Monday, 21 May 2012

Another Decade...

Well, if I've got to grow older, then I deserve cool stuff to make up for it.

So, roll on my newly acquired C R Clarke 1210 vacuum former. Photos to follow, but for the uninitiated, it's a plastic former that uses a combination of heating elements and a vacuum pump to form plastic over metal/wood/plaster/resin formers.

I've made some modifications already to the vacformer, the most major being the replacement of the rear rubber feet with steel slotted rail (actually DIN rail) to better bare the weight of the former across the rear structure (and offer a great way of mounting it to a workbench).

I've been mentally forming a list of things I plan to make on my new toy professional work apparatus, including hovercrafts, boats, chocolate moulds, ice trays and much more. Well, so much more that I'm forced to keep a list with me, adding lots at random moments of the day.

I've built plenty of formers in the past and have lots of experience with chipping plastic off of complex formers, spreading wax and other shit (recommended by clueless "experts") over the formers, burning plastic, cracking plastic and occasionally, making something really nice. My most successful former (a fairly complex wooden one, made of multiple laminations of wood) is still in heavy use in an engineering lab some 14-15 years later.

Anyway, I can't wait to start building formers - can't beat a present that keeps on giving...



Tuesday, 1 May 2012

Print, Cut, Fold, Stick...

...and wipe off the gluey finger prints.

My first foray into the fantastically detailed Scalescenes self-print OO (and N) gauge model kits. The idea is great; artwork in PDF form to build a highly detailed model, but the added advantage of being able to butcher and hack to build whatever you want, as you're in control of the print production.

I've bought a couple of kits, as they fit so close to what I want (still don't know what I'm going to model yet, but I know some of the bits I want in there) before I've even made one of the free ones.

I'm torn. I love the kits, the idea, everything, but my one let down is the cutting and sheet gluing. This isn't fault of the kits, more likely the fault of the crappy blades and steel ruler I'm using. Like the worst kind of hobbyist, I kitted myself out with everything I could ever need - glues, felt tips, stacks of board, matte photo paper, cans of fixative spray and a new safety ruler. On the upside, it did come in pretty cheap, circa £20, excluding the board, so even if this doesn't pan out it's not all going to waste.

Anyhow, back to me whining. I need to find a better cutting method, instead of the "40-stroke, cutting more metal off the ruler than card" technique, whether that be better blades or some amazing secret I've not been told of. Which, nicely comes back to one of the really great things about the kits - they're incredibly forgiving. Having built one of the free downloadable designs (the industrial unit in my case), even in a pseudo-half-arsed way, it looks damn good.

IMG_4400
Chop Chop Chop (goes the edge of the metal ruler)

But I suppose that's the point; don't go flying into building the grand design, start simple and get some experience, albeit find out how it's not done, before wasting time, materials and sanity.

The kits are well designed, they build upon a couple of principles; covering, wrapping and masking. Covering involves adhering sheets onto heavy boards and cutting them along the lines, obvious and simple. A lot of crapification occurs here; badly stuck down artwork, frayed edges, wonky cuts - you get the idea. This is a given, unless you've got a die or a big punch cutter, you're not going to get perfect edges, which is why no cut edge is ever exposed.

IMG_4397
Artwork + Pritt Stick + 2000micron Board = Covered Boards

The next kind of building block, wrapping, also starts with the covering stage, but the artwork is simple grey-line with white fill and results in pieces of board ready to be glued together or stacked, to be wrapped with the actual final artwork. This results in two edges having a seamless finish.

IMG_4417
Wrapping Step 1: The base layer with "cutting" artwork

IMG_4419
Wrapping Step 2: Wrapping base layer with the artwork

The remaining cut edges get their treatment, along with glued joints between different pieces with simple masking pieces of artwork, not stuck to board, just the weight of the matte photo paper, but with the white edges coloured with a average coloured felt tip. These masking pieces hide a variety of sins, including bad gluing, misaligned joints, really awful cutting and frayed edges.

IMG_4401
Masking Pieces

Based loosely on advise, I'm using Pritt-Stick (versus Uhu Stick), I think for the next models I'm going to try using the Uhu Stick, as Pritt-Stick doesn't seem to adhere brilliantly - even with what looks like an even coating applied. A real pisser I found after the first gluing session, was deformation of the board (whether it was already there I don't know) from the adherence of the artwork. I ended up stacking all of the glued boards, and weighting them down with heavy art books. It corrected most of the deformation, but not all. I'm thinking that a bit of hackery with offcuts, glued perpendicular will help to stiffen and keep the bad bits straight (and give the finished model a bit of extra strength).

