Whats on your 2mm Work bench

[trawest]

I do not normally display my models on this forum nor is 2mm to the foot my scale of choice. However, having admired for many moons the skill and accuracy and inspiration given by those that work in this scale I thought I would, for once, upload a few photos of my completed GWR Weighbridge office. The CAD drawings for the original 4mm build were halved in size and a similar process used to construct the model. Measurements were taken from the building in situ at Winchcombe on the Gloucester and Warks Heritage railway.

 

Trawest

[richbrummitt]

6 hours ago, trawest said:

The CAD drawings for the original 4mm build were halved in size and a similar process used to construct the model.

Are the carcasses cast in resin? The results look great and are painted to good effect. 

[trawest]

Richbrummitt - Thank you for your comments.

The carcasses are indeed cast in resin with the master copy constructed from Photo Etched Brass and Styrene sheet.

 

Trawest

[Nick Mitchell]

5702 progress report #2

 

The next job I tackled after my last update was to fit Simpson springs to the loco chassis.

With the worm on the centre wheels, springs have not been fitted here, as I don't want too much side-play, and the axle won't have scope to move vertically.

In fact, only the front axle holes have been opened out to 1.6mm, otherwise the chassis would want to rock about the centre.

Weight from the tender will bear down on the rear of the chassis, so creating slop in the rear bearings would result in the loco always wanting to lift its nose in the air.

Springs without slop have been added to the rear axle, just to help improve current collection.

 

 

I fitted the gear to the gear-muff, and using 1.4mm drills, was able to check the mesh.

 

 

As expected, things were too tight, so I needed to make a packing shim to lift up the worm shaft bearing block a little.

Knowing the height, I was also able to cut two screws to the right length so they wouldn't interfere with the worm shaft passing between the bearings.

 

 

With the mesh checked again, I made a universal joint housing, and fitted the worm shaft to the bearing block.

The other end of the cardan shaft (which will transfer drive from the tender) will be permanently fixed to the motor. I made a little fitting for this and attached it to the motor (having first reduced the shaft length, and cut off entirely the shaft at the opposite end).

 

 

Turning to the tender, Simpson springs were added to the centre axle only, and the centre bearings opened out to 1.6mm. This should hopefully keep all the wheels rotating more of the time.

I had to make a new pivoting platform for the tender, with hole positions taken from the one in the 4F kit. The 4F part was too short to couple to the Jubilee loco chassis.

The muff glued under the platform will be the pivot, and the PCB soldered near the middle will prevent the body twisting from side to side on the functional chassis.

 

 

The 1.4mm drill came into play again to test that the position of the platform was correct, and that everything was not twisted and sliding freely. Also the coupling distance was checked. Note the washer soldered on top of the tender-to-loco coupling, to give a mode robust bearing.

 

 

With everything (amazingly!) in the right place, I painted the chassis, and fixed the rocking platform in place with two 3mm long stub-axles which I made in the lathe. The marks on the platform in the picture below show where the stay-alive capacitors will fit in the back of the tender.

 

 

Meanwhile, the wheels were being prepared. Crank-pins soldered and balance weights glued in place on the driving wheels (and also axle lightening holes centre-drilled on the lathe), and all wheels painted and the tyres cleaned and polished. These wheels are all brass-centred Mk 4 wheels I had in stock.

 

 

This evening I fitted wheels to the tender, and epoxied the motor in place on the rocking plate. I needed to raise the motor 1mm above the plate to clear the wheels comfortably, and also to set the cardan shaft coupling at the correct height.

 

 

With the tender body screwed on to the rocking plate, the cardan shaft will emerge through the coal scope:

 

 

There is plenty of vertical movement at the front of the tender - far more than will be needed to allow the tender to follow any undulations in the track, whilst keeping weight on the back end of the loco. Here is the principle of the weighted tender in action:

 

 

Looking at the two photos above, i might need to adjust the fore and aft positioning of the tender body on the functional chassis.

 

Finally for now, here is a view underneath the tender, showing how it all fits together. There is a little side-play in the axles, but the wheels cannot touch the cosmetic outer frames, which are electrically isolated. A belt and braces approach would be to line the cosmetic frames with cyano-soaked fag paper or 5 thou plastcard, but I don't think that will be necessary for this tender.

