Friday, July 10, 2020

How I made a test track in the workshop

When repairing, maintaining or trialling new stock I've found it is handy to have some track nearby to give it a quick test run. Similarly, when setting-up a radio control receiver or, more particularly, a soundcard, it's really helpful to have somewhere to test-run a loco.

When my workshop was located in our conservatory, the railway was just outside the door and so it was relatively easy to put something on the track and give it a test. However, having spent last summer constructing a new workshop (see How I made my workshop), ......


.... and over the winter, becoming firmly established inside it, .....

.... I sacrificed the convenience of having a length of track just outside the door.

What I felt I needed was a test track inside the workshop. My first thought was to lay a couple of lengths of track behind the power tools on the bench, .....

..... but then I pondered the idea of extending that to run right round the inside of the workshop. This would enable to run-in stock more fully, or even just have something running while I was working on a project on the workbench. Maybe, if I included a couple of sidings, I could even run it as a short railway.

As you can see from the above photo, I have a stack of spare track in the corner of the workshop which I had bought before I abandoned the idea of creating a short branch from Beeston Market to the canal quayside. I worked out I had enough track in store to complete a circuit of the workshop, but figured it would be better to use R1 sectional curves in the corners. These would ensure the curves would be consistent and avoid the need to use a rail-bender - something I have never used or acquired. I investigated  buying sufficient R1 curves to complete a circle and was somewhat surprised at their expense, even secondhand! At this price, it would cost £120 (GBP) to buy what I needed. Far too much!!

I then had a thought! Around ten years ago, I had bought a secondhand Playmobil railcar for my young nephew to use when he came visiting from the USA. Since then, it has been lounging in the loft - together with a box full of plastic track!

Although I knew the Playmobil railcar runs happily on LGB 45mm gauge track, would my stock run on the Playmobil track?

I retrieved the track and set up a few lengths plus a turnout on the floor and, to my surprise, my stock ran through it!

But where should the test track be located? Near the ceiling? This would keep it clear of all-important shelving, but be inconvenient when requiring repeated test-runs of stock. Near the floor? I could then link it to the track outside, but that would require too much effort in moving all the existing furniture. The same height as the power tools bench? That seemed to me to be the least worst option. It would require removable sections across the door and the corner sink, but would be doable - with a bit of effort in re-positioning all the existing shelving!

I decided to start with the most difficult section - across the doorway. This turned out to be simpler than I expected - a few quick sketches in my workbook followed to weigh up the options. A lift-out bridge would need to be stored somewhere, whereas a hinged bridge would be much easier manage. However, it it lifted upwards it would either obscure the light switches or interfere with the hinged tool-board. However, if it dropped downwards ......
A brass hinge and a barrel bolt were acquired, together with a length of 6" x ¾" timber and, once the CD rack had been  raised slightly, the job was done.



It seemed logical that the next wall to be attacked was the one containing the window and the workbench. Firstly, the bookshelves needed to be lowered so the bottom shelf was at the same height as the track .......

....... and a portal needed to be cut in its side.

Then a length of 6"x¾" timber was positioned to span the rest of the void and the tool rack behind the workbench was increased in height to support it.


Next, I tackled the corner containing an ex-caravan sink. My initial idea was to use a hinged flap, but when I tried various configurations of trackwork across the corner, it seemed simpler to just place a shelf across the front of the sink.

There is still plenty of room to access the sink and, if necessary, I can always raise the height of the sink to match the railway.

The workbench for the power tools was the easiest part of the installation. It just required the tools to be moved forward and mains power routed under the bench to each tool.


Finally, putting the track along the back wall was another easy task. I had already installed adjustable shelving racks and, by coincidence, one of the positions for the brackets matched the height of the test track. The pre-existing shelf was lowered to below the railway shelf and some more brackets were acquired from my local DIY store. A couple more 8 foot lengths of 6" x ¾" completed the job.


I had to buy a few more straight sections of Playmobil track to complete the circuit and the two passing loops (why are there never enough straight sections in a train set???), but other than that, there was sufficient in the box to complete the test track.

