AjModels - NER Horsebox, Ivatt N1, Aspinall 27

[37255]

Not something I could really justify for any of my planned layouts (as diverse as they may be!) but that looks superb!

[S.A.C Martin]

I was in the market for commissioning a J50 kit to fit onto the Bachmann Pannier Tank chassis a while ago before "best laid plans" and all that with the job got in the way. It's not a perfectly correct wheelbase, but it is the closest and cheapest RTR chassis to fit to a J50 body.

 

I too would be very happy if someone did finally make the J50 (discounting Lima's horrendous model), and to be frank can't believe that the LNER "Jinty" so to speak, hasn't been made yet by either Hornby or Bachmann.

[cheesysmith]

Have you considered using a plastic chassis from someone like york modelmakers, laser cut to be like a brass chassis with spaces and using slot and tab to glue together in correct position. The bearings for the wheels could be from a sppecialist . Just a rough idea.

[S.A.C Martin]

Another quick thought while it's in mind Andrew - there's a specific photograph in Top Shed by Peter Townend which shows three N2s, each one with a different style of buffer shank. Perhaps to further detail the model, specific buffershanks could be designed in as a separate part of the kit? The two main styles have the round GNR style base and the later square base LNER pattern.

 

Having the buffer shanks separate would also allow the kit to be easily modified for brass buffer shanks if any so wished it, too, without much hassle removing them from the bufferbeam.

[marksouthcoast]

Another quick thought while it's in mind Andrew - there's a specific photograph in Top Shed by Peter Townend which shows three N2s, each one with a different style of buffer shank. Perhaps to further detail the model, specific buffershanks could be designed in as a separate part of the kit? The two main styles have the round GNR style base and the later square base LNER pattern.

 

Having the buffer shanks separate would also allow the kit to be easily modified for brass buffer shanks if any so wished it, too, without much hassle removing them from the bufferbeam.

Another quick thought while it's in mind Andrew - there's a specific photograph in Top Shed by Peter Townend which shows three N2s, each one with a different style of buffer shank. Perhaps to further detail the model, specific buffershanks could be designed in as a separate part of the kit? The two main styles have the round GNR style base and the later square base LNER pattern.

 

Having the buffer shanks separate would also allow the kit to be easily modified for brass buffer shanks if any so wished it, too, without much hassle removing them from the bufferbeam.

[marksouthcoast]

Hi ive being reading this topic with intrest, could the same technolgey be used to do a k1 using a cut down Hornby l1 tank chassies.

[Atso]

Hi ive being reading this topic with intrest, could the same technolgey be used to do a k1 using a cut down Hornby l1 tank chassies.

 

I've just checked the wheelbases. The L1 is 8'7+6'6+7'+6'2+6'3

The K1 is 8'11+7'6+8'9

The closest match for a Thomson/Peppercorn K1 would be a Bachmann K3 chassis which has an identical wheelbase and undersize wheels which may do for 5'2 drivers...

[AJ427]

Another quick thought while it's in mind Andrew - there's a specific photograph in Top Shed by Peter Townend which shows three N2s, each one with a different style of buffer shank. Perhaps to further detail the model, specific buffershanks could be designed in as a separate part of the kit? The two main styles have the round GNR style base and the later square base LNER pattern.

 

Having the buffer shanks separate would also allow the kit to be easily modified for brass buffer shanks if any so wished it, too, without much hassle removing them from the bufferbeam.

 

Hmnn....buffers. I notice you've said N2s there Simon rather than N1s? I can't find any pics of N1s with anything other than the GN round style. However, looking into this has led to another problem. I'd anticipated re-using the N2 buffers to fit into the GN style base but I could only make the hole quite small due to the wall thickness limitations of the prime gray material (see buffer on the left below). I've attempted to ream out one of the buffers to the correct size (see buffer on right) but I'm at the point where the material is starting to split and it's still not quite big enough to take the Hornby buffer. On the finished kit these parts will be printed with a different orientation so the hole will be through the layers rather than across them which may give a little more tolerence but I suspect not. So, the solution will be to have holes in the buffer beams and fully modelled non-working buffers as seperate parts that can be glued in place. This leaves the option for anyone who wishes to fit 3rd party brass sprung buffers to easily do so.

 

[S.A.C Martin]

I think I've got my Ns mixed up Andy...! However I do distinctly remember seeing an Ivatt N1 with the square based buffers. I will have a look through my books and try to find it. Since you're changing how they fit anyway it won't be a problem to replace the buffers. A good solution to the problem in any event.

