A first 006 diesel - footplate and chassis.

 Any layout, even a humble 'pizza', needs a loco, otherwise it's just a diorama. So I'm building one. This is purely freelance, and is just a 'quickie' for testing wheels and trying out ideas, so don't expect too much.

To get an idea of how the thing fits together I did a wee sketch, but rather than the usual fag-packet job I made it full-sized on graph paper which helped me position the wheels in relation to the motor with the motor in the cab;

The loco is being built along Saltford lines, at least where drive and pick-ups are concerned.

I started by turning up a set of wheels from nickel silver, which is a first as I usually use brass. These are 6.6mm dia. made using my 2FS forming tool. I'm using split chassis pick-up so the wheels are fitted to Acetal muffs;

Gears are KB Scale 15:1.

The footplate is made from .030" styrene, with square section bar used at the ends as frame spacers, faced to length using a self-centring 4 jaw chuck. The sideframes are made from 6mm x .8mm brass strip, fitted with bearings turned on the lathe. The frames have 12BA tapped holes in the centre, so that I can attach leads to carry power to the motor. 

Here's one sideframe attached to the footplate;

Note that the outer face of the frames have been treated with Birchwood Casey Brass Black. The footplate measures 36 x 16.5mm.

I've used a 12mm i/d Nigel Lawton drive belt to couple the axles;

To connect the motor to the frames I made up some small tags from scrap etch;

These are held in place with cut-down 12BA screws, which were a fiddle to fit! Using tags eradicates the need to solder wires to the frames, electrical soldering is not my strong point and the chances of melting the plasticard footplate can be avoided.

The motor is an excellent High Level Kits 1015, which performs very well indeed with 15:1 gearing. This does have a 1mm shaft, so I made an adaptor bush on the lathe. You can buy these but I had none. I've used 30AWG 'decoder' wire to connect up the motor, which was easier to work with than I imagined. However, I did manage to break one tag whilst trying to screw it into place (moving the tag too much whilst trying to position it and the screw), a job made easier by using a little blu-tack to hold the screw onto the end of the screwdriver. I worked that one out after I'd broken the tag! Note to self - motor positive to left frame.

Here's the chassis on my pizza;

But, how does it run? Actually very well! Surprisingly well in fact, even if I run it without any weight (I've been running it with my mint tin controller). I put this down to a mix of nickel silver wheels and the High Level Kits motor. One thing I'm not sure about is the effectiveness of the drivebelt, it feels a bit too loose to be of much use. I've had success coupling axles this way on a couple of Saltford Simplexes, but in this case I feel the wheelbase is too short for the belt that I've chosen, yet I feel that the next size down would have been too tight. I could have got around this problem (if it is a problem) by using larger diameter axle muffs. I have no intention of changing anything on this build, it is only a test piece and as such I feel it to be a success.

Cab next.

Paul.

Meridian Models/Mosskito Narrow Gauge MPD18 chassis

This is a nice little power unit with an 18mm wheelbase, designed to be used under a couple of Meridian Models loco kits, namely the Armoured Simplex and Billard T75D. These are now available under the Mosskito Narrow Gauge banner and are available from Narrow Planet (mine is an older Meridian kit, bought from a secondhand sales stand at an exhibition). I've wanted to build one of these for a while now as they look to be well designed and reliable, following the tried and tested band drive/layshaft/Tenshodo gears format.

The kit is etched in nickel silver, and includes everything that you need barring glue and solder;

The instructions cover 4 sides of A4, and can be seen here in pdf form.

The first job is to assemble the layshaft in its etched bracket;

To help position the worms and bearings there's some helpful markings on the etch;

The layshaft runs in roller bearings, I used my lathe to help push the bearings and worms onto the steel rod.

Next one side of the main body is folded up;

The layshaft assembly fitted into place;

And then trapped in position;

In the above photo can be seen the keeper plate, which clips in place under the chassis and allow the wheelsets to be removed. There are tabs etched onto the layshaft carrier which locate in the sides of the main body, once the unit is assembled these are bent over to hold the unit together without the need for solder.

