I am building a batch of 5 DHR diesel NDM6 loco in 1:19 scale.
Specs:
-scale 1/19 or 16mm=1foot
-gauge 32mm/45mm regaugeable
-all brass, M.S & S.S construction
-2.4 ghz RC & with powered by 12v deep cycle gel battery packs
-powered by 2 X 12v dc p.m motors with 1:36 all metal reduction gear drive
-detailed body overlays, photo-etched louvers, vents, name plates etc.
-prototypical DHR D style buffer couplers
-detailed cast/machined brass fittings like head/marker lamps, sand boxes, axle boxes, handrails, latches, radiator grill, footboards etc.
-directional head/marker lamps, working doors and hatches, glazed windows etc
-MS regaugeable wheels
More details on the build can be found on my website www.pline.in

Regards
Nilanjan Paul

I have now prepared the brass photo-etches for the locos, must admit a very nasty process in deed.
The photo-etches include the:
engine vents, louvers, "NDM6" name plates(in both hindi & english), loco number plates and builders plates.

Marked and cut out the chassis plate in 1mm thick half hard brass sheet and the body parts (engine cowl, cab front, rear & sides) in 0.6mm tick soft drawn brass sheet.

Prior to folding the cab ends on a press brake, cut out the window recesses using a fine chisel, then filed them to shape using jewellers files. Folded the edges for soldering.
Then cut out the door panel from the cab side sections and filed them to shape. The door panel would be soldered on to the cab sides using 1/2" brass hinges. They would open inside the cab as in the prototype.

Formed the engine cowl on the press brake and rounded the top edges on a self made wooden jig with curve radius R4
The taper in the front of the cowl was then marked and cut using a fine chisel and filed to shape.

Next the chassis was folded on the press brake. It is worth noting that the chassis of the ndm6 has a hexagonal shape.
The edges of the hexagon were silver soldered with 1mm thick brass gussets from the underside.

Moved away from sheet metal work to some gear & worm cutting on the hobbing & lathe. Prepared the worms & gears in brass the reduction ratio is 1:12. Formed the gear box housing by folding 1mm thick brass. Turned the bronze bushes (i/d 3.2mm)  for the gear shafts on my Hero lathe. Cut lengths of 3mm Spring steel for the gear shafts, the ends of the shafts were ground.
Next drilled the bush housings on the sides of the gear box and silver soldered the end bushes in place.
Initially push fitted the gears on the shafts and then silver soldered them on.

The worms were just push fitted on the shafts of the motors with loctite retaining compound. Left to cure for 48 hours and then the rest of the gear box assembly was screwed on to the motor.
Finally they were run in at low speed for 45 minutes, and light machine oil applied all the while.

So far so good. Will keep updating as I proceed.
Regards
Nilanjan Paul
www.pline.in



 

Beautiful stuff - you must have some good "karigars"

or do you do all this by yourself ?

Further progress made today on the NDM6.

Marked & cut out the hatch openings on top of the engine cowls with a 3" chiesel and filed the recesses to shape. Will make the hatch doors next.
Also soldered the doors to the cab sides using miniature 1/4" brass jewel box hinges. I generally use 1/2" brass hinges for 1/19th scale, but the hinges on the NDM6's doors appear to be smaller than those used on other NG diesel locos in India, namely the NDM1/ZDM1.

Made sure that the doors open and close with ease and that there are no gaps between the edges.
Note worthy is that on the Indian NG railways, unlike those in the UK, our doors open inside the cabs/coaches and not outside onto the platforms.
A safety feature perhaps!

Regards
Nilanjan Paul

Marked out and formed the bogie side frames today from 1mm thick brass sheet on my manual press brake.
Then drilled the 2.5mm dia guide holes for the cast/machined brass axle boxes, ofcourse the holes would then be enlarged to 8mm dia.
Would be silver soldering these to the underside of the chassis frame.
Some photos attached.

Regards
Nilanjan Paul

Further progress made on the NDM6 in 1/19 scale.
Cut and formed the chassis end plates and soldered them end-on to the bogie side frames, using a MS jig that I had milled out earlier in the week.
Re-reamed the axle box drill holes to 6mm dia.
Turned the Axle boxes from 9.5mm square brass stock on the lathe. The Axle boxes will take 3mm dia. silver steel axle ends and vertical lubricant holes will be drilled at a later stage.
On the chassis top marked and drilled out holes for the M2 brass bolts that would fasten the bogie assembly to the cab floor. The initial tab solder was to align and drill the axle box holes.
Regards
Nilanjan Paul
www.pline.in

Nice ... I can hear the real toy train's sound from my house at the moment. I'm in darj btw.

