Monday, September 20, 2021

Introduction to the blog

Introduction


This blog describes ongoing progress in the development of a G gauge Garden Railway from its inception to the present day. 

NEW -

When I became interested in building my own garden railway I spent a considerable amount of time (and money) on books, videos, DVDs and scouring the internet for information, ideas and inspiration. When I eventually started construction I used some of the ideas I had discovered, but also experimented with my own approaches. This blog outlines how I have gone about constructing my own garden railway. My aim is to provide the sort of information I was looking for when I was getting started and also to share what I've learned (or 'borrowed' from others). I've tried to include a few 'How I ........' postings interspersed with occasional 'Progress Reports'. I do not profess to be any kind of expert - what I offer here is an opportunity for you to metaphorically look over my shoulder to see how I have gone (and am going) about this fascinating hobby.

As this is a blog, the various posts are presented in reverse chronological order (ie the most recent first). To see a categorised list of contents go to the Blog Contents Page.


If you are thinking about building your own garden railway then why not join the 16mm Association or the G Scale Society - you'll get plenty more advice and opportunities to visit other peoples' garden railways
. Alternatively, browse through the G Scale Central website - there's plenty more guidance here and an opportunity to sound out the views of others through the G Scale Central discussion forum.


The Blog


The advantages of blogging are that it is immediate and uncomplicated when creating and uploading information. The other, of course, is that with Blogger it is free. The major disadvantage is that I have minimal control over how the postings are presented. The blogging system adds the most recent information to the start of the blog, hence the postings appear in reverse chronological order (most recent first, oldest last). Whilst there is a list of postings on the right hand side, it's not particularly easy to see what is there. This introduction is an attempt to provide you with a contents list of the postings organised into categories so, hopefully, you see if what you are looking for is presented in this blog. To ensure that it always appears at the start of the blog, I update its content and set its presentation date into the future each time I add a new posting.

Powered by WebRing.

How I constructed a Southwold Railway 6 wheeled Cleminson open wagon using PETG filament

I have always been fascinated by the Southwold Railway - its quirkiness and individuality as one of very few three foot narrow gauge railways in England. Their continued use of Cleminson six wheeled rolling stock is also another source of interest for me and so, when I got a 3D printer and developed skills in making my own drawings and designs, it seemed inevitable that I would produce my own 6-wheeled stock. Here's how I got on.

For this build, I also decided to experiment with using PETG filament rather than my more usual PLA. My conclusions as to how they compare are outlined in the conclusion.

 The wagon was first drawn as a kit of parts using a marvellous free online package called TinkerCAD.


The TinkerCAD design environment was developed for children to use and consequently its learning curve is quite shallow, unlike a number of other 3D drawing packages. Whilst it is not as powerful as these other programs, it is remarkable how fairly complex drawings can be made with a series of simple tools.


 For more detailed information on how to use TinkerCAD see How I drew a Southwold open wagon with TinkerCAD

Once all the parts needed had been drawn, exported, sliced and 3D printed, I set to work putting them together. The first task was to join the two parts of the wagon floor using the bridging piece - which also acts as the support for the sliding centre truck.

The bridging section was first glued to one of the floor halves ......

..... and then glued to the other, making sure the two sections of floor were properly aligned and square.

NOTE: For this build, I decided to use PETG rather than my usual PLA filament as an investigation into how they compared. See below for my conclusions.

You will notice that the pivots for the outer swivelling trucks differ slightly. The one on the left with the raised edge keeps the truck level as it pivots whilst the one on the right is flat and 1.5mm lower. This is to allow for some compensation of the right hand truck as it pivots.

Next, one of the end pieces was attached. To ensure it was perpendicular to the floor, a square was used while the solvent hardened.

The floor was positioned along the lowermost plank division line on the inside of the end.

This process was repeated for the other end piece.

The sides were then added.

To enable them to fit on the print-bed, these come as two sections - long .......