I've not had a clear run to build a kit, so have had to steal a few minutes here and there to glue a piece, clamp a bit, trim a bit and so forth. At the moment the industrial unit (low relief hence stubby side walls), can stand on it's own, with outer and interior walls. Next step is to build the office and add the sliding door details. Once the main bits are done, it's a case of masking and finishing with the finishing touches, and if it looks half-decent; a bit of extra weathering.

IMG_4410
The next kit; the Concrete Bridge (to be heavily adapted)

Anyway, check the kits out, they're great. If you've got patience to work with card (and to go through the effort of printing), then I think you'll be rewarded by going down this path. With all of the extra bits of artwork you can also get (matching textures for brick, concrete, tarmac etc), it's easy to hack and modify these kits to fit whatever need you've got. At the very least, try out the free kits...

As and when I finish the first kit, and move onto building the next kits, I'll post more images.

Tuesday, 20 March 2012

Jan/Feb Roundup

Well, a new year has come, and we're into March already. I've spent most of my free time procrastinating, making lists and watching action hero films ranging from Iron-Man (1 et 2), Green Hornet, Star Trek (2011 reboot) to X-Men (1-5), Daredevil etc. Pretty much sums up the year to date...

I have however spent time sourcing parts, and coming up with ideas for new projects and modifications to existing. So, a little roundup as to where we are:
  • RC Platform - I'm still in need of some parts to link the axles with the chassis - I've held back from building the chassis for that reason primarily, and for space the secondarily. At present I don't have any workshop/lab space to work in so it's on the back burner for now. I've sourced lots of pre-manufactured aluminium struts and plates, so this little project might end up parenting a few different RC vehicles.
  • RC Boat - as dumb as it sounds, I've had trouble trying to source female-female servo cables, and this has held me back (sourced some from China in December, and still not got them). I also had trouble with my Rx/Tx when trying my test Arduino code; no issues driving servos from the Arduino on a pre-programmed sequence or using a potentiometer, but I'm having trouble getting the Rx to get enough power from the Arduino (some buggering about with cables probably needed).
  • RC Hovercraft - as above, plus I still need to find a better way of cutting up plastic tubs to give me the air baffle I need. I can either keep it pretty on the inside, or just make use of copious dollops of industrial adhesive and scrap plastic. 
  • Train Control Panel - this thing keeps growing and shrinking - there'll probably be a few iterations to get what I want, but that's part of the fun (I think). I'm even considering using two panels and a touchscreen in the centre to fully represent the prototype - more on that later.
  • Train Control System - I began building my DCC system in January and February, losing time over the last 3 weeks with travel and what-not. I'm building a CAN-Bus based DCC and IO system using MERG kits and schematics, and a bit of glue in the form of JMRI and/or RocRail. I need to write up a post for the whole system and take some pictures before I finish it, something to do later I think, but in short the IO and DCC control will be coupled to a central controller via CAN-Bus, pretty much in the same way as conventional distributed IO.

Doesn't seem a complete list, but it's all I can think of at the moment. Expect this post to be edited heavily to make it look like I'm top of things.

Saturday, 5 November 2011

Train Cab Control System Part 2

I've written and rewritten this post countless times as I've played around with the design and as parts have arrived. It probably makes little sense, but at least you get an idea as to where things are going...

Main Controls

I've gotten most of the push buttons and physical controls, and have devised numerous solutions for the main quadrant controls now.

The first solution I devised, is to take some Telemec' joysticks, and rip them apart, building a custom aluminium framework to house them, and attaching a suitable mechanism to actuate a potentiometer. The second, is to not bother with quadrant controls...

As I've found, there are virtually no manufactures of them around, and those I've found are ludicrously expensive (or are an import job). In the end, the controls I thought would be the hardest to source (rotary hand wheels/levers) are actually proving to be the more easier.

So, for this first version, the brake will be a hand wheel with knob, and the throttle will be a rotary lever. I'm still awaiting the lever, but have already snagged a couple of the hand wheels. No picture at the moment, but will add one later.


