Great Indian Peninsular
WCG-1
Great Indian Peninsular
WCG-1
The Indian Krokodil (or possibly Garial?)
I found the information I needed on this one by luck -rather than research... The reason is that this locomotive has existed under several names and doesn't really fit in with any accepted English design school. It is of course an SLM design, (Swiss Locomotive and Machine Works), but made by a UK firm (Vulcan Foundry) -for use in Colonial India... They have the true "Krokodil" feel to them but they are distinctly English in appearance and operation. They are a 1500 Volt DC design as was common in the UK at this time with twin diamond pantographs.of the "Pierson" type
They have the sloping / curved fonts of an Edwardian era English electric locomotive -but have a purely SLM drive system, Yes, there are fly cranks, and conrods to counterweighted wheels etc This horrible amalgam does however look strangely correct in it's setting? I confess that it is the pure "impossibility" of the two that is it's chief attraction. It was a very successful locomotive design and they were loved by their crews. Here is a picture of the first one. It has actually been preserved
As I have never produced ANYTHING that looks like this, I am being very cautious, and I not transferring any power through the conrods and linkages -they will be purely "decorative" in this locomotive. This is my first working drawing for the SLM bogie.
As you can see the main power drive is to the central axles and there is a chain drive to the front one. What I think I am going to have to do is to make the front axle pivot slightly, (in the manner of a Klein Lindener), and this should improve it's cornering abilities. I will also have to produce some form of spring loaded coupling where the take off point is to the front axle from the triangular "Scotch Yoke". This will have to not only stretch and shrink as it corners, but be able to twist as well!!!
A couple of months have passed and lo and behold I have found the one thing that I have been searching for -a drawing! I had been using my home made techniques of image to drawing but this is a bonus. I am happy to say that the home made measurements are only 3% to 5% "out".
As you will gather the drawing had to have quite a lot of work with "GIMP" was done to it to make it "presentable"...
Well after a few weeks work I now have something resembling a "Working Drawing" that I can use to design my locomotive from. This now has to be broken down into the parts required and sources of parts (and even things that can be mangled to look right....) The power bogies are more than likely going to be fabricated from brass sheet, (good old K+S), and the central body made in the manner of an aeroplane body and plated with ABS.
This is the next locomotive to be built after I have finished building the EE-1.
I now have a back door into the SLM archives and via a dedicated Indian gentleman -the NLW drawings for this loco. They have been through the GIMP treatment and these along with some photostat drawings of the NLW General Assembly instructions -have produced a real headache... The SLM is pure Centimetre, the NLW is pure Imperial. However help was at hand as I re-drew the main drawings with my now much loved G3 rule from the Imperial dimensions and then divided the SLM by 22.6 to see if they matched. Mostly they did!
Having successfully carpeted most of the living room floor with sheets of A3, several problems rapidly emerged -chiefly that the SLM bogie drawings did not match the NLW ones... There were a few days when I honestly wondered if I had the right drawings. However the solution was in the scribbled notes at the side of the photostatted NLW drawings. Translated by a friend the INDIC scribble reads "These drawings are <expletive> the idiots have used 1 inch = 2 centimetres in some of the dimensions -use the SLM ones"
So, following my normal practice I have duly marked up a couple of sheets of 3mm birch ply and hacked the "primitives" that will become the bodywork and bonnets. Once everything is re-enforced and set then it gets "plated" with ABS sheet.
I think, (he says!), that this will be an easy locomotive to build after the nightmare that has been the EE-1.
Well construction has begun...
The plywood is 3mm Birch -normally referred to as "Marine Modelling Ply". It is very strong and light. It costs about £4.99p for a piece about 30cm x 90cm. It also bonds well with a number of glues. The rough carcass is assembled using CA and the re-enforcing pieces will use PVA wood glue. I sort of "tack weld" the pieces together with CA and then bond them with PVA rubbed into the joints. The joint holds for the 2 hours that the PVA takes to set solid...
Everything has gone very well -the expected warping of the ply is not too bad and the strengthening pieces that will bind the whole thing together will take care of the problem. As you will have noticed by the fact that I have had to use TWO steel rules in the shots shows that this loco has a length problem... My Gauge 3 "carry cradle" which is simply two lengths of angle iron on battens stuck to a length of plank is going to be too short to move this thing around on. My only option is to make the loco in pieces that can be assembled on the track. Fortunately the design easily breaks down into three units -two end bogies and a box cab. These are going to have to be connected by a socket system that is as yet -"lost in the aether"...
But what I think might be useful is, for once and for all to prove, (or disprove), that a Gauge 3 locomotive can be built on a shoe string budget. Admittedly some of the things are going to be "to hand" and relics of the "scraps pile". If we discount such things as postage, parking, etc -then it is going to interesting to see how much it actually DOES cost.
See Picture 5.
See Picture 6.
one sheet 3mm birch modelling ply £4.99p
one bag of 6mm sq pine strips £4.85p
running total : £9.84p
A Saturday morning trip to the local model shop, a real one that sells things not in boxes(!) has garnered me a couple of sheets of ABS to begin "plating" my loco body with. It is one of the certainties of life that you come home with sheets of differing colours. In short I had two sheets of white and one of black... All the putty that I have to fill the holes in in my creation is of course GREEN. It is thus always somewhat of a relief (visually) that everything gets sprayed in a neutral grey primer!!!
See Picture 7.