 

 

I think the next jobs will be to fit and quarter the driving wheels, make a cardan shaft, get the coupling rods on and test the chassis under power.

[nick_bastable]

 

the 2 Hal needs pick up beams added but is almost finished 😃 members of the zoom group may have witnessed it running

The 419 ended up as a heap of guano so stored with many others as to revisit in x years time

 

 

mean while as some light relief ( pun intended )

 

[Nig H]

On 17/07/2020 at 11:12, Nig H said:

Here are some pics of the test track I have been building. The District Engineer has been out to have an early look after hearing of construction problems and poor workmanship.

 

 

   

 

In an initial assessment, the DE commented, 'Carpentry abysmal, baseboard will probably just about do, track laying needs more care to ensure joints line up accurately, turnouts satisfactory as far as they go at the moment. Recommend carpentry and baseboard construction be outsourced if standards cannot be improved significantly'.

 

Oh!

 

This is my first attempt at serious layout and track building and on a positive note I think I've learnt  quite a lot, mainly don't bother. No, but I can see my standards will need to improve considerably to achieve something satisfactory to run stock on.

 

For information, the outer radius is c. 30" with Easitrac except the turnouts which are soldered (no chairplates) construction. I used a Templot printout for the latter. I've yet to fit TOUs etc, so plenty of scope to screw things up even more before I try ballasting and adding the inner circuit.

 

Nigel Hunt

How time flies! I have run out of excuses for not progressing my test track, so I've been looking at the electrics. I'd done more on this than I remembered and found I'd already attached a servo for the turnouts, and the associated wiring. Some of the turnout operating rodding was in place too. My plan is to use the servo to operate both the turnouts, and to use DPDT switches so that the crossing polarity of both turnouts is changed at the same time. Is this a bit ambitious?

 

Here is a pic of the crossing.

 

And some pics of the underside.

 

 

You can see that my wiring is a disgrace, and i hope with practice to get a lot better. In my defence I could barely see what I was doing as my eyesight is not great, and I'm used to working at a bench with a  lamp and magnifier. The size of these two boards made this very difficult.

 

Anyway, I connected the loose red and black wires from the switch to a controller and tested the servo. After a few false starts, I finally got the switch to operate the servo switch and move the yolk back and forth (or the other way round actually). The wiring is from a diagram illustrated by Izzy in his hacked servos topic:

 

I actually used the diagram on the N gauge forum link in Izzy's post, but I think they are the same, just different formats. I must admit that wiring and electrics is not my strong point, so trying to follow what to many of you is quite straightforward was a challenge.

 

Next I want to wire up the inner circuit crossing, then have a go at connecting the TOUs to the servo yolk. Fingers crossed1

 

Nigel Hunt

 

 

[Ian Morgan]

For the small cost of a servo, I would always fit one per point instead of all that complex mechanical linkage. Much easier to set the throw of each one separately.

They can still be connected to the same switch.

 

[Caley Jim]

When fitting memory wire actuators to some of the turnouts on Kirkallanmuir I tried using just one for a crossover, but I found that getting everything adjusted so that both sets of switches went fully over and the microswitch also changed was such a faff that it was easier to fit one per turnout and wire them in series. 

 

Jim 

[Nigelcliffe]

2 hours ago, Nig H said:

.................

 

 

And some pics of the underside.

 

 

 

Let me get this straight....  The picture appears to show the rear of a toggle switch (bottom of shot), which operates a servo motor, which in turn operates a toggle switch ?    

 

Could I suggest you get someone who knows about electrical stuff, switch types, etc.. to come round to talk through sensible alternatives.    There are lots of simple ways of doing this sort of thing.     

 

Which to suggest does depend on a few things, such as ease of access, type of control panel, and whether there is any budget to buy in mechanical devices which would make life easier.  

 

 

- Nigel

 

 

[Izzy]

55 minutes ago, Nigelcliffe said:

Let me get this straight....  The picture appears to show the rear of a toggle switch (bottom of shot), which operates a servo motor, which in turn operates a toggle switch ?    

