Designing For Laser Cutting

[Steph Dale]

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.

Cynric,

Same for me - couldn't have put it better myself really. The only difference is that in having spent time 'on my tools' and sitting all day at a PC, I like doing stuff by hand when I get home.

Watching this thread has got me thinking about how I could get a set of the late Maunsell stock built. I'll have to try and get some scraps of Rowmark to play with and see how it forms/bonds. And find out what thicknesses are available.

If you do buildings suitable for an MSWJR layout/Hampshire I know a chap who'd be very interested...

Steph

 

[28ten]

Rowmark bends nicely, I have .75 (the thinnest available) 1mm and 1.5mm I think 3mm is available as well. I am going to try and get some sample packs together in the New year but it has been crazy here this month.

 

[Dog Star]

It is a trip into the unknown for me as well

Here is a suggestion as to an end point, rather than the Restaurant at the end of the Galaxy. I have here, somewhere, a complete set of drawings for the station at West Wycombe, GW&GC Jt, circa 1904-6. Booking office, goods shed, lamp room, footbridge.... all bar the signal box ('cos the architects drawings for that were not kept at Paddington in the late 1960s). 7mm. Interested? I would be if you are.

reagrds, Graham

 

[Steph Dale]

Rowmark bends nicely, I have .75 (the thinnest available) 1mm and 1.5mm I think 3mm is available as well. I am going to try and get some sample packs together in the New year but it has been crazy here this month.

Need to think about that - Ideally I'd need 0.020" (o.5mm) and/or 0.010" (o.25mm) to use the Jenkinson technique as it stands, but there may well be a workable alternative - it's blindly obvious you can get better 'fit' of parts than I could...

Steph

 

[28ten]

Steph, I believe it is possible to laser the material used for stenciling (mylar?) and ABS is a possibility as you know plasticard melts, but with a quick pass it is possible to score plasticard and snap it but I have yet to try further experiments. Oh and I can cut stars on glitter paper

 

[28ten]

Here is a suggestion as to an end point, rather than the Restaurant at the end of the Galaxy. I have here, somewhere, a complete set of drawings for the station at West Wycombe, GW&GC Jt, circa 1904-6. Booking office, goods shed, lamp room, footbridge.... all bar the signal box ('cos the architects drawings for that were not kept at Paddington in the late 1960s). 7mm. Interested? I would be if you are.

reagrds, Graham

Yes but I do need to refine my methods first

 

[28ten]

Another test piece quick dash of Vallejo acrylics followed by mortar mix and dry brush - about 1 minutes work.
Im not sure this would work in 7mm (where I would favour mdf with a coat of Mr Surfacer and a dash of polyfiller) but its not too bad for 1/32 and 1/35

 

[Steve Cook]

Not bad
Can you get a similar effect if you peel the entire surface of an mdf test piece, then paint it? Going to need a lot more patience and time I'll admit, but worth a try....
Steve

 

[28ten]

Not bad
Can you get a similar effect if you peel the entire surface of an mdf test piece, then paint it? Going to need a lot more patience and time I'll admit, but worth a try....
Steve

It goes a bit furry this is actually cork sheet.

 

[Steve Cook]

It goes a bit furry this is actually cork sheet.

Furry is bad, well, for bricks anyway
The cork is perhaps a bit 'blobby' for want of a better phrase? Might look worse because its bigger than real life in the photo - it almost looks like it needs surfacer to smooth it out a touch...

Got to ask if its not too rude, how big is your reject development pile now

 

[28ten]

Reject pile is rather large now it doesnt look so blobby in real life, I will try and get a shot in daylight tomorrow. Ijust need to find a substrate that is a little less regular than mdf,

 

[28ten]

A slightly better shot of the cork in daylight- the colouring is a bit off though

 

[Dikitriki]

Use a yellow/brown/dark blue colourway, make the courses a little less regular, and I reckon it's spot on for dressed stone.

In fact, I can think of a layout where we it could be trialled.

Richard

 

[28ten]

Use a yellow/brown/dark blue colourway, make the courses a little less regular, and I reckon it's spot on for dressed stone.

In fact, I can think of a layout where we it could be trialled.

Richard

Good idea
If i get time this afternoon I am going to try a cardboard/mdf laminate the idea being to just cut the card for the brickwork

 

[28ten]

I hurt my back on xmas day so I havent been at the bench, but I have been at the computer In light of my experiments with the parcels office I think I can do better with the shed, so......... I have scrapped all the previous work and started again first steps being slots and tabs for a foundation which will also hold the ash pit


The book Colin recommended has been really helpful, so there should be some extra details going in

 

[Dog Star]

In light of my experiments with the parcels office I think I can do better with the shed, so......... I have scrapped all the previous work and started again first steps being slots and tabs for a foundation which will also hold the ash pit

I thought that the inner foundation layer for the office, with tabs to fit slots in walls, was a good idea so I am pleased to see that design feature is incorporated into the revised shed design (mk2?). A "ground" level datum around the outside and a "floor" level line around the inside might help us to see how the completed model is to fit into the landscape.

Ash pit inside a shed? Surely not.... given that boiler wash out would be done inside then any ash in the pit would get washed into the drains and possibly clog the grill in the side wall.

regards, Graham

 

[Dan Randall]

Ash pit inside a shed? Surely not.... given that boiler wash out would be done inside then any ash in the pit would get washed into the drains and possibly clog the grill in the side wall.

Perhaps "Inspection pit" was on Cynric's mind when he typed that?


Regards

Dan

 

[28ten]

My mistake it is an inspection pit I just read the word pit ! and this provides an interesting question what did the cast iron grating inside the pit look like?

This shows rail level, the base will sit 33.375mm (3ft6" scale) below ground level giving sufficient depth for the pit. The floor needs to slope towards the pit and according to my plan (GWR engine sheds London division p312) it is blue brick.

 

[28ten]

I realised that i need to 'lay some bricks' before doing anything else and this is how I do it. A really scruffy drawing in autocad, but you can see the yellow brick courses at the bottom and from this I can check and adjust any dimensions. the GWR are very specific about an English or Flemish bond wall being 1ft 1 1/2" thick they are working on a brick unit including mortar of 9"x4 1/2"x3" giving a brick size of 8 3/4" x 4 1/4" x 2 3/4" . The laser cuts down the center of this line so including the kerf it all works out quite nicely. Brickies would have avoided cutting bricks if at all possible so the reveal of 6'10" on the plan becomes 6'9" which works with the bond and an appropriate queen closer. There are other places where the contractors plan does not match photos so other adjustments are needed.

 

[Eastsidepilot]

[
The book Colin recommended has been really helpful, so there should be some extra details going in

Glad it's been of use Guv', I do have further reference books here which can probably expand on any details you may be dealing with, don't hesitate to ask mate
Excellent post by the way.

Col.