SimonD’s workbench

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simond

simond

Western Thunderer
Back to 3D printing, how’s this?


It’s a 3D printed point actuator, with the lid on its 50mm square by 28.5 high, and as I have wittered on about for some years, the servo is pretty much on TDC / BDC at each end of the stroke, and therefore does not get close to stalling, and does not get back-driven - that, of course might not be ideal if it flings your pride-and-joy into the cess.

It also incorporates a single ZM microswitch with change-over contacts for frog polarity.

I’ve been pondering it for a while and had sketched a few ideas, but basically drew the model yesterday morning, printed it overnight, reprinted the arms this afternoon and put it together whilst the France Poland match was on.

It’s intended for a garden application so the wires come out underneath. I’d expect it to be much better than showerproof, and a blob of silicone grease on the rod and the wires will keep out both water and spiders.

Whilst I was at it I printed a couple of horses and some engine room vent cowls that my puffer has been missing since I built it in 2010 - the wheels don’t grind fast down here! Both were a bit of a disappointment, the cowls were simply too thin (0.3 not good, 0.6 is fine) and the horses were lacking rear legs which seems to be due to insufficient supports under their hairy hooves.

A reprint sorted both problems

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This is the cover

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And the actuator in both positions

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Allen M

Western Thunderer
An original Big-Big (or Nova) Hymec. The little infill for the switches give it away (that's the white bits on the side). I did a bit of improvement to one must be going on 50 years ago now. Also a short artical published in Model Railways on converting to 12 volt 2 rail using the original motor.

Regards
Allen
 
simond

simond

Western Thunderer
yep, less than 20 quid, and the same again on wheels. I did something similar some fifty years back too. It wasn't very good!

Now to 3D print some functional bogies, and use up some of those bits and pieces in the bits box...
 
simond

simond

Western Thunderer
What became very obvious very early on is that when the machine is as capable as it is, you have to make a decision; if you’re trying to make a scale model, you have to get data as good as the printer - not having the detail data is holding up my match truck, and I hope that I can solve it by a visit to Didcot in the spring, with camera, tape measure, and laptop in hand.

The Hymek is more a bit of fun, and a learning tool, I guess, but any pretence to hi-fi scale accuracy is secondary to having a running loco.

The printing will address bogies & drivetrain, buffers stocks (buffers will need to be turned), fuel tanks, exterior details & cab interiors, pretty much in that order.

on the subject of data, if anyone has any dimensions of GW ogee gutters, I’d be very grateful. There’s a goods shed and a loco shed that could be much improved with rainwater goods!
 
simond

simond

Western Thunderer
thanks Dave,
I don’t remember that series.

At 20:14 I‘m sure it’s an Airfix crane base that the loco passes.

I’m planning on two tone green, but we shall see…
 
simond

simond

Western Thunderer
More butterflies…

image.jpg

I blame @Tim Watson, because he mentioned the MRC open day a couple of weeks back. I was quite keen to go, having never seen CF, but the stars did not align. But I found this on the MRC website and took a punt.

It’s clearly of its age, the lettering is quite nice, it looks the part, but it has no brakes, it’s coarse scale and not insulated for two rail!

image.jpg

Gentlemen, I think we can rebuild him…
 
simond

simond

Western Thunderer
A little thank you to John Baker and everyone else who has helped with the 3D printing lark

Iteration 5 (or 6, I’m not quite sure) is front centre, as Henry Higgins might have said “by gad, (s)he’s got it!”

image.jpg

I’m sure there will be more bin-fillers in future but I’m well pleased with progress - thank you all!
 
Rob R

Rob R

Western Thunderer
simond said:
A little thank you to John Baker and everyone else who has helped with the 3D printing lark

Iteration 5 (or 6, I’m not quite sure) is front centre, as Henry Higgins might have said “by gad, (s)he’s got it!”

View attachment 176358

I’m sure there will be more bin-fillers in future but I’m well pleased with progress - thank you all!
Click to expand...
Them there reject tanks will make good scrapyard fodder for someone..
 
Pencarrow

Pencarrow

Western Thunderer
simond said:
Back to 3D printing, how’s this?


It’s a 3D printed point actuator, with the lid on its 50mm square by 28.5 high, and as I have wittered on about for some years, the servo is pretty much on TDC / BDC at each end of the stroke, and therefore does not get close to stalling, and does not get back-driven - that, of course might not be ideal if it flings your pride-and-joy into the cess.