 

Could I suggest you get someone who knows about electrical stuff, switch types, etc.. to come round to talk through sensible alternatives.    There are lots of simple ways of doing this sort of thing.     

 

Hi Nigel,

 

If you read my thread on hacked servo's which Nigel H provided the link to the wiring and why it is will become clear.

 

Bob

[Izzy]

3 hours ago, Nig H said:

My plan is to use the servo to operate both the turnouts, and to use DPDT switches so that the crossing polarity of both turnouts is changed at the same time. Is this a bit ambitious?

 

Hi Nigel,

 

Like Ian Morgan I think that using one (hacked) servo per point would be the way to go. That's the way I do them, with pairs forming crossovers thrown together just using the one panel switch. You need to do it this way because the turnout crossing will need to be of opposite polarities whether both are set for the straight routes or for the crossover.

 

Bob

[Nig H]

After correcting the wiring for the crossing polarity changeover, I managed to run a loco through the crossover. I was also pleased that that the loco ran quite smoothly - thanks Templot.

 

Now I need to sort out the mechanics. It looks like I'll need to ditch the single servo idea, as advised by Jim, Ian and Izzy.

 

Nigel Hunt

Edited March 16, 2023 by Nig H

[Nick Mitchell]

5702 Progress report #3

 

A couple of weeks have passed since my last update. During that time we've had decorators in, followed by a German exchange student staying with us, so a busy "real life" and less modelling time than perhaps would other wise have been the case! Nonetheless, progress it being made on the loco chassis...

 

The wheels were fitted to the main frames and quartered using the Association jig.

These wheels are old Mk.4 ones that I have had in my gloat box for many years. After fitting, I discovered one of them had quite a pronounced wobble. A bit of judicious tweaking has improved matters significantly. It's not 100%, but certainly good enough, and the track tests (rolling freely through pointwork) were passed at this stage.

 

When testing the mesh of the worm again, it was a bit tight. (the slop in the 1.4mm drill rods obviously made a significant difference at the earlier testing stage) so I have increased the shim thickness by 5 thou. which has done the trick.

 

 

Once the wheels are in, the brakes can be added. This is always a fiddly job. (Actually, most jobs are fiddly!!!)

For the moment, I've left the bottom cross-shafts joined together to increase rigidity while the chassis is getting a lot of handling.

This is the view from below.

 

 

In the above picture, you can also notice that I have fitted the coupling rods. A crankpin washer is fitted to the rear drivers only. The front ones will be left as they are, and the crankpins filed back almost flush in order to give maximum clearance behind where the connecting rods will be.

 

 

Speaking of connecting rods, I have decided not to use the ones from the kit.

I'm actually using a few bits from the Association Black 5 project in this build, to make life more convenient.

I bought one of the Association Farish conversion chassis kits ages ago as a source of various Stanier valve-gear parts, and one of the sets of conn rods on that are the same length as Jubilee rods. I think they have a miniscule advantage over the ones in the Jubilee kit.

 

By way of comparison, the top rod in the picture below is one of the Association ones. As well as having the oil reservoir at the little end, it also has a more pronounced taper - the others below look parallel to me. I'm probably being unfairly picky here, but because I have both etches, I am free to choose.

 

 

Where I really need to use the Black 5 parts is in the area of the radius rod and lifting arm.

I'm going beyond the design of both kits in attempting to build the model in forward gear, and want these parts to move.

I have done this with a few chassis now, and I think the difference it makes is worth the extra effort.

There is nothing wrong with any of the bits in Nigel's conversion kit, it is just that the Black 5 ones are more amenable to being re-purposed in this instance.

 

In the picture below, the centre radius rods are the ones from the Jubilee kit, with the lifting arms an integral part of them. his makes for a much simpler to assemble arrangement. I don't like to make things to easy for myself, but I did not fancy trying to cut a slot in these parts however!

Above and below them are the Black 5 components, ready with a slot and a separate lifting arm.

These also needed modification (which had happened by the time I took this picture), by removing an extra pivot point at the slot end, and drilling a 0.3mm hole at the other end for the combination lever to attach to.

