NSR 4 wheel coach.

Around a year ago, I was presented with some 3D files (STL) for a 7mm scale North Staffs all 3rd class 4 wheel coach.

The artwork was done by Mark Smith of 5D models originally in 4mm for fitting to a Hornby Toad brake van chassis, but much more work was done by Mark but for one reason or another never came to fruition.

Parts had been pre grouped for machine printing such as shapeways, but sadly this wasn’t great for 3D printing in resin, so I had to find a way to reverse engineer as Mark couldn’t locate the needed files.


I started off with the coach body…

But to be able to print the model, I need to change it. It also has a basic roof.. and it’s all as one.. and when you try to edit, it’s all
Little triangle..

To print I can’t have an enclosed box. This caused the resin to
Pump. Bit like having a glass in the sink and pushing it under the waters surface or having it full of water and lifting it out. Glass is strong enough to not distort, but soft resin would distort with the pressure of moving the slightly less viscus liquid around, so I had to remove the roof and the floor.


And there we have the basics.
A separate roof was supplied by Mark for the all third, but the coach body should be 4 compartments so I also had to add new bulk heads.

Thankfully the chassis and frames didn’t need any work, although the other side of the chassis may need some levelling out to fill the gap removed where the floor was (seems daft having two flat surfaces sitting together when you can just use the chassis?

There were seats, but as the coach still had them inside, I didn’t use them.

Rather basic vac brake cylinder.. that appears to just sit on a block. Same with the tank, which I guess is for the gas lights.. and still not sure what the arm is at the end? Unless it fits on to a rod for the vac cylinder… which would make sense as there are other rods not included…

These had to be separated down back in to individual items and edited/repaired where the sprue had been cut away on the files, almost like you would with a kit, but alas a computer program doesn’t always have scissor type edit for these files, even less so a file to smooth it off.. so it’s back to a little detailed editing and learning a new program to do so.


Brake rigging, simple, but does the job quite well.
Vac pipes.. no idea why I needed 4?? I’m unsure.


And finally the hardest one to do.. 2 lots of double foot boards, 6 buffer heads, 4 buffer shanks and 2 more vac pipes..
but we got there.

Hopefully now with having the individual items I can have a crack at making one in the new year. But before we do, I started to “build” a virtual model..

 

as they are still STL files it presents a limit on what I can “paint”’ in fusion compared to normally.. so it’s missing a few bits of paint detail along the beading. Same with the cream panels I had to create a new part that was inset at 0.001mm thick to create a separate body colour. The same applied inside on the bull heads above the seats inside.
An early draft minus buffers and noting the lack of air vents above the doors.

The cream was then thinned back and edited to allow the panels to show though again.

I then started to add some lighting.

And finally as it is now.. with vac pipes and buffers.
Still need to complete the brake rigging and also draw some coupling hooks, T door handles and reverse C shaped grab handles.

 

As part of the editing of the STL files I downloaded NETFABB, its part of the Fusion 360 package from Autodesk. Its been quite something for the editing, fathoming it out as it doesn't work like the other systems (Netfabb being an older product that I think has been inherited and the front of house look jazzed up by comparison to an earlier limited trial version a friend sent me.. It was easy to follow, but the orientation with the mouse differed and your working in a central panel with two outer panels with data and option tools that you cant seem to resize. This on its own made work hard going wasting 2/3rds of your work screen... Then I find the cut tool will only size to the height of the outer size of your parts dimentions, so the only way the part like the foot boards could be edited was by keep rotating its orientation. very odd way to work and you often found the boundary box you were using for any cuts was no where near your part when you rotated the view

Anyway, it was supposed to be on a 30 day trial, but after only 9 days its crashed on me and I now cant get it to repair or run. Have another look on that issue as I was mid repair on another file and was going to finish off the brake rigging on the coach... but another day now. Sadly the older version doesn't do the cutting, only the repair of the parts>

 

I had no idea. Wow !

 

Looks like the netfabb program has gone belly up. Having spoken to an autodesk chap yesterday, it needs something with a . DLL file changing with C++
I told him I wasn’t messing around with that when no idea what I’m doing g and will find another product

 

Fidling with windows setup/operating files... yes. One false move and the whole machine may never work again..

 

Now that would be logical.. but alas, the said file was last edited in 2018 so no idea why its now an error issue after 9 days..
I have renamed it, and copied in a new one I downloaded in its place... to no avail... so I went with the second option. Download it on to the Laptop and see if I can run it there for the remaining days on the trial whilst I complete the repairs needed.

See what happens in 40 mins on my meal break.

 

SUCCESS ! on the lap top.

It works and I've been able to slice the final 2 parts... well, I say 2 parts... More like 1 as one is still going as it ran out of memory the first time...

 

Hold your horses. I still need to finish the last part! Seems the less you have left the longer it takes to complete a cut.
Need to wake the laptop now I’m up off the night shift

 

Yes! To both..

gave up. Went back to the tower and imported the STL in to 123D and redrew a new part.

still one more to do. Then we’re done… although I may look at the chassis re the blocks that the tank and vac cylinder don’t really sit well on..

 

Well the last arm is done and on the model. I’ve even “acquired” coupling hooks, but need to now create the door handles and grab handles to finish off. but that’s probably new year now if not before Xmas eve (wink)
But any printing may have to wait till sometime in the new year as I’ve run out of resin and probably money if the Mrs has done at smyths toy store!