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Discussion Starter · #1 ·
Dear all,

we are a couple from Italy, and we have built, starting in 2008, our small mining layout, depicting the loading station of a nickel mine, complete with operational 2-way hoist and skips, silos, conveyors, rail link, and operating rotary railcar dumper. Attached a link to a web page of SWR with one video of their 8 Dec. broadcast. At elapsed time 6 minutes 10 seconds, there is our layout, filmed at the Intermodellbau Dortmund 2012.

http://www.swr.de/eisenbahn-romantik/775-m...mhb0/index.html

At the time of this video, the layout was not 100% complete. At the following Euromodell Bremen 2012 and Jahresausstellung Eisenbahnfreunde Breisgau Freiburg 2012, the layout was (finally..) complete with the rail link to the dumper.

1) we would like to enter in contact with other modelers interested in mining layouts.
2) we are trying to post some photos of the finished layout (but, when a layout can be considered "finished"??). So, how can we post photos? Please help.

All the best for the coming year.

Mario & Bice
 

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Dear Mario and Bice,

Nice layout but couldn't find the video - only 1 picture. Why nickel mining by "Nickelminers". Did you have some connection?

I am in South Africa, model HO (Fleischmann/Uhlenbrock) and spent 40 years working in the mining industry based in South Africa, South America and the UK. I have had a close association with nickel mining (South Africa, Zimbabwe, Brazil, Australia and Canada) as well as gold, uranium, copper, zinc, lead, mineral sands, etc, etc and therefore wpould be very interested to see more of your layout.

The method I use to upload photographs is when you start a post or add a reply to an existing post, 3 text boxes appear at the lower bottom right had side of the screen. I press "Browse"and then go to the hard drive of my PC where I store photographs. I select the image I want, select open and then press "Upload"on the original post screen. The picture then is listed in the box above the first 3 boxes with options for placing it in the text of the post.

It is important to re-size the original photos to the correct size (pixels) on your hard drive before uploading. I use Microsoft Office Picture Manager to compress to "Document" size which seems to work well for the Model Rail Forum - the picture is normally compressed to about 120kb and I save them in a seperate file on the hard drive for posting. This works well for me which I figured out by lengthy trial and error. I am sure there are quicker and more efficient ways and hopefully somone else will be along to advise you. Try the Google custom search at the top right of the Forum page.

I look forward to seeing more of your work.

Regards,

Peter Smith
 

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Dear Pete

thanks for your reply and advice on how to post photos. "Nickelminers" means that we are just 2 (an old couple...). With regards to the video, click on the link to SWR, then click on the "Sendung zu sehen" (broadcasts to see) - "Zur videoseite" (to the video page), then go to 6 minutes something. I re-checked and it works. Another page of SWR has still pictures from the Intermodellbau Dortmund, but it is not this link. In short, with some minor deviations from reality, our place has become a purely sulfidic deposit with lodes of high-grade niccolite, exploited through conventional mining and stoping. Since the place is quite impervious, the most logic solution was a short private rail link between the loading area and the unloading (through rotary dumper), crossing a tunnel under a mesa. From the unloading/dumper area (beyond the limit of our layout) the ore is loaded onto larger trains that go the smelting factory through a class A railroad.

We try to give you some other links to videos of our layout, which a gentleman from Holland has posted onto Youtube some time ago. The videos were taken at the IMB Dortmund, and at the Euromodell Bremen.



It should work; otherwise, typing on Google either "consolidated nickel mines + intermodellbau" or "consolidated nickel mines + euromodell" , something comes out. The best available photos on the web are on the website of MOBA Deutschland, but they are a little difficult to find, since there is a misspelling of the name; it is necessary to go into the moba-deutschland website, and search among the photos of the Intermodellbau 2012.

Sincerely

Mario & Bice
 

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Dear Mario/Bice,

The Rotary truck dumper is truly awesome! Also the shaft, skip, conveyors, hoppers, etc, etc. Truly fine modelling and clearly intricate and home designed. Most impresive! The SWR videos don't work as well for me with a lot of bufferering9 where I am located we have poor internet infrastructure compared to Europe) but Youtube worked very well.

