Mickoo's BR modelling

[mickoo]

Not a lot to report this week, since disabling myself last week it's been a week of sitting watching the telly and poking around on the web here and there, today being the first day where I can effectively type and just manage some CAD work.

So I finally finished the 08 door stampings, the art work itself isn't that hard to accomplish, it's getting it to align with what's already there, virtually no two hinges or latches are in the same orientation, unlike the real loco, so each has to be measured on the model and then that transferred to the CAD art work. It'll go much more swimmingly tomorrow when I start some work of my own, no idea what yet, might be some bogie sides or a cab, what ever anorak grabs me first I suppose LOL.



I think I can shuffle the doors a round a little to get a better fit, because of the different combinations of compressor or exhauster you end up with more doors than you need, I'd easily get four sets to an A5 sheet if it were just for one set up, but I'm trying to get all variants onto one sheet to allow for more flexibility and not having to make three or four different sheets up.

 

[Scale7JB]

Hope all those doors are going to open to show a nice engine casting inside ?!

JB.

 

[mickoo]

Hope all those doors are going to open to show a nice engine casting inside ?!

JB.

Gads!, afraid not, I did think about it for a while but then there'd be no space for weight and a motor, it's a consideration for the second one mind, I have to come up with something to keep up with you and Colin on the detail stakes LOL.

The above are not the actual door, the doors are supplied in the kit but they are plain flat ones and I want stamped ones so I've made the stamped part as an extra layer to affix to the existing doors, mind if they are opened I'll have to make recesses inside to replicate the stamped part and hinging them will probably send me insane, let alone working catches.

Kindest

 

[mickoo]

Slight change of tack, progress so far on a pair of etched class 40 bogies, hopefully get the buffer beam and transverse beams sorted tomorrow as well as some fiddly bits like steps, angled brackets and mud guards etc, then onto the sub chassis for the wheels with CSB in mind.

It should all fit on an A5 sheet which is the plan!



Bahh just noted some half etch rivets not on there and some holes for pipework not added. must check more photos before signing off artwork!

 

[mickoo]

Onward and now what I hope is the complete set of 08 door stampings for the MMP kit and this is about as tight a squeeze I can realistically get.

I have only one concern and that's the half etch layer, now I get the principle and have followed as I think right, yet when I compare with other advice elsewhere my half etch layer looks nothing like there's, my understanding is that the red layer only has the half etch parts on it, when combined they look right but separate it doesn't look quite right somehow.

Base layer with full etch, I have a niggle that I might need to add the tabs in black on here too?


Red half etch layer, awfully sparse which leads me to think its not right.


Combined, all looks ok like this I think, and yes, I've also just noticed one of the half etches didn't flood fill


Right back to the Class 40 bogies now.

 

[BrushType4]

Mick,

Ŵhat software are you using to draw these?

 

[mickoo]

Mick,

Ŵhat software are you using to draw these?

Autocad 2008

 

[BrushType4]

What file format is required to get etched? I'm asking as I've for MS Visio and wondering if I could use that?

 

[tomstaf]

Slight change of tack, progress so far on a pair of etched class 40 bogies, hopefully get the buffer beam and transverse beams sorted tomorrow as well as some fiddly bits like steps, angled brackets and mud guards etc, then onto the sub chassis for the wheels with CSB in mind.

It should all fit on an A5 sheet which is the plan!

View attachment 19378

Bahh just noted some half etch rivets not on there and some holes for pipework not added. must check more photos before signing off artwork!

Hi Mick,

Good start. Are you planning on embossing each of those rivets individually?

Also you may want to consider including half etched locating recesses. That will make construction much easier for you. For example, the small section of L bracket that joins the sides to the buffer beam.

Cheers

Tom

 

[JimG]

Red half etch layer, awfully sparse which leads me to think its not right.

Mick,

I think there is a problem with your red layer. Here are pics of part of my etches - the red and the blue layers.






You will note that the blue, tab layer is completely filled including the tabs. Red is the half etch layer. I filled an ~A4
with ten of these for PPD to etch.

Jim.

 

[mickoo]

Hi Mick,

Good start. Are you planning on embossing each of those rivets individually?

Also you may want to consider including half etched locating recesses. That will make construction much easier for you. For example, the small section of L bracket that joins the sides to the buffer beam.

Cheers

Tom

Tom yes, that's why they are half etch holes, its not so many....honest LOL

I'm working on location tabs and the such like, the buffer beam is two laminates with a slot for the side frame to locate into, I could add the half etch for the angled brackets you mention but that'd mean etch on the other side of the half etchs for the rivets, I'm struggling with just one layer ATM LOL.

Kindest

 

[mickoo]

Jim,

Thanks for that, I kind of get where your coming from, but PPD don't show that approach on their web site, they show the red layer as the bits you want to etch away, your red layer shows the bits you want to retain and looks a lot more difficult to make

 

[mickoo]

What file format is required to get etched? I'm asking as I've for MS Visio and wondering if I could use that?

Phil,

Look here for what formats PPD support

http://www.ppdltd.com/web_site_3/DG_comp_gen.html

HTH

 

[JimG]

Thanks for that, I kind of get where your coming from, but PPD don't show that approach on their web site, they show the red layer as the bits you want to etch away, your red layer shows the bits you want to retain and looks a lot more difficult to make

Mick,

I couldn't get on with the instructions on the PPD site and I dug up instructions which I could follow on the Australian Hollywood Foundry web site - on this page, part way down.

http://www.hollywoodfoundry.com/HowToPapers.shtm

I had no problems with these files with PPD. I also suspect that they accept a wide range of files and formats and make them work on their system. I think they actually offer to do a fair bit of sorting out for you if you get into problems. I found I got on with the Hollywood Foundry method since the red layer was the uppermost layer in the half etch process, with all the fold lines shown, and all the cutout parts. The blue, bottom layer showed the tabs. I think you would have difficulty shown half relief lines and folds on the top layer otherwise.

