Type 4 couplings

I wanted to design some easy to make 006 couplings for fitting to locos and larger wagons, styled rather like my type 2 couplings but made from square styrene section for convenience. I chose to use 3mm material, and prepared a sketch on the back of an envelope (literally);

As I use link and pin couplings for 006 work there's a .4mm hole drilled for either a pin or split pin. The front face is filed to a curve.

The advantage of these is threefold, they're quick and easy to make, I can hold the material in a self-centring 4 jaw chuck, and, I can drill the pin hole by hand rather than set the machine up. 

Here's a batch that I've made (there were 6 but 1 didn't cut the mustard);

Note the front two coupled together. And that white plastic is a pig to photograph.

As these are 3mm square and I'm using a coupling height of 6mm a centre line needs marking on the bufferbeam of any vehicle they're fitted to, using a 4.5mm gauge that I made to use with my earlier couplings;

Once the height is marked a 1mm hole can be drilled and the coupling temporarily fitted;

The photo shows a 'link' coupling.

Like all of my 006 work these are an experiment, so I need to fit them to a pair of waggons to see how well they work.

Paul.

Hole punch

I needed a 4mm hole punch for a project. So, I made one;

It's made from 7mm dia. silver steel, 60mm long. The business end was drilled 3.7mm and reamed to 4mm, only about 10mm deep. A 60 degree taper was turned, using my compound slide, leaving a nice sharp edge. Then I heated it to bright red to harden it and followed that with a couple of hours in the oven at 200 degrees to temper the steel.

It's been tested, on leather and thin plastic glazing material, and it works well enough. It could do with a slot behind the cutting edge to eject the punchings, which I could have milled, but I didn't fancy the extra work. Punches are of course available to buy, in fact I have a set (which doesn't go down to 4mm) but I wanted to make one for a couple of reasons.

Making my own means that I can make punches to any size that I want (within reason), handy if I want to cut out glazing for loco spectacle plates. And some ready made punches are of variable quality, if mine are rubbish then I only have myself to blame.

Paul.

Drop spindle

Something different today.

I've mentioned before that my wife Dani is a keen knitter and sewer. She wants to try and spin some wool herself, using a drop spindle. If you're curious about drop spindles I suggest looking on youtube, there's plenty of videos showing you how to use one.

I decided to make one for her, using an off-cut of MDF and some dowelling, all left over from other projects. The tool comprises of a disc, which acts as flywheel, a shaft, and a hook to hang the wool from.

I started with the disc. I marked out a circle on a piece of 12mm MDF, which was then cut out with a coping saw and an 8.8mm hole drilled in the centre to suit the dowel. I then mounted the drill in the lathe with the business end inside the spindle and the blank shaft sticking out with just a bit less than the width of the MDF sticking out of the chuck. The disc was then pushed onto the drill shaft and held in place with a piece of brass pressed against the end with a live centre in the tailstock;

This gave enough friction to hold the disc without slipping whilst I trued the outer diameter;

The spindle is just a length of dowel with the ends faced off on the lathe and a hole drilled in one end for a hook (an opened out picture eyelet from Woolworths).

Job done;

The disc is a good friction fit on the shaft so the position can be adjusted.

This is just a quick and easy job, a bit rough and ready, just so Dani can try using a drop spindle without buying one. If she finds that she likes using one then I could look at making something nicer (or she could buy one), however it could be varnished (shaft) and painted (disc) if Dani wants to make it pretty.

Paul.

Gaiety N2 - pony truck

If you remember the pony truck was missing a wheel. Rather than take the sensible option of just fitting a pair of 12mm wagon wheels (Romford would suit) I decided to turn up a pair from brass. I started by turning two discs to the correct width and flange diameter, drilled 3.8mm for the insulating bush. These were then mounted on a mandrel and a step turned for the tread, leaving .1mm on the dia.;

With my compound slide set to 3 degrees the cone angle was turned on the tread;

After which I profiled the flange using a graver and my watchmakers tool rest, working by eye. Then the recess in the front of the wheel could be turned, to match the original wheel;

Job done;

I chose to blacken the wheels, and I was going to paint the inner face but I like the finish as it is so I've left them in blackened brass. I turned new stepped axles from 3mm silver steel. The original axle was 2.5mm, and a sloppy fit in the pony truck which is drilled, badly, 3.2mm(ish). I could have fitted bushes to the truck, drilled after fitting, and I may yet go back to that idea.

Here's the wheels fitted, with the old wheel and the fixing rivet;

Insulating bushes are turned from Acetal, and I probably should have sourced a length of red to match the old bushes.

