O Gauge Heljan 33 Improvements and JLTRT MK2s.

[Pugsley]

1 - They're usually referred to as warm white, golden white, or sunny white depending on who's selling them
2 & 3 - If you're fitting DCC, I'd personally wire it up to the decoder with a suitable resistor, anything from 470 to 2K Ohms (or more), depending on the supply voltage and the desired intensity.

 

[tomstaf]

Thanks Martin,

For the moment it's remaining DC, so any wiring suggestions for that?

Cheers

Tom

 

[Pugsley]

Set it up on a rolling road and check the voltage being applied across the COM and Front LED terminals on full power. If this is 12V, you can wire it in, but you will need a resistor between 470 and 2k ohms. If it is less, I'm not entirely sure, but you should be OK to wire it straight in as there will be a resistor in the circuit somewhere.

 

[Ian G]

I prefer to use MMP Loco detailing kits, they work out cheaper in the end.

Ian G

 

[tomstaf]

Set it up on a rolling road and check the voltage being applied across the COM and Front LED terminals on full power. If this is 12V, you can wire it in, but you will need a resistor between 470 and 2k ohms. If it is less, I'm not entirely sure, but you should be OK to wire it straight in as there will be a resistor in the circuit somewhere.

OK,

Thanks - seeming like this may be quite easy to do then. I do hope so

Cheers

Tom

 

[tomstaf]

I prefer to use MMP Loco detailing kits, they work out cheaper in the end.

Ian G

Ian,

MMP don't sell LEDs etc as far as I'm aware. What is your comment related to?

Cheers

Tom

 

[tomstaf]

Hi Fella's

Nice work and ideas

Helmsman do some warm white type LED's approx 3mm in dia or just under.

Am I correct in thinking that the marker lights are red only and that the Headcodes are white/red depending on direction of travel (I think that I am right in saying that in the latter days the markers weren't used). Out of interest - how does that work, with the HI light?

The MMP mainline diesel detail kits (primarily for RJH/PRMRP kits and upgrades of such) are good for odds and ends, yet they don't have a lot of Cl33 extras in them that would be of use on a Heljan 33, so not sure what you would gain from them?

I have been, slowly - as I was awaiting castings (and still am) - working on my two Limas so the MMP kits are a help. I also have parts from (RJH/NS/PRMRP) and Heljan.

Ironically I started working on them again - ten mins here and there - a week or two ago and a guy in the GOG Gazette wrote an article on fettling a Lima 33.

My take on such is a cross between Dickie Dockerill's and Ross' work - in the famous lyrics of RUSH 'it just takes me longer'

ATVB

CME

Hi CME,

Thanks for that pointer on the LEDs.

As for marker lights - 33s never had them, just tail lamps and the headcode panel. The tail lamps went out of fashion and were either pained over or removed completely. The head code blinds had red panels that were wound round when trailing light loco. The high intensity HL would always have been on as well as the code or white panels when leading.

I was never planning on using the MMP kit so not sure why it has been mentioned in this thread. I'm sure it's great but as you say the majority of parts aren't suitable for the 33 or the improvements I'm making.

You'll have to start up a thread on your Lima's when you get the bits for them. It's been a long time since I've seen one of them.

Cheers

Tom

 

[Yorkshire Dave]

I got my flat top (about 2.5mm square) Warm White LEDs from a company called Black Cat Technologies who also has a stand at model shows.

Ref PLCC2 Warm White LEDs sold in packs of 10 which include 470 ohm resistors for 12v but I use 630 ohm or higher for DCC.

 

[tomstaf]

Some development on the MK2s:

The various MK2s I building are all modelled in the mid - late 1990s era. By that time central door locking was standard and the orange external door lights aren't covered in the JLTRT kits.

I though about etching and lumps of plastic but that wouldn't give the translucent effect and would be rather time consuming for a rake. I also wanted the option of being able to illuminate them at some point. So after a lots of other distractions (IGAs, 33s, jobs, food et al) I decided to have a go at 3D printing. The result arrived on the doormat today. Unfortunately I'm disappointed with them, particularly as this isn't a cheap process. The 3 issues:

1. There is 'fish tail/arrow' shaping to the whole light, making the sides look unequal. This should be a perfect rectangle as drawn on the design;
2. There is no representation of the 8 screw heads. I thought the groove might not show up, but am surprised to see no representation of the cyclinder at all. My intention had been to highlight the screws with silver paint and weathering to give the complete look, and;
3. There are heavy 'plough' marks across the surface. In the picture they show up on the sprue more than the lights. Again not something I was expecting in UFD material, the most expensive and smoothest finish material.

This being my first go, so not being an expert, has anyone got any suggestions or can they recommend an alternative 3D printer please?