 

 

I'm getting slightly ahead of myself with the radius rods, however, so back to the connecting rods... which were fitted to the cast Black 5 cross-heads. The castings needed quite a bit of work to clean up the areas where they were attached to the sprue, and I had to file  a bit of material off the front of the connecting rods to get them to fit into the crosshead and pivot nicely.

 

For pivots I used Association flanged crankpins, with the flange diameter turned down from 1.5mm to 1.0mm, and just a stub of the short end of the shaft left protruding on the front face. I made an attempt to file a hexagon on this stub to try and represent the chunky securing nut, but it probably isn't noticeable even in close-up.  

 

 

Next I moved on to the cylinder block. This was assembled, then appropriately sized tubes fitted for the piston and valve rods.

The tubes were fitted flush at the front, and left over-long at the rear to represent the glands (once the cylinder/valve covers have been fitted over them.

 

 

I made a mistake here. I don't know if you can tell from the above picture, but the bore of the left hand pitson rod tube is slightly larger than the right hand one. They were cut from the same length of stock tube, and I must have drilled out one end for something at some point in the past... I must also have cut from the other end of the stock tube from the one I'd measured against the piston rods, and the result was the left hand tube had a ridge part way along where the diameter changed. This caused a problem when I first tested it, so later on I had to take the thing to bits and fit a new piece of tube. Very annoying and a waste of time, but with valve gear, everything has to be 'just so' at every stage or it won't run nicely later.

 

 

Once the tricky task of replacing the tube was accomplished, fitting the slidebars turned out to be no less tricky. The Black 5 ones (used because they would match the crosshead casting) are 3 layers, whereas the Jubilee ones are 2 layers. The also have chunkier parts to fit into the cylinder ends, which needed careful filing down. Several adjustments had to be made to finally get them in line with the tube and equally spaced from it so that the crossheads would slide up and down freely.

 

Below you can see the cylinder block slotted into the frames, with a cross-head in place to check alignment and clearances before continuing. So far so good... except for the rust starting to appear on the driving wheels! (I've not had this happen in the same way before)

 

 

The next item to be tackled was the motion bracket.

As with my previous Jubilee conversion, I have added the flange along the bottom of the girder, as I believe it makes a big difference to the authenticity of this part:

 

 

The two halves have been assembled onto a length of Association 7mm frame spacer PCB, suitably gapped. Cut-down crankpins form the expansion link pivots, with their heads providing a cosmetic foundation for the etched pivot covers on the outsides.

I've removed an area of copper at the back end of the spacer PCB, as this will be very close to (possibly touching) the double-sided PCB pads attaching one of the frame spacers to the main frames.

 

 

Here is the component test-fitted to the frames. It was necessary to file a little bit off the brake hanger on one side to get it to sit perfectly, and without wanting to push the brake shoe into contact with the wheel tread.

 

 

By using the loco chassis as an alignment jig, the next job was to join the motion bracket to the slide bars.

For this to happen, I had to widen the gaps between the 'jaws' of the motion bracket from 2.75mm to 3.5mm.

 

 

This results in a fairly sturdy and (for now) removable unit around which to construct the valve gear.

 

 

But before moving on to the rest of the valve gear, it was again necessary to check that the cross head was still moving freely in the slide bars. The left hand side was good, but the right hand side was tight, so a little adjustment was necessary.

 

 

This is where I'm currently up to, with the really fiddly and fun bits about to commence...

 

[Izzy]

 

Oh this is very handy Nick, thanks for detailing what you are doing. I'm just starting on a re-built Royal Scot from Farish bodies & Nigel's chassis and you're previous posts have helped me understand how the tender chassis goes together.

 

Bob

[Yorkshire Square]

I've been struggling to progress the right hand side of the layout where trains enter from the sector plate. I've eventually made a start on the overbridge and made a few changes to the buildings on the rear.

 

I'd picked up a couple of terraced house kits from Petite Properties  (usual disclaimer). These are laser cut cardboard and low relief. I didn't want to sit them straight against the backscene, but thought that with a bit of bashing they could be adapted. 

