Garden Railway Forum

I use a spring in my whistle pull so that the valve is pulled wide open without anything getting strained.





Best wishes,
Dave.

I've not had to machine gears yet, are you using commercial volute cutters, or do you make your own? It's a bit hard to work out from the photos, but could you fix the bevel gears on a sliding sleeve so they move together? Hi Graeme, I'm using a homemade cutter as detailed in this excellent resourc...

After yet more months of behind the scenes work I can now reveal the final transmission set-up. https://i.postimg.cc/65Jq6R4L/DSC09560.jpg The gears are in constant mesh and are connected to their shafts by sliding dog-clutches. The gears on the jackshaft are Loctited to the shaft, the other gears r...

A gas poker burner does not seem to be a very efficient way to heat a large diameter boiler as the surface area of the flue tube(s) is quite small compared to the water volume, this may explain why most gas boilers of 2.5 to 4 inch diameter sold for model boats use Cheddar type ceramic burners in f...

So where does the exhaust from the cylinders go? I think I'd prefer to have a open smoke box and no uptake if it were mine. The exhaust goes straight down behind the rear wheels.  This was a special set-up for an unusual model.  I think the boiler is efficient with the uptake, and is helped by bein...

GTB:94560 wrote: Great minds think alike......

They sure do :-)

What burner design are you using? The cab photo looks like they are your own build.

They are full length standard type slotted-top burner tubes. I used the popular 5/16" K&S brass tubing.

Best wishes,
Dave.

That boiler looks promising, can I ask why you have the internal uptake tube? I thought the air came in the back of the burner and out the front into the smokebox? I have to say, this project I am going to keep an eye on. :) I didn't have room for a smoke box, I wanted the largest possible boiler t...

A quick calculation suggests that a standard Roundhouse boiler would be able to steam four 10mm x 15mm cylinders (3/8" x 5/8" for the non-metricated). Excellent work Graeme. With my project, I calculated that my loco would use twice as much steam as a Roundhouse due to the gearing and cyl...

I'd recommend making your own boiler. I made a two burner boiler for my project, a great learning experience. http://s20.postimg.org/632nq4n0d/DSC04416.jpg Best wishes, Dave. Hmmm...  I would have liked to use a standard factory boiler, rather that getting a custom boiler built. Roundhouse is the on...

Thank you chaps.

David.

Which Mamod loco is the best bet? The saddle tank looks very attractive. But, would the lovely finish cope with the heat over time? http://www.mamod.co.uk/wp-content/uploads/2012/04/CRW_8310X31-300x300.jpg Would the standard loco be better? http://www.mamod.co.uk/wp-content/uploads/2012/04/CRW_8326X...

On Sunday we had a fine outdoor test of the new clutch and gearbox. https://i.postimg.cc/hPWsj6MQ/DSC00445-s.jpg https://youtu.be/cviKwhmRRpg I've been green and plumbed the excess engine oil from the muffler into the gearbox. The gearbox covers are to stop oil-spray and dirt getting in, and are not...

I have been working quietly behind the scenes for months. We now have a primary gearbox fitted with a 4-stage spur gear reduction. The gears are quite massive and the whole box weighs quite a bit. Here's a short video of me powering-up the box using the lathe. https://youtu.be/1-Oglt0SEbg Best wishe...

I don't like the sound of those resonator whistles either. Three of my loco's have homemade normal whistles, I think they sound great. Check out these for all three. One is much larger than the other two. www.youtube.com/watch?v=Jq4MbCBAF6Y www.youtube.com/watch?v=LNQcoanpK18 www.youtube.com/watch?v...

Excellent write-up Jim. We really appreciated it.

Best wishes,
Dave.

From an engineering point of view one should never put a flywheel at the end of a shaft, particularly with a single cylinder engine. you are going to get torsional vibrations at some revs or other. Worm gears are always less than 50% efficient, typically less than 25%, just saying. Thank you for th...

Lovely job Richard.

Best wishes,
Dave.

when you do eventually get round to encasing the engine you will probably need to consider forced cooling. The engine was originally designed to be forced cooled by an airplane propeller or in an RC car you generally need to keep moving to prevent overheating. I have been thinking of a fan cooling ...

These two videos show the effectiveness of the new silencer: First run on the track: https://youtu.be/VAau9DXbA4A New silencer: https://youtu.be/8rOLsg2fSXk I have bought one of these non-contact IR laser point infrared digital thermometer temp guns from our friends at ebay.  Excellent service, post...

I thought I'd try a massive secondary flywheel in a handy empty spot at the rear of the loco. It wasn't a success, it slowed the motor down a bit - needed more throttle, and always came loose. When still clamped securely it didn't improve running much. I've taken it off now. These are the latest pho...