To know about laterite deposits and design a system like you have, you must have had some connection in the past. I project managed a latrite mining and smelting project in Venezuela in the 1990's (recently effectively nationalised by the Chavez government) but it was a wet laterite. I visited most laterite nickel operations in the world but cannot imagine what yours might have been modelled on.

Regards,

Peter
 

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Discussion Starter · #7 ·
Dear Pete,

thanks again for advices on how to post photos. By now, we try and paste some links to our Flickr account, we hope it works.

http://www.flickr.com/photos/[email protected]/...in/photostream/
http://www.flickr.com/photos/[email protected]/...in/photostream/
http://www.flickr.com/photos/[email protected]/...in/photostream/

I am a chemical engineer, so I have a basic knowledge of mining equipment (even though I always worked in plastics...) The layout does not reproduce a specific mine, but we designed it from scratch. This had to be "our" mine, a kind of family-run small mine, using salvaged equipment from larger sites, everything placed in a small, remote area. This design also justifies the small size of the 3-section layout, which, disassembled, packs up into a 3-layer solid piece of 120 x 90 x 45 cm (which is the limit size for transportation in our car...)

Best wishes from Milan

Mario & Bice
 

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Hello Mario & Bice,

A very warm welcome to the Forum (* if a little late).

Wonderful modelling & for me anyway something very different. I have to say the working conveyors & the wagon loading & unloading arrangements, not to mention the "drum" wagon lift tipper, are fantastic.

Look forward to looking through the latest links & seeing much more of your skills, Cheers,

Norm
 

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Dear Mario/Bice,

Impressive engineering design and attention to detail - presume the rotary couplers operate in an arc which keeps their elevation constant with respect to the stationary truck and the tippling truck?

Regards,

Peter
 

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Hello again Mario & Bice,

Thanks for the latest / further info. all very very impressive modelling & interesting to see. Out of interest how long did the builds take from when the primary design was completed; I assume there was some degree of "tweaking" / fine tuning of the design during the build ?

Any plans for any exhibitions in the UK by chance LOL ?

Cheers,

Norm
 

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Discussion Starter · #12 ·
Pete,
you are right. The axis of the rotary couplers must coincide with the axis of the barrel of the dumper, and everything must stay there during rotation. In the modern "tippling" units, the barrel has a diameter large enough to allow keep the axis of the couplers almost into their original position (down), even if this generates a large imbalance in the barrel during rotation. In our little plant, the axis of rotation coincides approximately with the center of weight of the barrel loaded with full-loaded railcars. Take note that, in reality, nickel ore has a bulk density (weight per volume) of 2 - 2.5, much higher than that of coal or other materials. So, in the "prototypical" story of our place, the salvaged USRA 55-Tons cars that we use are carrying more than twice the load they were designed for. So, they underwent (in prototype) a series of modifications, such as reinforcement of structure and bogies (and their hoppers were permanently welded - they were not hopper cars anymore). In H0 scale, we had to do some adjustments to obtain the requested clearances and tolerances between railcars and barrel:1) We got rid of plastics wheels - spent a fortune to import from the USA some decent axles and avoid the railcars wobbling along the rails 2)We did some serious work on the plastic bogies, to guarantee a decent rotation of the bogie, no backlash, bogie axis really vertical, etc. Before adjustments, none of our cars was level or correctly aligned with the others. Now everything has been "straightened out" (in the real sense of the word), and, just to stay on the safe side, we keep the two 4-car consists in a fixed configuration.
Sincerely
Mario & Bice
 

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Discussion Starter · #13 ·
Hi Norman,