Cheers

Tom

 

[alcazar]

Had you thought of etched surrounds with the bolt-heads left half etched? The plastic would show through....if you painted the etch and placed the plastic behind it, the paint would fill the crack.

Not sure about better 3-d , can you polish them?

 

[tomstaf]

Had you thought of etched surrounds with the bolt-heads left half etched? The plastic would show through....if you painted the etch and placed the plastic behind it, the paint would fill the crack.

Not sure about better 3-d , can you polish them?

I considered it but you'd loose the overall translucent effect. I've got some translucent orange paint for these, and real things are all one piece. I think it'd show up too much if the material wasn't consistent. Not sure about polishing, but the idea of drawing them and paying for them was to remove all the faff of cutting, finishing etc. I'd designed it so that the sprue balances itself, one pass of the airbrush and they're all painted orange in a matter of seconds. Drill one hole in coach, and glue in position. When weathering dap the screws with silver paint - simples. And for 7 coaches worth I'm not wanting to take ages on each light (4 per coach). I'm still frustrated... and breathe and calm

Cheers

Tom

 

[alcazar]

I see your point.

OK, could you machine polish them in situ: felt on a dremel, bit of T-cut?

And for the bolts, make pin-point HOLES with a compass point, fill with silver paint? It MIGHT work.

 

[mickoo]

Regarding the groves you need to orientate your part to minimise this, 3D printing is formed by applying small layers and I suspect your part in the 3D program was laid on its end and the 'feed' part stood vertically, you can see the lines running down the round tubes that hold your coach indicators.

Attached a simple diagram that might explain it better I have only drawn you oblong block section.


I suspect your part was orientated in your CAD program like that on the left, you need to rotate it so that its like that on the right, then the printer will lay a flat layer on your lenses, you will get ridges on the bevelled edges of your lenses but the area is so small it'll hardly be noticeable, this will also probably be why you have no rivets, if the rivets fall in a gap between layers they will not print, on the flat example at least part of the rivet will cross at least one or two layers....one hopes.

Its all about orientation my good man you need to think about how the printer actually prints to understand how best to orientate your work to minimise the ridges, which at even the best affordable fine quality will still be present and at even expensive rates they still show, as witnessed on a recent 08 I saw previewed somewhere (JLTRT or Dapol?) anyway, you could see the fine ridges on the bonnet doors and battery boxes, I've also seen it on a large scale A4 model, maybe gauge 1?, once you know what your looking for then it leaps out and smacks you good and proper when your looking at resin or 3D printed models LOL.

UFD ridges are quite fine and most go away with sanding or paint, sadly you do not have that luxury as yours need to be see through.

One other point, I would change you lens feed to a square and make it a little larger, even with translucent paint on you will still see that circular feed from behind, unless you are cutting it off but then you'd have to polish the base to remove it so it doesn't show through, if you change the feed to square it will look like the base of the fitting and match the squareness of the lens, a round part, no matter how faint will draw your eye in an instant, square on square will almost certainly not be noticed. You'd need to still drill a hole, just a little larger that's all, you'd have to judge the size so that the hole drilled to accept the square feed isn't so big that it shows around the outside of the lens, then what I'd perhaps do is add some fine putty to the hole and then push the square feed through to fill the small segments, other than that I doubt you'll see them especially if all sides of the lens are painted, front and back.

Hope that helps a little.

 

[tomstaf]

Thanks for the advice Mick.

I didn't think the round locating pin would be so noticable. It was designed so it'd be a simple fit onto the side of the coaches - and may even work as a feed for anyone who fancies attaching an LED to it. But square it'll have to be - as you say it's far too noticeable. And I'll alter the orientation too/ask Shapeways about whether I can specify this.

Any idea why they haven't come out rectangular and have the little tales on 2 corners and rounded corners opposite?

Cheers

Tom

 

[mickoo]

Yes, again that's down to the printing orientation and I hadn't noticed that in my initial inspections and proves that your orientation was as I suspected, I.E the oblong column was vertical and not flat as per your images.

I think Shapeways uses the tank full of medium approach but I've seen one in the US (hellish expensive) that had a hopper feed and basically three nozzles that moved. The medium was heated and fed through the nozzles and where they met formed a solid, the nozzles moving in x,y,z axis to form the part, its not 3D printing as we know it today but something similar and the name of the process escapes me, anyway, suffice to say you started with an empty chamber and the machine built up a 3D part by injecting liquid material, they were making 1:1 AAR brake stands for rich modellers who had full loco cabs in their hobby rooms, or any other control that had been robbed by the scrappers or whom ever.

