N Gauge Wagons - PXA / FEA-(BEFS) / KTA / KFA / Binliners

[Vonzack]

Hi Ben,

 

No I haven't got round to priming them yet, I'd like to be able to do them this week, but I might not get round to it until after TINGS.

 

Yeah agreed, the floor is too angular compared with the prototype. Now that I've got the bulk of it done and I know it prints OK, I'll polish it up a little.

 

The problem I continually hit is that Sketchup doesn't like to work with radii less than 0.5mm. To the extent that it just won't draw them. To do the rounded tanks, I had to scale up 100 times, draw the domes, then scale back. Even then, when I re-loaded the model for export, I found issues with the mesh at the ends of the tank which I had to correct by hand. It may well be easier to draw the models 100 times larger and then re-scale the exported mesh before submitting it to shapeways.

 

Cheers, Mark.

[Vonzack]

A sample of the KTA Floor with rounding.

 

 

Cheers, Mark.

 

 

Edited September 2, 2013 by Vonzack

[Wild Boar Fell]

Hi Ben,

 

No I haven't got round to priming them yet, I'd like to be able to do them this week, but I might not get round to it until after TINGS.

 

Yeah agreed, the floor is too angular compared with the prototype. Now that I've got the bulk of it done and I know it prints OK, I'll polish it up a little.

 

The problem I continually hit is that Sketchup doesn't like to work with radii less than 0.5mm. To the extent that it just won't draw them. To do the rounded tanks, I had to scale up 100 times, draw the domes, then scale back. Even then, when I re-loaded the model for export, I found issues with the mesh at the ends of the tank which I had to correct by hand. It may well be easier to draw the models 100 times larger and then re-scale the exported mesh before submitting it to shapeways.

 

Cheers, Mark.

Hi Mark,

Good work with the wagons,

I have the same problem when drawing my stuff regarding small details, so I use 100x scale for N and 10x scale for OO (except the Claughton which I think is 1000x OO). Also I would advise against scaling in sketch up, it just creates a mess of lines and gaps, I would do all scaling post drawing software such as NetFabb.

Hope this may be of use,

Regards,

Wild Boar Fell

[Revolution Ben]

Hi Mark,

 

That's really coming together now.  You may find you want to increase the radius of the cutouts a little further.  Finding photos of the insides of the pocket wagons seems tricky, but here is one that gives an idea:

 

 

One of the best places to photograph Freightliner stuff from high up is Southampton Maritime; searching flickr for that location gives this.  There may be more elsewhere on the web too.

 

http://www.flickr.com/photos/banburybob/5668616704/in/set-72157608114495102

 

HTH

 

cheers

 

Ben A.

[Glorious NSE]

I've some high-angle shots of them in this collection if it helps - one of 97768 is centred on an empty well:

http://ukrailwaypics.smugmug.com/UKRailRollingstock/K-Tops-codes/KTA-Pocket-Intermodal-wagons/

[Revolution Ben]

Hi Martyn,

 

That's a great shot and illustrates exactly the point I was trying to make!  Thanks for posting!

 

cheers

 

Ben A.

[Vonzack]

Hi Guys,

 

Here's the latest version of the KTA Wagon. I think I've got the framing at the wagon ends pretty close, but agree looking at the pictures that there's still some work to do on the pocket floor. Interesting how the framing cut outs increase in size as you move out from the centre of the wagon, that's what I'm looking at now.

 

 

Ben, Martyn, thanks for the info.

 

Cheers, Mark.

Edited September 4, 2013 by Vonzack

[Vonzack]

Hi,

 

OK, finished the work on the pocket floor. It's still not perfect, but a little closer to the images. The main problem is that I've used the wrong angles for the bracing (115 / 65, rather than 90 degrees). I will need to re-draw the entire floor to get it any closer. Hopefully I've managed to capture the size difference of the triangular openings of the floor.

 

 

 

Cheers, Mark.

Edited September 5, 2013 by Vonzack

[Revolution Ben]

Hi Mark,

 

It's your call, of course, but isn't one of the advantages of modern 3D techniques that the CAD drawings can be manipulated until they're right before and actual physical copies are made?

 

Given all the brilliant work you've put in so far, I suspect this would always niggle.... though to be fair I don't know enough about CAD drawing methods to know how involved changing those angles would be!

 

cheers

 

Ben A.

[Vonzack]

Hi Ben,

 

Indeed, I wouldn't be able to live with it, so I'll re-draw the floor in the next few days. I suspect it will be quite a challenge to lay out correctly with all the different size openings in the floor, so I'll draft it on it's own and then join them together.

 

Cheers, Mark.

[Revolution Mike]

Hi Mark

 

I try to draw as much as possible in distinct modular units so I can a) re-use them and perhaps more importantly b) when I make a mistake it is easier to rectify on one small-ish part than having to re-design large chunks of the model!

 

Anyway hope the floor re-design isnn't too painful!

 

Cheers, Mike

[Revolution Ben]

Hi Mark

 

I think you're doing the right thing.  As Mike says, I hope the re-drawing isn't too onerous!

 

cheers

 

Ben A.

[Vonzack]

Hi,

 

Well, I've been playing around trying to get the KTA Pocket Floor better and I think I've cracked it. It looks very close to the photo's in the thread to me, but would value second opinions.

 

 

 

 

I try to use components as much as possible, but as you can see from the designs above, the floor has various different sized openings (I guess to lighten the structure without losing any integrity). This is the bit that proved difficult as to get the openings looking similar to the prototype needed allot of trial and error.

 

Cheers, Mark.