with regards to the "tweaking" we would say that it was like any full-size project. Everything was planned, designed, calculated, and, when transfered into the operational phase, the usual (nasty) surprises came out. One significant design issue was to transfer into H0 scale the rotating-cone dosing units/feeders that feed the conveyors with a constant flow of ore from the silos. Obviously, the design parameters of full-size plants did not fit into the tiny H0 scale. It took some trial-and error with operating mock-ups before the system worked properly. Another "trivial" issue was the material for the conveyor belts. We tried several materials with the required combination of high tensile modulus of elasticity, and low bending stiffness. Most of the materials disintegrated after half an hour of operation. In the end, we selected specific cotton ribbons, which exhibit the required strength, and also simulate well the texture of belts composed of steel-mesh scegments (note: the ability of Bice as seamstress was fundamental in splicing the ribbons into a loop - the splice itself was another very critical issue). Some anecdotes: most of the structure of the landscape is made of fiberglass. One lot of epoxy resin we used was defective, and took eternities to polymerize (imagine some dm2 of fiberglass mat, carefully draped into the final shape, the resin carefully brushed onto the fiber, wait 24 hours, resin still wet, sticky, jelly. Spend the next day with hairdryers, heating the mess with the hope to force the resin to harden (it did, in the end). Other anecdotes: metal parts carefully machined and honed, just to realize that we carefully machined all of them into the wrong size. And so on. Anyhow, the construction started at the beginning of 2008.

With regards to exhibitions in the UK, we would be very happy to take part to some. Unfortunately we have no contacts in the UK. Can you be of help???

P.S. we post some other photos. In one, there is our control unt for the dumper. To be noted, all our simple 3-section point-to-point layout is DC. The feed to the rail comes from a benchtop current-controlled DC power supply. The advantage of current-control is that it automatically compensate for variations of rail-wheel electrical resistance, keeping the motors of the locos at a constant torque. Speed is controlled in 2 ways: one by setting a certain current with the power supply, the other with a rheostat that progressively short-circuits the selected section. This has proven to be very effective in generating a realistic braking and millimeter positioning of the cars into the dumper. OK, do not shoot at us, it is not DCC, we have no sound, etc. etc. We know. But it works.

Sincerely

Mario & Bice

http://www.flickr.com/photos/[email protected]/.../in/photostream
http://www.flickr.com/photos/[email protected]/.../in/photostream
http://www.flickr.com/photos/[email protected]/.../in/photostream
http://www.flickr.com/photos/[email protected]/.../in/photostream
 

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Discussion Starter · #14 ·
In order to answer to the same questions from many of our acquaintances: "How do you stuff the layout into the car??? (the vehicle is a 2-door Ford Focus hatchback)

1. The backs seats of the vehicle are removed and stay in our garage as a piece of modern art.
2. All the tall components of the layout (larger rocks and peaks, silo n. 1, hoist tower) are disassembled and removed.
3. The layout is disassembled into its 3 sections.
4. The main section, 120 x 90 cm becomes the "base" and 4 plywood plates are fastened to its sides.
5. The other 2 sections (rail link and rotary dumper section), together with the large vertical underground landscape of the mine, are fastened onto the top of the plywood plates. The result is a solid piece (see photos).

http://www.flickr.com/photos/[email protected]/.../in/photostream
http://www.flickr.com/photos/[email protected]/.../in/photostream

6. The smaller section with the exit from the dumper is disassembled into "flat" pieces that stay in a small box.
7. All the tools, rolling stock, other pieces are packed into flat wooden boxes, which become the first layer on the floor of the trunk of the vehicle.
8. The solid piece of the layout becomes the second layer, which enters with close tolerances into the vehicle - crushed fingers and curses are the norm.
9. All the other material (stem lamps, legs, cross bracings, personal luggage) stays either in the remaining space in the vehicle or in the roof box of the vehicle - awful, how the roof box spoils the aesthetics of our car…
10. In the end, some small space even remains available for Bice's evening dresses and high heels ;-)

As a reference:
Time for unloading the fully-loaded vehicle and assembling the layout: 12-16 man-hours (2 persons, 6 or 8 hours, mainly dependent on the amount of damage in transportation…)
Time for disassembling the layout and loading the car: ca. 6 man-hours (2 persons, 3 hours)

Sincerely

Mario & Bice
 

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Hello again Mario & Bice,

Only just caught up again with your thread & your excellent latest posts & information. You certainly have both done your homework on this very unusual subject & through excellent modelling skills produced an exceptional series of models.

