Jump to content
 

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


Recommended Posts

Hi,

Inspired by some of the great modelling work on here, I've decided to knock together some wagons in N Scale, starting with a KTA Pocket Wagon. At the moment, this is just a design and I'm waiting for the test print to arrive from shapeways.

Here are some pics:

post-11575-0-17327800-1376399291_thumb.jpg

post-11575-0-14312800-1376399289_thumb.jpg

As I've dabbled before with some 3D Prints, I've added some strenghtening bars to the wagon pocket that will hopefully keep everything square and in place while the FUD cures. As for bogies, I'm intending to 3D print them as well from BSF along with a NEM Pocket for couplings.

I believe this is also quite similar to a KQA, the major diference being a rounded step down to the bottom of the wagon rather than a 45deg angle. But then I've seen KTA's with both rounded and angled steps, so I'm sketchy on this.

Feel free to comment.

Cheers, Mark.

Edited by Vonzack
  • Like 2
Link to post
Share on other sites

  • RMweb Gold

 

Hello Mark,

 

Nice job so far! AFAIK as Martyn says above the KTAs were all recoded from KQAs and I'm not aware of any with an angled bogie fairing, though could of course be wrong.

 

The Y25 bogies for these are available as one-piece plastic mouldings from the NGS and ATM with NEM pockets, though the low track force IOA bogies are not available as spares, even though they've been moulded by Farish for their Freightliner hoppers. I mention this because I'm not yet aware of any long term running of pin point axles in printed polymer bogies, and therefore not sure how long lasting they'd be.

 

The KQA/KTA and IOA have both been produced by Dapol in 4mm and may well be candidates for scaling down.

 

Another useful flat wagon would be the KFA ( either Rautaruukki or Standard Wagon versions) which are used by Freightliner, in bin liner traffic and for MOD traffic. The problem with this one might be weight - you'd probably need to design in cavities for liquid lead or similar, or maybe have it printed in metal. (Is that possible?)

 

If you're looking at a box wagon the ex-rail track JNAs might be good - again injection moulded bogies already available for both types and neither likely to be on a manufacturer's radar just yet!

 

Cheers

 

Ben A.

Link to post
Share on other sites

Hi,

 

Doh, both rejected by Shapeways this morning with a couple of wall thickness errors, corrected now, but will have to sort out another order.

 

Thanks for the comments guys, will definately go for the ATM Fabricated Y25C bogies for the KTA as I kind of prefer NEM Pockets and Dapol dummy knuckles for my stock these days.

 

@Ben A, yeah I think you're right about that, checking images on the web, they all looked to have rounded bogie fairing's so I've changed the design a little. I've also created a set of bogies in WSF using Parkside Dundas top hat bearings and although my original dimensions were a bit oversized, they still run well, so I would imaging the same method could be used to create some bogies for the IOA.

 

post-11575-0-51915500-1376481787_thumb.jpg

 

Cheers, Mark.

Link to post
Share on other sites

  • RMweb Gold

 

Hi Mark,

 

Bernard is endeavouring to get himself sorted out following his move. As has been said the NGS and I think Osborne's Models may have them in stock.

 

With the KTA you've picked up on the distinctive twin air tanks at one end but because they are so visible on the upper surface you may wish to give the ends of each tank a more parabolic profile...

 

Cheers

 

Ben A.

Link to post
Share on other sites

Hi,

 

@Porkie, I'm pretty sure they are used for transporting Ballast or other aggregates for the track bed.

 

@Ben A, the parabolic ends are a tricky one with SketchUp, as it can't draw a curve with a radius lower than 0.5mm, maybe I could scale the drawing up, draw it and then reduce it back. Also the brake cylinders have a hexagonal collar and a cone shaped end. Today's project :locomotive:

 

Cheers, Mark.

Link to post
Share on other sites

  • RMweb Gold

Hi Mark,

 

Yes, good spot with the brake cylinders though the edge is octagonal, not hexagonal, see here: http://ukrailwaypics.smugmug.com/UKRailRollingstock/K-Tops-codes/KTA-Pocket-Intermodal-wagons#!/i-5gtrDqT/A

 

Your progress is really good on this and I'm looking forward to seeing how your prints come out!

 

cheers

 

Ben A.

Link to post
Share on other sites

The Y25 bogies for these are available as one-piece plastic mouldings from the NGS and ATM with NEM pockets, though the low track force IOA bogies are not available as spares, even though they've been moulded by Farish for their Freightliner hoppers. I mention this because I'm not yet aware of any long term running of pin point axles in printed polymer bogies, and therefore not sure how long lasting they'd be.

 

Another useful flat wagon would be the KFA ( either Rautaruukki or Standard Wagon versions) which are used by Freightliner, in bin liner traffic and for MOD traffic. The problem with this one might be weight - you'd probably need to design in cavities for liquid lead or similar, or maybe have it printed in metal. (Is that possible?)