The pony really is crude, just a bent piece of metal, surprising really as the company made decent quality die castings;

Here's the truck fitted, with the tension lock coupling attached;

I don't think the new wheels look too out of place.

Pick-ups next, then testing.

Paul.

Plastic feet

 I need 4 feet for a little project. These will sit underneath a ribbed box, the ribs forming a diamond pattern which dictates the size of the feet. I'd usually use self-adhesive jobs, but to be honest I couldn't be bothered searching for suitably sized ones so instead I pulled out the lathe and turned 4 from Acetal rod. Each foot is 10mm dia. x 4mm high and is drilled and tapped 8BA;

Job done. These will be screwed in place from above when I replenish my stocks of 8BA screws.

I like having a lathe!

Paul.

Type 3 couplings

This style of coupling is based loosely on the type fitted to many Hudson Hunslet diesels, albeit simplified by making it with a single slot rather than two.

I started with my usual rough sketch, which after making a couple of prototypes ended up being re-drawn in something-angle projection;

(With no apologies to any engineers, real or model, who've stumbled upon this page - I make things rather than worry about proper method.)

With the Unimat 3 set up as a mill and a piece of 6mm dia. brass set up in a dividing head the basic shape can be milled;

To mill the slot I use a .5mm slot drill with the work held in a collet chuck clamped to the saddle;

A .4mm hole, for the coupling pin, is then drilled, but left blind;

The last machining operation is to turn a 1mm dia. locating spigot on the rear and then part-off;

Before each part is parted-off the buffer face needs to be filed to a gentle curve. Here's the almost-finished result;

Now they can be fitted with a pin, .4mm brass wire cyano'd in place with 2mm left protruding.

After much deliberation I've decided to use a coupling height of 6mm for my 006 stock. To set the height for these couplings I first turned a 4.75mm height gauge to mark the centre of the coupling (coupling height minus half the coupling, 1.25mm);

Once a 1mm hole is drilled on the centreline the coupling can be tried in place;

And checked with a second gauge, turned to 6mm;

The finished coupling is a result of quite a lot of work, but to my mind the right coupling can make a loco.

These are destined for 006, for 009 the coupling needs to be lengthened to 3mm.

Paul.

Rail bender

I need a rail bender for a project, to suit code 40 rail. As far as I can tell nothing is available to suit code 40, so I made my own. I already own a KB Scale bender, but this is made to be used with code 83 for building O14 track, and is designed to give specific radii. As I had it already I made a replacement set of rollers to suit the finer rail, just as an experiment. My rollers worked well enough but as can be expected the bender didn't give the amount of curvature that I require. It did however provide a basic design that I could adapt for my own use.

Here's the KB tool, fitted with my code 40 rollers with the KB rollers next to it;

I started with a length of 25mm x 5mm aluminium bar, cut and faced to 50mm long. I chose 5mm thick bar as it will be easy to hold in my bench vice when in use. I then marked out positions for the centre slot (mine is designed to be adjustable) and two separate hole positions, at 26 and 34mm centres. This is for adjustability, whether I will need the inner holes or not I will only know when I start using it. Once the bar was marked out it was held in a machine vice and the holes and slot machined, the holes being drilled 1.8mm to suit 8BA and the slot had a series of 1.7mm holes chain drilled before being milled 2.2mm wide (again to suit an 8BA bolt).

New rollers were machined from brass, to the same dimensions as before but drilled and reamed 6mm dia. Hubs for the rollers to spin on were machined from silver steel, drilled 2.2mm (8BA clearance) and turned to suit the rollers allowing them to spin freely when the hubs were tightened up. The middle adjustable roller is held in place in the slot by means of a thumb nut underneath the baseplate.

The unit assembled;

Here it is in use;

It appears to work well enough, but I do need to test it properly.

Notes on design;

The rollers should ideally act on the web of the rail (the thin middle section), the KB Scale one certainly does, but with code 40 being only 1.1mm tall that is impractical as the web is tiny. So, my rollers act on the head of the rail, with an undercut at the bottom of the roller to suit the wider foot of the flat bottom rail (the KB Scale rollers also have an undercut). I also copied the upper flange of the KB Scale rollers, this holds the rail in place as it moves through the bender. Hopefully the fag-packet sketch below will give some idea of how the rail sits;

I've not added any dimensions, the sketch is just there to give the general idea and hopefully can be adapted to suit other rail profiles.

Paul.