..... and a short.

They were glued together when they were joined to the floor - the division between the two sections coinciding with the joint between the opening doors.

I have also produced two variants on the design the match those found on the originals. One variant has no centre straps on the doors, .....

.... whilst the other variant has the coal merchant's name, MOY, in slightly raised lettering.

The second side was then glued on and the body left to harden off. 

NOTE: For PETG, I have to use a plastic solvent (I use Plastic Weld) which takes a couple of hours to harden whereas for PLA, the thick superglue sets within a couple of minutes.

To hide the joint between the two parts of the wagon sides on the solebar, a couple of filler pieces were glued on; .......

..... one on each side.

 I next turned my attention to the three trucks. The W-irons were glued to the cross-members.

NOTE: Before glueing on the W-irons, it may be necessary to to open out the holes for the axles to 3.5mm with a drill. This will depend on how cleanly your printer produces the parts.



One of the outer trucks then had two 1.5mm strips glued along its centre line to give it a very simple (but effective) form of compensation when mounted on the flat pivot.

At this stage, I test-fitted the Bachmann 21.5mm diameter wheelsets to ensure they ran smoothly in the bearing holes.

NOTE: I don't generally use brass bushes as bearings in the holes. Maybe my wagons don't get sufficient usage, but I haven't experienced excessive wear or binding over the years.

The trucks were left overnight for the solvent to harden before moving on to the next stage.

The centre truck brackets were cleaned up (PETG tends to produce a lot of strands and whiskers as it prints) .......

.... as were the holes into which they will be inserted.

Two brackets were then glued into place .....

..... and the centre truck positioned between them.

The other two brackets were then glued on.

NOTE: Since taking these photos, I have redesigned the brackets with larger flanges to more reliably hold the truck in place.

The outer trucks were then attached to their respective mounts (the compensated truck on the flat mount) with self-tapping screws.

The trucks were then tested to ensure they slid and pivoted smoothly.

The wagon was then tested on the track.

It was then given a couple of coats of Halford's grey primer from a rattle can aerosol and then given some light weathering. Buffers and my own design of hook and loop couplings were added and the wagon entered service.

NOTE: These photos are of the centre strap-free variant

 

PETG v PLA - My conclusions

As mentioned above, I decided to explore the possibilities of using PETG for this build to see how it compares with my more usual PLA filament. Firstly, I had heard accounts from some fellow modellers that PLA has a tendency to warp when exposed to hot sunshine and secondly I was slightly anxious about the biodegradability of PLA when being used in an outdoor environment.

Here are my conclusions

  • PETG prints at a higher temperature than PLA and so will probably be less susceptible to the effects of hot sunshine
  • PETG is a lot more tacky and so sticks to the print bed without any problem. Following advice, I coated my glass print bed with Pritt adhesive - not to improve adhesion but actually to help with removal of the parts after printing. Unlike PLA, one coating of Pritt lasts ages.
  • PETG tends to string more readily than PLA and so doesn't require as much cooling (which exacerbates stringing). I set my fan to 25% - some recommend not using cooling at all
  • The print temperature is more critical for PETG than for PLA. Too hot and stringing increases, too cool and the layers don't adhere. I'm not sure I yet have the temperature perfected as a lot of the surface detail on the parts (eg bolt and rivet heads) is being lost. I may need to tweak the temperature to improve this.
  • I struggled to find a solvent which worked with PETG. Superglue didn't work, Pipe Weld adhesive was unreliable for small parts. Eventually, I discovered Plastic Weld was OK - but inhaling its fumes need to be avoided. A disadvantage of using Plastic Weld is that it takes far longer to harden off than the superglue I use for PLA and so construction time is extended to days rather than hours.
  • I haven't experienced any issues with painting PETG as yet - but my experience is limited to only a couple of models.

