Etched Pixels

N or OO ?

Not entirely - it seems their bounding box code is buggy - if you pack them at an angle with other shorter stuff to form a square thats under 150mm it works fine - but their web site and tools are either too daft to or intentionally make it hard to do this.

I've printed polished 26m 1:160 stock this way

Polished WSF is a bit variable but it's what I use for things like coach roofs. It usually comes out better than FD.

You can polish 3d prints a couple of ways yourself depending upon the material - airbrushing with acetone (while wearing appropriate safety gear, with good ventilation and I wouldn't advise smoking on the job), or abrasively with a rock polisher being two - but for WSF that has its own problems including the amazing quantities of dust it produces and the time taken. Another one you don't want to do without safety gear.

I leave it to Shapeways to polish mine, saves beer drinking time.

Alan

For the one I am building I plan to put pickups in the trailer and run fine decoder wire between the two so I can get better power pickup.  It's also possible if you move the wheels around as per my blog entry to shorten the Tsugawa so you could power the trailer too.

Transfers look neat - nice solid white with no bleed. What system are you using to do these ?

Alan

I checked with the NGS shop a couple of weeks ago - the Stove-R chassis has sold out but will be available again at the end of the year - which is why it's vanished from the shop listings.

Roof horn mountings or is that an intentional omission ?

Somebody in this thread returned a faulty Dapol Western to DCC Supplies, only for it to be returned with the fault not repaired sufficiently well, so he had to return it a second time (at his own cost, natch) to be repaired. Second time round, it had been repaired.

If he was charged the second return and it was not his fault but a failed repair then that somebody should send DCC supplies the bill.

Etching is a lot cheaper than it used to be- as a process anyway. Metal costs have skyrocketed though.

Give ppd a call as they will do small sheets and the like.

Ebay is not an auction (and in the real world auctions don't determine market price either, only in beginner level economics fantasy land).

Alan

Looks interesting. I'd hate to try and assemble it without some pins/holes so it all lined up nicely though

Also from experience if you print the two halves in WSF you've no guarantee that they'll get polished down the same amount. Thats usually not a problem but in this case I wonder if it would be a bit awkward..

Think I'd split it interior + wheels/body + roof so any join was hidden. Some modern busses would be nice though, perhaps a bendibus with smoke generator 8)

Is that pricing it for FUD or for Polished WSF ?

http://www.ngaugeforum.co.uk/SMFN/index.php?topic=10303.0

and

http://www.ngaugeforum.co.uk/SMFN/index.php?topic=434.0

has a thread including scratch building a Dellner for 57315

I've done custom LBSCR ones for people. I imagine LSWR is also doable. Depends how much of a hurry you are in.

Alan

If you release lots of models at once you have to have the capital up front to pay for all the tooling. Farish Mark 3 stock has I think two tooling variants and can cover almost the entire range. Dapol has to do one tool for each - hence all the catering coach fudging.

Alan

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

The ATM bogies appear to be off the market at the moment with BernardTPMs move. I'm still waiting some from a month ago ?

I use 1:160 figures for 1:148 N, I guess HO figures for OO wouldn't be unreasonable in some cases ?

If you can do 3D you can do 2D - etching is basically 50% 2D CAD 25% origami and 25% knowing what you can get away with ;-)

andy: they are quite modern although some of the older wagons in a similar style go back to steam days.

The pivot arrangement looks good. I guess in theory you can identify the location of the pivot on the real wagon by working out the diameter of the circle visible in the join in the photo

First thought would be that if you mount the second bogie on a piece of thin metal strip pivoted off the bogie at the join (ie off the same mount and the bar able to rotate separately ditto the second bogie)  then it ought to go around anything. Might look a bit odd on a 9" curve but it ought to traverse it fine.

Not sure that is so true in N. You end up with a very fragile framework and a minimum of scale 5" x 5" ribbing and even that is likely to warp if not with a fair amount of trussing. FUD can do 0.1mm detail on a solid 0.8mm backing but it can't do 0.5mm thickness in thin air.

The cheapest way is still to get out the craft knife and the microstrip

Shapeways don't care about "one part per print" - in fact for FUD they positively encourage sprues or multiple parts by their pricing. As to buffers. In N for some stock I couldn't get the right buffers at acceptable prices in small volumes so I 3D print them but keep them as fittings. That way if I do ever break one I can just swap it.

I've done vans both as FUD prints and also as a WSF framework+roof with glued on etches. There are tradeoffs in each approach. The etched one definitely looks better and in any volume is cheaper to produce but needs more fiddling or cunning origami to get the right raised details. The FUD ones cost more, need more cleaning up and have a slightly poorer finish but they are one part and you can often get raised detail in one go. In both cases the very small details like torpedo vents I put holes in the 3D print and fit off the shelf plastic or white metal vents into them.

The main tip I'd give you is to start on a shortish wagon (cheaper). For longer vans in FUD IMHO it is worth putting some cross bracing into the body shell to strengthen it. Unlike plastics you don't have to worry about shrinkage messing the sides up.

Alan

Devonport flask would be very interesting to me too ;-) especially as it seems Bachmann are issuing the Mark 2 squaddie coach that goes with it.

Alan

Hi Jonathan, the software will be licensed to me - Rhino will be main 3D modelling program

 

David

The other thing to watch is the university regulations small print. Lots of them in this time of grasping commercialism like to claim they own the rights to anything you do as part of a university course or hand in as an assignment etc. It's been a big problem in the software case. Some are more obnoxious than others but Bristol is fairly typical for example I have to hand in saying

In the event that an undergraduate student or a postgraduate student on a taught course generates intellectual property in the course of a University project, either solely or in collaboration (where the collaborators may be fellow students, members of University of Bristol staff, employees of a sponsoring organisation or collaborative partner or a combination thereof), he or she is asked to assign to the University any intellectual property that he or she may generate. Assignment will only take place in the event that intellectual property is generated. A student shall then give to the University all reasonable assistance to enable the University to obtain patents or other forms of legal protection for the intellectual property.

So be very careful not to mix student stuff and work or you may get a nasty shock.

Given the time it takes I can't see why its worth taking the risk of not giving it a good dose of polyurethane varnish before assembly.

Alan