Enclosure

The new enclosure arrived - I'm somewhat limited to space and initially to the kind of enclosure, so for the first panel, I'm tied to the dimensions based upon the largest pre-manufactured enclosure I could find.

Boss Enclosure
Boss Enclosure
The enclosure consists of two panels - a main aluminium plate, where all of the controls will go, and a top aluminium plate, where the feedback and a couple of additional controls will go. The rear of the enclosure will sport a couple of connectors for power and data.

The enclosure should be deep enough for most of the components - where possible I'll tier/stack the Arduino boards on the back of some of the interface elements, and the others will be placed at the rear/back (the deepest part). Some of the Telemecanique controls are deep, so I'll have to cheat with positioning if I hit problems.

The layout of both panels will be done in CAD; I'll outline each component, and include it's cut-out, allowing me to shuffle around. I'll digitally precision cut a prototype panel out of card in our engineering lab, so I'll have something I can mount the controls to, and sit into the enclosure to check it works, and feels right.

Once I'm satisfied, I'll use an accurate overlay to mark the aluminium and to cut it. I don't have access to a laser or CNC cutter so I'll have to do it carefully with a bench drill - most of it is circular so no big issues. For square cuts, I'll have to ensure that the control has a bezel that will hide any imperfections.

I've got a large stock of anodised aluminium extruded profiles, so I can easily build up and build down for some of the controls - perhaps making some look modular or segregated. Anything I make will bolt together - I'll rivet if needed, and I'll avoid welding the aluminium if at all possible.

Even though the enclosure is a beautiful shade of fresh-vomit-beige, I'll hopefully be spraying it to a bluish-grey that's common for modern train cabs - I'll need to play around with shades to get it right, and I'll avoid two-toning the plastic case. The aluminium probably needs painting as well, again that'll be a nice bluish-grey, though I may make it a dark grey for better contrast with the labels and pilot lamps.

All of the legends and labelling will be printed/precision-cut polyester, with a polycarbonate laminate - it's what's used on control panels, and should look great. Not sure whether to completely cover the aluminium, or just do it around each control. The CAD will help immensely in getting the artwork accurately shaped and cut.


Controls

As mentioned in the previous post, there's going to be a bit of work involved in integrating the panel with a DCC system. It's not going to be quite as easy as focusing on controls first and then programming afterward - I'll need to know how the programming will work, in order to figure how the controls can be implemented (and which are needed or should be avoided).

I would hope/expect at the least to have the following controls:
  • Throttle
  • Brake (with simulated deceleration/proportional braking)
  • Emergency Brake (emergency stop controls, bypassing the deceleration configuration)
  • Direction (forward/off/reverse)
  • Horn A (high tone)
  • Horn B (low tone)
On top of those controls the following could be included:
  • Parking Brake (on/off with pilot indicator)
  • Pantograph (up/down with pilot indicator)
With it being a DCC controller, there's a lot of benefits in having a full compliment of controls that can be mapped to the function keys, and have them labelled in accordance to what they normally are (and coloured/laid out appropriately). Then again, there's finite space, so some will be tactile, and others will have to be soft-controls, and accessed through JMRI or a DCC-orientated keypad (like a PS/2 keypad etc).

Telemecanique Joystick & Keyswitch
Telemec' Joystick & Rotary Key Switch
Telemecanique Stop Button
Telemec' Mushroom Key Button
Telemecanique Push Button
Telemec' Push Button

Information Panel & Feedback

Part of the panel is to control a train, and part is to control the DCC functionality (such as consisting, selecting a train etc). Looking at modern train cabs, many feature glass-panel displays for diagnostics, train overviews (i.e. showing the rolling stock, consisting etc) and schedule information. In our case, we have JMRI, which will be offering a big chunk of this information - and in the same way as the real systems will need to have some form of tactile interface (touch screen or keypad), we'll need the same.

I don't want the DCC aspect to be obvious - it's whether I include a tactile interface on the panel, use a touch screen or rely upon an external keypad. Whichever, I need info from JMRI, and I need info for the DCC controller. And I need to control them both.

There's quite a bit of feedback for the panel to display - indicators, LCD's and needle gauges. I'm inclined to avoid needle gauges, and use multi-line LCD displays in their place.