I was pleased to discover that most of my stock successfully negotiates its way through the Playmobil points, despite them being of a unique design with only one moving blade. They, and the ordinary track, also appear to allow stock with plain unflanged wheels to pass through, so their design is quite ingenious. However, some of my stock, particularly wagons and bogie coaches with finer flanged wheels had difficulty passing through the frogs when taking the curved route through the points and so I have installed thin aluminium shims to widen the check rails which helps to guide them through.

So, my Playmobil test track seems to be quite successful.


The weather for the past few days has been appalling, with almost continuous and heavy rain. It has been quite stimulating to have trains running around me whilst working at the bench and it has provided an inducement for me to finish off the fitting of my own design of couplings to the last remaining unfitted items of rolling stock (See Progress Report 82). The tight R1 curves are probably the ultimate test as to whether I've got the placement of the couplings right!

Already, I have found it extremely handy to have a length of track just above the workbench. I can immediately test what I've been working on. If it's a loco, I can even send it around the track to retrieve the next item of stock requiring attention!! I suppose, my next job is to be able to operate the points remotely so I don't even have to get up out of my chair to select the stock on the track .... or am I getting a bit too lazy!

Wednesday, July 08, 2020

How I used bike brake cable to operate remote pointwork

I have two points (turnouts) on the far side of the baseboard at Beeston Market Station which I can just about reach by stretching across the tracks.

However, if there are wagons on the cattle dock siding and/or a train on the main station loop, then the point levers can be difficult to reach.

(I'd just trimmed the hedge when I took this photo!) I wanted to replace the brake cables on my bike and so decided to order more than I needed. After sorting out my bike, I had sufficient cable left over for the two points.

I measured how much I needed ......

..... and then took the sleeve into the workshop where I used a slitting disk in a mini-drill to cut through it.

I had read on the web that a slitting disk is the best way to cut through cable without fraying it and so cut the cable in the same way, adding around 60mm over the length of the sleeve. I was surprised at how easily the disk sliced through the cable, having experienced all kinds of problems in the past with trying to hack though it with snips or a hacksaw.

Ferrules were slipped over the ends of the sleeve .....

...... and then the cable was then slid into the sleeve.

The end of the cable was tinned with solder ........

.... and a piece of 1.5mm brass rod soldered on to it, .......

.... before the rod was trimmed so about 30mm was left attached.

After the old point lever had been removed, a 5mm diameter hole was drilled beside the tie bar, at an angle of approximately 45°.

The brake cable was then threaded up through the hole.......

...... and the end of the brass rod bent up into the slot in the tie bar.

The brake cables were then fixed to the underside of the baseboard with 5mm cable clips, .....

..... leaving  around 10-20mm protruding at the edge of the baseboard.

The points can now be operated easily from the edge of the board, without stretching, even if the cattle dock is full and the loop roads occupied.

They have been in situ now for a month and seem to be operating without a problem, though I have dribbled oil down into the end of the cable at the points end to discourage moisture from running into them. I anticipate that oiling will be a regular task


Monday, June 22, 2020

CTC DIY A8 printer - Part 2 - Setting it up

Contents



As indicated in Part 1, I assembled a CTC DIY A8 3D printer from a kit which I picked up on eBay for £80GBP. It has enabled me to explore the potential of 3D printing for my 16mm scale garden railway at reasonable cost and I am pleased with the results I've had so far. It isn't perfect - but considering the printer was substantially cheaper than many alternatives, I think it was well worth the outlay.

Part 1 covered putting the kit together, this part outlines how to get the printer up and running for the first time. As discussed in Part 1, the instructions lack some clarity in essential places so, if you are following in my footsteps, hopefully I can help you take your first steps.

There are several steps which need to be taken before the printer can be used for the first time - some of which do not seem to be covered in the instruction manual.

It is a good idea to preheat the bed and printhead before making adjustments, and it's essential before loading the filament. On the A8, it is quite a simple process.

Turn on the printer and after the LCD has displayed its welcome message the screen presents a summary of the printer's status.

Access the menu by pressing the centre button to the right of the LCD screen

Once the menu has been displayed,

..... use the lower button ......

..... to move the highlight (square) down to "Quick Settings" ....

...... and then press the right hand button to select this option.

This displays the Quick Settings menu.

Move the pointer (square) down to "Preheat PLA" and press the right button to select it.

