DL3 is alive

[Perko7Participant @perko7]

Finally close to completing my 5" gauge petrol loco modelled after Queensland Railways DL class. Been a long process with lots of new things to learn but with several successful tracks tests the beast is now 95% complete. Have added a headlight and cooling fan since photos were taken, still need to add a few cosmetic items but they are jobs for another day. Pulls me quite happily at a decent speed, could probably pull 2-3 adults but not tested that yet. Now on to the next project, hope it doesn't take as long as this one!

[Perko7Participant @perko7]

[Roger BParticipant @rogerb61624]

Looks good

What engine and transmission are you using?

[HopperParticipant @hopper]

Looks like the sugar cane trains that chug past my place in the "crush" season, just south of Cairns, only the DL was much bigger of course. The same ganged counterweights outside the wheels. I hear rumours there is still a DL in use out on the Normanton line. Or was a few years back anyway.

She looks good, anyway. Yes, surprising how much work goes into such things. And they never really are done with. There is always something…

Edited By Hopper on 15/12/2022 10:57:14

[Perko7Participant @perko7]

Roger B, engine is 25cc 2-stroke out of a line trimmer positioned longitudinally, repositioned the carby and made a custom exhaust to fit inside the hood, retained the centrifugal clutch then 2.5:1 reduction chain drive to a drive shaft leading to an angle grinder gearbox to drive the wheels. With the custom exhaust it doesn't sound much like a line trimmer. The exhaust actually discharges through the exhaust pipe you can see in the picture, which is able to be rotated 90 degrees so it doesn't blow in my face when driving. Tried making a forward/reverse gearbox but did not work reliably so that's an upgrade project for another time.

[Perko7Participant @perko7]

Hopper, yes of the 4 locos built to this design all are still in existence. DL1 is in running order at the Ipswich Workshops Museum, DL2 is mounted on a plinth with an awning over it in the town of Forsayth which was the terminus of the line these locos were built to operate, DL3 is in working order at the ARHS Rosewood railway, and DL4 is in operating condition at Normanton and used regularly to haul the 'Gulflander' tourist train.

[Perko7Participant @perko7]

Just an update, I have successfully run it several times now for extended periods with no problems other than an occasional lack of traction particularly on wet track. It’s only a light-weight loco so that I can carry it unaided between car and track when necessary. A bit of hand pressure on the cab roof usually helps it ‘find its feet’ again.

It will happily pull my 85kg body on a 2-axle riding car, plus my two grand-daughters and their mum on a separate bogie riding car, but that would be close to the limit of it’s capacity with the current gearing and weight. More weight and lower gearing would increase hauling capacity considerably but would take away most of the fun of driving it.

When I work out how to add videos I will post a short one of the loco running.

 

[Russell EberhardtParticipant @russelleberhardt48058]

Nice looking example.  Well done!

Russell

[Nigel Graham 2Participant @nigelgraham2]

Fine work!

I assume the angle-grinder gearbox is to give a right-angled drive, as well as its own reduction.

Reversing gear…

Have you considered combining that right-angle reduction drive function with the forward/neutral/reverse gear by using a bevel-gear reverser, in a single unit?

If you’ve not encountered this arrangement, its input shaft passes the outer face of the output bevel gear keyed or pinned to the end of its own shaft, centrally, at right-angles. It carries two bevel pinions straddling the larger output gear, linked by a sleeve with a groove to engage the selector fork; and keyed to slide along the shaft to bring one, neither (neutral), or its companion into mesh with the driven wheel on opposite “sides”.

[Neil WyattModerator @neilwyatt]

Replacement angle grinder gears are a ridiculously cheap source of step down helical bevel gear pairs.

I used one on my own loco.

Neil

[Perko7Participant @perko7]

Hi Nigel, yes the angle grinder gearbox converts the in-line drive from the engine to a transverse drive to the axles along with a suitable reduction.

I have used the angle grinder gearhead complete, and it is not possible to modify the gearhead in the way you describe as it is a diecast assembly. I would need to make a new steel casing to contain the gears and bearings. I did build a reversing gearbox for the back of the engine based on a tumbler reverse as used for lathes, but found it too hard to maintain the gears in correct mesh so did not pursue that.

For now I’m happy having only a single forward speed, but I do have ideas for a reversing drive which will be similar to your description. Just need some time to make it and then even longer to get it working properly!

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