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cakebox Gn15 Rowland Emett



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#1 riscosuser

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Posted 22 January 2018 - 10:24

I was discussing the BRM Cakebox challenge at the Manchester show.

It was commented that there was not much space.

"I could fit a circle of track in that space " I replied.

T gauge, Z gauge or 009 a possibility? people mused, but that would be silly!!

 

So Gn15 Emett it had to be.

 

I have pre-tested some items so some pictures are post-assembly

 

The initial concern was bending the (code 100) track to the correct diameter never having tried this before.

 

I was advised to use bullhead rail rather than flatbottom, which is good advice, but having none in my bits box flatbottom rail it was.

 

Since the inside rail was only going to be 3-inch radius (76mm), care bending was clearly needed. 

 

I used a metal (magnetic parts) tray to help bend the rail.

 

Rather than use a track joiner rail was soldered directly to 6mm PCB sleepers. The rail being cut to size in situ.

 

IMG_20180121_195342_1.jpg

 

I also realised it was going to be easier to use the tray to form the track reducing the radius to 72mm in the process.

 
The second rail, pre-bent in a similar way, set using a track gauge to 16.5mm.

 

IMG_20180121_195535_6CS.jpg

 

The PCB copper was then split by grinding the top surface off rather than cutting. I prefer this method both aesthetically and mechanically.

 

The prime mistake was to use a cake base, as the corners started to curl. So this was cut to leave a track base, a plywood base to be added later.

 

 

 

 

 


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#2 Hroth

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Posted 22 January 2018 - 10:36

You could do a model of Trevithicks "Catch Me Who Can"....

 

Trevithick's_steam_circus.jpg

 

 


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#3 outcastjack

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Posted 22 January 2018 - 12:25

I think, this is fantastic, a real challenge to get something of that gauge top run nicely with a >20% difference in distance at the outside rail vs the inside one.

 

Will you be trying to use normal stock or building something special to suit?



#4 riscosuser

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Posted 22 January 2018 - 15:17

I already had a potentially suitable loco. However, time had not been kind.

 

The rear split axle, a Romford axle cut in half, had split the plastic joiner.

 

After trying a few methods the one that worked was to take a solid plastic rod and drill a 3.2mm hole using my little unimat.

 

A spot of cryo on the end of one axle half, as an insulator, and the two half pushed together. Success!

 

IMG_20180122_144806.jpg

 

All the original driver's chair plastic surround was smashed, so a new one made from wire as per the cartoon.

 

The axle width is 38mm, it does negotiate the curve but wheels spin/drag is inevitable.

 

IMG_20180122_144640.jpg

 

I still need to make a pair of "mudguards" however the height issue means little space for an umbrella.

 

I hope this answers outcastjack's question.

 

 

 

 

 

 

 

 


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#5 riscosuser

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Posted 23 January 2018 - 11:43

I've noticed other people are quoting a build list.

 

The only thing I've bought so far is the rod to repair the back axle, and a 1:24 trilby ( I couldn't find a cap) rest is cardboard, packaging glue & parts out of my gubbins box.

 

 

From the beginning, it was clear all main items needed to be on a common centre.

 

First item the platform.

 

IMG_20180122_152756.jpg

 

At this point, I did a test run to check clearances.

I've noted that at min speed power consumption is just 65ma so I'm wondering about using battery power.

 

Next thing station building. 

I spotted a sandwich filler tub.

A nice lean to the building?

 

IMG_20180122_153138.jpg

 

I intend to have a tree(s) so I cut down the container to just over half size and put in a back.

 

A few evenings work and this is the result.

 

IMG_20180122_153332.jpg

IMG_20180123_112705.jpg

 

next the roof!

 

 

 


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#6 ukpepsi

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Posted 23 January 2018 - 19:10

I already had a potentially suitable loco. However, time had not been kind.

 

The rear split axle, a Romford axle cut in half, had split the plastic joiner.

 

After trying a few methods the one that worked was to take a solid plastic rod and drill a 3.2mm hole using my little unimat.

 

A spot of cryo on the end of one axle half, as an insulator, and the two half pushed together. Success!

 

attachicon.gifIMG_20180122_144806.jpg

 

All the original driver's chair plastic surround was smashed, so a new one made from wire as per the cartoon.

 

The axle width is 38mm, it does negotiate the curve but wheels spin/drag is inevitable.

 

attachicon.gifIMG_20180122_144640.jpg

 

I still need to make a pair of "mudguards" however the height issue means little space for an umbrella.

 

I hope this answers outcastjack's question.

Perhaps the umbrella is still possible. AFIK it only has to transportable in the cake box, so once removed to show it running, the umbrella can be added.