Drilled the cab control holes to house the 3-position DPDT power on/off/charge switch, 2-way DPDT lights on/off switch, charging socket and fuse holder on the inner face of the cab front.
Regards
Nilanjan Paul

www.pline.in

More progress made on the DHR NDM6 locomotives!
-used a mallet to raise the frames and edges of the cab windows and doors and then soldered 28swg copper wire beading to the periphery.

-next turned to the chassis and soldered on the axle boxes.
Note the 1.8mm dia oiler holes drilled on the underside of the axle boxes for lubrication.
-Inserted two 3mm dia Spring steel axles and the gauge adjustable wheels (32mm or 45mm track gauge) were slid in along with the main brass spur drive gears (21T & 48pitch).
The grub screws on the wheel hubs would be tightened later once the gauge is set using a jig.

Next will build the worm reduction gear boxes with the first stage brass 1:12 worm & wheel followed by the 2nd stage 1:3 spur reduction, to get an overall 1:36 reduction on each axle.

Regards
Nilanjan Paul

www.pline.in

Worked on the NDM6 chassis all of last week.
Marked out cut and formed the 1st stage worm reduction gear box sides, drilled and tapped to take in M2 fastner screws to hold the gear boxes.
Turned on the lathe phospher bronze gear shaft end bushings and drilled 2.5mm dia holes in them to take the shaft ends.
Soldered the bushes to the appropriate holes on the gear boxes.

Next marked out and cut the sand boxes on 0.6mm thick brass shims, prepared the steel jigs on a mill to fold the sand boxes to shape. Finally used a wooden mallet and the press bake to fold & form a few sand boxes for the locos.
Will solder and file the joints later for rigidity.

Here are some photos.

Regards
Nilanjan Paul

www.pline.in

Got the worm/wheel 1st stage reduction gear boxes assembled over the past few days.
the gears boxes will house 1:12 worm reduction drives followed by 1:3 spur reduction gear sets. To give a final reduction drive of 1:36 over each axle.
All the gears are in brass.
Regards
Nilanjan Paul

www.pline.in

Will the brass gears be running dry? Or is there some oil bath system?

Delrin gears are good, don't need lubrication, but then they are not scale........

D/Sir
the gear box is stuffed with grease and will be fitted with my standard snap-fit brass lids.
I try to use all metal gears in all my garden railway products as that is a standard amongst most garden railway manufacturers.
Moreover my battery powered locos have to compete with live steam ones in the market 
Regards
Nilanjan Paul

www.pline.in

Finally got the power chassis up and running!!
Regards
Nilanjan paul

now that I have a running chassis, started work on the body shell.
-soldered on the cab sided and front and the bonnet to the chassis plate top and the foot boards
regards
nilanjan paul

www.pline.in

Moving fast now

yes i got to move fast on this.
have a delivery date on the first batch in late August 2013

Regards
Nilanjan paul

www.pline.in

Some more pics of the body shell
Regards
Nilanjan paul

www.pline.in

yet more pics of the body shell
Regards
Nilanjan Paul

www.pline.in

cut and folded the bonnet side boxes from 0.6mm thick brass, then filed them to fit on both the edges of the bonnet as in the prototype. There is a left hand & right hand box.
Aligned them with the cab front using an engineer,s square and finally soft soldered them in place.

Marked out the positions of the brass photo etched body overlays on both sides of the cab and bonnet. Used a very fine set of scribes and a pair of fine center punches to mark out the positions.
Next will soft solder the brass photo-etched details (completed earlier on 23swg soft drawn brass sheets).
Regards
Nilanjan Paul

www.pline.in

Formed 4mm X 4mm brass angles on the press brake and soldered them to the edges of the bonnet hatch recesses to act as hatch retainers.
The rail god is slowing down work at the workshop!
Regards
Nilanjan Paul

www.pline.in

Formed the bonnet top hatch covers from 0.6mm thick brass sheets. The hatch covers are snap-fitted on the recesses for easy access to the inside of the bonnet.
Also soldered into position the NDM6's signature photo-etched nameplates and builder's plates, onto the photo-etched louvers.
Regards
Nilanjan Paul

www.pline.in

Started soldering the photo-etched body overlays onto the body shell of the loco. Had to form and add a few cosmetic detailing like hatch locks and hinges etc.
More photos as I proceed further.
REgards
Nilanjan Paul

www.pline.in

Love the locks! So, so realistic! 

Now I have the handrails, wrungs, hatch lifts etc. formed and soldered on to the bodyshell.
Note the photo-etched nameplate markings are in Hindi on the RHS of the cab and english on the LHS.
Regards
Nilanjan Paul

www.pline.in