The shot above shows the 40 thous thick sheet after having been persuaded to curve at the end -initially with the aid of a rolling pin and then a length of steel tube wedged into the end of the hot tap. The chassis formers are finely sanded down with 800 wet&dry to give a smooth surface for the ABS to be veneered to. Once the thick CA has set the top of the sheet solid to the chassis, the rest of it is then bent over the carved Balsa wood "nose" and then saucepan of hot water placed over the nose to complete the shape forming. The formed nose is then bonded to the chassis with more thick CA.
Cost of 40 thou ABS sheet 98p
Cost of 60 thou ABS sheet £2.20p (2 sheets)
running cost £13.02p
Now that things are (nearly) back to normal I can return to playing with my models. After a couple of slow evenings work I have finished plating the sides of the body with the 60 thous ABS sheet. The doors and grills are emerging from the oddments box -so I will say that they are free.
See Picture 8.
I have built the flange that holds the bellows to the front and rear "bonnets" of the loco. The bellows will actually be made from glued strips of folded cartridge paper -the originals were rubberised canvas.
Well after an evening of playing "crack and snap" with ABS offcuts I have reached the point where I have to order the "twiddly bits". The first of these are the Finestruct mouldings from Squires. I have ordered the "L" sections, "I" beam sections, and the flat strappings that form the framework that the bodywork panels are riveted to. I do have (somewhere!) some Cambrian Models stick on rivets from building the "S" Motor. But given the number used I am definitely going to have to get some more...
The doors have been fixed to their places and the rectangular slots for the louvres punched through. The saddle grabs for the bonnets have been fitted -but not yet punched through. Next thing on the list of, "things to do", is to make all the window frames and the sun visors for the cabs. These will all have to be punched through and glazed -after painting...
MS-419 F/LINE MICROSTRIP 1.00 X 4.76 10 PACK £3.10p
AFS-6P F/LINE ANGLE 4.8 X 4.8 X 0.75 5 PACK £4.99P
BFS-10P F/LINE I BEAM7.9 X 4 X 0.96 4 PACK £5.35p
running cost £23.36p
After another gentle evenings playing "crack and snap" with the nice lengths of Finescale Plastruct lengths supplied by Squires -in under 24 hours(!)
Here is the Windows side of the model.
See Picture 10.
You can see that the 5mm wide strapping has been applied to the outside of the bodywork and the windows punched through with a die cutter -which is an L profile chisel. The holes in the saddle grabs have been punched through with a cutting needle and a scalpel blade. The doors have been affixed and their holes punched through with the die cutter. The window openings have been "lined" with the 5mm L section strip.
Here is the Power side of the loco.
See Picture 11.
The three squares that will become the exhaust vents for the Power side are quite easily visible as the large air intake square at the bottom right. These will be punched through and then "grilled over" the frames of the vents being made from more L section strip. The Windows side of the loco will have a "connecting corridor" between the cabs made of a sheet of balsa. It might seem a little strange -but I feel that if you are going to the trouble of making inlet and exhaust vents -then they should at least work! I have a few old "486" CPU fans that will provide a suitable draft through the loco.
Well after a little delay, I do have the contents of my wife's summer house in my shed while she decorates the inside of it, (somehow a sun lounger and a lathe do not go together...) I have been able to ferret through my collection of "bits" and I have unearthed the collection of Cambrian rivets, (these were left over sprues from building the "S" motor). Studying the side photos and modern shots have given me the locations of the main forged joints in the shell of the loco body. Since none of the panels were "structural" in the original they are only found where the members cross. The shot below shoes the "measled" bodywork, with the grids for the air vents fitted over the cutouts.
See Picture 12.
The grids are made from 10cm polythene(?) squares that are sold for small girls to produce X-stitch on with large bodkins and lengths of wool. They are £0.72p for a pack of 5. I am going to use a few more as I go on....
The next step is to make the eyebrows and punch the windows out in the end of the loco body.
Cambrian rivets -Free from left overs
Dace Plait £0.72p
running total £27.08p
The next stage of operations is to produce the power bogies that will hold the wheels etc. Normally these would be made from sheet brass (yes K&S!!!) but in the interests of shoe string experiment I think that they are going to be made from sheet steel -or aluminum...
The front axle will be driven by chains and my "patent" dodge of turning a 15mm "Yorkshire" plumbing fitting into a <<Systeme Hagans>> axle. This will be made easier this time as I have now got a milling machine so I can simply "mill the slots" rather than drilling and filing....
In case anyone is wondering how I do it... There is a 15mm dia wooden bead drilled at right angles with projecting 3mm bolts epoxied into it. These then sit within a 15mm pipe fitting with 3mm wide slots cut longitudinally in it. Thus the torque is transmitted by the 3mm bolts onto the edges of the slots regardless of the angle of the slots to the bead. The thrust of the weight on the axle is transmitted to the wheels by the bead and the torque from the driven inner shaft is transmitted to the tubular axle by the projecting bolts.
Sorry for the delay in getting back to this -but I have other pressing reasons... Now that I feel comfortable with an X-acto knife in my fingers, I can sit and fiddle with the model again. I ordered some bits from GRS -the van strapping and open wagon pieces. I will confess that I have never used them for a wagon -but as the basis of things that I can hack to produce the parts I need from. The "S" motor used quite a lot of these, but, typically enough, I did not have the right parts from the stock of bits that live in the scraps box.