Just a thought.

 

Pepsi



#7 Northroader

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Posted 23 January 2018 - 20:17

On very tight curves, wheels sometimes get sniffy at the rail joins, so it might help to have check rails there. Like it, but then I’m an Emett fan.

#8 riscosuser

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Posted 24 January 2018 - 10:02

I think I have the basic shape of the roof done.

 

It passed the clearance test as well.

 

I've cut a new base so that's the next thing.

 

IMG_20180122_153906.jpg

 

I am a bit concerned I might have misjudged the height when the new base is added.

 

The 6" height is giving me multiple issues.

 

It's a pity it's not an 8" cube!


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#9 peter220950

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Posted 24 January 2018 - 13:07

Spring load the top roof section, so it will retract when needed, that should solve the problem!

Peter

Edited by peter220950, 24 January 2018 - 13:07 .


#10 dave ottney

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Posted 24 January 2018 - 14:46

I really like these Gn15 fantasy themes. The cartoonish (kind of steam punk) character makes me chuckle and I'm always in awe of the builders' creativity. Great job can't wait to see the progress.
Dave

#11 riscosuser

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Posted 24 January 2018 - 20:10

Spring load the top roof section, so it will retract when needed, that should solve the problem!

Peter

 

Is this permitted by the rules?

 

I had wondered about animating that section by rack & pinion or crank & slider.

Only problem being you would see the mechanism.



#12 peter220950

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Posted 24 January 2018 - 21:01

Is this permitted by the rules?

I had wondered about animating that section by rack & pinion or crank & slider.
Only problem being you would see the mechanism.

The rules state it must fit in a cakebox, not that it has to remain in it to be displayed, my thoughts were a lightly sprung top part which would retract when the lid was closed, thus fitting in the box.

I think the general sprit and point of the Competition is about modelling, not being too pedantic about rules. - Particularly with the sort of eccentric delight you are building!

As with the best Formula 1 innovation and design, the first thing to do is take the regulations and see where the loopholes are.


Peter

Edited by peter220950, 24 January 2018 - 21:01 .

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#13 Northroader

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Posted 24 January 2018 - 21:22

That’s the trouble with modelling on an Emett theme, everything has not much length, not too much width, but far too much height.

#14 009 micro modeller

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Posted 24 January 2018 - 23:28

I like the loco. Watching with interest as a couple of my ideas might involve continuous run.

#15 riscosuser

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Posted 25 January 2018 - 17:47

Board cut to "size" clear measure twice didn't work as I've since found it is a fraction oversize. At least I have a rotary sanding table.

 

Part of the concept is that the parts will separate so this makes life a bit easier.

 

IMG_20180125_165846.jpg

 

I've gone to the battery power supply option. Just wondering whether to embed them in the model or have them removable.

 

After ballasting the track cleaned the paint & glue off the rails and ran a quick test.

 

 

Link fixed :)

 

 

 

 

 

 

 

 

 

 


Edited by riscosuser, 25 January 2018 - 18:19 .

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#16 riscosuser

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Posted 29 January 2018 - 00:43

Station progressing, will upload a photo when done.

 

Getting any trees to fit is definitely an issue.

 

I was asked at the 7mmnga show on Saturday about the battery setup. 

 

I hope this diagram is more useful than my verbal description was.

 

BRM PSU-Control.png

 

The total cost of the above is under a fiver!

 

The PWM module is rated 5A, although it should shut down in an overload (short) situation, I've played safe and used a 4A limit on the battery protection board.

 

I could have used smaller rated components but there was no cost saving and I may wish to reuse them in another project.

 

N.B. This setup would work rather nicely on a simple garden battery loco.

 

For my purposes (assuming 2.4Ah capacity)

 

Loco 65ma * 2x leds @15ma (approx 0.1 A) = 24 hours runtime or a 3 Day exibition on one charge.

 


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#17 riscosuser

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Posted 31 January 2018 - 13:43

IMG_20180131_100703.jpg IMG_20180131_100641.jpg

 

Board now within size, I used my bench belt sander...took nearly a minute to do.

 

Made some progress on the Station, not 100% happy yet think I need some ridge tiles/capping of some form.

 

I've managed to get within the height limit by removing the lid from the filler tub. This means the roof sits more a little more on the walls.

 

Wondering whether to tone down the colours, or leave them as they are?

 

The tar/felt paper roof method works, I used acrylic on masking tape, but I feel the strip edges need a bit more definition at this scale.

 

Struggling a bit for the trees, I'm thinking of attempting to do a bespoke Emett style tree in wireframe. Again the height is an issue.

 

Currently doing the signs.