One wheel on each axle needs to be removed, with a suitable puller to allow each wheelset to be built up using an etched washer, a sleeve for the worm gear to sit on, and two bearings. The sleeve needs to be glued in place, I used Loctite 603 but cyano or even a thin smear of epoxy would work if applied sparingly with care. One of the bearings in my kit was oversize, to save time I made up a new one on the lathe, which would have been much quicker than contacting the manufactorer for a replacement;

Wheels are by North West Short Line, and run on brass axles. Having brass axles running in brass bearings is considered to be bad practice, so it will be interesting to see how this chassis fares in the long term.

Here's the wheels and keeper plate test fitted;

On the etch there's a pair of T shaped parts. These aren't mentioned in the instructions, but fit into slots in the sides of the body;

They're not mentioned because you they're not needed. I found this out after fitting one thinking it would help when fitting the pick-ups, it doesn't so ignore them. I made this mistake so that you don't have to!

The motor is from Nigel Lawton's range, and as its rated at 10 volts a resistor is supplied to allow it to run on 12v. Its held in place with an etched strap on the top of the unit;

Pick-ups are made from phospher bronze wire soldered to a small piece of copperclad board which in turn is epoxied to the main unit, and are only fitted to one side as the wheelsets have one live and one insulated wheel.

Here's the other side of the unit, with the one end of the resistor soldered to the body and the other attached to the motor wire;

Note how on both sides I've trapped the wires under the motor strap.

The complete unit;

To attach the chassis two etched mounts are supplied to suit either the Simplex or the Billard. I'm building a Billard, here's the mount folded up;

There needs to be a 12BA (not 10BA as the instructions state, you'll need to know that when you lose one and have to find a replacement!) nut soldered to the top of the mount, if its fitted underneath it will foul the end of the layshaft. Guess how I know that...

The instructions don't cover making up the mount or fitting it to the chassis, however it is pretty straightforward, the pulley end of the chassis clips into the folded part that hangs down and a screw runs through the keeper plate and body and locates in the nut soldered to the mount;

I did have to take a file to the mounting plate, a little more clearance was needed at one end (left hand end in the above photo) to clear the motor when fitting the unit.

Another view;

Very few problems were encountered in this build. The holes for the screw needed broaching out, and I had to slightly modify the mounting plate. I spent a fair amount of time scratching my head about those little T shaped mounts that weren't in fact needed, and my I had to solder wires together, which I'm not very good at. Soldering brass I'm fine with, soldering electrical stuff makes me swear. Work that one out. Another problem was that one axle was out of alignment so the unit rocked when on a flat surface due to my leaving a little cusp behind when cleaning up the etch. A quick stroke of the file sorted that problem out. And I feel that the motor strap could be a touch longer, a little more strap poking through the buckle would be easier to grab with pliers when tightening.

It runs nicely. Very nicely in fact, even with no weight on the unit. With a body in place it will I'm sure be a superb runner. I've enjoyed building this, it has lived up to my expectations, and I will at some stage build another just because its so well thought out.

And finally, this is the mark 2 version of this chassis, see this post by Michael for a comparison between this and the earlier version.

Paul.

Another A1 models diesel - part 2 chassis.

This is my second home brewed 009 chassis, and in the main the chassis follows on from the my first attempt at a scratchbuilt 009 chassis, seen here.

The frames are made from 8mm x .3mm brass strip, two sides being soldered together so that they can be drilled for the axle bearings and spacer locating holes. Bearings were turned on the lathe as were the spacers, lathe ownership does of course mean that I can produce the parts that I want and not rely on commercial sources. These spacers (6mm wide) are both drilled through and crossed drilled so that they can be used to hold body and chassis in close harmony as well as hold both frame sides together for soldering. Here are the frames clamped together, bearings soldered in place, ready to have the spacers soldered up once I'm happy that everything is nice and square;

Note the lengths of 2mm dia. silver steel being used to check that both axles are in perfect alignment (I'm using 2mm axles).
However, when I test assembled the chassis with the layshaft loosely supported by the motor and bearing mounts it became obvious that fitting the layshaft into the chassis was going to be rather difficult...