Overall, at this stage, I don't think any advantages of PETG outweigh those of PLA - at least in the climate of Northwest England. I doubt the sun's temperatures will be so excessive that printed parts will suffer unduly and reading further suggests that PLA biodegrades very slowly (40 years when buried in a landfill site). 

Once this reel of PETG has been exhausted, unless I have a major breakthrough with solving the problems of stringing and gluing, I will probably revert to PLA

Tuesday, August 17, 2021

Progress Report 92

 July has been an extremely busy month family-wise and so very little has been done on the railway. A pity, really, as there have been some good spells of weather. However, I've been told that there are times when the family must take precedence and who am I to argue?

I have managed to complete three projects - a new siding was added to Bickerton Station, scratchbuilt manual point levers and I have found a way of controlling points with servos using cheap servo testers. Apart from those projects, the railway and workshop have lain dormant for a few weeks.


Permanent Way

New siding at Bickerton

Over the years, I have been steadily constructing, adapting and acquiring goods rolling stock because I really enjoy the operational aspects of running my railway. I have developed several computer based freight management systems to make the handling of goods traffic more interesting (see Computerised freight management and Managing freight with my Psion pocket computer).

There are five stations on the Peckforton Light Railway, each with sidings, and three additional lineside industries served by their own branchline or sidings. Over the years I have steadily expanded the number of sidings at each of my stations, apart from one - Bickerton where, until now, I have always thought there was insufficient space for expansion.

I created room for another siding simply by adding a plank to the front of the station which is mounted on a couple of paving slabs.


 I took the opportunity to improve the appearance of the rear of the platform - using PVC foamboard and 3D printed fencing.

Owing to a combination of family ties and poor weather, I've not yet had a chance to run trains since this modification was completed, but I'm hoping the weather will improve before August is over.

For more information see - How I added a new siding to Bickerton Station


Scratchbuilt point levers

Although LGB point levers are spring-loaded and are fairly robust (the can withstand being stepped on) they are not particularly realistic when compared with the weighted point levers found on most UK based narrow gauge railways. I therefore decided to construct my own. After a few experiments, I have perfected the design which makes use of a couple of sleepers from a plastic sleeper strip, a few bits of brass, some brass disks and some brass M2 screws.

They allow stock to trail through the point against the route set but, unlike LGB point levers, the blades don't swing back. It might be possible to achieve this by altering the distance between the pivot and the linkage on the lever, but I've not yet found a reliable means of achieving this and so, for now, I'm happy for the blades to be switched by the flanges on the wheels.

For more information see - How I construct point levers


Controlling points with servos and servo testers

The majority of points on the railway are operated manually with a mixture of LGB and scratchbuilt point levers (see below). However, some of the more inaccessible points are operated remotely using LGB point motors and a modified Deltang radio control system (see How I operate some of my points using Deltang equipment)

I have two sets of storage sidings at opposite ends of the railway (see How I made storage roads in the garage). Until now, I have resisted operating the points in the storage sidings remotely - after all, they are only ever used at the start and end of operating sessions. However, I got fed-up with trotting in and out of the garage and lean-to to change the points and so looked for ways of operating these points by remote control. The points in the lean-to are now operated using simple point rodding (see Operating points with simple point rodding) but this wasn't feasible for the points in the garage as space was much tighter and so I found a way of modifying cheap servo testers to operate them with servos.


The two points in the garage are now operated by servos ........

...... controlled by a couple of toggle switches mounted in a box which hangs from a hook beside the access flap to the sidings (the other switch is the on-off switch).

For more information, see How I operate points remotely using servos and servo testers


As I look out of the window while writing this update, the rain is starting once more. After the heatwave in June, the weather is now unseasonably cool and the weather each day is very unpredictable - certainly not conducive to running trains.

At least it's providing me with an opportunity to catch up with a few jobs in the workshop - see next month's progress report.....