See Picture 13.
The huge headlamp stuck on the corner piece comes from Imp Models and was part of a grab bag that I got when they moved from Long Eaton To Uttoxeter. (So I class this as free). The air intake grill at the bottom is made from more plastic lattice and pieces of van strapping. Other pieces of wagon strapping can be seen at the corners of the "bellows" housing.
See Picture 14.
This is the other end and you can see quite clearly the foot plate above the air vent made from another piece of van strapping.
At the moment I am causing great hilarity with my wife while I experiment with "how to make a bellows"... The origami method I used as a teenager for my Hornby 00 layout used cartridge paper and this is just too fragile. So, I have "upscaled" it to slices of Cornflakes packet -held together with "Bondaweb", a iron on dress making re-enforcer, as a "hinging" medium. And so far everything has gone well.
Indian "Darj" headlamps -free
Black Bondaweb offcuts -free
Cornflakes empty box -free
SG1123 £3.96p
SG1124 £3.96p
running total £35.00p
I have a deep dark antipathy to the people I call "colour freaks". I mix, (or have mixed), the paint and that is good enough for me. The problem I have now is that no-one is quite sure what actual colour "Brown Lake" IS... The colour I THOUGHT it was, was the "Brown Lake" as used by the Penn RR(!)
I do have a very few colour photos of GIP locos and I am aware that the colour emulsions can alter and degrade over time. For instance I have an early polaroid shot of my mother -now all in shades of green... So I sent out a request to a friend -who sent a request to his family on the India / Pakistan border, and we got back a sample of the GIP version of "Brown Lake"...
I looked at him, he looked at me, and we both said; "That's Brown Lake???"
At this point we took our piece of painted panel to the resident colour genius (my wife) and said; "Match That". And after three attempts -she did.
The "recipe" is: 7 parts "Nut Brown", 3 Parts "Burgundy", 1 part "Insignia Red".
For "historic" reasons I normally use the Pasti-Kote range of paints and blend from them. I still use "edible" paints on my work -despite the fact that the majority of small teeth that might chew on them can now spell!
I know that there was some "consternation" when I took "Maude" to the last Gauge '3' AGM in 2009. Her Mauve colour did not seem to sit too well with the Malachite, Crimson Lake and Black that the rest of the locos near her were painted with. However Maude was Pan Tone paint matched and is correct. What happens when "Sir Lesley" arrives at the 2011 AGM painted in GIP "Brown Lake" will be anyones guess. We shoved the sample from India under the Pan Tone sensor and got a Pan Tone number. So now it can be said with definite authority it really IS that colour!!!
Well the madness that is Christmas has passed (both of them) and The Hogmanay / New Year festivities have nearly been consumed... There is now enough room on the kitchen work surfaces to to return to important matters -namely making locomotives!!!
The shot below shows the roof section -which was cut at the same time as the floor section from the same piece of birch ply -thus they warp in exactly the same manner. Lengths of 5mm pine strip from the bundle bought at the start re-enforce it and provide a location lip for the whole roof assembly.
See Picture15.
You can see that the eight 3mm holes for the fixing studs have been bored through the roof into the sides of the model bodywork. The next shot shows the roof pinned to the body and the location of the cooling fan (40mm) has been marked and pilot hole drilled.
See Picture 16.
The next shot shows that the 60 thous ABS sheet has been laminated to the top and the tank cutter has cut a hole in it. The hole is off set by 10mm -this puts it in line with the heat sink for the ESC. The wooden wall sides for the plenum have been CA'ed to the ABS sheet. Yes, I know a "comb joint" is not really needed in anything this small -but it gives more glue area and should add that little extra bit of strength...
See Picture17.
The shot below shows the ABS sheet has been laminated onto the sides of the plenum and the cross pieces, (again lengths of 5mm strip), have been CA'ed to the assembly. These will provide support, (and something to glue to), for the base of the four "Snorkel" air intakes to the plenum chamber.
See Picture18.
The next shot shows the top of the plenum chamber CA'ed to the grid work of pine strip. The next stage after this is to fill in the gaps with putty and generally get things smooth before I start gluing snorkels to it.
See Picture19.
The snorkel columns will have air filters in them, (again pieces of Dace Plait), this should stop ingested grass seeds etc!
The pieces of Dace Plait that form the air filters have been fitted to the lumps/offcuts of 5mm sq strip. Each of these has been positioned roughly at the end of the air intake to the plenum chamber. The sides of the snorkel are made from lengths of scrap ABS from the bits box. The shot below shows the entire assembly prior to the fitting of the balsa wood rooves to the snorkels.
See Picture 20.
The green putty is very messy -but wonderful!!! I use it to fill in the cracks and gaps in my models. I do not know if there is any significance in the colour of the putty, (grade etc), but the green seems to work for me.
The time has come to do the main mechanical parts of this loco... In short -the power bogies!!! Normally I would wander along to my local model shop and pick up a couple of sheets of K&S Brass and chew them to shape. This time however in keeping with the premise that a G3 loco should be cheap to build I have opted for plastic. I "know" very few plastics well -but there is one that I used everyday in my designs and this is TUFNOL. Tufnol comes in a number of "grades" and the type I normally designed with is termed; "KITE". The engineering grade is termed; "WHALE". There are also "TROUT" and "CARP" grades! This stuff is dirt cheap -but P&P is a killer.
