Building and completing my 4mm 3D Printed GNR Coaches

[MikeTrice]

During the lull in building I have had some samples printed by Shapeways using alternative printer orientations.

 

Looking at an earlier image the current run of models have visible stepping on the waist panels, however other areas seem fine:

 

The first alternative reorientates the sides by about 30 degrees seen here with a very light spray of Humbrol Primer:

 

Banding is still visible and also impacts the vertical panels.

 

When sprayed with Halfords' Filler Primer the stepping is still visible:

 

Rotating the model still further to almost 80 degrees the print looks like this with Humbrol Primer:

 

Banding is less apparent but the panels are not as smooth.

 

One downside is that the roughness caused by the support material is starting to appear:

 

I have found that support material marks can be improved by burnishing them with a cocktail stick. Here is the second side after burnishing and a coat of Halfords' Primer:

 

The images above are huge enlargements of the actual model prints and as such are fine for showing the surface finish, however as I have said before they are not so apparent to the naked eye. To try and demonstrate this here is a smaller version of the Halfords Primed sides.

 

Option 1 - 30 degrees:

 

Option 2 - 80 degrees:

 

So there it is. Do I leave the models as they currently are, or do I reorientate the sides? If so which option?

 

I also took the liberty of having a pair of the original sides printed in Shapeways Frosted Extreme but only just managed to squeeze the sides to fit the box limitations for the material. Superb:

 

 

 

 

 

[MikeTrice]

Some minor process has been made. Crude partitions cut from 40thou styrene:

 

And glued in place:

 

Moulding lines on the roof have been sanded smooth:

 

And sprayed with Humbrol Matt White:

 

 

 

[teaky]

During the lull in building I have had some samples printed by Shapeways using alternative printer orientations.

 

Looking at an earlier image the current run of models have visible stepping on the waist panels, however other areas seem fine:

IMG_3686.JPG

 

The first alternative reorientates the sides by about 30 degrees seen here with a very light spray of Humbrol Primer:

IMG_3843.JPG

 

Banding is still visible and also impacts the vertical panels.

 

When sprayed with Halfords' Filler Primer the stepping is still visible:

IMG_3870.JPG

 

Rotating the model still further to almost 80 degrees the print looks like this with Humbrol Primer:

IMG_3848.JPG

 

Banding is less apparent but the panels are not as smooth.

 

One downside is that the roughness caused by the support material is starting to appear:

IMG_3852.JPG

 

I have found that support material marks can be improved by burnishing them with a cocktail stick. Here is the second side after burnishing and a coat of Halfords' Primer:

IMG_3869.JPG

 

The images above are huge enlargements of the actual model prints and as such are fine for showing the surface finish, however as I have said before they are not so apparent to the naked eye. To try and demonstrate this here is a smaller version of the Halfords Primed sides.

 

Option 1 - 30 degrees:

IMG_3870s.jpg

 

Option 2 - 80 degrees:

IMG_3869s.jpg

 

So there it is. Do I leave the models as they currently are, or do I reorientate the sides? If so which option?

 

I also took the liberty of having a pair of the original sides printed in Shapeways Frosted Extreme but only just managed to squeeze the sides to fit the box limitations for the material. Superb:

IMG_3872.JPG

The Frosted Extreme is very good but other than that Mike I think the current one looks the best and/or appears to require the least smoothing.

[gr.king]

My impression from the above is that the original orientation of print gives best definition to the beading and that although there are bands / ridges in the waist panels there's no particular difficulty in dealing with those.

[MikeTrice]

Original orientation is also the cheapest ;-)

[gobbler]

Having looked at all the pictures above. I would say that the frosted print looks like the best quality side. However as I've said in my previous post on this thread the print grain enhanced the wood grain effect.

 

Can't wait to see the axles and wheels

 

Scott

[MikeTrice]

Can't wait to see the axles and wheels

 

Scott

Here you go ;-) :

[Irish_R_M]

Very impressive finish with the FED! Quick question, the Mother of all Sharp things - where would a fellow get such tasty looking bits of kit? Rich. 

[N15class]

Having looked at all the pictures above. I would say that the frosted print looks like the best quality side. However as I've said in my previous post on this thread the print grain enhanced the wood grain effect.

Can't wait to see the axles and wheels

Scott

Railway works spent a lot of time and effort to remove visible rough grain and make the sides smooth so that when painted or varnish they flat and shiny.