3 point track gauges

I plan to make a small 006 (6mm gauge, 4mm scale) 'pizza' layout, and for that I will need a pair of three point gauges to lay the track with. As nothing is commercially available for this gauge (as far as I know anyway) I've made my own.

This type of gauge not only holds the rails parallel to each other but, more importantly for my intended use, automatically gives gauge widening on curves.

I started with a length of 20mm x 5mm aluminium strip, which had the ends machined square before being marked out with the hole positions, noting that the two in-line holes are twice the track gauge apart, in this case 12mm. Also note that the distance between the in-line and single holes, that sets the gauge, must be set at the gauge plus the width of the slot, that is if the slot is, say, .6mm then the holes must be drilled gauge plus .6mm apart, that is 6.6mm in this case. Then, with the Unimat 3 set up as a mill the strip was clamped down and three holes drilled 2.8mm then reamed out to 3mm, using the machine to index the hole positions rather than my marking out (which was done just as a guide);

Once drilled each part was sawn off the strip, and machined to size. I also machined angles on the sides;

I ended up with these;

For the 'pegs' that hold the rail in position I used 4mm brass rod. Each peg had a .6mm wide by 1mm deep slot milled in the end, to suit the code 40 rail that I plan to use;

A gentle touch is needed here, I took a series of .1mm cuts using the fine feed attachment.

The other end of the peg was turned down for a sliding fit into the baseplates, to allow for adjustment on assembly. Here's the parts ready, with the baseplates cleaned up;

Each peg was glued in place with a smear of 5 minute epoxy, to allow time for adjustment. The two in-line pegs were aligned using an off-cut of rail;

The single peg was just set by eye.

Here's the finished pair;

Now all I need to do is cut some wood and lay some track.

Paul.

Update - some measurements have been changed and additional information added. Slots are now .6mm wide rather than .5mm.

A lamp housing for a GVT coach.

 I was recently asked if I could turn a lamp housing for an N Brass Models Glyn Valley Tramway coach, in fact the same kit that I attempted some years ago. There's nothing supplied with the kit, and photos and information of this early coach are scarce. Will, who was building the kit, provided a drawing to work to based on some poor quality photos. Neither of us were happy with the result so Will revised his drawing. Again the results weren't quite right. At the third attempt we came up with something that we were happy with, and this is the result;

This was of course turned from brass on my trusty Unimat 3. The gently curved top was formed using a graver and my watchmaker's tool rest. To form the base to suit the roof curvature I first roughed out the bottom with a half-round Swiss file, then finished by drawing the base back and forth along a piece of wet & dry held on a roll of brown parcel tape, which was a rough match to the roof curve.

Here's another side-on view;

A simple enough job, the only complication was working out the size. It may or may not be accurate, so it's a case of if it looks right then it is right. Now all I need to do is send it to Will, and turn another for myself.

Paul.

A new volume knob for a valve amp.

 I like music, there's usually something playing in the house, and as part of that I have an interest in hi-fi. A recent purchase was a valve amp, bought from a chap that retired and needed something to do so he bought 6 kits from China, built them with upgraded parts (mainly tubes and capacitors) and sold them on. I was following his work on a Facebook group that I'm a member of and when they came on the market I contacted him and one came my way;

It sounds really rather good, despite my speakers not quite having the sensitivity to make the most of it. I decided to replace the plastic volume knob with one made of brass, not really necessary but I fancied a small project and it's a way of adding my own little touch.

The volume pot. has a splined shaft, so to fit the knob I made an insert from Acetal to suit, taking the inner diameter from the old knob (5.7mm) and turning the outer dia. to 10mm. For the main body I used 16mm brass with the outer dia. lightly skimmed and drilled out to suit the insert.

Here I'm skimming the top of the brass;

After drilling the knob and parting it off I used a graver and my watchmakers toolrest to round off the corners;

With the Unimat set up as a drill press a reference mark was drilled using a slot drill;

Here's the rear showing the Acetal insert;

Old and new side by side;

And fitted;

Ignore the wonky tubes, I have straightened them!

Paul.

And another 03 chimney.

 After publishing my last post concerning making an 03 chimney in N gauge I was asked if I could make another in 4mm scale. So I did;

It's a pretty simple part to make (I've made one before in 4mm), but care (and a specially ground tool) is needed to turn the top recess and setting the correct angle to turn the taper requires a bit of trial and error. 

By the way, that's a pair of surgical forceps holding the part in the photo above, acquired from a local seller who cleans out stock from Sheffield factories. Very useful, not only for modelling but also for threading up sewing machines.

Paul.