The Hollywood Foundry papers also give very good allowance figures for undercuts, etc.

Jim.

 

[mickoo]

Jim,

Yes I'd see the HF pdfs and that was what was throwing me as they were making etching masters like you are, yet PPD show a inverse method, I think your method and HF produce what is the final style ready for printing, the PPD format must require some after work to get it into the format ready for printing. I think the nearer one can get to the final print PPD requires the cheaper your tool work should be.

I'm half way through the 08 doors and copy / pasting between layers in Autocad is not as intuitive as it could be! If it were StudioMax then what's taken me two days would have been done in 20mins LOL

Now I have to work out how to write white lettering on a red layer, or more correctly see through lettering with a red outline so I can flood fill around it....does it ever end

I'll whizz a picture up the 08 doors in the new format once they are done.

 

[JimG]

Now I have to work out how to write white lettering on a red layer, or more correctly see through lettering with a red outline so I can flood fill around it....does it ever end .

Mick,

I remember that taking me a while to work out. I'm not exactly sure I can remember exactly what I did, but I think I used CorelDraw to generate the text, then, using vectors, exported a DXF file to import into the CAD drawing. As far as I remember, all the Corel text was good for resisting flood filling, with no "holes" in the vectors. I didn't worry too much about font sizes in Corel since I could re-size in Drawsight - which I was using at the time - and I find it flood fills easier than Acad LT. I also got into the habit of drawing everything using polylines, or using Pedit to make polylines, for use in flood filling.

Jim.

 

[mickoo]

Jim,

And I thought you were going to sally forth with a simple solution! For such a powerful and complex program it seems to miss out on some bleedin obvious fundamentals, I mean, why would anyone want to have a font colour that'd be different to the layer colour, I mean C'mon, sheesh! LOL

Polylines, yeah had that pain all day yesterday, I tried to join them and got no where, a quick trip around Google land provided the answer whereby you only have to make one a polyline and then you can join the rest to it and they take that attribute, only thing you cannot join are ellipses, ended up doing them long hand with three arcs, they're not a perfect curve but once etched and at that size it'd be impossible to notice.

Kindest

 

[tomstaf]

Tom yes, that's why they are half etch holes, its not so many....honest LOL

I'm working on location tabs and the such like, the buffer beam is two laminates with a slot for the side frame to locate into, I could add the half etch for the angled brackets you mention but that'd mean etch on the other side of the half etchs for the rivets, I'm struggling with just one layer ATM LOL.

Kindest

Wow, that's a lot of work. Etching them so they protrude is pretty effective.

Btw, I've never drawn the front and back in 2 lawyers. Just do it all on one with red and blue and they didn't say anything but then again I only had 2 rear half etches. I'd drop them an email to ask if they're ok with it all on one lawyer as it'll be quicker and easier for you to draw up.

Cheers

Tom

 

[mickoo]

Tom,

It's only about 100 per side LOL, half etch would be good but that will make the whole side thinner and less structural strength, it's an option for some parts but I don't think it's an option for the whole side of the frame.

I've saved the original artwork for the 08 so will send both. Layers are not a problem and I'm sure they are well versed in adapting peoples art work, I was/am just trying to make it as easy as I can for them and in the process, learn to do it the right way.

 

[mickoo]

Right back to the Class 40 bogie, much as I hoped for, both are not going to fit on an A5 sheet and once that was realised I worked out what Tom was on about with minimum sizes etc, getting both bogies on one sheet will make the sheet too large for effective postage so it'll have to be one bogie per sheet. Which with hindsight...or is it foresight as I've thought about it before Capt 'cock up' and his pals knock on the door? Only getting one bogie per sheet will mean that the initial cost will be lower and if there are any mistakes less material is wasted and only one bogie needs adjusting.

The real pain is all those mud guards, they eat up so much space and I need to try and re-arrange them better to save space, further, how wide do they need be, obviously to cover the wheels but S7 width or wider to cover O/FS etc, opted S7 initially as thats what I'm modelling but it is a consideration for the future as is side play in S7.

Side play on 1:1 is 1/16th" on the front and rear drivers and 1/2" on the intermediate...no wonder they suffered from cracked frames, having no secondary suspension didn't help as well and there is no bogie tilt facility due to the way the body is supported on ring segments, all hogging and sagging is taken up on the axle springs.

I'd like to replicate that lack of bogie tilt but the track work had better follow real practice then , I'll aim for a soft CSB deviation of 1mm which should cope with most track. It was joked on the LMR in the early 60's that any track irregularities would soon be steam rolled flat by passing EE type 4s, I can see why now LOL.

Haven't yet worked out how to swing the pony, probably not with slides (head can't cope with that math right now LOL) but with a long narrow beam whose fulcrum is back behind the first driven wheel and side control will be essential to keep the nose going where you want it and most of all, prevent shorts on sharp radii. I will also have to watch the upward deflection to make sure it doesn't short out on the drag box plate work, so it'll need some sort of CSB springing in there as well. Actually a single CSB down the centre line would allow side play control as well as vertical play but it wont control the racking of the axle within the bogie so two CSBs with a free floating bogie and no swing arm might work.

I still need to add more drag beam steel work along with side beam supports to affix to the inner chassis. Tail beam needs adding as well as a ton of minutia and tabs.
Also need to work out the minimum space one can have between parts or thickness of supporting etch around each part but it is getting there, I've keep my original style which follows PPD advice on their 'how to do it' pages but will take their guidance on what ever they say when I send a draft over.



Right time for some coffee and hot cross buns