This should then take you back to the main screen, only this time "Preheat PLA" is displayed at the bottom of the screen and you should see the temperature readings rising at the top of the screen .....

.... until the actual temperatures of the printhead and the printbed have reached their targets (190 and 55 degrees respectively).

NOTE: At any point you can move back to the previous menu by pressing the left button

Tighten the four spring-loaded screws holding the printbed to the baseplate until the printbed is about 1/4 of the way down each screw.

Slide the printhead carriage (on the X-axis) and the printbed (on the Y-axis) so the printhead is roughly in the centre of the printbed.

NOTE: If the printhead carriage and the printbed won't move, the stepper motors might have been actuated and so they need to be disabled - see Disabling the stepper motors below

Lower the X-axis by twisting the threaded rods on either side of the printed with your fingers/thumbs until the printhead just touches the printbed.

NOTE: If the Z-axis microswitch stops the left had X-axis plastic bracket from being lowered sufficiently, then slacken off the two screws holding the microswitch mounting plate and slide it downwards.

Measure the height of the left hand X-axis bracket above its stepper motor and make a note of the height.

Measure the same height for the right hand bracket and adjust it by twisting the threaded rod until it matches the height of the left hand bracket.

The printbed must be perfectly level to ensure the printhead remains the same distance above it when printing.

Move the printhead close to each corner of the printbed and adjust the spring-loaded corner screws until a piece of ordinary printer paper is just released from beneath it.

NOTE: You may need to go round the the bed doing the adjustments twice as the baseplate has a tendency to distort when the screws are tightened.

The next job is to adjust the Z-axis microswitch so detects when the printhead is at its home position above the printbed.

Loosen the two screws holding the Z-axis microswitch bracket so it can slide up and down.

Slide the bracket up until you can hear the microswitch click as it makes contact with the lower part of the plastic X-axis bracket.

NOTE: I find it easier to tighten the left hand screw first and then swing the bracket up and down slightly to find the exact point when the switch clicks, then tighten up the right hand screw.

NOTE2: It is possible to download and print out Z-axis adjusters from Thingiverse to make this process easier - eg https://www.thingiverse.com/thing:2456067

To move the printhead carriage and printbed manually, the stepper motors need to be disabled.

Access the main menu on the LCD display by pressing the middle button.

Move the pointer down to "Quick settings"

Press the Right button to select it

Move the pointer down to "Disable Stepper"

Select this with the Right button

If you haven't already done so, preheat the printhead for the type of filament you are using (see above)

The first job is to cut the end of the filament at an angle with a pair of scissors or snippers. Then make sure the last 10cm of the filament is perfectly straight. If it is not, it will curl up inside the extruder and miss the entrance to the printhead.

Next, release the tension on the extruder by depressing the lever section on top of the extruder with your thumb - it is a good idea to support the bottom of the extruder with your fingers so the carriage isn't put under too much pressure.

Feed the filament into the hole (beside your thumb). You might need to twist the filament if there is a slight bend in it so it locates the hole into the hot-end of the printhead. You will know when you have been successful because melted filament will appear out of the printhead.

Release the lever so the extruder wheel can grasp the filament.

To check the extruder is feeding the filament properly, access the main menu on the LCD panel by pressing the middle button.

Use the lower button to scroll down to "Extruder"

Select this option with the right button. From the next menu select "Extr. Position" with the right button

Use the UP button to feed the filament through the extruder (Yes, it's counter-intuitive but the Up button feeds the filament downwards and the Down button feeds it upwards).

You should see the filament oozing out of the nozzle when the up button is being pressed. If not, give the filament a bit of assistance by pushing it down into the extruder with your fingers. You might hear a clicking sound if the knurled wheel in the extruder is slipping on the filament.

If it doesn't work, you might need to disassemble the extruder and clean the knurled wheel - it can sometimes get clogged with plastic.

Finally, I feed my filament through the handles of a document clip attached to the top of the printer frame to help ensure it doesn't become snagged.

You can download and print-out various filament guides from Thingiverse if you fancy something a bit more sophisticated.

I have positioned my reel of filament as close to the height of the printer as is possible. At the moment this is on top of a couple of boxes on a shelf - eventually I will create something a bit more elegant!

