, the front fascia strip will be far enough away that I can switch to a doubler on the front side.  The horizontal pencil mark is for the lowest notch for the main track spline and the bottom of the skin sheet for where the trestle will sit.

Center section of the front frame scrap bits.

The butt-splice joint was made between the two scrap pieces at an angle.  The heavy pencil marks will show the future cut-out section for the main track spline and the trestle pit track.  The trick is that this only leaves about 3/8" left of the scrap front frame to bear all the weight of the future module.  The doubler will be offset vertically to keep more structure below this notched area.

The right end can step back up for the last 11.5".

The right inner frame is also lowered by 0.65", so my doubling front frame will use this extra height on the bottom to form the glued joint.

Two clamps temporarily holding the front frame doubler in place.

The pencil mark on the center notch area shows me where I need to cut away material.  I took this piece off and cut the 1/4" deep notch on the table saw.  

All Clamped Up

Awe clampit!

With the notch done, I brought it back, applied the Gorilla Glue, and then all the grip clamps I could get my hands on!  The twist of this much off-center weight of the clamps became a challenge, so I supported the tail of one of the larger clamps with a piece of 3/4" plywood.

End view of the clamps in place.

The 1/4" MDF strips can try to swell as the Gorilla Glue cures, so I added a sister blocks from a couple of the spare 1/2" MDF end plates, that I cut the other day, as horizontal keepers.  As these were not glued, just held in place by the clamps until the glue dried, and then removed.

Front doubler strip in place with notch.

The front frame is now about half done.  I still need to take the saber-saw and finish the shape of the notch in the original front frame strip.  One point I should make here is that the extra 1/4" below the rest of the frames is to match the end plate at the right end of the Module #3, so that they should be able to sit flat on a folding table, as I'm planning to be able to take the modules on the road if I want in the future.  So having the modules be able to sit flat with only minimal shimming is ideal.

Top Skin Check

I've been placing the "top skin" of 1/4" MDF back and forth to sit on the module or remove it to work on the sub-structure as needed.  I may end up cutting it up more, removing the sections that will need only the scenery foam and allow for slight changes to the alignment of the dump trestle positioning, once the main track and spline support is built.

In Closing

I've noticed as I'm starting to work around the corner that I'll probably need to look in to building the next section of LED lighting and mount it to the ceiling leading over towards the Bartlett corner of the room.

The right end of the skin seems to have a slight error... oops?!

But of the more present concerns I'm having now is that the switch to the dump trestle will be almost perfectly split across the module joint with the door section, which is certainly NOT ideal.  I may decide to shorten the whole module and move the joint back behind the heels of the frog far enough to be safe from messing with the switch's alignment.  If I do that, then I'll have to cut off the nicely glued end-plate and cut notches in the right-wall doubler to again allow the plate to fit inside of the outer frame, and then have the same lapped joint I did before, but a few inches shorter.

Jason Hill

Related Articles:

Jawbone Branch Layout Build Index - Master list of previous blog posts on my Jawbone layout.

SP Jawbone Branch (Part 47) - Owenyo 3rd Module Construction - Previous post in the series...

SP Jawbone Branch (Part 35) - Cutting Out Owenyo #3 Module - Last post on Owenyo #3 from 2022, on Aug 30!  Wow, that seems like such a long time ago.