Garden Railway Forum

As mentioned on the 'What have you been up to...." thread, I've decided to turn my spare Bachmann Lyn motor block into a Kerr Stuart Skylark.

There were quite a few variations on the basic "off the shelf" design and so I've decided to go for that used on the Metropolitan Water Board Railway.
As with all my loco builds, I've started with the running plate.
I'll get that printed out and see if it needs any further tweaking to fit on the motor block before going any further.

Rik

A bit more progress. While I'm waiting for the running plate to print (14.5 hours), I thought I'd crack on with some of the other bits. Normally, I'd do the cab next but this time I thought I'd start with the other end.

Smokebox and its support Boiler next, I think

Rik
PS - As you can see. This version of the Skylark had very few rivet or bolt heads - quite a smooth finish.

I might have to rename my locos. This one was called Sunbury. I name my steam locos after local villages and I already have one named Bunbury. I think it would be more appropriate to call this one Bunbury

Rik

Looking forward to seeing this progress, I don’t live far from the site of the old water board railway and have always thought it’d make a nice modelling project!

That is a really nice little locomotive to have doing some light work on your line Rik. I was most tempted to buy the PDF Models version when it was introduced but missed out on the special offer. I can't find their website now, are they trading again following the tragic loss of Peter?

Peter Butler wrote: Wed Oct 06, 2021 2:46 pm That is a really nice little locomotive to have doing some light work on your line Rik. I was most tempted to buy the PDF Models version when it was introduced but missed out on the special offer. I can't find their website now, are they trading again following the tragic loss of Peter?

Yes they are still trading and still doing the Skylark for £120

https://www.pdf-models.co.uk/product-pa ... rt-skylark

Well, the running plate has printed OK.
The motor block has been lightly butchered:
Before
And after
The outside frames have been removed (I'll print more appropriate ones later), the tops of the cylinders have been clicked off and the moulding at the back attached with a razor saw to take the running plate - which, I'm pleased to say, is a good, snug fit.
I can now play around with the cab and boiler parts which might need to be remodelled to accommodate the top of the motor block.

Always a very satisfying feeling when the running plate has been done.

Rik

Excellent start Rik and a sound foundation to support the superstructure too. Looks like a decent surface finish with not too much preparation work required for a good paint finish.

Now pressing ahead with the rest of the boiler. My model is a compromise between the proposed design for the MWB locos and what was actually produced. The proposed locos had a longer driving wheelbase (much closer to the Bachmann Lyn dimensions) and the step down in the running plate was further back (which fits the block better). I've decided to keep the larger firebox though, (not on the proposal) as this is quite distinctive.

So, here's the boiler - modified slightly to fit over the motor block
And here's the firebox. 3D printing is better at producing curved edges than even my most careful filing and sanding achieved on my plasticard builds. Again, the cut-out is to clear the top of the motor block.
Rik

On reflection, I decided to enlarge the cut-out on the firebox to give more room for batteries and other gubbins.
Rik

A bit of cosmetic work on the backhead (stolen and then reworked from my Schull loco)
Rik

Cab sides and front and back now done - and the boiler parts are being printed.
Rik

Those drawings are most impressive Rik. Every time you post a drawing, I just wish I could get on well with Tinker!

Thanks Philip
I supposed my bodgelling background helps. You'll notice on most of the drawings there are tiny flaws where some shapes aren't quite aligned properly. I think most conscientious modellers would keep going back to make minute adjustments until there was perfect alignment. I've learned to live with those small anomalies. I've realised that, with a 0.4mm diameter nozzle, they aren't picked-up during the printing process.

If I was selling the drawings or the models, I might be a bit more assiduous.

Rik

ge_rik wrote: Fri Oct 08, 2021 9:19 am I might be a bit more assiduous.

I believe you can get an ointment for that now!

The front end is slowly getting there ...... .....but the back end less so. They say every day is a school day. I thought I might be able to get away with printing the firebox as a single unit hoping that the inherent stringiness of PETG would enable it to bridge the void beneath the backhead ...... no such luck!
The strings turned to blobs which caught on the nozzle and pulled it off the bed.

So Plan B. Sliced the firebox into two and print the two parts separately.
Not wasting the bit I've already printed, though. I'll tidy it up and stick the backhead (which is now printing) to it. Waste not want not.....

Rik

Tanks now drawn. After my previous experience, I'm trying to decide on the best orientation to print them. There are overhangs whichever way I turn it. I don't like using supports unless there's absolutely no alternative.

Rik

As a bodgeller, I don't tend to plan ahead and so I tweak and adapt each model as it progresses. In the days when I was doing this in plasticard, I would sometimes have to hack bits off a partially constructed model so the next bit would fit. I've extended that bodgelling approach to 3D drawing and printing.

Now I've drawn the tanks, I've realised I can do away with the lower section of the boiler to provide more uninterrupted room inside for the electrics. So, I've sliced away the lower half of the boiler where it will fit against the tanks. I anticipated that might happen so that's why I've not printed he boiler as yet.
Rik

The drawings don't show the tank fillers and the photos don't help much, other than that they seem to be round. I can't see a handle or hinge so have improvised. As my loco is an amalgamation of what was proposed with what was actually produced, I think I can I'm allowed some artistic licence. Drawn in two parts to overcome the dreaded overhang.
Rik

The two parts of the firebox have now been reunited ....
.... and so the loco is beginning to take shape.
Rik