It also incorporates a single ZM microswitch with change-over contacts for frog polarity.

I’ve been pondering it for a while and had sketched a few ideas, but basically drew the model yesterday morning, printed it overnight, reprinted the arms this afternoon and put it together whilst the France Poland match was on.

It’s intended for a garden application so the wires come out underneath. I’d expect it to be much better than showerproof, and a blob of silicone grease on the rod and the wires will keep out both water and spiders.

Whilst I was at it I printed a couple of horses and some engine room vent cowls that my puffer has been missing since I built it in 2010 - the wheels don’t grind fast down here! Both were a bit of a disappointment, the cowls were simply too thin (0.3 not good, 0.6 is fine) and the horses were lacking rear legs which seems to be due to insufficient supports under their hairy hooves.

A reprint sorted both problems

View attachment 175682

This is the cover

View attachment 175683

And the actuator in both positions

View attachment 175680View attachment 175681
Click to expand...

Great work Simon. I understand cowls on a puffer but where do the horses go?
 
simond

simond

Western Thunderer
Pencarrow said:
Great work Simon. I understand cowls on a puffer but where do the horses go?
Click to expand...

I guess pulling a “lurry” in front of that rather oversize goods shed. One day…

they were a simple free download ont’internet, rescaled. There is a wealth of animals, more or less suitable depending on your region, era, and imagination, available for free, and some are really excellent, and mostly only need a bit of judicious rescaling to make them useable. Typically, there’s room to wedge a sheep, goat, dog, whatever onto the build plate whenever doing something serious, and you effectively get a free gift with every print! The horses claimed to be Clydesdales, I’m far from an equine expert, but they have the “look“ to me. Someone did a good job.

There are loads of little details that spring to mind that can just get added to a print run. Loco lamps, bench vices, central heating radiators, chimney pots & telephones I have done, signal, tail & side lamps to do, along with wheelbarrows, sack and platform barrows, a binnacle and wheel for the Puffer, rainwater goods, desks and chairs, the drawbridges for the coal hole…

Currently working on wagon underparts.

what are you going to do about the pannier?

atb
Simon
 
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simond

simond

Western Thunderer
I am enjoying this printing lark.

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the vintage wagon now sits on a sprung 9’ underframe. More below.

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Dean axlebox on 4’6” leaf springs with J hangers. The spring leaves look a little undernourished but that’s not a difficult change to make. They’re currently 0.25mm thick which scales as a little over 10mm. The gaps between leaves don‘t show very much if at all, so they might have to be exaggerated (I think they call it “artistic interpretation”, oh dear, he’s been marked down by the Russian judge again :) ). I do like the visible bolt heads on the hanger shackles.

Do, please, ignore the poor fit of the toolbox to the chassis. They were my first print, and will be redone when I have better data.

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this is the tank, loosely installed on the original kit chassis. That begs questions which I don’t want to answer, there’s no point in replacing the chassis, which isn’t bad, but if I had access to really good data, could probably be printed better. I did make brass globe valves for this, but I will now draw up some to print, as they’ll definitely be better than my free-hand form-tool grinding.


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and this is a 9’ sprung chassis (with the wrong ride height, about 2mm low, easily fixed). As a first attempt, I’m delighted by how good it is. It uses a variant of CSB suspension, using 0.3mm guitar string wire, supported both ends of a 20mm space, and the resulting ride is pretty smooth.

the intent is to print the axlebox as part of the slide-part, so it can’t fall out of the W irons, though in fact it’s trapped by the axle anyway. The strap across the bottom of the W irons is solid, they go in from the top.

I think I’ll modify the slide part so the wire is trapped in a hole, currently it can get the wrong side of the cheek, and would be a pain to sort if assembled to a wagon.

I’m going to have a think about Parkside / Peco wagons, because the same approach should be applicable.

I’m also going to have a think about brake gear. And valve gear…
 
simond

simond

Western Thunderer
Well, I didn't expect to be doing work stuff on my 3DP, then again, I’ve done a fair bit of modelling on the machine tools at work, so I guess it’s a fair exchange. :)

Anyway, I slipped in a few pulley blocks, which might add a bit of nice detail to the puffer. Easier to paint whilst still on the supports!

image.jpg

Atb
Simon
 
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