[gr.king]

Hi Andrew, are you any further on with this project or has the dreaded four-letter-word (work) been getting in the way?

[AJ427]

Hi Andrew, are you any further on with this project or has the dreaded four-letter-word (work) been getting in the way?

 

Hi Graeme,

 

Yep, work had got in the way somewhat (I can only really work on it when i'm in the office). However, this week I've managed to get a fair bit done and I have the model just about ready to print in two possible forms:

 

1) simple kit option which will have most of the large flat(ish) body parts and the boiler done in prime gray. There will be just 9 seperate prime gray parts. The kit will come with a choice of smokeboxes for the saturated and superheated versions of the loco. The following detail parts will be done in FUD: smokebox door, chimney, dome and cosmetic buffers. The smokebox door will be offered as a BR version with a blank number plate and as an LNER version. I'm currently in discussion with i-materialise about print orientation for this model before I can get it printed. For this version I will buy in the parts in small runs for resale.

 

2) full 1-part body in FUD. This will be offered as a direct end-user print from Shapeways in several variants: BR/LNER, saturated/superheated, with/without condensing equipment, with/without cosmetic buffers. Most of this is essentially done and ready to roll-out.

 

The part I still need to work on is the condensing equipment - possibly this could be an additional add-on kit but maybe better included in the main kit.

 

Pros and cons are:

 

Option 1: Pros: lower cost, takes advantage of prime gray's shiny flat high detail top surfaces, less cleaning up. Cons: it's a kit. Consolidation of parts and onward postage by me.

Option 2: Pros: One piece, higher resolution general detail. Cons: more expensive, cleaning up of all surfaces.

 

So there we are. I'd be interested to know folk's preferences.

[gr.king]

Sorry to be a bit slow to reply. If you can really make the advantages of the selectively orientated printed components count, then that does tend to nulify my previous preferences for the benefits of the one-piece body, more or less making it a 50:50 decision. What do you, and others, consider to be the most user-friendly, initially adjustable, strong, shock resistant adhesive for a multi-part printed body? If the available glues are not convinicingly good, then that might sway the argument somewhat.

[AJ427]

Sorry to be a bit slow to reply. If you can really make the advantages of the selectively orientated printed components count, then that does tend to nulify my previous preferences for the benefits of the one-piece body, more or less making it a 50:50 decision. What do you, and others, consider to be the most user-friendly, initially adjustable, strong, shock resistant adhesive for a multi-part printed body? If the available glues are not convinicingly good, then that might sway the argument somewhat.

 

Well the argument has now been well and trully swayed by i-materialise. Basically they won't entertain a sprued model of any sort so each part would need to be printed seperately, each with it's own set-up cost on top of the print cost. The policy is designed to prevent people duplicating complete models in a single file to circumvent the set-up charge so I don't really feel that a sprued multi-part single model falls into that category. Nevertheless they are sticking to the letter of the law (if not the spirit IMHO) and will not deviate. Of course it can still be done this way but costs will be prohibitive - the additional set-up costs will add in the region of euro 20 to 40 to the cost of the model depending on quantity! On top of all that they wouldn't guarantee 100% that the parts would be printed the correct way up! I think this option is dead in the water for anything other than a master prototype for creating moulds.

So I am plowing ahead as a single part model which will be offered via Shapeways FUD. I'm on track to have all permutations (as indicated in post 36) ready this week and I'll then be uploading to Shapeways for a prototype.

[S.A.C Martin]

That's a real shame Andy. However if the Shapeways alternative comes out well enough for detailing and finishing off, then all's well and the problem posed by Graeme regarding glues, at the very least is no longer a factor.

 

Looking forward to seeing the prototype.

[Etched Pixels]

Shapeways at least don't object to sprues, in fact for small stuff they positively encourage it.

 

 

You could print the buffers on a thin stalk on the inside of the body shell and hope i-materialise don't know about trains ;-)

[RichardJones]

Well that's a ######, and my LNWR brake van out the window. (or readjusted and shipped off to shapeways)

[34theletterbetweenB&D]

It's a very basic chassis, but the Bachmann TTTE 'Donald and Douglas' are on a 7'3"+9' chassis according to this thread. http://www.rmweb.co.uk/community/index.php?/topic/62739-converting-the-Bachmann-donald-into/&do=findComment&comment=809605

[45568]

Hi Andrew,

Still interested in getting one down to Oz!! Will keep watching this thread.

Cheers,

Peter C.

[AJ427]

It's a very basic chassis, but the Bachmann TTTE 'Donald and Douglas' are on a 7'3"+9' chassis according to this thread. http://www.rmweb.co....to/#entry809605

That is interesting, certainly worth further investigation.