The Shapeway approach (and I could have this wrong but the principle is the same) is to fill the tank with the printing medium as a very fine powder, then they fire three lasers on a x.y.z axis and where they meet they fuse the material soild, now if that happens to be on the base of the tank then its solid underneath, in your case where it came to do the corners that have tails (remember your part was printed vertically) it only had more material underneath (fine powder) to support the part as that layers was printed, in the few millionths of a second that it took to from that corner it dropped slightly and formed for want of a better word icicles.

Now if you orientate your part as per your pictures you will get a smooth lens face, but you may run the risk of the edges that overhang free space (fine material in the tank) may droop a little, but that'll be on the back of the part and could be sanded flat easily enough.

Orientation, you decide the orientation in your 3D package, I've no idea what package you used but most have a 'world' scene, in 3DStudio Max you need to set the 'world' scene axis correctly, for example in plan view X will be top, Y will be left and Z will be straight up, most scenes auto set the x,y,z axis so you should be all right, but that world axis may differ from what Shapeways expects to see. What I need is a screen grab of your part in what ever package you are using, once I see that then I can advise which way you need to rotate your part so that when you send the file to shapeways it'll be the right way around.

Now I'll come clean here, I've never printed a thing in 3D yet, but I do know my way around 3D programs very well and as it turns out these same orientation issues are critical in game simulations, you need to make sure your world axis matches what the game expects to see, if not you can get planes that are backwards and upside down, flies fine but looks a real mess in the game LOL, I've sent some cabs to Shapeways and they show you a preview window of how your part is orientated and I'm not sure which is the correct one that previews the axis orientation, the still image or the rotating one, if you can screen grab your two as well as what you see in your 3D package we should be able to work out which orientation you need.

OK here's my view in Max, note 'Gizmo' which is telling you the direction of x,y,z axis and note cab is flat on floor which means axis Z is vertical, this is the correct orientation for MS Flight simX and MS Train sim, no idea about Railworks or Trainz, never worked on them but I believe this is industry standard?


Now the static view in Shapeways, again cab is flat and Z axis is vertical


Now the stone in the shoe, the rotating preview, here the model has been up turned and the Y axis has become vertical!.


I'm sure somewhere in the Shapeways tutorials it tells you which axis is vertical, the other two don't matter, we're only after the one that makes flat surfaces ridge less and that will be the vertical axis we need.

Its late and wife's in for an op tomorrow but will try and check for you in a short while, hopefully the above will help, now if I had a Class 40 cab to print I'd do that and see how it goes, but I'm still working on the bit and pieces for that LOL.

So to surmise, if you can replicate the three screen shots above then we should be able to reverse engineer and sort out your axis and thus solve the ridges across the lens issue.....hopefully LOL, Shapeways I don't think can help, they only take your raw file and print, even if the orientation is worng I'm afraid.

 

[Bob Reid]

I know it's not improving the prints, but have you thought about casting them in clear resin from a master Tom?

Bob.R

 

[mickoo]

Tom, one final thought crossed my mind last night, have some sacrificial ones printed in the cheapest format first, that way you can see which way the ridges go if you are unsure of Shapeways axis orientation.

One other point, you pay Shapeways by material volume, that big block you have to stand them on cost you money and it's not part of the final model, probably only pence but on a 1:32 cab I did the difference between 3.5mm thick sides and 2.5mm was quite a lot, not sure how 2.5mm would stand up to supporting its self during the printing process but volume is important to remember when drawing up parts for 3D printing.

 

[tomstaf]

Hi Mick,

Thank you. I'm new to 3D drawing so it'll take me a little while to absorb it but I think I'm with you so far. I'm using Blender to draw my stuff. Here is the screen grab:


I can't get onto Shapeways at the moment so will try again later and take screen grabs from there.

Cheers

Tom

 

[SteveO]

Tom, can you make up 'wheels' of these door-lock indicators - that would avoid the need to make a base for them as they can support each other. You could make 4 units per 'wheel' then get them printed on a per coach basis.

 

[mickoo]

Tom, ok I can see your Gizmo axis is the industry standard ie Z is vertical and Y is forward and looking at your printing it looks like Shapeways uses Y as vertical which would fit the spining view I get with my cabs.

At the moment your large base block follows the Y axis, you will need to rotate the whole assembly so that the large base block follows the Z axis, in other words up end your part so that it's standing up and looking like a big traffic light signal, not one flat on its back, I'll try and check the Shapeways help info and see if theres any other help in their, not my intention to 'waste' your money but I still suggest a sacrificial print in the cheapest format possible to ensue the layers are going the way you want.

Seem to recall seeing some 3D stuff in the scale 7 forum and seeing some of his work at Sudbury (no idea who and its very late at the end of a tiring day LOL), whose next meet is this Sunday so he may be there and I'll ask around for thee, so don't get a blood rush and run off and print a load more off LOL.