Irish O Gauge Coaches (Sort Of)

[DJ Dangerous]

For anybody interested in Irish O Gauge, Heljan are releasing BR Mk2A coaches:

https://www.hattons.co.uk/newsdetail.aspx?id=612

Seeing the skill of some modellers on here, they could be nice for conversion.

[WRENNEIRE]

Good spot DJ, but £200 a pop for a 6 or 7 car rake, janey mack!

[DJ Dangerous]

Yeah, a GAA Special would set you back a good two and a half grand without a loco!

[David Holman]

Same problem with Hattons A3 and A4. £750 is a decent price for RTR Pacific in 0 gauge, but eight coaches for it to haul will cost a couple of grand. That said, if you have ever made a coach, either kit or scratch, then you know how much work is involved, so £200 for a brass coach is actually good value.

[DJ Dangerous]

They're now priced around £240 STG, so even more than anticipated!

Moving on from this topic a little, and maybe an insider like @BosKonay, @Warbonnet, @WRENNEIRE or @Garfield could offer some insight, but how does the whole scanning and CAD process translate for different scales?

For example, I assume that MM still have the scanning and CAD work for their OO gauge locos, so would that same groundwork be appropriate for O gauge locos?

LIkewise how would IRM's A Class scanning and CAD apply to an O Gauge loco?

Does it all have to be done again, or is it all the same?

I'm not really talking about the financial viability, no matter how cool the locos would be in O gauge, more the technical side of the pre-tooling work.

I mean, the locos would probably have to sell at €500 a pop, so the market would be limited, I know.

[David Holman]

I know a couple of people who do this stuff and seem to remember that the cost of starting a 3D print is around £800 - £1200, though I guess it very much depends on how much you want to charge per hour.

 What I know about CAD can be written on the back of a postage stamp with room to spare, but would think that once a file has been created, then rescaling is a simple matter. As to the cost of actually producing either an etched kit or a 3D, the former is down to the cost of the metal and the etching process and I believe is not that high, probably under £100 per unit. As to 3D printing, much will depend on the equipment used, though time is also a factor.

 It would certainly be interesting to know what it would cost Murphy's to turn out say a B class in 7mm scale, or N gauge for that matter. However, suspect that while an injection moulded/3D printed model would cost very little, a working chassis is another matter entirely.

 For example, a 7mm scale rtr wagon costs about £40. Scratch build it and wheels cost £10, couplings a fiver, buffers the same or double that, depending on type and brake gear another  five to ten as well. Hence the big bit, then body is worth three fifths of five eighths of not very much!

 On another front, was doing a buildings demo at a show and a gent asked me if I did commissions. I told him no, but when I mentioned the locoshed on my display had taken me somewhere in the region of 80 to 100 hours, it didn't take him long to work out how much it would cost - even at minimum wage. Ten quids worth of materials, but who knows how much in terms of paid time.

 Quite how Dapol can churn out 7mm rtr locos at under £200 is beyond me, but guess a J26 or similar will remain the stuff of dreams for a while yet.

[KMCE]

13 minutes ago, David Holman said:

once a file has been created, then rescaling is a simple matte

Correct - scaling is a very simple matter in AutoCad.  Generating a file for printing would take slightly longer.  Printhing time would be longer, but not excessively when compared with scratchbuilding.

14 minutes ago, David Holman said:

the cost of the metal and the etching process

As per my workbench post, I commissioned an etch for the DWWR ballast wagons which cost for photo etch, metal (330 x 230mm), and shipping c. € 75 (4 wagons).  A reprint of the same etch was € 27.  So 8 wagons cost € 102.  Add to that wheels, axle boxes, springs, and buffers to complete.  Still not a bad price €12.75 per wagon etch?

Ken

[WRENNEIRE]

8 hours ago, DJ Dangerous said:

They're now priced around £240 STG, so even more than anticipated!

Moving on from this topic a little, and maybe an insider like @BosKonay, @Warbonnet, @WRENNEIRE or @Garfield could offer some insight, but how does the whole scanning and CAD process translate for different scales?

For example, I assume that MM still have the scanning and CAD work for their OO gauge locos, so would that same groundwork be appropriate for O gauge locos?

LIkewise how would IRM's A Class scanning and CAD apply to an O Gauge loco?

Does it all have to be done again, or is it all the same?

I'm not really talking about the financial viability, no matter how cool the locos would be in O gauge, more the technical side of the pre-tooling work.

I mean, the locos would probably have to sell at €500 a pop, so the market would be limited, I know.

I still have me slide rule, I dont think I was in school the day they did Auto Cad
But I passed Latin......

[murphaph]

I guess there's a little bit more to it than just scaling up the 00 tooling cad work as presumably some of the smallest parts are slightly overscale in 00 due to manufacturing limitations whereas they could be scale in 0 gauge. But I could be talking nonsense.