Now you have finished setting up your printer, we come to the exciting part - printing out your first object.

First, you need to find an object to print out. I would suggest you start with something small scale. This helps you avoid disappointment if it doesn't work out, doesn't stretch the settings on your printer and overtax your setting-up arrangements and also won't keep you waiting too long until it's finished.

As my garden railway is 16mm scale and set in the 1930s, I opted for  something which might have been found on a platform during that era - a wicker pigeon basket.

Firstly, I went to the Thingverse.com website and searched for 'Pigeon basket".

I then downloaded the files on to my computer and extracted them.

Once the files had been downloaded, I loaded them into the version of Cura which came on the CD included in the printer kit. When Cura loads, it might indicate that there is a more recent, more powerful version of Cura available but I discovered that the latest version won't run on the antiquated laptop I use in my workshop and so I have remained with this earlier version.

The model of the basket was far too large even for a 16mm scale railway and so .......

,,,,,, I selected the scaling tool (the middle icon in the bottom left of the screen). I worked out that the length of a basket in 16mm scale would be about 30mm .......

....... and so changed the Size Y dimension to 30

I next had to check that the settings were correct for my printer and the filament I was using.
NOTE: If you have the most recent version of Cura, you can select the settings for an Anet A8 printer.

It is important that you set the size of filament to 1.75 and the nozzle size to 0.4 (at the base of the basic settings)

You might need to experiment with the settings for the printhead temperature and printing speed to get the best out of the combination for your printer and the type of filament you are using but for now, try using the settings shown above.

NOTE: To help ensure the first layer sticks to the printbed, I would suggest using a Brim support.

Once you have done this, the software will tell you how long the print will take and how much filament it will use. Don't worry if your figures are slightly different to mine, I have been tweaking some of the settings in the background since I got the printer.

You now need to generate the slicing code used by the printer. From the file menu, select "Save GCode".

Save the file somewhere you will be able to relocate it and then save it or copy it on to a Micro SD card.

Once saved and ejected from the computer, the SD card needs to be inserted into the card slot on top of the motherboard on the printer.

Access the main menu on the LCD screen and select "SD Card" from it (with the right button)

Then select "Mount Card"

Next, select "Print file"

You may only have one file on the card initially, but if not scroll down until you find the gcode file you saved on it (in my case PigeonBasketAllClosed).

The display should now revert to the home screen, with "Printing" showing up at the base of it.

It might take a short while for the printer to start as the bed and printhead temperatures need to be adjusted to those required by the gcode for your object.

Once the printing has started, you will be able to watch in awe and wonder as it gradually takes shape on the printbed.

You can check the progress of the printing by seeing how much, in percentage terms, of the model has been printed so far.

If something goes wrong, you can abort the printing by either pressing the reset button in the middle of the motherboard or, less dramatically, by selecting "Stop Print" from the SD Card menu.

You can then send the printer carriage and the printbed back to their origins by selecting "Home All" from the Quick Settings menu. You might then want to disable the stepper motors if you want to re-level the printbed.

This may all sound daunting at first but you'll be astonished at how quickly all this becomes second nature to you.

Don't despair if, or rather when, things go wrong. With such a complex process, it's inevitable that something will go wrong at some point. I am rapidly collecting a box full of misprinted or part-printed parts. Rather than seeing them as failures I am trying to see them as learning experiences.

I suppose my most ambitious print so far has been two 3D printed diesel locomotives which I have coupled back to back as per Australian sugar cane railways. (See How I 3D printed a pair of diesel locos - pending)

I still have many ideas for the printer. All I need is time to implement them - but life keeps getting in the way!

There is plenty of information on the internet about how to get the best out of your printer. I've lost count of the number of forum posts I've read, web pages I've browsed through and YouTube videos I've watched on various aspects of the 3D printing.

I'm now on my third reel of filament and have made quite a few changes to the printer which came out of the box a few months ago. When I first floated the idea of investing in what must be the cheapest commercially available 3D printer with some fellow modellers on one of my forums, one responded, "Don't think of it as buying a printer, think of it as taking on a project". He wasn't far wrong.

Good luck and happy printing!

If you want to see what modifications I have made to my printer so far, see Part 3 - Modifying my budget 3D Printer - pending