I unfortunatley do not have any links regarding exhibitions in the UK, but certainlyother members do, or would be able to suggest possible contacts for them. A good starting point I would say may be Brain Considine, who along with a collegue regularly attend shows in the Kent area, which given your location would be an idealpossible area. It might be worth sending a PM to Brian, or see if he spots this - he is at Canterbury show today / tmz; so may not get a reply untilearly next week. Other members may also be able to offer advice / contacts or even invites !

It sounds like you have the dismantle, pack & set up down to a fine art - evening dress & all LOL !!!!!

Best of luck & please keep posting, Cheers,

Norm
 

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Discussion Starter · #17 ·
Hallo again,

following a frequent question that we have received: "How do you weld together steel wires?":

The issue is that "steel wire", "piano wire" , or "harmonic wire", is a wire produced by drawing, usually made of high-carbon, mild-alloyed steel. The presence of alloy elements improves the tensile strength and modulus of elasticity of the material. Also, the alloy elements allow the material to passivate, (creating a thin layer of compact oxides), greatly improving corrosion resistance. Increasing the level of alloy elements, the result is the austenitic stainless steel, which is immune to corrosion.

The average piano wire used by modelers is made of ferritic steel covered by a thin oxide. As known, the wettability of this steel with common tin-lead solder is limited. Usually solder flux cannot chemically attack the oxide layer, and the steel wire is considered "not weldable" by most of modelers.

The solution is relatively simple:

First, do a thorough cleaning of all the residues from the drawing process and excess oxide. Usually, we put the one-meter wire sections on a spindle, and grind the surface with 600-grit silicon carbide wet grinding paper until a glossy finish of clean metal is obtained.

Then, wipe away any residues of abrasive with a paper cloth (also the thin dust of abrasive repels the solder)

Then, do a chemical etching (pickling) with a mild chemical, such as Oxalic Acid or the commercial "rust converters", which usually is an (overpriced) solution of Sodium Dithyonite. The result is an increased wettability of the steel surface. Then, rinse the wire with water and dry with a paper cloth.

At this stage, the steel surface can be brazed with conventional Tin-Lead solder and Zinc Chloride flux, and conventional soldering iron. a 15-watt iron works well for thin wires (0.5 - 0.8 mm diameter ), 50 - 75 watts are recommended for larger (1.5 - 3 mm) wires

Many times, somebody had asked why we do not "harder" welding/soldering media, such as Copper/Zinc/Cadmium + Borax flux. Excellent idea, but it needs a flame (soldering temperature is ca. 550 C). The result is a very solid joint, but the piano wire itself undergoes annealing, losing its strength and warping badly. The same annealing and warping happens with spark welding or resistance welding. These methods work well for iron grids, but they are not suitable for precise modeling works. Sometimes, we have used Copper-based brazing + Borax for larger structural parts. But any times you use a flame, you parts will undergo some deformation and will need re-machining. The same logic of "full scale" welding applies to our small parts.

Sincerely

Mario & Bice
 

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Discussion Starter · #18 ·
Hallo again,
following up an amicable debate with modeling friends about "materials to build layout landscapes":

1) The "traditional" materials: gypsum, papier-mache, paper, vinyl-based adhesives
2) Expanded polystyrene
3) Composites: polyester- and epoxy resin, fiberglass, and similar stuff

Advantages of "traditional" materials: they are inexpensive, cleaning their residues is relatively simple (with water and soap). They are very effective for the "final" (external) layer of the landscape, where applied onto an existing structure. We have friends who are able, with old newspapers, gypsum, and vinyl-acetate glue, to build up spectacular finishes.
Disadvantages of "traditional" materials: they are structurally weak and prone to cracking, sensitive to moisture (sometimes, storage conditions of layouts are less than optimal). Drying, especially in the case of thick maper-mache parts, takes eternities.

Advantages of XPS: relatively easy to model, lightweigth. We have friends who are artists of hot-wire cutting of XPS, and really able to create very good stuff from blocks of the white material.
Disadvantages of XPS: cutting a block of XPS generates cubic meters of white fragments. As a rough evaluation, the waste volume is the same as the volume of the final "mountain" - 50% of material is scrapped. Hot-wire cutting generates fragments, but sanding/sawing XPS generates cubic meters of electrostatically-charged dust , which sticks to everything and resists to vacuum-cleaning. Moreover, the structure is solid, and carving out passages for wires/etc. sometimes difficult.