I ordered my 3mm thick sheet over the net and my 300 x 1,200 piece will come soon. They do do smaller sheets but the P&P is the same regardless of the size of sheet -so it will not go to waste.
It does also give me a chance to play with my new toys that I got for Xmas(!!!)
Whale Grade TUFNOL 3mm sheet 300 x 1,200 £12.03p
Running total £47.03p
Well now that the weather has warmed up(?) I have returned to my shed (with large mugs of hot steaming tea!) I spent the morning sawing off the tufnol sheet, four 5cm x 30 cm strips with a fine tooth hacksaw. I would advise not using a jigsaw for this, as despite the fact that tufnol is a plastic it generates large amounts of dust that gets blown everywhere... After examining my strips for "squareness" and being vastly disappointed by my sawmanship -I then set up the milling machine and began work. The first job was to produce a straight edge from the strips. I started out by roughly sorting the pieces to some sort of flattish "best side" and drilling a couple of 3mm holes to lock everything into place.
The picture below is "posed" for the camera -there is no way on this Earth that my fingers would be anywhere near a working milling machine!!!
See Picture 21.
The TiN drill is not really needed for drilling tufnol -but it works very well. You have to use very sharp tools -not because the stuff is hard to cut -but because of the friction and hence heat that blunt tools generate. Heat produces melting and your drill bit rapidly clogs up and if you are not careful it physically welds and embeds itself into your work piece. The only way to remove it -is to break the work piece...
Another problem you will encounter is clamping the work piece to the mill!!! WHALE grade Tufnol is used as a bearing surface, and with the average mill being "slightly oily" the thing skids around when you are cutting it like it was alive. The best method is to clamp it against a soft piece of "sacrificial" wood (I use balsa) thus the friction between the wood and the oily metal is not as high as it would be with just the raw tufnol.
The standard method of milling tufnol is to cut from the edge to the centre -which is the reverse of milling metal. This makes the tufnol turn into dust -rather than having the mill flutes propel shards of sharp tufnol around the mill (and at the operator!) This also prevents the tufnol from cracking.
See Picture 22.
The shot above shows the first pass to produce a "true" edge. The mill is an 8mm HSS one it is going through all 4 sheets (12mm) at about 1000RPM. At this point I am still not sure whether I want to make horn blocks and guides -or simply drill 10mm holes for the bearing to sit in(?)
I have decided to simply bore holes for the axles rather than going to the trouble of building horns and guides. This will make the model cheaper and easier to build. I have Sunday Lunch to cook -so I will not be able to get back into my shed until after "a suitable repast", (and maybe a hot water bottle comes with me to the shed!!!)
Well after a cold morning in the shed.... The tufnol sides of the bogies have been edged with 5mm sq pine strip and the "bonnets" similarly lined -this ensures a perfect fit during assembly / re-assembly. The ends of the bogies are currently held together via 60mm M3 nuts and bolts and a piece of wood that will be the basis for the "cowcatcher".
The initial tests with the scrap box collection of gears and so on -prove the concept will work, (deep sigh of relief!). The inline 5 pole motor drives a worm to a 60 tooth MOD1 gear. This then drives a 40 tooth MOD1 gear this transmits power to the two other 40 tooth MOD1 gears on the rear driving axles, (a so called triangle drive).
The net reduction is 45:1 which sounds rather high but the loco was never designed to move much faster than 45mph, all be it pulling carriages and wagons up a 1 in 70 incline... Also there is my own personal vanity at stake, after having taking all the time and trouble to produce a genuine scotch yoke assembly it would seem to be a waste of time if people cannot see it working(!)
12Volt 5 pole motor @ £2 each £4.00p
Running total £51.03p
The shot below shows one of the "bonnets" with its motor installed.
See Picture 25.
The next problem is actually one of dynamics.... The IDEAL pivot point is directly in line with the end of "bonnet" closest to the body of the loco. HOWEVER the weight of the motor will make the cornering slightly "sluggish" -so some thought will have to be done (and a few scribblings) to get the point of balance of the bogie to sit directly under the bellows joint between the bonnet and the bodywork. This can only really be done when I have the completed bogie and wheels etc assembled. So, the next step after the gears arrive, I haven't got an invoice yet from the suppliers yet -so I can't tot up the running total, is to make some wheels.
I am not very good at making wheels -let me be the first to admit!!! What I have decided to do is order some "slices" of steel rod and then lathe them to shape. After having done this and produced the raw blank the problem then is -do I cut spokes on them? Using the rotary table and my small mill it is possible to cut spokes in a radial manner and then machine out the waste to give the correct look. Something to think and doodle about in the lazy Sunday afternoon....
Well the nice people have dispatched my order, and this is what I bought.
4600-138 MOD 1 40T Plastic Gear 6 £8.16
4600-141 MOD 1 60T Plastic Gear 2 £2.94
4604-012 Metal Shaft 4x150mm Pk 1 £1.49
4601-002 Plastic Sprocket 16T 10 £1.52
4601-006 Plastic Sprocket Chain 1m 1 £4.75
4600-037 Standard MOD 1 Worm Gear 3 £2.19
Total: £27.68
Running total £78.71p
The question is now -how much more do I have to buy and how much more do I have to build? Because it is starting to get "close"... I am now fairly confident that I can build the loco for under the £200 mark.
