Since this location is up on the far end of the garden, and near the "open grass lands" of the lawn it seemed appropriate to make a model of Dduallt station building to fit this situation.
It is the original wooden construction of course that interests me - not the modern stone one. The drawings were given to me by a local 7mm modeller David John, for which I am grateful.
The sides will have to be printed in 2 parts - as will each side of the roof, otherwise each component should fit on my printers bed in one piece.
So that is the sides, floor, chimney porch and urinal created. The roof will be the interesting thing to draw because I want overlapping slates again like on my previous buildings. I have so far got away with overlapping the components for this (because my printer can cope with it) but I will try to make the individual slates an exact fit on the subframe this time. More to follow:
The drawing is based on photographs, and has been manipulated to make the verticals vertical, and to maintain the proportions.
So to create my model I have imported the drawing into sketchup, and scaled it on the basis that the door frame would be about 6' tall.
I then used the drawing to create each side on top of the drawing. Then I moved the sides into place.
Having drawn the walls and added the plank detail on top of each side I created guide lines along the top of the building. That enabled me to fine tune the sides so that the guidelines all intersected. I then drew 4 lines to make the shape of the roof panel. It required a few attempts to make sure that the guide lines were exactly true, but the effort resulted in a rectangular box which filled automatically. So a solid surface which I pulled 2.5mm I find that panels like roofs and walls need to be at least 3mm which to remain flat and have strength. So 2.5mm is a good base to build detail on top of it.
This roof panel was made into a component. Using components ensures that the shape you have created does not distort as you move it around. It also means that the thing you have made can be used again. So one roof panel copied and pasted makes the two sides of the roof:
After making the basic panel as a rectangular block I then edited the component (another advantage of components is that you can go back and improve it later - and the changes will be applied to every copy of the component you have used). I have also adjusted it so that it overhangs appropriately over the walls. I added more guide lines to help me make the top corners of the two panels meet accurately and the eaves to be horizontal ready to take the valences:
So that is the basic roof.
Now I want to create slates. I measured the slates on the drawing and it looks like they are 13mm wide and 20mm tall (in 16mm to the foot scale of course).
So I made a rectangle that size sitting on the roof panel. That was also made into a component. Then I edited it:
A rectangle parallel to the plane of the roof, manipulated. Firstly I added a line along the centre of each of the sides. I then moved three of the top corners inwards to represent the tapered surface on the cut edges of slates. I intersected the slate with the top of the roof panel and deleted everything below the intersection:
This is the first layer which is a sort of filling layer which sets the angle for all the other slates. When it is in place on the roof it can be rotated so that it sits truly on top of the roof panel. It is just a matter of copying and pasting the slate along the bottom of the roof panel:
You can see that there is a slight gap between each slate (as there should be), and that I have adjusted the spacing to accurately fill the roof.Incidentally I have made that first row of slates into a group. The second row will be another group, and eventually I will group all of the rows together with the base panel into another group. That will help when I want to pick out the roof panel to copy and past it to the other side - and to make an .STL file for printing. I have started to create the slate which will fill the rest of the roof.
I placed it on the roof at a higher point so it half covered the first slate, and rotated it so that it sat truly onto of the first slate. That meant that the top of this second slate disappeared into the roof. So intersect the slate with the top of the roof panel again and delete everything below the intersection. A bit of messing about drawing lines was needed to get a solid undersurface, but here is the second row slate:
You should just be able to see that there are two distinct surfaces on the underside. Well near enough. I may improve it later. And this is how it sits on the roof:
It isn't in the right place yet, and I need a half width version of it as well for this layer, but more of that later.
You can now see a two clear flat planes on the underside of this slate.
I copied and pasted this slate onto the next layer, and made them into a group. Same again for the next layer, remembering to move all the slates to overlay the last layer, and adding half slates at each end.
So now there are slates lying cleanly all the way up to the ridge - but of course the top layer are too tall, and overlap the ridge.
We will get rid of the overlay next.
There are the guide lines in with the component, and I have drawn lines along those guides to form a vertical face. Now I can "select all" and "intersect - with selection". This creates lines where the vertical face intersects the slate. Now manually deleting the bits that are above the vertical face, and the vertical face leaves this:
Because I had made this top row of slates unique editing the one like this does the same to all of them. The final view of the roof next.
Bear in mind that this top edge doesn't really need to be perfect because it will be covered with ridge tiles - which are components already used in other models (Tanybwlch station building and goods shed to be specific).
Selecting the roof base and each layer of tiles I then created it all into a group. It took a couple of attempts to make sure I had picked up all the different groups and component that I wanted. Then copy and past in place created another copy of half the roof superimposed on the first half, which I could move to one side. Under edit there is a commend "group" which has a subset" flip along" and along " groups green". So that created the second half of the roof which just needs moving into place. The second half is really just for show - although it does make sure it fits properly into place. When I come to export the .stl files for the slicing software I will only export one half - and print that half twice. The final roof:
Door windows and porch roof next I suppose.
I have also created a length of slate walling which I intend to run along the edge of the track behind the building:
I have some copper wire which I can interlace between the slates like in the prototype. I am currently printing 6 lengths upright at once in PLA. I'll let you know if it works!
The wire I have wound around the tops is a bit thick - probably will buy thinner wire in due course.
As a long row of fencing I think it will work - particularly as a background for photos. However I will have to keep the petrol strimmer away from it if I use it in the garden.
I made it in lengths of 150mm, made 8 of them at a time in PLA, and directly onto the bed.
I have added the STL file for it to the files section in case anyone else is interested.
My printer uses a flexible build plate which has a film glued to it. It is a replacement item. So to print the section of slate walling I used a new one. The PLA which I used for the slate walls adhered well to it, and came free when printed by bending the print plate - as the manufacturer intended. Those parts were made without a raft or brim.
However ABS is different - and mostly I use ABS. My first attempt at the floor in ABS, with no raft came off the bed quite quickly. The usual method of helping ABS to stick to a bed is to wash the bed with an "ABS slurry" - which means resolving ABS in acetone, and rubbing that on the bed. I have tried that with various thicknesses (more or less ABS in the mix), and a fairly weak mixture seems to work best.
Now we come to the next issue. The bed plate, treated with the slurry causes the ABS to stick so well that it is difficult to get the part off the bed without damaging the film on the plate, or the part just printed.
So I have gone back to using a raft. I lift the part 1mm above the bed, add supports, and slice with a raft. That allows me to get the undamaged part off the raft easily. It does mean I have to clean off the supports from the underside. I can then destroy the raft chiselling it off the plate without damaging the film on the plate. If I don't lift the part 1mm then the part sticks to the raft and is almost impossible to get off cleanly.
So perhaps this explains why I am using a raft. Perhaps my printer does compensate for a lack of a levelling mechanism by using rafts - but I am not so sure that it is actually correct now. I can print quite accurately over the whole bed area without a raft - but with PLA!
So the two sections of end walls and the floor assembled:
The top surfaces of the prints look good to me - with the plank joints clearly visible and evenly spaced. The one end which has planking on both sides has poorer quality on the inside - the face which the supports were attached to, but that is inside and I don't think it will be noticeable.
This is the issue:
You can see long lengths of filament running along the length of the planks which are not attached to anything.
I will explain it in the next post.
Now look at this shot.
It shows the first layer of the actual model. Can you see that the supports are now covered by the first layer, and that the lines of the supports are running in the same direction as the planks. It is printing the plank edges by going up and down - in the same direction as the supports.
So the issue is that when it is printing the planks the filament is falling into thin air between the supports. Hence the loose strands.
The solution - turn the model through 90 degrees so that the supports run at 90 degrees to the planks.
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