I didn't allow for a spacer being in the way. Ideally I want to be able to assemble the layshaft before sliding it through one end, the worms being small enough to fit through the front bearing hole, which is drilled 4mm, to suit the roller bearing that I'm using at the pulley end. My solution was to remove the turned spacer from one end and replace it with one made from brass strip, suitably drilled to attach chassis to footplate. Here's a pic. of the modified chassis frame, next to the front motor and layshaft bearing mount and rear bearing mount;

With the layshaft and axles in place, complete with gears, the front and rear mounts can be tacked in place. The gears need to be fitted at this stage to check that they're meshed correctly. To stop any stray flux corroding the steel axles I smeared them in oil. Once I was happy with the position of the mounts the layshaft was removed (slid out through the front mount) and the mounts soldered up. I did manage to solder up the front mount slightly wonky, but the beauty of soldering is that any joint can be adjusted.
Here's the chassis with the axles and layshaft trial fitted;

After I was happy with everything, I did double check with the gears re-fitted after the mounts were soldered in place, I added two little triangular strengthening brackets (made from scrap etch) to the motor mount to stop the motor vibrating. This is a problem on my first chassis, it doesn't affect the running but the the unit is noisier than I would like. At the same time I soldered in a spacer in the middle of the chassis to hold the pick-ups in place;

The mounts and pick-up spacer are made from 6mm x .5mm brass strip.

When I made the wheels I drilled them out to 1.9mm, I wanted a light press fit on the 2mm dia. axles so the plan was to broach them out to just under 2mm. This method has so far worked well on previous locos, which have had axles varying from 1mm (Kato) to 1/16" (Saltford) diameter. This time though I had trouble, two of the wheels had a pronounced wobble*. To remedy this I took the drastic step of mounting the wheels in a collet and drilling them out to 3mm. Then I turned a length of brass bar to 3.05mm and pressed a wheel onto the end. After a quick check that everything was concentric I drilled the wheel to size and parted it off. Repeat for the other wheel. Again they were broached to a press fit. My thoughts now turn towards drilling and reaming wheels 1.5mm and using 2mm axles with the ends stepped down to suit. This would also set the back to back.
Once the wheels were in place and I was happy I assembled the layshaft;

The roller bearing at the pulley end was simply glued into its mounting hole with cyano. There's a tiny spacer between that bearing and the pulley, one of the smallest parts that I've turned measuring a mere .4mm long. Gears are Tenshodo.
The motor is epoxied to its mount. Its a little Chinese 12v job bought for less than £2 a pair off eBay, measuring 7 x 16mm with a 1mm dia. driveshaft. They were so cheap that I bought 10, and this is the first time that I've used one. Nigel Lawton pulleys and drive belt are used, 1.2mm root on the motor, 4mm root on the layshaft coupled together by a 6.5mm ID belt.
The completed chassis;

Pick-ups are always a pain. A piece of copperclad sleeper is epoxied between the wheels, with the pick-up wire formed from 36swg (.193mm) phosphor bronze wire (from Eileen's). Solder the pick-up wire on the pad with 188 degree solder. Then the motor wire with 145 degree. And the pick-up springs off, heading for the carpet... Continue, holding everything in place with bits of wood, tweezers etc, until the job is done and the air has turned blue...

Before wiring the chassis up I held it in a vice and applied power to the motor leads, letting it run for an hour or so, making sure to change speed and direction a few times. The motor seems to perform well, although there is some vibration and noise, which isn't a problem and is what you'd expect for something that costs under a quid. It would be interesting to compare one with a higher quality job. Once the pick-ups were installed I ran it around my oval of Kato Unitrack (I don't own a layout). It ran well from the start, and continues to improve. I took it with me to a recent narrow gauge show where Will King very kindly gave it a test run on his layout (I was keen to see how it went through points), and again it ran smoothly. All very promising for future builds.