 

<<< Previous Progress Report              Next Progress Report >>>

 

Wednesday, August 11, 2021

How I construct point levers

 After adding a new siding to Bickerton Station recently (see How I added a siding to Bickerton Station), I was asked for details of the point lever which is connected to the point (turnout) leading the the siding.

These point levers are a fairly recent innovation and are slowly replacing LGB point levers which, until now, have been my default method of operating points manually.

The great advantage of LGB manual point levers is they are fairly robust (they can survive being stepped on) and are spring-loaded and so allow stock to trail through if the point blades are set against them. Their disadvantage is that they do not look particularly realistic.

Mine look reasonably realistic and allow stock to trail through, but don't take kindly to being stepped upon.

They are very easy to construct requiring only a few pieces of brass, some small brass nuts and bolts and a couple of sleepers from a piece of LGB, Piko or Trainline track.

The base

The base comprises two sleepers, removed from a length of plastic sleeper base for straight track.

One end of the two sleepers was removed with a razor saw in line with the web linking the sleepers.

Both webs were left in place at this stage but one will later be removed once the point lever is finished.


The pivot plates

As I was mass-producing levers to eventually replace all the LGB levers, I marked out a piece of 0.036" thick half-hard brass sheet which I had bought from Eileen's Emporium.

The dimensions of the pivot pieces aren't critical but, after some experimentation and various prototypes, I have arrived at the following:

The pivot plate - all dimensions in millimetres (not to scale)

The centres of the holes were punched with an automatic centre-punch - I find it's easier to drill the holes before cutting out the individual pivot-plates.

The plates were then cut from the sheet using heavy duty tin-snips.

The bends were then made by putting the plates into a vice, aligning the bend-line with the jaws of the vice, and bashing the protruding part of the plate with a hammer.

One advantage of mass-production is that I was able to match-up pairs of plates - as you have probably noticed, my workshop techniques are more approximate than precise and so sometimes the holes and the bends wander slightly.

 

The lever

The lever was formed from a 46mm length of 4mm wide x 2mm thick brass strip - once more from Eileen's Emporium.

The lever all dimensions in millimetres (not to scale)

Two 2.2mm diameter holes were drilled 4mm and 7mm from one end, and the other end was filed to a curve.

My first early prototype point levers used half-cent Euro coins as balance weights but once my supply (ie that pot on the bookshelf containing all those oddments of change from foreign holidays) became exhausted, I searched eBay and took delivery of fifty 16mm diameter brass disks. Apparently, these are used for jewellery-making.


 

 By the way, as you can see, it pays to shop around as prices can vary widely .......

Four disks were soldered together into two pairs.

My technique for soldering them together was to tin one side of each disk with solder using my 45W soldering iron. The two tinned faces were then placed together and the iron placed in top of the topmost disk until the solder between them melted. The upper disk can be slid about until the two disks are aligned. I find that melting a small amount of solder beneath the iron and the topmost disk helps to transfer the heat more quickly.

The disks were then soldered to the lever, about 7mm from the curved end.

As can be seen, I constructed a simple jig using four brass nails tacked into a piece of plywood around the perimeter of a disk. This helps with the alignment of the disks while soldering - as they have a tendency to slide about once the solder has melted and the disks are a bit too hot to handle!

Of course, there is a 2mm gap between the two sets of weights. 

I have tried filling this with solder, but found it was a bit tricky, so I now just use plastic putty filler.


Assembly

With nearly all the parts prepared, it was time for assembly.

One of the pivot plates was placed over the end of the plastic sleeper base, roughly central to the web at the uncut end. A 2.5mm drill bit was then passed through the holes using a mini-drill to create matching holes in the plastic base.


Two 80mm long x 6mm wide x 0.8mm thick brass strips (again from Eileen's Emporium) were then cut.

Two linking strips cut from 0.8mm thick brass.

One of these linking strips was then inserted into the hollow underside of the drilled sleeper and slid up to the closed.end. The position of two holes were then marked on the strip using a scriber and 2.5mm diameter holes drilled in the strip.

Two M2 brass bolts were then passed through the holes and nuts tightened on to them.


NOTE: The M2 cheesehead brass bolts from Eileen's Emporium are 12mm in length. I needed to cut them in half. My method for this was to thread a nut on to the bolt, place the end of the bolt in a vice, cut the bolt in half with a slitting disk in a mini-drill, tidy up the cut end of the bolt with a file and then remove the nut which helps to tidy up the thread.

NOTE2: It has since occurred to me that if the bolts are passed through from the underside and the nuts tightened on the top surface of the pivot plate, the nut will look more realistic than the cheeseheads on the bolts.

The lever and the second pivot plate were then loosely connected to the first plate with a piece of 2mm diameter brass rod, sandwiching the lever between them.

The rod was then cut to length using a slitting disk in the mini-drill.

You'll have noticed, I try to avoid measuring where I can - most of my bodgelling is done by eye. My apologies to those with a mechanical engineering background (eg my brother) who are probably shuddering and reaching for their micrometers at this point.

Two 2.5mm holes were then drilled in the plastic sleeper using the holes in the pivot plate as a guide.

As previously, the linking-strip was placed inside the the underside of the sleeper and the position of the holes marked and 2.5mm holes drilled.

The second pivot plate was then bolted into place.



The 2mm rod for the pivot was then soldered into place. 

  I used my humble 45W soldering iron for this despite the fact that its heat was quickly dissipated and hence it was difficult to get the solder to flow. I didn't want to risk melting the solder holding the balance weights on the lever by using my 75W iron.

Once the solder had set, the excess was filed off,

The web linking the two sleepers ..........

.... was then removed with a razor saw, Allowing the lever to swing freely.

The point lever assembly was now offered up to the point with the ends of the linking strips being slid into the sleepers on either side of the tie bar (you may need to open up the ends of the sleepers on your points). The position of the holes in the turnout's sleepers were marked on to the linking-strips (or drill new holes if your point doesn't already have them).

Two 2.5mm holes were drilled in the ends of the linking-strips to align with the holes in the points' sleepers. At the same time, two 2.5mm holes were drilled through the sleepers on the point lever assembly and into the linking-strips as shown below.

Bolts were fixed into the holes in the point lever sleepers ........

Similarly, the linking-strips were bolted to the holes in the points sleepers.


One end of a length of 2mm diameter brass rod was bent into a U-shape and passed through the hole in the end of the point lever

The lever and the tie-bar were put into their central positions and the other end of the brass rod cut off with around a 10mm excess. The end of the rod was then bent through 90 degrees and passed through the slot in the end of the tie-bar

The upper end of the rod was then bent again ......

..... and the lever tested.


I recognise that these levers are not entirely prototypical, but they are functional, they are relatively easy to construct and they do look more realistic than the LGB levers which I am replacing.

By shortening the distance between the pivot hole and the linkage hole in the end of the lever it is possible to increase the amount of throw on the lever - ie getting it to lie flat at the end of each throw. However, I have found this prevents the point blades from being allowed to be trailed-though in the reverse direction, which is a feature I find useful. I might try experimenting with different distances between the pivot and linkage holes to see what effect this has on the operation of the points under different conditions.

 

Addendum

 Since writing the above, I have made a few more point levers and have realised that the bolts look more realistic if they are inverted, so the nuts are on top rather than beneath the sleepers.

Washers are needed beneath the nuts at the turnout end, to stop them from sinking into the plastic.

 

Conclusion

As with most of my projects, these levers are a bit of a compromise between realism and practicability, but they work and, to my mind, are in keeping with narrow gauge railway practices. More importantly for me - a bodgeller - they are simple and fairly quick to make. Inevitably, one or two of them will get stepped-on when I have to cut the hedges behind the railway - but I am happy that it will not take too much effort for me to repair or completely replace any which suffer this fate.