The indicators could include:
  • AWS
  • Alarm
  • Overload/Trip
With displays/guages including:
  • DCC Config
  • Speed
  • JMRI Info
Naturally there are quite a number of input controls and output indicators I could include, but it really comes down to how realistic the panel is to be, and whether it's worth including them for the sake of doing so.

Telemecanique Amber Pilot Lamp
Telemec' Amber Pilot Lamp (sans-bulb holder)
Telemecanique Red Pilot Lamp
Telemec' Red Pilot Lamp (sans-bulb holder)

Programming & Function Mapping

An important part of designing the panel, is ensuring there are enough input controls to cover the most important functions, and mapping them correctly. This requires a bit of deep research, figuring out what standards there are, what I can actually control and how they're controlled. Simply, if a horn is generally a specific Fx number, then I need to know which it is, so I can map it to the correct button, conversely some functionality that should be on the control panel might not be controllable - it might need to be programmed instead or is hardwired, such as lighting etc.

As it seems that I'm headed towards an information display as part of the overall panel, then most of the functionality will be mapped out in a GUI form (mimicking a real-life HMI) - this should also serve as a means to select trains and interact with the LCB as needed.

Bigger decisions are with the underlying electronics and interfacing. I've spent a good few weeks researching the electronics, both prototype and scale, my conclusions of which are far too long for this post, so I'll ramble along on that subject later. I've got quite a few design considerations to make, and to decide on the buses and technologies that I'll build the panel and future layouts upon.

Resources

My first port of call will be MERG, the Model Electronic Railway Group, a membership-based society in the UK that focuses solely on the electronics aspect of model trains - there's some really interesting projects I'll probably cover in the future, including position locations using RFID and servo point control.

A great resource is OpenDCC, a German-based OpenSource project, that consists of hardware and software - including great guidance on implementing and programming DCC. The English translations are a little ropey in places, or missing altogether, but nonetheless this is the best resource I've seen (and seems to have the best technical understanding).

The JMRI project is of course an excellent source of information, though a quick Google search turns up some great blogs and presentations on JMRI.

Another great project that I recently found, Rocrail, offers an attractive alternative to JMRI, and something worth looking at.

Another useful resource is the NMRA, the National Model Rail Association - though US based, is pretty much the norm for most model rail standards, so will be reference for any integration with DCC.

Next Steps...

As you can see, I'm still trying to figure things out, and am planning/designing on the fly. I started writing this post weeks ago, re-writing every time something new came up, or a problem was solved, or a new problem was found. I'm getting closer, I think...

Wednesday, 26 October 2011

Train Cab Control System Part 1

In the effort to occupy more of my spare time, and to create a problem to be solved, I decided that a regular DCC controller for my forthcoming OO layout is just not good enough.

Looking around, I've not found anything good enough or cheap enough to use, nor anything that's actually good-looking or remotely fun to use. So new projects, here we come.

The Idea

The idea is to build a pseudo-realistic control panel, that mimics the pre-requisite controls, and the type of touch and feel found in the cab of a real train. Because I don't have a specific train cab in mind, I'm not replicating a prototype panel in existence, but taking the essence of the feel of the cab and condensing that into something small enough to be used practically at home.

After seeing the InterCity APT a few weeks back, I've been inspired by the simplicity and general layout of it's controls. Coupled with images scouted from Flickr and with Google, theres enough scope to do something that is original, yet quite obvious as to purpose.

The Look & Feel

I started researching and planning an older style panel, but gave up when I made little headway in sourcing real (actual used/new parts) or pseudo-real (stuff that vaguely looks like the real thing) levers and parts. It seemed I'd be forced to make replicas; either approximate in size, or scaled to fit, using vac-form plastic and wooden parts. While relatively straight forward for me, I just don't have the time or space to be doing that at the moment (though I'm really keen to build a mini-vac former so I can do it in the kitchen).

Having stared at the pictures of the APT cab, it dawned on me that not only can I build a modern cab using actual components (allowing me to get away from the "hand-made" look), but I'd have enough wiggle room to build something that could look like a prototype off Bombardier or Siemens' next design.

By using the same kind of switches and selectors as would be used in an actual cab, the panel should have the same feel - even with clunk-click selector switches for direction, and large illuminators for feedback. I'm not planning to use electronics parts (the kind you pick up at Maplin), but the regular day-to-day heavy duty controls that we use in proper control panels.