The gears have arrived and I have had the chance to "play" with them. Everything fits as it should -but I am looking at the 3mm thickness of the Tufnol and I feel that this is just too thin to take the bearing load of the loco. So, what I will do is make some washers and bond those either side of the hole in the chassis rail and insert a length of brass tube to take the wear. This will give me 9mm thickness of tufnol and a steel to brass bearing surface -which should be more than adequate(!)
See Picture 26.
The power take off chain and sprocket will be on the central axle, (the one on the far right of the picture), to the front axle, then a chain and sprocket to the "drive wheel" from the front axle. Mechanically speaking rather messy -but it will keep all the linkages aligned while the beast is in motion...
I would love to go and play in my shed and get it all working -but it is snowing madly and the last time I tried something at these temperatures my skin stuck to bed of the milling machine.
Such was the madness and desperation that at 8pm that night I gave in, wrapped myself as best as possible went out into my shed and started to play!!!
The next shot shows the start of the Krokodil drive axle. The 16 tooth sprocket has been drilled to 3.9mm and the shaft forced (very unwillingly!) through it... On the ends of this have been placed the drive / flywheel / cranks, (I am going to call it the Krokodil axle), that provides power to the scotch yoke and thus power to the other 6 wheels on the bogie. YES I admit that they are Mamod locomotive wheels and are (mathematically) 0.75 inches (scale) too big, but I bought a scrap bag of them several years ago, some of them have holes and are painted -the rest require "some work"...
See Picture 27.
After some epoxy the brass screw and steel nut will not move, (ever).
See Picture 28.
If you examine the drawing above then everything in the above shot should make sense. The drive chain to the front axle allows greater lateral movement, (something that splitting the chain and driving off the Krokodil axle would not). The Krokodil axle is then driven from this and everything should now move in synchronisation with the large 60 tooth spur gear, (he says....)
Time to start fettling the bonnets to fit to the bogies -this time somewhere nice and warm!!
Now that it is (theoretically) British Summer Time and despite the fact that it is snowing outside I am now in a position to begin the final run into the bogies. I ordered my twelve 10mm slices of 55mm steel bar from Mallard Metals and I have some Webb H wheel covers to applique to them.
I had resigned myself to having to cut the wheel blanks and then mill the spokes out on a rotary table -however as I was passing the Williams Models stand I saw the H section wheel covers and these plus some 60 thous PlastiKard will become my wheel spokes. I plan to simply CA the brass etches to the sheet and then cut and file the gaps. After a few very squinty hours with a broach, X-Acto knives, and a set of needle files -I have the following photo. I would have posted it before but, (typically), when the camera started up I got the "Please Recharge" sign...
12 H section wheel covers £12.00p
10mm wheel slices 55mm bar £32.35p
Running total £123.06p
“Rob” at Mallard Metals has delivered his twelve slices of steel and the construction of the wheels has begun. I will have to “pose” some pictures later on as, (yet again), my camera has given me the “Please Recharge” request sign, (I think it could need new battery!?!?!) I have “faced off“ one side of my slices and using a “Slocombe” drill centre bored a 3mm hole through it. This will be used to align the Mamod wheel on its 3mm shaft to the the centre of the driving wheel. I will then bore through the 3mm crank hole and thus (hopefully) all the offsets will be the same and the whole thing will move without binding(!) The connection between the wheel and the axle shaft is I have to admit a bit of a fudge. There will be a length of brass tube into the wheel, this will then be silver soldered to it. The brass tube then slides over the 4mm thick axle made of “piano wire” and a 2mm hole is drilled through both of them. A 2mm nut and bolt then unifies the assembly. This loco will have classical English type wheels rather than the “Colonial Wheels” used by my last loco.
After a few minutes in the charger the camera had enough power in it to take this shot. This shows the Slocombe biting into the wheel blank. The rough facing is not essential but makes it easier for me to handle. I know that most of that side of the wheel will have to be machined away to to produce the wheel shape -but for the time being it is smooth and has few gash producing swarf edges!!!
After another evening production in the shed I have six of the twelve wheels machined to thickness (8mm). I did debate whether to drill the pin hole for the cranks before or after the main machining. I opted for “before” and frankly it was a mistake! I should have kept the steel hole-less as when the cutter passes of it it creates a knocking vibration that showers swarf chips all over me... Anyway here is a picture of the mill with the 10mm blank slice with a Mamod wheel bolted through the drilled 3mm central hole.
At the end of another evenings work I now have twelve 8mm thick wheel blanks. The next step over the weekend will be to start working out the cut in sections for the spokes inlay for each wheel. The inlay has to be circa 1mm smaller than the section that it is going to sit in. This will allow the epoxy that will unify the inlay and the section to ooze around the corners. The spoke has to lie up with the hole for the crank pin -so that the crank pin sits between the spokes. This also allows me to nut the inlay to the wheel -which will really hold it steady while the epoxy sets...
After some thought I have decided to abandon my tube and 2mm nut and bolt idea for fixing the wheels to their axles. Instead I am going to opt for something more unorthodox -but I think easier to do. I intend to thread the axle and then thread the hole in the wheel. If I apply a locking nut against the inside of the wheel with some CA or thread lock then it should hold rigid. The only real problem will be the accurate positioning of the wheel along the thread. There may be some inaccuracies but I don’t think that they are going to be major -as one complete turn of an M4 thread is 1mm. Once the back-to-back is set on the axle it will simply be a case of turning the wheel until the cranks all engage.