Advantages of composites: the structure is hollow, very strong, very lightweight. Curing time from resin to the finished part is defined.
Disadvantages of composites: playing with resin and fiberglass is a very dirty job: resin is sticky, can be cleaned only with solvent (before curing). After curing, resin cannot be removed, it is solid and insoluble. Cutting fiberglass cloth generates irritant dust. It is always recommended to use industrial-grade gloves, eye protection, and overalls, and lining the floor with plastic film.

In our particular case, we have extensively used composites. The larger "hills" of the layout are made with fiberglass cloth draped onto plywood formers; the smaller "hills" and the structures at ground level, soil, etc. are made of Kraft paper infused with resin.

Just to have an idea, herewith some photos:
Plywood structure in position, plywood formers to be installed - the structure is ready to accept the layer that form the "soil" (in this case, due to the small area to be covered, it was Kraft/resin composite)

http://www.flickr.com/photos/[email protected]/.../in/photostream
http://www.flickr.com/photos/[email protected]/.../in/photostream

Structure is ready to be cover, module is aligned with the previous module, in order to align the landscape in construction with the preceding landscape.

http://www.flickr.com/photos/[email protected]/.../in/photostream

The covering has been draped onto the straucture, infused with resin, and, after curing, the piece is detached:

http://www.flickr.com/photos/[email protected]/.../in/photostream

The structure of the soil is applied: the components are some wrinkled Kratf paper, sand, pigments, and eposy resin:

http://www.flickr.com/photos/[email protected]/.../in/photostream
http://www.flickr.com/photos/[email protected]/.../in/photostream

The finished part with the applied soil and ground texture is ready:

http://www.flickr.com/photos/[email protected]/.../in/photostream

The construction continues with the subsequent module no. 4, which is aligned with the previous module (with a plastic foil as "release" separator from the contiguous parts) - The sequenc e of operations is the same: landscape base, first resin coat, structure of the soil, final resin coat, finishing with pigments . Note: an excess of pigments and sand must be used, in order to adsorb all the excess liquid resin; if any "wet" spot appears, it must be re- coated with excess pigment 8otherwise it appears as a glossy "plastic" spot.

http://www.flickr.com/photos/[email protected]/.../in/photostream
http://www.flickr.com/photos/[email protected]/.../in/photostream

Comparing the composites with more "conventional" methods, the time spent in preparation of the work is considerably long. Before starting to actually make the part, it is necessary to have all the pieces into position, resin, brushes, and other components ready.
When the actual work starts, everything happens quickly. A typical long-curing infusion 2-component epoxy resin starts polymerizing as soon as the 2 components are mixed, and has a"pot life" before gelling, of approximately one hour. In one hour, before the resin crosslinks, the parts must be infused. Immediately afterwards, the structure of the soil must be applied (note: subsequent application of resin onto previously hardened resin parts has a poor adhesion - in case of very large parts, it is better to coat a smaller section, then prepare another batch of resin and continue coating another section, blending the second coat with the non-completely crosslinked resin of the first section, and so on).

Once the resin gels (one hour), there is no way to re-arrange things. The time to complete crosslinking of the resin is approximately 24 hours at room temperature. After curing, the pieces are surprisingly resistant.
The subsequent "details"of the landscape (small rocks, bushes, trees, etc.) are subsequently applied ald glued with cyanoacrylate adhesive, or 2-component fast-curing epoxy adhesive. Final nuances of color can be applied by spraying a thin layer of nitrocellulose lacquer ad dusting pigments onto the wet lacquer.

Again, time to preparation of a composite is a bit long, but then, everyting goes on very quicky. Cast-molding-grade epoxy resin can also be used as structural material for artificial rocks, with the same silicone molds usually used with gypsum.

In the end, there is no "universal" solution for material. Some of our modeling friends like to toil over square centimeters of landscape for hours, and abhor the idea of a composite that quickly freezes in to its final shape. Someone else enthusiastically sands huge blocks of expanded polystyrene, filling their homes with tons of XPS shavings (this seems to have been one major factor in model-railroading-induced divorces...), and loath the idea of playing with sticky resins. Someone else uses hybrid solutions, such as composite- or resin-based finish onto XPS.
With regards to this latter issue, one final consideration: epoxy resins are compatible with XPS. Conversely, fiberglass-grade polyester resin dissolves XPS.