 

With FUD the answer is 'not very long'. With WSF so far so good. It's not really a big problem in either case as you can easily include holes for top hat bearings. The big problem with the bogies is the 15mm long axles + the wall thickness constraints. You end up with rather fat bogies (even fatter than the usually overwide N ones). 2mmSA axles work great though as they are about 2.5mm shorter.

 

You can print in metal but the price is high, precision is a little low and the detail lacking somewhat which IMHO makes it less useful for model making. You can also use 3D prints to cast investment moulds into aluminium and you can directly 3D print moulds for casting white metal, pewter and friends including casting around a metal strengthener. Shapeways may not be suitable for anything but the lower temperature metals as WSF melts a bit too easily but ABS prints should be fine. The common sense things also apply - the tool should be within a metal box or similar so that if it cracks nothing bad occurs.

 

With FUD you can also leave holes for threading strengthening metal rod through. It's a bit of a fiddle to thread but it can strengthen the item against warping quite a bit.

 

Given you don't need that much weight and you want it low my first thought would be to instead whitemetal cast the bogie mount and pins and if need be cast some blocks to fit within the bogie space out of sight. If the weight is over the bogies or better yet actually carried directly on the bogie frame you shouldn't need much to get it to ride well.

 

Alan

Link to post
Share on other sites

For that tank end, try drawing a closed arc and then use the follow me tool to sweep it around the circumference of the cylinder.

 

For the life of me, I can't get this to work. I'm pretty sure it's down to the scale. If I scale up, the method works fine, but when you scale back down, everything disappears again. Very confused :jester:

 

In the end I created the mesh by hand, but I don't fancy doing that each time.

Link to post
Share on other sites

Hi,

 

Here's are the latest mods to the KTA - rounded ends on the air reservoirs (both ends), changed the buffer profile and a corrected design for the brake cylinders.

 

post-11575-0-06947600-1376585409_thumb.jpg

 

post-11575-0-27374300-1376585410_thumb.jpg

 

Thanks for you help guys, much appreciated.

 

Cheers, Mark.

Edited by Vonzack
Link to post
Share on other sites

Hi Alan,

 

 

With FUD you can also leave holes for threading strengthening metal rod through. It's a bit of a fiddle to thread but it can strengthen the item against warping quite a bit.

 

That's an excellent idea.

 

Given you don't need that much weight and you want it low my first thought would be to instead whitemetal cast the bogie mount and pins and if need be cast some blocks to fit within the bogie space out of sight. If the weight is over the bogies or better yet actually carried directly on the bogie frame you shouldn't need much to get it to ride well.

 

Hadn't even thought about that, too focused on doing everything in the single FUD print.

 

Cheers, Mark.

Link to post
Share on other sites

Hi,

 

Just received the test prints for the KTA and IOA Wagons, here are some pictures (excuse the bogies, just ones I borrowed from an unfinished NGS Kit.

 

post-11575-0-97555500-1377196990_thumb.jpg

 

post-11575-0-49899900-1377196993_thumb.jpg

 

post-11575-0-93606700-1377196995_thumb.jpg

 

post-11575-0-19667800-1377196998_thumb.jpg

 

post-11575-0-60256200-1377197000_thumb.jpg

 

post-11575-0-90368400-1377197003_thumb.jpg

 

A few things need to be changed, for the IOA the brake cylinder is way too big and needs to be scaled down a bit. Also the relief on the end of the wagon probably needs to be more pronounced looking at how it printed. For the KTA, the bogie mounts need to be about 2mm higher and the pocket needs to be made wider and longer as a Dapol container is too tight a fit.

 

Cheers, Mark.

  • Like 5
Link to post
Share on other sites

  • RMweb Gold

Hi Mark,

 

Before you make any changes I'd give them both a wash and then a blast of Halford's grey spray primer.  It gives a really good coating and will give you a better idea of how pronounced the ribs/relief etc are as I feel he translucent plastic is very deceptive.

 

Both look very good indeed.  For the IOA maybe a few spare HHA Freightliner hoppers will have to donate their bogies!!

 

cheers

 

Ben A.

Link to post
Share on other sites

Hi,

 

I've managed to do a little more work on the wagons, I've revised the brake cylinder on the IOA. Increased the pocket of the KTA so that it accepts a Dapol container (16.8mm wide, 82.8 long) and extended the bogie mounts as they were too short.

 

post-11575-0-07665900-1377860394_thumb.jpg

 

post-11575-0-11657000-1377860310_thumb.jpg

 

post-11575-0-22026800-1377860309_thumb.jpg

 

The only containers I have are the Dapol versions that came with an FEA-B set, does anybody know if the other manufacturers offerings fit into the 16.8mm x 82.8mm footprint?

 

Cheers, Mark.

  • Like 1
Link to post
Share on other sites

  • RMweb Gold

 

Hi Mark,

 

Did you get a chance to prime them? As I said before, a coat of grey primer will often show up issues you might have missed on the screen.

 

Also, and this may not be something that bothers you, but the corners of the triangular floor cut outs should be a little more radiused....

 

Cheers

 

Ben A.

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...