Footplate next.

Paul.

*In the previous two examples (Kato and Saltford) the bore diameter was smaller than the bore length, on these wheels the bore diameter and length are the same. A five sided tapered broach was used. Could the problem be in the relationship between bore dia. and length when using a broach? Hmmm.

OO9 Ruston Proctor part 2 - chassis.

One of the reasons behind this build was to scratchbuild my own chassis, which has been an ambition of mine for quite a while now. Putting a ready made (or kit built body) on a scratchbuilt chassis might seem rather odd, but a lot of OO9 kits are designed for RTR chassis, some of which are out of production or just plain wrong for the loco modelled so learning to design and build my own running gear will have distinct advantages. And it should work out cheaper as well...

The frames are made from 1/4" x 1/64" brass strip, soldered together for drilling and milled down to 5.5mm deep. 1.7mm holes are drilled in the ends (10BA clearence) to allow the frames to be bolted together using 6mm long turned brass spacers;

The 10BA screws and nuts are removed after the spacers are soldered in place. Axle bearings are also turned on my Unimat. Note the milled cut-out under the frames, this is to provide clearence for the pick-ups. Also note that the turned spacers are cross drilled, these will be used to fasten the chassis into the body.

Motor/front bearing mount and rear bearing mount are made from the same brass strip. To locate them I fitted the axles with the gears in place, then used an off-cut of .040" plasticard to space each mount away from the gears. Checking the mesh was a tad fiddly, a case of tack then check with the gearing fitted in place before making the joint permament. The front gears are a little tight for my liking, but it runs without fuss so I'll leave alone.

Tenshodo 14:1 gears are used, the axle gears are supplied with a 2mm bore so I pressed them onto brass sleeves to reduce the bore to 1.5mm. The sleeves were made a sliding fit onto the axles, to be Loctited in place after the wheelsets were fitted. The worm shaft proved to be a fiddle to fit, mainly because of a lack of room due to my turned spacers. Sealed bearings are fitted both ends, held in place with super glue as Loctite wouldn't set, possibly because the bearings are stainless steel rather than the mild steel?
Here it is fitted up with the motor epoxied in place;

I've used one of Nigel Lawton's 10mm x 12mm Mini Motor's, these are rated at 12 volts so no resistor is needed unlike some of Nigel's smaller units. Power is transfered to the worm shaft using more of Nigel's components, a 1.2mm root pulley on the motor shaft and 4mm root pulley on the worm shaft, with a 6.5mm i/d drive belt. I'd rather have used a larger driven pulley but my chassis design wouldn't allow anything bigger between the frames, a design weakness which I shall just have to live with this time.

Wheels are Parkside 6.2mm disc. I wanted one side of the chassis to be live so that only one set of pick-ups were required, so on one side the wheels were modified by removing the tyre from the moulded plastic inner, and pressing the tyre onto a turned brass hub. I've done this before when converting Parkside wheels for split chassis use, described here.

Pick -ups are made from .315mm phospher bronze;

On the bench the chassis is a nice smooth runner, and once I'd adjusted the pick-ups its pretty good on my oval of Kato as well. I may yet swap the pick-up wire with thinner phospher bronze, to see if I can improve the running even more. When I fitted the pick-ups I soldered the motor wire on first using 188 degree solder then use 145 degree for the pick-up wire, so I should be able to unsolder the pick-ups without disturbing the motor wire. Thats the theory anyway...

So, thats my first scratchbuilt OO9 chassis. The basic design is nothing new, in fact its a bit of a cliche, and if I was starting again I'd do things differently, perhaps using with 4mm diameter spacers rather that the 5mm dia. ones that I used, which would have made fitting the worm shaft easier. It would also have been far better to shorten the frames at the front, basically cutting away everything ahead of the motor/bearing mount to allow a larger driven pulley to be fitted, but I wanted the chassis to be attached at the ends, for stability as the body is quite a bit longer than the wheelbase. Still, if nothing else it looks neat!

Next job is to mount the chassis into the body.

Paul.