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Fox Walker 0-6-0ST 2mm scale


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Thank you!

 

I thought I would have the wheels finished by now, as the future Mrs Degree has gone on yet another weekend away with the girls. And, as I'm literally left holding the baby, that leaves me in front of either the 'box or the desk.

 

Having made a trial run with my spare wheel on the etch I soon found it was going to be VERY difficult putting these wheels together without some sort of aid. Cue a handy baby building block, and a few minutes later, a jig!

 

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That brass wire is 0.3mm, and I drilled the pilot hole!

 

This is the first one complete. Another 5 to go. I was going to have a relaxing soak in the bath reading about Hymeks. I guess I'll have to put off this week's bath and have a special one next week. I may even use soap!

 

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Wheel assemblies fixed to temporary axles, chassis made up and brake assembly fixed on. I've yet to bend the brake shoes to the correct position but this is a simple and fiddly job best saved for another day with a bit more sleep.

 

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The curved hangers sticking out are the brackets that the rods coming out of the piston tubes fix to. Apologies for my lack of technical terms but I have no idea what they're called. It's probably an opportune moment to tell you that I've never been very close to a real steam engine before, unless you count the one I drove past on Brighton sea front a few weeks ago...

 

Close up you can see so many errors that are invisible with naked eyes at a normal viewing distance. The layered wheels, for example, look awful! During the making of this engine I use an illuminated loop. My other hobby is collecting and trading gemstones so I need a good eye glass for that too. Incidentally, if anyone's getting engaged or needs a stone for a special occasion please get in touch!

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While waiting for a client to get back to me with feedback, I couldn't resist trying out fitting one of the connecting rods. To stop excessive friction from the rod scraping on the wheels, I folded the ends double so it stands off while the wheels turn. I tested it out and it works great! I tried pushing it along to make a video but it needs more weight for traction on most surfaces, but it runs along my finger very well.

 

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I've now encountered a problem: how do I block the ends off so the rods don't slide off? I could add a blob of something but it would be very obvious in close-up photography. Ideas or solutions very welcome!

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Thanks Andy. God's honest, never anything like this. Airfix and Tamiya kits are the closest I've got but that was 25 years ago! My approach to this has been science, logic and super glue. And plenty of patience...

 

When you say 'temporarily hold' do you mean that something else is used later or held for when you need to take them off for repair or maintenance?

 

I've yet to do the other side as I don't have a ruler accurate enough to measure 9.42mm. Bogieman has been very kind enough to send me a piece of track for me to measure the gauge so I'll wait for it to arrive before completing this stage. After that it's the incredible delicate outside motion - the piston cylinder (?) is on it's way in the post. For the motion rods (?) I'm using jewellers 0.3mm brass wire.

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When you say 'temporarily hold' do you mean that something else is used later or held for when you need to take them off for repair or maintenance?

 

Usual 2mm practice is to use the insulation collars whilst the valve gear is being set up, a brass washer being soldered (carefully) on as a permanent solution. In your case I'd avoid solder - the fumes given off by superglue when heated are nasty, and as you're building an unpowered chassis, the connections shouldn't be subject to the same stresses as if a motor were fitted.

 

Andy

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Thanks Andy. My powered version definitely will be soldered so I'll bear that in mind.

 

I can't continue with the chassis build until I get a couple parts, namely the cylinder tube and the kindly donated piece of track. So tonight I started to build the cab. These are the constituent parts cut, bent and ready for glueing. You'll notice that I've modelled the interior of the cab, based on other Googled small engine interiors. Just in case this half-etched version failed (it was quite curly when I received it) I had also included a plain cab front on the etch. I've managed to straighten this one so I'll keep it.

 

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Roof glued to front and back, just test-fitting the cab bunkers...

 

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And the final completed cab all glued together.

 

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While I'm building this I'm correcting small errors on what will be my final motorised etch so this is a very worthwhile experience. For example, I'm now making the wheels a slightly larger diameter so I can get them turned or filed down to the correct profile and not have that soft-edge layered effect that they have now. Also, not having half-etch tabs connecting half-etch items, which are very liable to bend when you cut them free! Other than that, everything has gone together quite well so far, which nobody is more surprised at than me.

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Guest Natalie Graham

 

For example, I'm now making the wheels a slightly larger diameter so I can get them turned or filed down to the correct profile and not have that soft-edge layered effect that they have now.

 

An alternative might be to make them without the flanges so you could fit a turned tyre, or else maybe if your turned them down and then got the wheels nickel plated you might get a better finish for running purposes as well more realistically coloured rims.

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...more realistically coloured rims.

 

I have been fretting over this exact point. The solution I'd thought of was to get the wheels etched in nickel silver, and they'll be harder wearing too, or to coat them in solder but I wasn't sure how long that would last. I hadn't thought of separate tyres, which would also introduce the possibility of some sort of insulation. I'll certainly think about this more as I get closer to the final etch. Thanks Natalie.

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Before I retire for the evening (my birthday tomorrow!) I just thought I'd show my workbench.

 

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What you see here is a small kitchen cutting board, various modellers tools (though I could do with some smaller ones!) and my illuminated jewellers loop. Except for cutting the cylinders with my new saw, this is all I've used to to construct my little loco. Even though I have a set of tweezers, I find them more difficult to use than the small curved nose pliers, though through the loop they look huge!

