Scratch building a battery powered steam loco

M

Moonraker

Registered
25 Oct 2009
875
15
South Australia
My Bachmann chassis arrived a couple of days ago and I am starting the build of the South Australian Yx loco this weekend. Price was US$45 plus US$40 shipping...very good value. If I build it to 1:19 scale then the wheel diameter is spot on and the wheelbase is only 11% too big. That makes the chimney height 185mm and I have to check that it will go through my tunnel. I will be putting the batteries in the boiler, so that their weight aids traction, and the RCS radio control, MyLocoSound soundcard, 50mm speaker and charging socket in the tender.
Regards
Peter Lucas
MyLocoSound

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M

Moonraker

Registered
25 Oct 2009
875
15
South Australia
Today I removed all the excess plastic, pipes, etc which I did not need for the Yx loco. Also removed the excess wiring because the loco will be battery radio control. I will not be using the chuff cam because it only has two contact points and therefore does only two chuffs per revolution rather than the correct four. (Why did Bachmann do that, was it an error or deliberate?) I am then left with just four wires going to the plugs at the back, two to the motor and two from the battery.

Biggest problem now is how to fit the two wheel front bogie so that it runs freely and does not derail every five minutes. The bogie wheels are almost completely hidden by the outside axleboxes so, If all else fails, I could just glue the axboxes to the frame and have rimless wheels or even no wheels at all! However I would rather have proper rimmed bogie wheels so does anyone have any ideas?
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Tony Walsham

Tony Walsham

Manufacturer of RCS Radio Control.
25 Oct 2009
2,116
10
Casino, NSW
Hello Peter.
Pity you couldn't get the latest version of the chassis as it has a completely different way of mounting the pilot.
However, I wouldn't worry too much about the front pilot shown actually derailing the loco.
Add as much weight to the pilot that you can and keep the slider bearing surfaces well lubricated.
 
P

Paradise

Registered
28 Jan 2010
709
81
I cut my 4-6-0 chassis front short at specific points (obvious molding features) and embedded a 30mm x 5mm wooded strip in the chassis to stiffen and securely attach the front.
I intend to mount a front pilot that pivots from the extruding bolt in the picture from below. Best to pivot the pilot back some distance for good pilot geometry. My Accucraft 2-6-0s are about 90mm from pilot axle to the pivot. The set-up below will only give a distance of perhaps 65mm if pivoted from the bolt very close to the box part of the chassis. Hopefully that will be enough. Pivoting from further back will be problematic.

You may be using a different front and cylinder position but the geometry and limited space will be similar.
Your wheels will need to be roughly where the dropped down section is where the existing pilot slides. That may have to be removed for the pilot wheel clearance. An entirely different pilot set-up is needed for a 2-6-0 compared to a 4-6-0.

 
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M

Moonraker

Registered
25 Oct 2009
875
15
South Australia
The bogie conversion turned out to be quite easy. I took the Bachmann 4 wheel bogie, moved the sliding pivot to one end and replaced the wheels at the other with a pivot. Seems to work well in limited testing.
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P

Paradise

Registered
28 Jan 2010
709
81
Ah! that worked out well for you. The wheels don't collide with the dropped down section that is usually between the cylinders as I thought. It was too wide and visible for my USA style 2-6-0 conversion so I removed it. Having the pilot's guiding slot will help matters. A flat triangle shaped sheet of metal on top of the plastic pilot with added weight will make it more robust and improve tracking. The pilots are prone to breaking on this 4-6-0 version.
Considering your cylinders are above the pilot axle you will probably not need to shorten the main rods either. Just make sure the angled cylinder centre line goes through the driver's axle centre.
 
Rhinochugger

Rhinochugger

Retired Oik
27 Oct 2009
25,783
761
North West Norfolk
That looks neat - I'm assuming you've tested the curvature of your line :clap::clap:
 
M

Moonraker

Registered
25 Oct 2009
875
15
South Australia
That looks neat - I'm assuming you've tested the curvature of your line :clap::clap:
I don't have any tight curves and it seems to go through my crossovers quite nicely. I'll hook up a battery and do some runs around the whole railway at the weekend but have to remove about ten thousand pine needles first. I have a couple of spring loaded points at exits to loops and these will be the main test....will the bogie derail as it forces the blades over?
 
Rhinochugger

Rhinochugger

Retired Oik
27 Oct 2009
25,783
761
North West Norfolk
I don't have any tight curves and it seems to go through my crossovers quite nicely. I'll hook up a battery and do some runs around the whole railway at the weekend but have to remove about ten thousand pine needles first. I have a couple of spring loaded points at exits to loops and these will be the main test....will the bogie derail as it forces the blades over?
Yeah, I don't have any points set like that, don't like 'um - even though they're prototypical on some light railways

I'd have thought that pony truck would do 8 footers OK :nod::nod:
 
Tony Walsham

Tony Walsham

Manufacturer of RCS Radio Control.
25 Oct 2009
2,116
10
Casino, NSW
Peter.
Weight on the pilot truck will not help a lot.You will definitely need to spring load the pilot quite a lot. A spring strong enough to let the pilot truck go through sprung turnouts will mean adding a fair bit of added weight in the boiler to keep the front of the loco down.
 
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M

Moonraker

Registered
25 Oct 2009
875
15
South Australia
Peter.
Weight on the pilot truck will not help a lot.You will definitely need to spring load the pilot quite a lot. A spring strong enough to let the pilot truck go through sprung turnouts will mean adding a fair bit of added weight in the boiler to keep the front of the loco down.
I strapped on a battery and gave the chassis a run round my railway and through the sprung points. It went round smoothly and no extra downforce on the bogie was needed.

Regards
Peter Lucas
MyLocoSound
 
Tony Walsham

Tony Walsham

Manufacturer of RCS Radio Control.
25 Oct 2009
2,116
10
Casino, NSW
That is great Peter.
That proves I was wrong then.
 
M

Moonraker

Registered
25 Oct 2009
875
15
South Australia
Finished at last after a year and a half. Business (MyLocoSound) has been brisk and modelling time limited so the South Australian Yx loco I started building in April last year was finally finished and taken for its first public outing last weekend. Total cost was A$745 (about 400 pounds), a third of which was the radio control and sound. It is powered by 12v batteries in the boiler. The chassis was purchased from Bachmann as a spare part (US$45), the tender wheels from Slaters, the front headlight from GRS and the rear coupling from Kadee. Everything else was done on my laptop computer at home. The cab and tender were drawn up using CorelDraw and were then laser cut in 3mm MDF by a local company for A$40. Everything else was drawn up in 123D Design and was 3D printed on my own UP Mini2 printer. Lining was done in Microsoft Paint and printed on decal paper. Handrails and cow catcher are brass wire.

Now to start on some rolling stock for the loco.....

Peter Lucas, MyLocoSound
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tac foley

tac foley

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11 Apr 2017
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That, Sir, is nothing less that superb. My cover is removed in your presence.
 
Riograndad

Riograndad

Model Railroading, boats and oil painting,
6 Jul 2013
1,683
335
65
Northampton UK
Great build ,well done sir!!!!:cool:Any chance of some different angle pics?
 
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Rhinochugger

Rhinochugger

Retired Oik
27 Oct 2009
25,783
761
North West Norfolk
Nicely antipodean :clap::clap:

Does it have sound ;);):p:p