Studholme 6 - Legging it.

DB Says:

The Fremo120 standard has the tracktop height set at 1200mm above the floor and recommends having some means of adjusting this to account for build-tolerances and non-level floors. Something one would have thought unnecessary until I saw the surprisingly un-flat floors when we were setting up the big 9mm layout in Christchurch a few months back. 

So this means legs. If there was one thing I did like about the 9mm layout, it was how the legs folded up into the module, so everything was self-contained. 

While on my shopping expedition at Bunnings a few months back, I spotted these 1.2m long 18mm square sticks that might do for legs. They seemed tiny, but surprisingly strong when you lean on them, and my modules are not expected to be very heavy, or to be danced upon, and any force is coming vertically down, (horizontal force will tip everything over rather than bend the legs). 

So I gave them a pop. Out of about 25 sticks available, I selected the straightest 8. Look out for twists in the wood too, which can be a pain when you attach the cross braces.  Apparently cheap replacement wooden broomhandles make good strong module legs too but I don;t know where you find these. Maybe a dollar shop?

I've had a few iterations of legs and fixing methods during recent experimental months, so will just discuss my favourite method.

Basically the leg set is screwed and glued together, braced just so, and fellow Dandrufers will tell you that what looks like an exceptionally spindly setup is actually really solid (there is a little torsional twist, but that's not the direction of force that needs to be dealt with in a modular setup!) :

If you remember the old bomb disposal joke: "Cut the red wire..." snip. "But first, cut the brown wire" you'll know not to make one of these yet, otherwise it won't fold up into your module. Well mine didn't, twice.

Things to think about before you start carpentering: 

• How broad will the leg set be ... presumably for stability, about as wide as will fit (make sure you allow for the broader width of your adjustable feet (and don't install those either yet)).

• How will the legs be attached to the module? After thinking about and trying hinges and little steel L brackets (all relatively heavy, clunky, pricey), I reckon the same 8mm wooden dowels that I'm using to align my module set together is the ideal pivot. Strong, cheap, easy. I have used little bits of what used to be called 4x2 to put the holes for the dowels in. 

Consistent pivot locations using specific bits of wood to mark these out on my bits of 2x4. That's also the Bunnings 18mm x 18mm x 1.2m barcode FYI...

• Related, where will the actual pivot point be located on the module? This was critical for me as I have fairly shallow 6cm deep module side fascias. I hadn't thought about this when I decided on 1200mm long modules, but you obviously can't fold 1200mm long legs inside a 1200mm module, especially when each end plate is 18mm deep, plus I need some pivoting room for the legs, so that eats up about 50mm of that internal space. Fortunately, you obviously don't need 1200mm legs as you can move the pivot point further away from the top of the track (probably why 10cm deep sides are preferred!) and as close to the ends as possible. This way your legs can be shorter and thus fit into the module when folded. Be aware that the  pivot hole in the leg obviously can't be at the very top of the leg or everything will snap.

• From that, you can derive a leg stick length (taking into account the adjustable feet) and make sure that this will all fold up into your module... and most importantly, when you add it all up, it has the top of your track 1200mm above the floor when the adjustable feet are at about their midpoint of extension. 

• Lastly, back to the bomb disposal men, if you build the complete leg set first and then attach it to the pivot... unless you have a laser-sighted CNC drill press, there is a fair chance it won't fold up into the module. This is because if you are out just a fraction with your drilling/alignment of the pivot holes, the two pivots won't be magically aligned in exactly the right place (and you have two dimensions to screw up in at both the module pivot hole and again in the leg hole). Thus when I attached and triumphantly folded my pre-made legs up, the pivots weren't perfectly square so one of the legs banged into the long-side fascia of the module top. So I now assemble the leg set in situ.

All of this made my head hurt for a week.

So what I have settled on is:

1. make some calculations.
2. cut/measure/drill my little 2x4 pivot pieces and attach them to the module (screw and glue) 
3. calculate 1200mm less "track to centre of pivot (45mm for me)" less "allowance for feet in halfway extended position (25mm for me)". This is the distance between the bottom of the wooden leg to where you drill your pivot hole in the leg. I don't recommend doing it the other way around (drilling the hole close to the top and cutting off the bottom to suit) because its really hard to drill a big hole near the end of a thin leg without shattering the wood. I measure, gently clamp the leg together to be sure, drill the hole, then cut off the excess length from the top of the leg, and then apply some woodglue on the surfaces to add a modicum of strength.
4. Cut the legs to length if you haven't, and drill/attach the feet, do a dry test or two before you make that final cut to make sure everything will fit. If you have a problem, you may need to rethink your pivot point!
5. Drill good sized pilot holes in the delicate legs for screws to go through to attach the leg set cross pieces. Attach top and bottom cross pieces to ONE leg, not screwed too tight
6. Dry apply the dowels to join legs at the pivot points (3/4 in with no glue).
7. Fold the legs up inside the module and center them nicely (pack with wood against the inner faces of the module top) and only then attach the other leg to the cross pieces with the legs folded for as much of this operation as possible. Glue and screw everything for strength.
8. Fold everything out and treble check you can get a level and 1200mm rail height before the glue sets in case you need to pull it apart to make adjustments.
9. Fold the legs back in, attach the angled brace piece, and screw everything tight.

Somewhere in these final stages, you might chose to gently glue the dowels into either the leg (for strength) or pivot point. Be careful not to do both!

Legs extended. 

Legs folded cleanly:

How the calculations worked for me:

As for feet, I started with these relatively cheap ones with plastic press-in nuts, but the plastic nut bits broke off or lost their thread surprisingly quickly...

So have upgraded to these steel M6 T nuts gently hammered into the legs and these more robust feet below. You obviously need to drill two sets of holes in the ends of the legs first, one deep enough to take the T nut body, and one smaller diameter hole drilled more deeply to take the threaded rod when it is screwed all the way in (which it might need to be, to fold into your module).

One of my three Studholme modules will have leg sets at each end, and the other two will have just one leg at one end, with the other end being supported by the adjacent module.

...By the way, I've also put some coal in my two 3'6 LCs (at the far end) and added a ridge pole to an older one, plus experimented with colouring pencil on the KS doors with mixed results:

Quite like the way these four wheelers have all been resurrected and enhanced, with the possible exception of the LPA with the badly applied tarp, which I thought was 'clever and quirky' at the time, but now is just 'annoying' me.