With the best wishes from Italy

Mario & Bice
 

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Discussion Starter · #19 ·
Dear friends,

Herewith a note relevant to the drives used to drive the machinery at Consolidated Nickel Mines Co. We have used the known technique of "hacking" radio-control servos. These servos are tiny and powerful. Depending on their size, at their nominal voltage of 4.8 or 6 Volts they produce torques of 0.5 - 2 kg * cm.
This a tiny electric motor, a cascade gear train with a gear ratio ca. 1/200 or 1/500, a tiny angle sensor on the largest gear, and a small electronic circuit. The RC input is a pulse-width modulation signal, and the electronics drives the motor until the desired angle of the exit shaft is reached.
Sizes of RC servos are rather standardized among the producers, from "normal" to "medium" "mini" "micro" and "pico".
But, for the model railroader, there are 2 limitations in using RC servos:
1) RC servos have travel limiters on their exit shaft. They are intended to operate in a limited arc (usually they drive levers, connected to steering controls) - that is fine to operate a turnout - note: the turnout on our layout is also operated with a hacked RC servo. Conversely, all our machinery (conveyor belts, etc) needs continuous rotation
2) The RC electronics and encoder is redundant and must be removed (unless, a solution for a driven specific angle of rotation is to feed the servo with a "servo tester". With this cheap electronic gadget you can drive the exit shaft to a desired angle. It can be useful for specific RR stuff.
If somebody wants to play with RC servos the following recommendations apply:
• Choose the size you want
• Choose servo type "analog" (to say, the encoder is a tiny potentiometer); there is no need to buy more expensive "digital" servos, since anyhow you remove the electronics and all
• Choose gear train material: NEVER use metal gear. Brass metal gear is prone to wear and backlash. "Standard" gear material is Polyamide - a white plastics, and resist well. An improved gear material is carbon-fiber Polyamide - a black plastics, and has an extremely high resistance to wear and backlash. In our case, some drives turn 8 hours per day continuously at the shows. We changed some plain-polyamide geared servos after ca. 100 hours a precaution, but they showed only very minor signs of wear. The carbon fiber-polyamide gears result immune to wear after ca. 300 hours.
With regards to prices, a good RC servo costs 8 to 15 Euros.

And now, how to do the job:

http://www.flickr.com/photos/[email protected]/.../in/photostream

First, the tools: these things are small. In order to see something, we use a stereomicroscope, in a range of magnification from 10X to 20X. A good magnifying lens is also an alternative. Other tools must be adequate (note: inspecting tools at high magnification always shows how much inadequate they are... ;-) Seriously, we did some filing/grinding/de-burring on our smaller tools.

http://www.flickr.com/photos/[email protected]/.../in/photostream

Then, after having cut off mounting flanges and other odd protrusions from the frame of the servo, we carefully disassemble it. The photo shows the cascade gear train, with 5 reducing steps. The larger gear has a diameter of ca. 6 mm.

Now, the travel limiter, which impedes the complete rotation, must be removed. These photos show the crown gear with its limiter. In the second photos, a needle indicates the limiter. Note the needle, which seems perfect at the naked eye, when inspected at higher magnification...)

http://www.flickr.com/photos/[email protected]/.../in/photostream
http://www.flickr.com/photos/[email protected]/.../in/photostream

So, we carefully remove the larger gear. The limiter is clearly visible. The apparent burrs are traces of the original lubricant (it must be left in position). And now, a VERY important issue. NEVER use abrasive tools such as cutting discs, etc. We made this mistake in our first tests: the net effect is that even minute quantities of abrasive will stick to the gears, and, during operation, everything will wear out very quickly. Note: plastic gears must be lubricated with the original fluoro-silicone grease. Conventional lubricants do not work well on plastics, and plain silicone grease has poor lubrication properties. It is better lo leave the original grease at its place.
The tools to use are: flexible shaft with milling bits, or, simply, a micro-cutter. In this particular job, we have used a very small balsa cutter.