The cranks are going to be another problem for the midnight oil to solve... I think that I am going to have to use brass tube silver soldered into the conrods. These then sit around the M3 crankpins and I have nuts at the end of them. I am not too sure about “quartering” them as no power is transferred via the conrods. I do like the 120 degree crank separation rather than the 90 degree one. I know this is not the most efficient -but it does give smoother running. The “counterweights” on the wheels will simply be made from built up pieces of scrap PlasiKard and these will simply be bonded to the brass etching. All in All I think it is going well.
Some days have passed due to travel and work problems The wheels have been turned and the brass fret and ABS spokes epoxied into them. There was some problem with the mill in the 3mm hole to punch through the brass fret, but this was due to the mill teeth clogging up with the soft ABS rather than the power or difficulty of the operation. The best technique turned out (!) to be to use a hand wheel brace and a vacuum cleaner of the type used to clean computer keyboards with. Once the mill was through the ABS it cut a neat hole through the brass fret in seconds...
The shot below is a “rough up” assembly of the “B” bogie. The wheels do not have their sabots which connect them to the axles and are simply “blu tacked” on to the end of them. The whole thing rests on a couple of screw boxes -but the effect is I think easy to see.
I had hoped to begin construction of the conrods and scotch yoke assemblies but unfortunately I have run out of gas for my bottle torch... So I have a diagram of the conrod and Scotch Yoke linkages to show you instead. The conrods will be offcut / scrapbox lengths of 32 thous 1/4 inch K&S brass strip. The conrod ends will have a brass tube through the strip with a couple of washers silver soldered to it for re-enforcement as the amount of metal that will be left after the tube has been inserted will be 1.125mm either side of it(!) The Scotch Yoke ends will be more of a fork end end thus stronger -but it will still get the washer treatment.
After an evening of work -spent mostly uttering Burmese swear words, (a boyhood gift from my father), I have begun cutting the sabots that will hold the wheels to the axles. Because it was the first thing to hand that was the right diameter I used a length of aluminium rod... This was a mistake -however I have got this far so I will have to continue. The idea is that the sabot is threaded and sits on a threaded length of bar (i.e. the axle) and is locked into place via “Loctite Green Sleeve Retaining Compound”. This is a direct crib from the method I saw being used as a boy -except the wheels were held in place via long pins. This made converting wagons from Cape Gauge to Metre Gauge by turning the wagon wheel three times clockwise -pretty easy!!! The sabot then connects to the drive wheel by the 3mm crank pin through it.
The problem with the aluminium is that it produces long streamers of tinsel which promptly envelop the cutter and it flies around the work shop like evilly malign confetti...
After having turned my workshop into a mad version of Xmas with all the aluminium swarf streamers that it produced I have a bogie with six wheels screwed onto the axles. The 19mm dia Aluminium bar was chopped into 11mm lengths and them turned down to 10mm for 6mm of its length. Then six of the twelve sabots were then bored to 4mm and tapped to M5 the remainder drilled to 5mm. The brass rod axles were then tapped to M5 at one end and "Loctited" into the threaded holes -this gives me one end of the axle that is fixed and I can use the wheel to pull/push the axle through the chassis sides. The other side of the axle will be drilled and pinned through the sabot for ease of removal.
This means all my gears will have to be drilled to 5mm (easy!) and then once both bogies are on rails I can think about the construction of the "Scotch Yoke" and conrods -plus the pivot points. This would then complete the bulk of the mechanical work. Then it is the simple part of wiring all the motors to the relays for fwd/rev and then the ESC to the power supply.
As most people will have gathered there have been "sight problems" with errant volcanoes... However after having got back home and got rid of the backlog of stuff that had built up I am now able to continue with the loco!!! I have tapped the shafts at one end and then "loctited" them into position. One of the main problems that people get with "sleeve retaining compound" is that don't allow it time to grab solidly-this can take anywhere from 10 to 20 minutes -and the joint never quite makes the grade.... My solution to this is to apply bucket loads of compound and then allow the compound to cure overnight. This does mean that you have to clamp whatever it is quite firmly and for extended periods of time. I normally use either the Drill press or my Mill (at the moment I am using both!) to hold the axle in a truly vertical position relative to the wheel while the compound sets.
The sabot has been milled from the front to produce the slot that the sawn off M3 bolt will rest in. The shot below shows the section of bolt.
By Friday Morning I should have 6 completed axles and then I can move on to the "fun" part of the bogie -building all the linkage. Despite careful examination I am still not sure of the correct dimensions and (to be honest) I don't think that some of the figures on the drawings are anyway accurate. As explained elsewhere the Vulcan drawings are dimensionally suspect as some of them are based on 2cm to the inch(!) What I have a feeling that I am going to have to do -is guess and hope... SLM were an extremely conservative company and really didn't like doing things anew. Thus it is very likely that another loco of theirs has the same power bogie and I can crib from that.
Time to dig out the collection of postcards...
This is always sort of a "momentous occasion" for me -whatever I build... The model is 82cm from nose to nose, (the cow catchers and buffers have yet to be made). It stands 19.5cm from the rail to the top of the snorkels and is 12.5cm wide. As you can see it it nearly takes up a complete yard length of track(!)
The next step is to "crib" the linkage dimensions from a Swiss loco that I found in my collection of postcards -it is termed by Swiss trainspotters as a "Flatiron". This is basically a "Krokodil" bogie with a cab on it -in fact that is exactly how some of them were made... I have put in my "request" to friends at the BLS Transport Museum and I will get them e-mailed me later this week.