[MikeTrice]

Very impressive finish with the FED! Quick question, the Mother of all Sharp things - where would a fellow get such tasty looking bits of kit? Rich. 

Are you talking about the Shapeways' prints or the wheels and axles? See the link in my signature for Shapeways. The FED print is a test print only. The wheels and axles are from Wizard Models.

[Joseph_Pestell]

I think all the prints look good once painted. At normal viewing distance, they actually help with the teak effect.

 

But with regard to the roof, would it not be easier to stick fine tissue paper or silk to them to replicate the canvas?

[Atso]

Hi Mike,

 

I've been reading this thread with interest and have been enjoying seeing what you have been doing with the printed coach sides.

 

I thought I'd share my own effort at a GNR six wheel full brake in N gauge. This has been printed in FXD by Shapeways and is in the process of being cleaned up - almost there but not quite.

 

 

It is a rather cruel close up (it's only c. 66mm long!) and shows that I've still got a couple of bits to sort out around a couple of the panels and re-scribe a couple of the doors. I've mainly used a chisel type attachment for the vertical panels and a sharpened jeweler's screwdriver for the horizontal ones. The roof was sanded using sanding sticks from Flory Models and Albion Alloys as they are quite cheap and foam backed so they follow contours pretty well.

[JCL]

Are you talking about the Shapeways' prints or the wheels and axles? See the link in my signature for Shapeways. The FED print is a test print only. The wheels and axles are from Wizard Models.

 

I thought it was your beefcake chisel affair.

[sem34090]

Hi Mike,

 

My greatest apologies for not reading through the other thread (yet) but may I ask what CAD software you use? I am still stuck with sketchup for the moment, and was wondering if you could offer any advice for forming carriage tumblehomes with panelling. Over on the pre-grouping forum we are running a mini-experiment with the same sketchup files for Stroudley 4-Wheeled coaches being used to create CAD for Laser-Cutting, Silhouette Cutting and 3D Printing purposes, and (as the person who is trying them as 3D Prints) I am currently trying to fathom how to form the tumblehome.

[chris p bacon]

Mike uses Blender ...or at least he was the last I knew.

[MikeTrice]

Chris (Dave) is correct, I use Blender. It does take some getting used to and JCL's (Jason) tutorials proved invaluable: http://www.rmweb.co.uk/community/index.php?/topic/91147-a-beginner-starting-in-3d-printing-with-blender-update-may-18th-layers/

[MikeTrice]

I am trying to decide the best way of fitting the end handrails. As can be seen from this photo there are two mounting brackets at the top of the end:

 

Suggestions welcome.

 

 

[MikeTrice]

No suggestions? I am not surprised.

 

My first attempt was a disaster so I will not even show it. Clearly I needed help so I knocked up a quick drawing in Inkscape showing the profile of the handrail and its mounting points then produced a crude jig from mount board. Superglue has been used to reinforce the card edges:

 

I wanted to use 0.4mm N/S wire but did not have any (some is now on order from Eileen's Emporium) but did find some 0.4mm brass instead. A small right angle bend is formed first:

 

The bent leg is then fed through the right hand mounting point (I am left handed so the way I am doing it might look odd - you want to try operating a camera left handed!):

 

Holding the right hand side of the handrail tightly in place I started to form the top right hand curve:

 

The springiness of the wire will not let you accurately form the curve at this stage. Now I fought on and bent the left hand mounting point thus:

 

I then removed the handrail from the jig and manually tried to match the curve. Not perfect by any means:

 

Now life would have been a lot easier if I had removed the handrail and formed the upper curve BEFORE bending the left hand mounting point. Oh well there is always next time.

 

Two tiny "L" shaped bits of 0.4mm wire are formed with one leg trimmed short:

 

The longer legs are threaded through the upper mounting points in the jig with the tails facing inwards. The previously bent handrail is repositioned on top and clipped in place:

 

The upper mounts are fluxed and soldered together in the jig. On removal we have two upper mounting points fixed to the handrail. Not prototypical but with a small degree of strength against knocks:

 

The soldered joints are cleaned up of any surplus solder, especially on the visible external faces.

 

After a bit of trial and error and opening the mounting hole up to 0.5mm in the body the new handrail fitted in place and attached with tiny amounts of Superglue:

 

After spraying with primer:

 

The tiny hole where I elongated the mounting hole will be filled later.