[Noel]

On 27/11/2019 at 6:34 PM, DJ Dangerous said:

For anybody interested in Irish O Gauge, Heljan are releasing BR Mk2A coaches:

https://www.hattons.co.uk/newsdetail.aspx?id=612

Seeing the skill of some modellers on here, they could be nice for conversion.

Might be an easy respray depending on how easy it is to temporarily remove the glazing. Masking those windows effectively is nigh impossible. Might be of interest to some at WMRC for their fantastic vast O gauge layout, but they still don’t yet have any Irish O gauge diesel locos. 

Edited February 27, 2021 by Noel

[DJ Dangerous]

1 hour ago, murphaph said:

I guess there's a little bit more to it than just scaling up the 00 tooling cad work as presumably some of the smallest parts are slightly overscale in 00 due to manufacturing limitations whereas they could be scale in 0 gauge. But I could be talking nonsense.

That's where it gets interesting, and what I was wondering about. Surely, for the different scales, certain items woulf either have to be omitted, modified or re-scaled, as there's always going to be a trade-off between realism and practicality. Is there a raw CAD base which is 100% accurate, which in turn is modified to suit each scale, maybe?

16 minutes ago, Noel said:

Might be an easy respray depending on how easy it is to temporarily remove the glazing. Masking those windows effectively is nigh impossible. Might be of interest to some at WMRC for their fantastic vast O gauge layout, but they still don’t yet have any Irish O gauge diesel locos. 

The interiors would be wrong on the O Gauge coaches, though, no? And, weren't there only six Mk2A's? So we'd still need some Mk2C's and Mk2B restaurants to complete the rake, plus a box-shouldered modified Dutch van?

And an infinite bank account.

[jhb171achill]

In all reality, perhaps as involved as scratch building, and massively more expensive?

[DJ Dangerous]

1 minute ago, jhb171achill said:

In all reality, perhaps as involved as scratch building, and massively more expensive?

£240 per coach is the guts of €280 in real money, plus time, effort and paint, so about six times more expensive than an MM ST Mk2D.

Still, be very very cool to see a rake of them one day.

[Brack]

On 27/2/2021 at 6:23 AM, murphaph said:

I guess there's a little bit more to it than just scaling up the 00 tooling cad work as presumably some of the smallest parts are slightly overscale in 00 due to manufacturing limitations whereas they could be scale in 0 gauge. But I could be talking nonsense.

You know, I've had a lot of people (who don't do CAD or 3D printing) that rescaling is easy, just a couple of clicks. Yes and no.

As someone who has produced the same loco in CAD for 3D printing in 1/43, then 1/24, 1/17 and 1/32 scale, it certainly isn't just a matter of rescaling!

The loco in question is the smallest Bagnall standard saddle tank (4"x7" Sipat class).

1/43 (this is mine - the others below are customers models)

1/24

1/17

 

If the 2 scales are fairly close you can just rescale and get away with it, but for a bigger jump (e.g 4mm to 7mm, or 4mm to 2mm) the thicknesses, detail levels and sizes of everything are pretty different. The easy bits to rescale are fortunately the hardest to draw in the first place (chimneys, domes, steam manifolds/ boiler fittings). Provided you drew them at the limit of what is possible in the smaller scale, you can enlarge them and they'll work fine. However bodywork thicknesses and strengths vary enormously, and the different scales of loco had to be adapted to their various mechanisms, so effectively large bits were redrawn from scratch. All in all I reckon it took 50-60% of the time it took to draw the thing in 1/43 to get it rescaled to 1/24, both redrawing bits and adding extra details that I couldnt have done in the smaller scale. If you drew the first CAD in a larger scale you'd run into problems as none of your fine detail parts would be viable when reduced as theyd be too weak, too small and likely beyond the capabilities of the machine, assuming you worked to its capabilities in the first place.

I mean, you can just select it all and use the rescale command and it'll work, but it won't get you a good result (in my opinion).

Obviously a coach is a slightly different matter, but I would hope they would use the same idea/process of re-evaluating which detail can/should be included and redrawing things to the best fit for fidelity, robustness and machine capabilities.

Edited March 1, 2021 by Brack

[Warbonnet]

On 26/2/2021 at 3:54 PM, DJ Dangerous said:

They're now priced around £240 STG, so even more than anticipated!

Moving on from this topic a little, and maybe an insider like @BosKonay, @Warbonnet, @WRENNEIRE or @Garfield could offer some insight, but how does the whole scanning and CAD process translate for different scales?

For example, I assume that MM still have the scanning and CAD work for their OO gauge locos, so would that same groundwork be appropriate for O gauge locos?

LIkewise how would IRM's A Class scanning and CAD apply to an O Gauge loco?

Does it all have to be done again, or is it all the same?

I'm not really talking about the financial viability, no matter how cool the locos would be in O gauge, more the technical side of the pre-tooling work.

I mean, the locos would probably have to sell at €500 a pop, so the market would be limited, I know.

Any scan is delivered in full 1:1 scale.

Mind you only some things are scanned, and even then it's not something importable into CAD. It's merely used as a reference point in the design process.