[AJ427]

The single part (well almost) N1 arrived from Shapeways earlier. The images show the FUD printed model straight from the box with still quite a lot of the support wax residue in various nooks and crannies. It's quite hard to make out and I'll upload some better shots once it's been sanded and primed - this weekend time permitting.

Shapeways appear to have ignored the orientation in my CAD file (boiler up) and printed it from the bottom up. However the smoothness is still pretty good, especially on the smaller curved parts which have come out rather well. The smokebox door and cosmetic buffers are on a sprue that sits under the bunker area. The idea of having the door seperate like this was to avoid stepping issues when printing with it facing up (which unfortunately is the way it's ended up anyway). Had the model been printed as intended the door would have been side on. Nevertheless, it's still quite smooth and so for future prints I'll re-integrate it to the rest of the model as the orientation doesn't seem a particular issue. The cosmetic buffers have come out rather well and can be glued and dropped into the recesses on the buffer beams and used as is. Alternatively the recesses should also accept Alan Gibson GNR type sprung-buffers.

One downside is that there is some quite strong banding, especially on the boiler and tank sides. It looks a lot worse in the photos due to the transparancy of the model and I suspect they'll easily scrape or sand out. They are certainly a lot less prominent than the very obvious stepping on the earlier primegray prototype which also required filling as well as sanding.

I now have my CAD model set up to easily change between a variety of detail differences with BR & LNER smokebox doors, saturated or superheated boiler types and some or all of the condensing apparatus. This one modelled is 69434 which seems to have flit about between the south and the West Riding before working the Queensbury lines from Bradford Hammerton Street in the early 50s and ending her days at Copley Hill. I have several photos of this loco from that time where she's shown retaining the tank vents but no other condensing gear.

 

[gr.king]

That looks good, although the translucent raw prints are a swine to photograph effectively, aren't they? Can you be bothered to ask Shapeways why they disregarded your orientation request, or is the amount of effort you've already put-in beginning to feel like too much?

 

After I'd decided to be really thorough, and gone ahead with use of a strong degreaser (white spirit) on my O4/5 body from Bill Bedford's design, further discussion with Bill persuaded me that use of only soapy water might have been best. Apparently spirit cleaners can strip out excessive amounts of residual firm wax from the surface of the print, creating even more "texture" that needs scraping / smoothing /filling.

[billbedford]

Shapeways don't allow you to specify the orientation.

The idea of having the door seperate like this was to avoid stepping issues when printing with it facing up

You will alway have stepping on a shallow curve like a smokebox door, the choice you get with orientation is whether the steps are a series of rings or straight lines.

[AJ427]

After I'd decided to be really thorough, and gone ahead with use of a strong degreaser (white spirit) on my O4/5 body from Bill Bedford's design, further discussion with Bill persuaded me that use of only soapy water might have been best. Apparently spirit cleaners can strip out excessive amounts of residual firm wax from the surface of the print, creating even more "texture" that needs scraping / smoothing /filling.

 

Thanks for the tip Graeme.

 

That looks good, although the translucent raw prints are a swine to photograph effectively, aren't they? Can you be bothered to ask Shapeways why they disregarded your orientation request, or is the amount of effort you've already put-in beginning to feel like too much?

 

Shapeways don't allow you to specify the orientation.

 

You will alway have stepping on a shallow curve like a smokebox door, the choice you get with orientation is whether the steps are a series of rings or straight lines.

 

It wasn't a request as such, rather I'd orientated the model one way and they'd printed it another. Of course, as Bill says, this wouldn't have eliminated the stepping, just altered its orientation which in some cases makes it less noticeable or easier to deal with.

[Rabs]

Looking good!

I imagine that you already know this but:

The boiler looks like it may be made up of separate flat surfaces (or is this just the same banding that is on all the surfaces?). Some CAD software will automatically smooth the display of polygons into smooth curves, but stores the polygon as the actual shape. Hence you think that you're getting a nice, smooth curve and in fact you get some octagonal monstrosity - no prizes for guessing how I know this . There's usually a setting in the software to display the actual geometry without smoothing.

[AJ427]

The model has now been primed and an initial scraping undertaken. It's starting to feel pretty smooth now but I'll probably need to do this again. The main issue is the unwanted banding that has appeared on each side of the model. It's slightly worse on the left side. The top and the front/rear of the model are quite smooth.

 

The cosmetic buffers have just been placed into their holes for the photos and sit there nicely without any glue.

 

After spraying but before scraping:

 

After an initial scrape last night: