Designing For Laser Cutting

[28ten]

Guv,
Not wishing to sound pedantic but was the brick arch lintol over the door based on a prototype, usualy there are a couple of extra bricks on the top row creating staggered vertical joints. I have attached a page from a building construction book of mine showing what I mean.

Excellent work mate ATB, Col
P.S. I can see me commissioning the walls for a certain loco shed in the future

From the rather poor picture I have it seems correct. the building was erected between 1940 -43 and I guess it was pretty much thrown up, of course my interpretation of the picture could be all wrong I will double check, id rather rip it up now than when it is painted! Interesting book, whats it called?

Mike, i dont think i am ready for mass production yet it needs to be easier to assemble. Im half tempted to use 3.2 mdf, the only problem is that it is too thick to represent one brick in 1/32, but then 2mm is too thin I could possibly rebate the 3.2 and do a box joint along the courses which would be stronger and easier to build.

 

[Eastsidepilot]

Interesting book, whats it called?

The book is titled "Architectural Building Construction" Vol 1. It was published by the Cambridge Uni. Press in 1938 It has excellent detailed drawings of a brick cottage and garage folded up and tuck inside the cover, you could build an excellent scale model from them.
There are several books on building construction over the decades, if you can find one that was printed pre-war they are better for the older traditional methods of building, mine have all come via my Father and Grandfather's.
Longmans Building Craft is another good one to look out for.
The WMR mob have used these books for reference on buildings, invaluable

ATB, Col.

 

[28ten]

Thanks Col, a copy of the 1950 reprint has been purchased c/w the plans

 

[Eastsidepilot]

Thanks Col, a copy of the 1950 reprint has been purchased c/w the plans

Out of interest Guv, where did you source your copy?

Col

 

[28ten]

Alibris http://www.alibris.co.uk/ I could have taken a trip to Hay on Wye but postage at £2 is cheaper than petrol

 

[28ten]

Apart form going to see Santa today I spent some time looking at joints between walls. whilst the 45 deg chamfer worked I dont feel that it is sufficiently robust or accurate enough. So I have been experimenting with box joints - lots of box joints



this shows the best version, without glue of filler, i think it shows promise, it would also work for 7mm if I mill a rebate on each piece to get the scale width for a header.

 

[Steve Cook]

Wow
Thats very impressive Guv.
Getting closer then

 

[28ten]

Wow
Thats very impressive Guv.
Getting closer then

I think it is going in the right direction. im getting silly ideas about the interior now

 

[28ten]

This quick shot shows how it would work in 7mm with a rebate taking the 3.2 mm mdf sheet down to 2.64 which gives the correct header width for the box join. The downside is the extra machining and costs involved.
3.2 and 2mm mdf laminated, continently scale at a sniff over 9 inches and if a pocket was routed around the window reveal the the window mouldings and glazing could be trapped between the two sheets giving brick detail on both sides of a wall - ideal for engine sheds or signal boxes not that I am getting carried away with detail

 

[Ressaldar]

- ideal for engine sheds or signal boxes not that I am getting carried away with detail
View attachment 8224

of course not - but having gone this far...........................................why stop.

Great work Guv and at the end of the day, you are realy (re)-producing a true scale version of a brick wall, with the bricks properly bonded - a much better and stronger 'finish' than chamfered joints. As I said earlier, start thinking about packaging and marketing. We'll be seeing you on 'Dargon's Den' before long!

cheers

Mike

 

[28ten]

Mike, it is probably my restless mind but I always think there is a better solution, and I cant claim too much credit http://www.ndetail.de/modellbahn/de/eisenbahner-wohnhaus.html my time spent with the ipad isnt entirely wasted

 

[Ressaldar]

ah, but it's 1:45 so does not count! Shame that the English translation button did not work - but that's the europeans for you

Very good detail again - especially the windows and 'detail' sprue - might be worth considering just doing that aspect as a 'sideline' as it's those pieces that modellers need/want - as York Modelmaking & Kirtley laser bits.

cheers

Mike

 

[david bigcheeseplant]

I have used 1.5mm Rowmark that works out the correct 4 inch in 4mm scale and have made toothed corners, I will post some pics, although I think I favour going back and mitreing the corners.

David

 

[28ten]

I have used 1.5mm Rowmark that works out the correct 4 inch in 4mm scale and have made toothed corners, I will post some pics, although I think I favour going back and mitreing the corners.

David

I can see that boxjoints would be less practical with 1.5 rowmark, although I wouldnt have thought that mitres are that easy to make? I presume that the join is the outer part of a lamination?

 

[28ten]

Another evening and another test cut - plenty of rejects to practice painting!

Freshly cut parts, 33minutes to cut this lot

Lift the surrounding waste off .......



Assemble no glue needed at this point. the lower slots are for a base which can be seen in the shot above. the lower 3 courses are below ground level so the tab will not be visible. There is a plasticard window sill slotted in place. The box joins are a nice firm fit and need a little care assembling, but the walls are up in about 4 minutes and once a floor goes in the whole lot is ready for glueing.



Im about 80% happy with this, a little more refining is needed, whilst the box joint is stronger I want to revisit the mitre to see if I can improve on it

 

[Dog Star]

For me this thread is an adventure into the unknown with a good guide. Informative, entertaining and a "must read". I like the thinking of the tab base, design of the first order, makes a sturdy foundation upon which to locate the internal floor (planked of course, with cut nails, splikts and nails).

Now a question. MDF end grain (if there is such a thing with this board) is a very different texture compared with the smooth surface of the face.... how will the "open" surface affect the painting process and subsequent appearance?

thank you, Graham

 

[28ten]

For me this thread is an adventure into the unknown with a good guide. Informative, entertaining and a "must read". I like the thinking of the tab base, design of the first order, makes a sturdy foundation upon which to locate the internal floor (planked of course, with cut nails, splikts and nails).

Now a question. MDF end grain (if there is such a thing with this board) is a very different texture compared with the smooth surface of the face.... how will the "open" surface affect the painting process and subsequent appearance?

thank you, Graham

Fortunately the laser burning seals the end grain and with a good coat of primer it is not noticeable.
Im looking for a methodology and workflow that will be quick and efficient to both design and build and rather like etching you have to kiss a few frogs until you get a princess

 

[Old Buffer]

Fortunately the laser burning seals the end grain and with a good coat of primer it is not noticeable.
Im looking for a methodology and workflow that will be quick and efficient to both design and build and rather like etching you have to kiss a few frogs until you get a princess

Cynric,
Those look almost perfect, as Graham said it's a trip into the unknown for most of us, a bit like Star Trek really. It is interesting reading the thread and just goes to show how modern technology beats the old ways in some cases.
You can kiss the frogs, we would like the the princess.
Alan

 

[28ten]

Thanks to Col for putting me onto the book


Really useful and two nice plans



The cottage is ideal for a Home front military diorama I have planned

And I may have found a princess this morning




Lovely texture and slight irregularity

 

[28ten]

Cynric,
Those look almost perfect, as Graham said it's a trip into the unknown for most of us, a bit like Star Trek really. It is interesting reading the thread and just goes to show how modern technology beats the old ways in some cases.
You can kiss the frogs, we would like the the princess.
Alan

It is a trip into the unknown for me as well
I started work at Jaguar racing as a modelmaker back in the 80's and it was just the cusp between hand drafting and the CNC revolution, and as soon as I saw a CNC mill make a wheel I knew that was it.
imho any idiot can use a computer and Laser or CNC mill/Lathe, the skill is in having ideas, designs and then seeing solutions.