 

 

 

 

 

 

[gr.king]

I'd probably settle for the use of a couple of small handrail knobs to function as the brackets near the roof-line.

[micklner]

Solder a L shaped piece of  0.45mm to thinner wire to a small piece of Brass sheet , " put the corner of the bend" on the edge of the sheet , the sheet then lays flat against the coach body, then Araldite the sheet/wire to the inside of the coach , at the same time passing the wire through to the outside of the coach, via the mounting holes.

 

Hope that makes sense !!

 

Amended text ,I will do a picture tomorrow if needed.

 

 

Edit

 

 

Glue this onto the inside of the coach end, and pass through to outside at the same time, then solder as per normal , I have just superglued this onto some scrap, much better joint soldered.

 

 

Edited March 21, 2018 by micklner

[MikeTrice]

Got any photos? Struggling to follow.

I'd probably settle for the use of a couple of small handrail knobs to function as the brackets near the roof-line.

That would have been plan C

[Compound2632]

No suggestions? I am not surprised.

 

My first attempt was a disaster so I will not even show it. Clearly I needed help so I knocked up a quick drawing in Inkscape showing the profile of the handrail and its mounting points then produced a crude jig from mount board. Superglue has been used to reinforce the card edges:

IMG_3883.JPG

 

I wanted to use 0.4mm N/S wire but did not have any (some is now on order from Eileen's Emporium) but did find some 0.4mm brass instead. A small right angle bend is formed first:

IMG_3884.JPG

 

The bent leg is then fed through the right hand mounting point (I am left handed so the way I am doing it might look odd - you want to try operating a camera left handed!):

IMG_3886.JPG

 

Holding the right hand side of the handrail tightly in place I started to form the top right hand curve:

IMG_3890.JPG

 

The springiness of the wire will not let you accurately form the curve at this stage. Now I fought on and bent the left hand mounting point thus:

IMG_3893.JPG

 

I then removed the handrail from the jig and manually tried to match the curve. Not perfect by any means:

IMG_3895.JPG

 

Now life would have been a lot easier if I had removed the handrail and formed the upper curve BEFORE bending the left hand mounting point. Oh well there is always next time.

 

Two tiny "L" shaped bits of 0.4mm wire are formed with one leg trimmed short:

IMG_3896.JPG

 

The longer legs are threaded through the upper mounting points in the jig with the tails facing inwards. The previously bent handrail is repositioned on top and clipped in place:

IMG_3901.JPG

 

The upper mounts are fluxed and soldered together in the jig. On removal we have two upper mounting points fixed to the handrail. Not prototypical but with a small degree of strength against knocks:

IMG_3903.JPG

 

The soldered joints are cleaned up of any surplus solder, especially on the visible external faces.

 

After a bit of trial and error and opening the mounting hole up to 0.5mm in the body the new handrail fitted in place and attached with tiny amounts of Superglue:

IMG_3908.JPG

 

After spraying with primer:

IMG_3915.JPG

 

The tiny hole where I elongated the mounting hole will be filled later.

 

IMG_3919.JPG

 

That looks the business. Handrail knobs would interrupt the smooth flow of the handrail as seen in the prototype photo.

[gr.king]

A variation on the handrail knobs idea, if you happen to be sufficiently fussy about one very small aspect of the appearance of the coach end: Fit the knobs and the rail in the normal way, tweak until happy with the fit, use a very quick sizzle with the soldering iron to solder the wire fully into the knobs, then gently file off the upper and outer part of each knob, leaving the rail anchored in the lower and inner part of each ball.

[MikeTrice]

Solder a L shaped piece of  0.45mm to thinner wire to a small piece of Brass sheet , " put the corner of the bend" on the edge of the sheet , the sheet then lays flat against the coach body, then Araldite the sheet/wire to the inside of the coach , at the same time passing the wire through to the outside of the coach, via the mounting holes.

 

Hope that makes sense !!

 

Amended text ,I will do a picture tomorrow if needed.

 

 

Edit

 

 

Glue this onto the inside of the coach end, and pass through to outside at the same time, then solder as per normal , I have just superglued this onto some scrap, much better joint soldered.

 

 

IMG_5884.JPG

So do you just solder the handrail to the tip of the wire?

[chris p bacon]

So do you just solder the handrail to the tip of the wire?

 

I think that's how I understand it, the flat plate is for attaching the wire inside the coach.

 

That would be a bit too delicate for me, I prefer your way or handrail knobs.