After having dutifully emptied my e-mail box this morning and obtained the drawing I required from the BLS Transport Museum I translated the dimensions into G3 and sat down with my morning coffee and dunked a Bagel in it -or two... The Lunchtime Soda Farl was munched in deep meditation... By the evening meal I had a rough idea how I was going to do it -and by 6pm I had enough courage to start operations!!! After some evil marking out, delicate sawing and precision bashing with a hammer -the roughs were ready to meet the drill.
What you are looking at is the raw cut and drilled pieces of K&S brass.
The large rectangular piece has to be cut and shaped into the familiar triangular shape of the Kando. The next shot is the vertical slice through the drive, forgive the mish mash of nuts and bolts -all this will be silver soldered on final assembly.
To the important question "Does It Work?" the answer is Yes -it squeaks horribly too...
I am going to have to put some sort of “floor” or “pan” on the bottoms of the bogies. This will keep the chains free of dirt, (hopefully), and generally improve the visual aspect, (i.e. no dangly chains). I also feel that a flip forward hinge at the front of the bonnets will enable easy access to the gubbins below (yes I was fascinated by Triumph Heralds as a boy!)
To the tumultuous cheering of the assembled, (father, son and spouse), "B" bogie moved under its own power for the complete 1 yard length of the test track and duly fell off the end at 8:30 pm this Friday evening.
I have to admit that this is one of the nastiest pieces of home made engineering that I have had to do. Even with marking and drilling everything to a fractional millimetre of its life -the thing would still "bind" at the odd angles... I took it apart and gently filed the "egg oval" shapes for the Kando holes for more times than I care to remember(!) The chief problem I have now is the fact that the bogie is really too light for effective testing and I have had to tape a pair of SLA batteries to it to give it the correct tractive weight for the task -otherwise the thing simply sat there with its wheels going around -going nowhere...
At the moment the motor is simply lashed to the bonnet floor with a couple of cable ties, (this is going to have to be improved) -I think I mount a plastic panel and then use M2.5 nuts and bolts to hold the motor in position. Allied to this there is going to have to be a more rigid worm gear mounting, as the worm is simply pushed onto the motor shaft and is unsupported at the end where the spur gear meshes. This is fine for testing, but when the real torque is applied from the ESC, rather than a single AA NiMH, the free end will flop around and wear itself out quite rapidly.
After a nice wet Saturday -therefore I had to go and play in my shed -rather than dig weeds... The body is now mounted on the bogies and the “A” bogie has all the cranks and linkages working. This time it took less than an hour to do -as I now knew what I was doing. The balance problem with the bogies and the body work is far more than I had feared. It seems that a weight of about 800 grammes will be needed at the ends of the bogie to settle the flanges into the rail heads. I was actually hoping for a little less...
The body is “Z” mounted to the bogies, this is a pivot mounted at one side of the bogies -not centrally inline with the length of the loco. This is a method of making the body self aligning -but it does mean that the bogie subtends a different arc to the body depending on which way it is cornering. However, since each pivot point of the “Z” is on the opposing side of the bogie the net effect cancels itself out. Similarly the balance weight will have to be located on the opposing side to the pivot and at the end of the bogie. The weight of the body at one end of the bogie and weight of the balance weight will cause the bogie to flex slightly and give a primitive compensating effect for track irregularities.
The last purchases for the loco are the Radio Control (R/C) system and the Electronic Speed Controller (ESC). I could simply home brew the latter but I think that would defeat the purpose of the experiment. As with the NER EE-1 I have opted for a 2.4Ghz transmitter but I have gone for a simple ESC rather than the more complex programmable one I used there. This I believe completes the purchases for the loco so that a final tally can be put down. The remaining parts and so on will come from the scraps pile and bits boxes.
Giant Cod 2.4Ghz 4 Channel Tx and Rx £27.42p
Electronize FR8T-PS £36.60p
This brings the total cost of the build to £187.08p over the course of 9 months OR £4.80p per week over 39 weeks...
I may be biased but I think the experiment was well worth it, as it has proved that a Gauge '3' loco can be easily affordable. The biggest expenses were the Wheels and the R/C equipment. The R/C equipment alone accounts for 34% of the total cost and if this were an issue it would be easily possible to use a Dual Pole Dual Throw switch to provide Fwd and Rev from a 2 Volt Sealed Lead Acid battery.
What remains to be done now is the essential "faffing & nit picking" that goes with the end phase of any model, the gap filling, wet sanding and priming that completes the model. I will update what goes on as I finish it -but essentially the construction phase is now complete.
A few long hot evenings have passed and I have been doing other things (See Part 5). But slowly and surely the paintwork has been applied and the details added. One think that slightly annoyed me was that the Standard for G3 has been slightly altered and the buffer height and spacing is “just that bit” different. Having worked out my buffer arrangement for the old Standard I am a little bit miffed that this is now incorrect!!! I have also had to decide which is the front and rear of my loco. Not a difficult thing you may think -but the front is the end that gets the lamp and is (hopefully) the better looking of the two ends. The home mixed “Brown Lake” proved to be an absolute nightmare to get right I am still not happy with it and I think that if I layer any more of it on the bodywork the rivets and things will start to be submerged under it! When time permits me to build its sister loco -the GIP E/A1 I will simply use Maroon paint with a glaze...