 

Through my inexperience, I noticed that I've missed out a way to fix the cylinders to the frames so I'll have to make something from the etch border. Also, I don't exactly know what I'm going to do about the boiler furniture yet.

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Completely off-topic, but I'm changing storage facilities for my gemstone collection and I had the camera out shooting some ebay items. This is what I normally use the loop for.

 

These are most of my rubies. Largely from Madagascar but I also have 3 Burmese:

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These are blue and a few coloured sapphires. Almost chemically the same as rubies, both are corundums. Again, there are some Madagascan but there are also some Ceylon/Sri Lankans in there too:

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As a contrast, these are fairly common quartz, Amethyst and Citrine. Some fairly big stones here:

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And lastly a selection of other smaller collections. Top is Brazilian Topaz, left D Block Tanzanite and right are Pakistani Peridots.

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These and the other stones are going into new secure storage tomorrow. Nervous night tonight!

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Thanks Peter, I have so many interests it's hard to concentrate on one for too long before I start looking at another for a while. I've been collecting stones since I was about 15, so over 25 years. Apart from owning something beautiful and natural, not forgetting comparatively very rare, I love the trading aspect too.

 

As my collection has grown and become quite valuable I don't have them readily available to look at any more so this was a good opportunity to get reacquainted. They all need a good clean as the storage conditions are not ideal. They're normally very sparkly!

 

Returning to the Fox Walker tonight, back on topic.

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Hello The Nth Degree,

 

WOW!

I just didn't think you were working with a loco this small!

Post #66 just has me in awe of your work!

I love what you have done and so quick and effective too.

 

Now, getting to a prime mover for little “Fox Walkerâ€.

There really is not a lot of room there!!!

I'm afraid I can only see problems ahead. Have you sourced an 8 or 16 pole stepper that can fit in Fox Walker yet?

 

A “micro†stepping controller not only requires the electronics to control the 2 windings of the stepper but, in addition, it also requires a separately controllable power supply for EACH winding!

In other words – more complexity means more space.

I don't think I can recommend a stepper in your particular loco.

 

I thought (for a short time) that an AC synchronous motor might be better bet than a Stepper as ALL the electronics could be in the (specially made) controller which only requires 2 wires to the motor, well rails in this case.

The advantages would be:- 1; no electronics in the loco, 2; accurate speed control.

The disadvantages are:- 1; size – still too big, 2; controller electronics complexity (but at least size doesn’t matter here!), 3; limited speed range – synchronous motors are optimised at line frequencies (usually 50 or 60 Hz), 4; and this is the killer (excuse the pun) they usually run at mains voltages! (Anyone fancy 240 volts on their tracks?)

DON'T TRY THIS AT HOME FOLKS!

 

I might have stumbled across something that might suit (fit) your requirements.

I have posted, on my 2012 Challenge - Smart Driver Board – post #19, a picture showing a little servo that I acquired in XiAn.

If you dismantle it then you have all the parts required to drive/power your Fox Walker – and all for £2!.

But, and this is one giant great huge but, you will need to interface to, and (re)program, the electronics contained in the servo's driver PCB.

The dc motor size is approximately 6mm diameter by 10mm long. The PCB looks to be about 6mm by 12mm. But, again, I have no idea what the circuit is. (Apart from it being a standard servo PCB.)

You may be able to find a “friendly†servo that you could use a donor to power your loco.

 

(There is a bit more I need to post here but it really depends on which way you go.)

 

Regards,

Kev.

(Sorry, no 5p pieces here so I had to improvise!)

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WOW!... Post #66 just has me in awe of your work!

You, sir, are making me blush!

 

There really is not a lot of room there!!!

Agreed.

 

I'm afraid I can only see problems ahead.

I see them too...

 

Have you sourced an 8 or 16 pole stepper that can fit in Fox Walker yet?

Yes I have, it's a 6mm x 7mm bi-polar stepper. It's beautifully engineered but, I regret, I've decided not to follow this route. There are so many complications to overcome and all I really wanted to do was save the space a gearbox would take up with a small chip. That, clearly, is not going to happen. I have one or two other options I can explore before I resort to a very small rubber band...

 

Kev, thanks for taking the time out of your project to help, I really appreciate it.

 

I've not been doing anything on mine for a few days as my vision started to go very blurred and niggling headaches started to come and go. So I took my O gauge goodies out of their boxes and looked at those for a couple days. Nice. I also bought a new toy:

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Hopefully this will stop the ailments and I can carry on. I'll give it a go tomorrow in good light as I've done all my proper fee-paying work tonight, just in time for Match of the Day.

 

Steve

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but the liquid in the other glass won't...

Peter, it's all I can do to remain sane over this! After a good few days' rest my eyes are back to normal. I'll be back on this later tonight, providing clients don't have other plans...

 

Some wonderful work here. Have you considered a career in watch making?

 

Following with interest.

Thank you! The trouble is, I've been 'watching' for far too long, hence this jump into the deep blue. I really am enjoying it so far, apart from the eye trouble. A '90 Rioja sorted that out though!

 

Thanks for your interest!

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