 

 

 

 

 


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#18 Mikkel

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Posted 31 January 2018 - 20:33

Very nice work, and deceptively simple. Not an easy look to get right, or to solve mechanically. Yet another proof that this really is the greatest hobby in the world  :)


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#19 riscosuser

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Posted 02 February 2018 - 09:57

A quick visit to my local model shop confirmed I'm going to have to scratch build the rest.

 

Some brass angle strip has added another £2.00 to the build cost, so I'm rapidly heading for the £10 budget I set myself.

 

Shame I wasn't doing 1:12 scale (plenty of dolls house items in this scale).

 

Last night I did the wireframe for the "Emett" tree, First "coat" is still drying so I'd mention how I do wireframes.

 

( N.B. if you want to zoom on the bark effect open picture in another window on your browser)

 

IMG_20180202_085630.jpg

 

Materials are just garden wire, a reel is £1.00, cheap acrylic brown sealer again a gun cartridge is £1.00. 

 

Tools, well pictures speak a 1000 words. I use neat car windscreen antifreeze as acrylic thinner. 

 

IMG_20180202_085836.jpg

 

My tip for keeping the sealant in the cartridge fresh is to NOT use the nozzle as intended, instead use it as a cap after use.

 

Make the frame from cut lengths of wire twisted around themselves, if unsure cut longer than you think you need...it's not as long as you think.

 

Don't worry if what you have looks ugly at this stage.

 

Squirt sealant into a sealable container and then apply neat over the wire frame with a spatula (coffee stirrer).

 

Sweep along the length of the wireframe.

 

Leave for about 8 hours. A quick spray of leftovers in the tub will stop it drying up.

 

If the "bark" is too coarse for the tree you are modelling carefully apply finger pressure all around to smooth the effect at this stage.

 

There will be gaps, don't worry now fill them in. If the sealant is too thick apply more thinner.

 

Finally, the tips can be painted with thinned sealant before applying foliage.

 

In the case of this tree that will be limited.

 

Even if you have to go out and buy the materials, £2.00 will build a small forest!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


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#20 Northroader

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Posted 02 February 2018 - 14:33

Good going, you e captured the “Emett” tree look perfectly.

#21 riscosuser

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Posted 05 February 2018 - 15:59

Still working on the tree's.

 

I had thought to use a grey acrylic wash to "lighten down" the trunk to be more like Emett's drawings.

 

Did not get the result I expected.

 

IMG_20180205_124832.jpg IMG_20180205_124907.jpg

 

The Second tree won't fit, but the colour change is quite dramatic. Saved for Smokey Mountain I think.

 

 

 

 

 

 

 


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#22 riscosuser

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Posted 07 February 2018 - 21:21

In keeping with the concept of being able to remove the station in sections. I thought about lighting.

 

<cheapskate mode on>

 

I removed some SMD LED's from a dud LED spotlight. Quite simple if you use an old scalpel blade under the SMD when desoldering.

 

To work out the voltage drop connect a 1K resistor to the LED connect to a power supply to measure the forward drop, in this case, 3V.

 

I found only a small drop in light from running them at just 5ma rather than 10-15ma since this is going to be battery operated it was a no-brainer.

 

Connecting 2 together gives a 6V drop, the maximum battery voltage is 8.4V . So resistor needed R=V/I , 2.4V/0.005 = 480 Ohms.

 

Since I had some 430 Ohms in my bits box that was close enough.

 

I then used two coffee stirrer ends sunk through the platform with corresponding holes in the plastic tub (building).

 

I used impact adhesive to fasten the LED's in place and then set it using superglue.

 

quad_pic.jpg

 

I think the end result works OK.

 

IMG_20180206_163451.jpg

 

Working now on attaching the other trees, and some static grass.

 

 

 

 

  


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#23 riscosuser

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Posted 09 February 2018 - 23:47

Most of it done, need to tidy up a few things including the control. Then landscape the rear centre.

 

Just wondering whether to take it to Doncaster for a size check.

 

IMG_20180209_233234_1CS.jpg

 

Sorry about motion blur on the loco.

 

 

 

 

 


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#24 riscosuser

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Posted 11 February 2018 - 15:30

I took it down to Doncaster on Saturday.

 

Confirmed it fit's into a cake box. it then sat running on the BRM stand for over 7 hours, so I think it's fair to say it's reliable.

 

The "removal from the cake box" handle raised a few smiles.

 

Was told get a move on and finish it. :)

 

IMG_20180210_102011.jpg

 

 

 

 



#25 009 micro modeller

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Posted 11 February 2018 - 17:29

Good to see it at Doncaster and see the loco running.











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