[Revolution Mike]

Hi Mark

 

Looks good to me. I've just noticed on Martyn's picture there are some beams underneath the cylinder end (and presumably at the opposite end) ie it has the cylinders, cylinder framework, floor with cutouts, supporting beams then bogies - see here: http://ukrailwaypics.smugmug.com/UKRailRollingstock/K-Tops-codes/KTA-Pocket-Intermodal-wagons/i-3RN2rxJ/A

 

They are basically similar to the support beams you have under the well floor.  You might not be able to fit them in if they interfere with the bogie.

 

Cheers, Mike

[Revolution Ben]

Hi Mark

 

I've managed to dig out an old disc and found some of the original research material for the KQA which I did a few years ago.  Here are some (admittedly low res) drawings showing the basic profile of the lower deck.  These were on a former incarnation of the Tiphook or GE website IIRC.  I think you're pretty close now; the main thing to notice is that the inner triangular holes are considerably smaller than the outers.

 

 

HTH

 

cheers

 

Ben A.

[Vonzack]

Hi,

 

Here's a picture of the undeside of the KTA with the revised floor. I'm still a little way away from Ben's drawings, but I think it's close enough for another trial print fom shapeways.

 

Mike, I can see some of the support structure you're talking about, but I haven't seen any pics which show what's under there in any kind of detail, so it would be a bit of a guess, unless somebody does have a good shot. As you can see though, there's plenty of room (around 2.5mm) of space to add some detail in there, so if I can get an idea of what lurks under there, I can certainly try to add it.

 

 

Cheers, Mark.

 

 

[Revolution Mike]

Hi Mark

 

I've just noticed this shot on Martyn's site: http://ukrailwaypics.smugmug.com/UKRailRollingstock/K-Tops-codes/KTA-Pocket-Intermodal-wagons/i-BrPm7Mp

 

It looks like an I-beam type construction that follows the struts where the cut outs are.

 

This pic might help as well: http://ukrailwaypics.smugmug.com/UKRailRollingstock/K-Tops-codes/KTA-Pocket-Intermodal-wagons/i-CSD5jRQ

 

Cheers, Mike

[bmthtrains - David]

Looking very impressive, I really can't wait to see the print on this!

 

David

[Vonzack]

Hi Mark

 

I've just noticed this shot on Martyn's site: http://ukrailwaypics.smugmug.com/UKRailRollingstock/K-Tops-codes/KTA-Pocket-Intermodal-wagons/i-BrPm7Mp

 

It looks like an I-beam type construction that follows the struts where the cut outs are.

 

This pic might help as well: http://ukrailwaypics.smugmug.com/UKRailRollingstock/K-Tops-codes/KTA-Pocket-Intermodal-wagons/i-CSD5jRQ

 

Cheers, Mike

 

Hi Mike,

 

I've been looking at the pics you linked. I can see the detail under the ends of the wagon clearer now, just wondering what to do. If I draw in the beams and effectively another section of floor with cut outs, it will increase the cost of the model and I'm not sure how good it will end up looking because of the material tolerances, it would end up being a very fat 'I' beam. I could increase the depth of the floor to around that of the height of the 'I' beam, as it would close any gap between the top of the bogie and the chasis, but again this will increase the cost. I've decided at the moment to leave it as is, I'll wait for the test print and if the gap is obvious between the bogies and the end floor, then I can have another look.

 

One thing I did pick up on was the floor opening around the bogie mount, which on my drawing was too large, so I've reduced it a little. I've included some pics of the original to show the area I've changed.

 

 

 

Cheers, Mark.

[Steven B]

Would it be worth putting the airbrake gear (reservoir tanks, brake cylinders etc) on a seperate sprue? Perhaps part of the structure you're using to re-inforce the well for the 3d print?

 

Might make it easier to paint - getting a paint-brush under the lower side of the reservoir tanks looks a little tricky,

 

Happy modelling.

 

Steven B.

[Revolution Mike]

Hi Mark

 

I fear you have come up against one of the problems I struggle with! I wouldn't worry too much about the material cost - the marginal difference shouldn't make that much difference.  On having to design to suit the material/process tolerances rather than to scale - that is a really difficult one. I think that we all accept compromises where they are necessary. 

 

Cheers, Mike

[Vonzack]

Hi,

 

I managed to put a quick dusting of primer on the IOA and old KTA Wagon yesterday. On the whole I'm happy with the results as spraying isn't really on my modelling CV (yet).

 

 

After being primed the model seems to show allot of Horizontal banding, but this can only really be made out if you are close to the model (<10cm) and I guess will lessen when painted properly. The primer has picked out the end detail and the side ribbing quite well.

 

 

Although this is the first test print of the KTA, I though I'd practice priming it before starting on the latest one which arrived a few days ago. Again, the primer has picked out the detail really well.

 

 

 

 

These are a few pics of the final version of the KTA. Compared with the Dapol FEA-B, the buffer height is OK and as the container is only 8' 6", when in the pocket its about 2mm lower than the one on the FEA-B which would make the pocket depth about right for a 9' 6" Hi Cube.

 

I'm happy enough with both of these now, so they are available from Shapeways.

 

Cheers, Mark.

[bmthtrains - David]

Really impressive when printed!

 

What's next on your list?

 

David

[Revolution Ben]

Hi Mark

 

That looks really nice.  I look forward to seeing it finished off!

 

Great work.

 

cheers

 

Ben A.

[Vonzack]

Really impressive when printed!

 

What's next on your list?

 

David

 

Hi David,

 

I've a part done FEA-B which just needs tanks and bogie mounts, but I'm quite taken by the look of the new EcoFret's so I hope to be able to progress both in the next few weeks.

 

Cheers, Mark.