http://www.flickr.com/photos/[email protected]/.../in/photostream

With some patience, the limiter has been removed. Keep the shaft of the piece with small pliers and a soft cloth, shave off thin slices of plastics at a time, do not attempt to cut off the entire part with a single katana-style cut (also, yelling during this phase of the job does not help at all...). Be careful not to damage the teeth of the gear, work only on the flat side of the gear, and hold the piece from its shaft only. Even if you do not get a perfectly flat surface, that is right; this is the non-working side of the gear. Carefully remove burrs.

http://www.flickr.com/photos/[email protected]/.../in/photostream

Next step is electronic surgery. Remove the small PCB, re-wire the motor, and remove the encoder. Usually, the encoder slips out easily, since it has an independent shaft and a joint (a kind of miniature dog-clutch joins the encoder to the larger gear or to the exit shaft).

http://www.flickr.com/photos/[email protected]/.../in/photostream

In this photo, you see the remnants of the 3 connections from the encoder to the PCB. The encoder was facing up, towards the backside of the shaft of the larger gear.

http://www.flickr.com/photos/[email protected]/.../in/photostream

At this stage, we carefully re-install the machined larger gear. The visible dust on the photo is non-abrasive dust coming from the atmosphere, sticking to the lubricant. Experience shows that this dust has no detrimental effect (and any attempt to remove dust from the lubricant is futile...)

http://www.flickr.com/photos/[email protected]/.../in/photostream
http://www.flickr.com/photos/[email protected]/.../in/photostream

This is the re-assembled servo. Now, we have to connect it to some working machinery. The shaft exiting a servo is a short splined stub, with a longitudinal threaded hole. In its intended configuration, a plastic lever with a broached section fits to the shaft, and is fastened to it with a small screw. In our case, we install a pinion onto the shaft. The pinion of the following photo originates from scrap consumer electronics (printers, floppy disk drives).

http://www.flickr.com/photos/[email protected]/.../in/photostream

The pinion has been re-bored to the correct diameter to fit the shaft, and fastened with the original screw.

http://www.flickr.com/photos/[email protected]/.../in/photostream

A "hacked" servo equivalent this one described is installed in the railcar positioner of our rotary railcar dumper. The pinion engages onto a larger gear, which drives a pulley and the positioner. At larger magnification, the pinion is (barely) visible at the center of the photo. The servo is under a metal sheet part, resembling the "real" piece of equipment.

At their nominal voltage, these servos have a colossal torque, far in excess to any RR modelling requirements. Rotation speed is ca. 60 - 90 RPM. Usually, we operate the servos at 3 Volts (half of the nominal). Many of our servos are also speed-controlled through rheostats, and turn at 10 - 30 RPM.

With the best wishes from Italy

Mario & Bice
 

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Hi Mario & Bice,

Hope all is well in the wilds of Italy.

The content & detail of your posts is second to none, but I will have to digest it in stages LOL ! The various alternatives for landscaping / scenery firstly. I can only agree on your summary of the pro's / con's for the traditional & the XPF; & certainly the "mess" / wastage factor on XPF, which I can vouch for currently first hand. Although the hot wire cutter does offer the advantage of sealing the cut surface. However, it does generally look like its snowed indoors !!!!

Your resin / final method is very interesting, & I take it the approach / method you now use. Are there any problems with fumes / flamability / needs for doing the work "outside" or in a very well ventilated space. It appears from some of your pics, certain stages were undertaken "outside". Fine for a modular / demountable layout; maybe more of a problem for a fixed layout. Say as my loft layout, shown in the layouts thread - but no doubt possible.

The advantages in terms of the finished landscapes lightness & strength / impact resistance, must be a real major benefit, for exhibition / demountable layouts; over the vunerable final product with traditional & XPF methods.

Thanks again for the detail, & excellent food for thought. You mention in the text re - others using the various different methods, are they also Italian railway modellers; is it a popular hobby over there, out of interest ?

Next I will attempt to understand the technical side of your wonderful model - it could take a "while" LOL !!!!!!

Cheers,

Norm
 
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