We continued to apply the Resin and Fibreglass layers to the Filter Parts. We completed all of the insides with their two layers as well as the two layers on the insides of the lids and side panel. The outsides of the filter will have a single layer of resin and fibre-glass as they will not be submersed permanently in water so need less protection. The outside of the swimming lane return channel was coated last thing today.
In better weather we completed the boarding of Sections D & E. We are getting better at cutting boards the correct size first time.
We have now covered 140 square meters of roof which is 38% of the total in 7 days so we are on schedule to finish in about 20 days…
Stephen fails to do a ‘Shaun wave’ @ 4:37
We had a delivery from UK-Mail today and the driver hit our fence post and snapped it off! He appeared to hit the post and break it off as well as flattening a few road cones placed by the fence to warn drivers that it was there! We have contacted UK Mail and will wait to see what they say about it.
This morning, our 75 sheets of pretty plywood arrived. The lorry managed to get down our Loke, and we placed our flat bed trolley alongside. We then pulled off the plywood, sheet by sheet. This allowed the delivery bloke to get off to his next port of call.
We then moved half the pile by taking 3 sheets at a time and walked about 15 metres to our new storage tent. Eventually, we were able to move the trolley itself, with much slipping and sliding on the snow, and got the remaining sheets unloaded.
This plywood is much nicer than the last lot (well we bought it as pretty)
After lunch, we resumed in the lovely and warm workshop and created five more rafters.
That’s was enough for Shaun’s back so tomorrow we will finish off the last two rafters and get ready for doing the “K” section by measuring the final set of rafters! Hurray!
This morning, we tackled the next rafter, the A4, to slice the bevel on the end of it, analysing the results. It was still inclining to curve outwards during the sawing and we surmised that the saw blade was ever so slightly off line. So we attached a thin 1mm plastic spacer on the sled at the bottom left corner to try and offset this skewness. And yes it did seems to do the trick. We then did the next rafter, A5, and repeated the bevel slice and this time we got a much better cut first time. We are a little bit more confident of the machine now. The proof came when we took these two rafters outside to get them up and installed. We decided to try and man handle them up ourselves as we had a great advantage with these rafters as the wall ends fits like a glove and actually anchors the whole rafter into place. We only needed to hold the top end to relieve the strain and make sure we don’t accidentally break the Bird’s mouth joints.
We fixed them the same by screwing a 8mm coach screws, one in the bottom and one in the top of each rafter and also glued of course too! It went very well and flat against the PA diagonal beam which further enhanced our confidence that the Bevel Slicing Machine is performing better.
Then after lunch, we went around measuring the other similar sections of the roof, namely the “M”, “I” and “E” sections by moving the tall scaffolding tower around, as all are having the same 32degrees slopes. During this task, we were concerned that we were getting spurious misleading measurements along the top flange distances because our template was not going flat against the Kerb of the Skylight and this was proven when we placed the spirit level on the template and the position of the Kerb was slightly proud of the steel webbing underneath. This caused us to reconsider and switch over to measuring the bottom flange distances instead as we realised that this aspect of the rafter element is much more “stable” and the main structural load points is on the bottom flange at the top and the shape of the wall end (the top-plate and legs) are much more accurate to where the Bird’s Mouth goes. So we took down a series of distances to then enter into our spreadsheet, ready for preparing the elements of the rafters in our workshop tomorrow. There are 10 more long rafters to make and a heap of the bevelled rafters to fill in those corners of the roof sections.
The metal splice plates for the O ridge have been welded together. More care was taken to weld them in short stages and swapping from one plate to the other resulting in almost no warping of the plate.
Now we have to make the wooden parts of these beams…
The parts of the metal work for the K ridge were welded together, after they were finished it was noticed that the big metal plate had been distorted by the heat of the welding. We will have to investigate how to reduce this for the O ridge plates!
Tomorrow we will make the parts for the O ridge and maybe start welding them.
After finishing the construction drawings, fabrication of the metal work started with drilling 64 holes in the flange reinforcement strips.
Then the two side plates were cut out and drilled for bolts.
Tomorrow the sockets for the adjoining rafters will be welded on.
While half the workforce is disabled, Stephen was busy designing and building several new pieces of equipment and tools to help with various future jobs that will be needed to be done as part of building the rafters and walls.
The tools were created approximately in the following order:
Polystyrene Foam Board Hot Wire Slicer
We needed a tool to slice our pile of 8 foot by 4 foot 120 mm thick boards into much thinner sheets (38mm thick) and a few different heights (between 248mm and 265mm). We couldn’t buy the correct thickness of sheet (only 35mm or 40mm) and 120mm thick boards were much less than 3 times the price of the the thinner sheets so we decided to slice the thick sheets down.
Using high resistance wire to form the basis of the machine, we can have 1, 2 or 3 wires, fully adjustable to different heights and separations, and connected to a high powered electrical generator to heat up the wires to melt the polystyrene foam.
Router Jig to Cut Rafter Slots in Cement Boards
This template slots on top of the wall, at each rafter and leg position, to guide a router to slice out a vertical slot in the wall cement boards. These slots allows the top flange of the rafters to pass through the wall and stick out to form the eaves.
It is adjustable to accommodate the different angles of the rafters.
Laser Guide for Wall to Steel Framework Alignment
We needed to transfer the position of the Wall Legs where each Rafter sits on, up to the Steel framework so the rafters will be exactly in the correct orientation and be locked into place. The steel framework will have planks of timber glued and screwed against the webbing and flanges of the steel i-beams, but also these timber pieces will have a series of 10mm deep slots sliced in, at the regular 612mm spacing. We need to make sure these slots are perpendicular in relation to the wall legs that the rafter will be joining onto. The laser is aligned to a leg and projects a line at right angles up to the steel beam.
Using our 3D printer, we designed a glue spreader to help us lay down a thin film of the glue on to the timber and stick down other materials like plywood etc. The glue is pumped into a the open space via small tubes, the chamber has a notched side to allow a controlled amount of glue to be spread as the tool is dragged along. The first version was drawn on the computer and then converted into a multi-layered object for the plastic extrusion printer to build, layer by layer, into a solid object.
In the afternoon we started to cut and fix the short pieces of timber which fit between the lintels over windows and doors and the top of the wall. These short studs will provide places to attach some of the roof rafters (rafters will be attached to nearly all legs). We completed 5 of the openings before stopping early for other commitments.
Further commitments will mean no further work outside until Saturday but we will be ordering the LVL beams.