As I have said elsewhere I like to use wood for my buffer beams. This may make them thicker than scale -but I find them to be robust and practical. The central hook has been fitted and the holes for the buffers drilled. I intend to use the GWR spring loaded ones from GRS. Naturally the spares box has unearthed THREE of them -somewhere there is the fourth.... Safety chains and vacuum pipes are not going to be needed as, (strictly speaking), this is a freight loco, but I will fit them anyway, and it gets more stuff out of the spares box used up. The running lamp is a spare from the box and as I have only the one it means that I have to decide the code that I am going to use. The options seem to point to “C” and “D” as being a good bet, “Fast Freight vacuum stock” or “Empty Carriages”. This has the running lamp on the Left Hand Side of the buffer beam -so whatever I couple up to the loco is always correct!!!
After a coolish Sunday in the shed -the home straight is now in sight. I have begun transferring the blu-tacked wiring to the roof to the underside and gluing bolting it into place. There are still two power cables sticking out of the side window -but this is the power input from the shed PSU -a genuine Farnel type 7 lab pack(!) I have to admit that it was an impulse buy -but there is something about a KT88 valve regulated Power Supply... The relays have been glued to the roof, the 50mm coolant fan installed in the snorkel chamber and the circuit breaker installed between the batteries. The use of circuit breakers is, I have to admit, a personal foible of mine as the first time I took a loco out to a G3 get together the wiring had become shaken by the taxi from the Railway Station and inline the fuses were dislodged and broken, since then I have used circuit breakers...
The pantograph has emerged from the box of K&S tubing as expected this is my own variant on the Henry Greenly pantograph as discussed in "The Newsletter" (the Gauge ‘3’ Society magazine). The kitchen "Creme Brulee" maker also doubles as my blow torch for small silver soldering jobs. Making a "panto" is not a hard job -it is however mind numbingly tedious. The standard diamond panto requires EIGHT lower arms and EIGHT upper arms. These are duly cut from tube with a small K&S cutter. Then 1cm long stubs of 1mm brass rod are chopped up -you need THIRTY SIX of these... Each 1cm length of rod is then crimped into a 3mm ring connector -do this THIRTY SIX times. The rods are then fed into the end of the brass tube and crimped -do this THIRTY SIX times. Then when you have done all this, gone out side and screamed(!) you can begin to assemble the bow collectors. I "cheat" and produce a bow collector where the ends of the bow are joined together -this produces a stronger bow and it can take the knocks from impacts that a "true to scale" one would not.
The ends of the bow are bent using the ends of a (modified) clothes peg, this provides a set shape. The ends then have a length of wire placed into them to hold them together while I hit it with the torch and silver solder.
Well I tried a power test and, (not unexpectedly) -nothing moved...
It was not as I had expected the worm gear being “thrown” off the spur gear -but something far worse(!) What was happening was the spur gear was going round and the side thrust from the worm gear was forcing it to cut a neat spiral thread in the shaft from the grub screw that was pinning it to the shaft. “Words” were muttered and I dug out my 3mm drill and bored some holes between the two sets of gears. NOW the spur gear from the worm drive is BOLTED to the drive gear in two places -needless to say everything is now moving as it should do... I am really going to have to do something about the weight distribution problem on the bogies. I have tried epoxied pieces of steel scrap -but it seems that the only real solution is to mix some “concrete” and pour it into bricks that I can squish/stick in the right places. By “concrete” I mean a mess of epoxy and fish tank gravel -heavy and hard.
I did some experiments with a “Joss Stick”, (it is after all an Indian Loco!), to see how efficient the fan was at pulling air through the body of the loco and found that the best position for the ESC heat sinks is slightly to the rear of the central window(?) Rather than use the smoke from the burning stick, I used the colour and intensity of the glow from it -to judge the amount of air passing around it. I have to admit though that the appearance of the smoke being blown out of the snorkel vents was more than a little worrying.
I think that once the balance and weight problems are sorted out then the loco should be looking for a short test run on the kitchen floor test track. All 3 lengths of it...
Well after some weeks of work in the garden I have arrived at the final parts to be added. These are the pantographs, the hand rails and the buffers. The paint has been “touched up” after the inevitable scratching that always occurs during getting things to fit and then the cables need dressing to make sure that they are held in a secure flexible position -but not where they can get chomped by the gearing(!) I have to make the defining thing for an Indian loco the white bars across the windows that is a feature of any Indian loco. Quite how I am going to do this at the moment I have no idea. My initial thoughts were to simply bend some 1mm thick brass rod and just paint it with enamel. However the test piece looks WRONG -just why it does so I cannot say...
The buffers are the GRS ones for a GWR loco. They look to be the right type and to be honest are as near as I am likely to get to the originals.
Tomorrow is Sunday -the day of the shed! when I have finished my normal Sunday duties of Head Chef and Waiter I will start boring polite holes into my nicely painted model for the hand rails to fit into. I have found that a “Wood Bit” is the best thing for drilling through ABS -as the central spike sticks in the ABS and stops the bit “wandering”.
This is the last shot of the model as further shots would be just “twiddles”... It shows the pantographs in their place (but not yet sprung). The model is for all intents and purposes -complete. The experiment has lasted a little over 10 months and has I feel been a success.
It is possible to build a Gauge ‘3’ model on a shoestring!!!
Q.E.D.