The Controls & Electronics

The manufacturers of train control systems, for the most part, use these electrical components in their panels - there will however be some difficulty in sourcing the two quadrant levers used for speed and braking, and any needle gauges (yup, seems like they're still being used). My initial thoughts are to utilise LCD displays for speed, braking and "general information" (i.e. the DCC train selected and other programming stuff).

I'm also considering how advanced it should be, as a keypad might be useful - then again, with the palette of functions in DCC, provided I settle on function numbers for each function layout-wide, there'll be actual buttons for those functions - two-way horn buttons, light switches, pantograph controls etc. A ball-mouse or trackpad is probably overkill, but worth considering for JMRI integration.

It'll basically be a panel building job, tied into an Arduino based I/O card, and a couple of extra bits of electronics for the gauges. I'll also finish it with nice rugged connectors for power, data and USB (interfacing the Arduino).

For the most part, I'll used Telemecanique buttons and switches, though the quadrants might be a custom build using Telemec bits and bobs, and some scratch building for the framework. The LCD units will be of course interfaced with the Arduino, but are as close to what would be used, that they'll be fine. I'm not going to use little LEDs etc, but instead use actual pilot lights (big, but the real thing).

I've sourced a large angled console enclosure, that features a display panel - and excellent mimic of the real thing. Using aluminium, I'll build one or two brackets, one to hold a mini LCD display (for JMRI) and one to hold some additional controls I might implement in the future. I'd love a touchscreen, but I think it might knock the panel over using it, so that'll be a separate project (a signal operators panel I think).

It'll be tied together by a paint job to the case (greyish blue/bluish grey) and polycarbonate-coated polyester labels (again what's used in combination with traffolyte for the real thing).

I'll of course go balls-out on the internal cable looms, even though it'll spend most of it's time sealed. Might put thumb-screws on for easy internal access...

DCC Integration

The biggest issue that was always going to present itself, was integration with a DCC system. After spending time chatting with the folks at MERG, it seems that my original thoughts are correct, and that unless I plan to write an entire DCC stack (ermmm, no), then I need something else to do the DCC control.

So this leads onto JMRI and CAN-Bus.

I have two options at this stage, both involve JMRI as the core DCC control stack. The panel can either interface through customer code using USB and acting as an input to JMRI, or it can be part of a CAN-Bus network, and the CAN-Bus controller can interface JMRI. Thanks to the work at MERG, the latter looks to be the easiest.

More to come, plus I'll start posting pictures of parts as they arrive. Lots to think about on the code side, and integration, so again, more to come.

Stay tuned.

Monday, 10 October 2011

Monkey-fun

In a packed weekend, I got to see lots and lots of Barbary Macaques up-close in a forest... Oh and I got to drive two trains.

Oh yes.

Not only did I get to drive a class 03 diesel shunter (03703), but I got to drive a class 73 electro-diesel locomotive tractor unit (73006) too... Both were in their BR colours; a wonderful combination of BR Blue and yellow (with the body in the distinctive BR greyish-blue and the cabs in the normal yellow).

DSC00038
Class 73 Electro-Diesel (73006)

I'm not sure which I loved the most, driving a 600hp generator on rails (the 73) or the 200hp farm tractor on rails (the 03). Both are so different, but both fantastic to drive; the former is what you'd expect from a train - ammeters, voltage regulators and a wide range of mode selectors, and the latter is a simple combination of air-selected gear changing and a throttle.

DSC00071
Class 03 Diesel (03073)

A short post, but I'm in the middle of getting the Arduino code right for the twin-thruster controls... Oh, and I've got plans for a few of new projects, including an OO (1:76) track inspection carriage (a real one, that'll use image analysis software) and a DCC control panel that mimics a real set of cab controls.

Lots of pictures to follow...

Thursday, 6 October 2011

RIP Steve Jobs

I've never been one to idolise, nor one to have personal heroes, but to me, Steve Jobs has always been a hero and an inspiration since my first foray into Apple Computers, and it's colourful history. I love watching his keynotes (even after knowing what was launched or announced), they motivate and captivate like no other. His attention to detail and passion are present in every product. His vision and his compelling ability to excite and inspire will be sorely missed, but never forgotten.