 

I built the kits as per the instructions but built up the gable end of the left hand one to give it a full profile. The backs are a bit messy, but out of site when they're in position. The kits went together very nicely. I covered them with Scalescenes brick paper and used Redutex tiles for the roofs.

 

The terrace will sit on a slight raise with retaining wall and small embankment. I need to print a road sign, probably the rather unoriginal Railway Terrace.

 

The retaining wall needs more work, possibly buttresses, and cap stones and I'll need to sort guttering etc.

 

 

 

[garethashenden]

I've been building myself a test track. Basically just a crossover with four stub tracks. It also gave me an excuse to try out the etched chairs. They're really fiddly! But they do look good. I was getting the hang of it by the end. Still needs tiebars, wiring, and testing. 

[Nig H]

Here is a video showing some locos running through my crossover. Not Spielberg quality, I'm afraid. I took the advice of those who know better (Ian, Jim and David) and used one servo for each crossover. I used as much of what I'd already done so I only needed a SPDT switch for the additional servo, and wired it to the existing panel switch. Once the servos were fixed down I had do adjust the length of the omega wire connecting one servo to its TOU, but that was quite easy.

 

The two locos shown managed to get from inner to outer circuits and back the best. Longer wheelbase locos including a BR 9F and a Princess Coronation pacific struggled, probably due to a combination of long wheelbases and limited sideways throw of the bogies/pony trucks. An LMS Black 5 failed to get through because of the limited clearance between the back of the loco and the tender footplate (I think), and an LNWR Super D kept derailing as it entered the crossover. I suspect that's a back to back issue. The track work itself needs a couple of tweaks ( I tried a bit of filing inside the check rails and the crossings) but the whole exercise has been useful in highlighting issues on individual locos requiring attention. None of these would have come to light just using a piece of plain track.

 

Nigel Hunt

 

 

[Nick Mitchell]

5702 Progress report #4

 

Since the last update, I have finished off the valve gear.

The first job was to make and fit valve and cylinder end covers.

The front valve covers were made with a location spigot, and the rear ones had a hole to slip over the protruding tubes.

 

At the same time, I added a rear flange to the motion bracket that isn't catered for in the kit.

 

With the valve end covers in place, thoughts turned to the valve spindle crosshead guides, which would need to be fabricated.

Some left-over etched wagon axleboxes caught my eye, and I thought they could be converted into the little crosshead guide slidebars.

A few strokes with a square escapement file made the round hole into a rectangle...

 

 

My idea was to solder one of these little rectangles to to an outline shape of the brackets, to gain some relief.

The brackets would have a fold-up section at the front end with a hole that could slip over the protruding tube to locate and firmly fix them in place:

 

 

 

The idea worked, but the fold in the bracket (I'd filed a fold line) proved to be a weak point, and within a few minutes of fitting, BOTH had snapped off when I tried to adjust them.

I had to think again, and in the end I settled on another ring of brass to slip over the protruding tube. This was soldered in place, and the outside edge filed flat, to act as a surface on which to attach the remains of my little bracket. A much more secure fixing was the result. I filed the top edge of the brass ring flush with the top edge of the bracket, and the result is rather pleasing:

 

 

Then it was on to the valve gear proper.

I fabricated some valve spindles by my usual method of squashing the end of some 0.45mm brass wire in a vice, and soldering onto the ensuing wide flat area a 0.3mm etched washer.

These were attached to the top end of the combination levers, along with the radius rods. Because these joints are so close together, they had to be made at the same time.

I needed to make some "double washers" to retain the joints.

Here's one about to be soldered in place (with apologies to Tim for my continued use of Rizla paper as a solder barrier... it works for me):

 

 

These are the completed pivot joints, from in front and behind:

 

 

These bits then need to be joined to the crossheads via the union links.

Said union links can be improved by thinning them a little bit.

The photo below looks a bit crude, but please bear in mind how small these things are!!!

 

 

This completes the first sub-assembly of the valve gear - the front section. In the picture below, you can see where I've filed a chamfer on the top front edge of the crosshead castings to ease their passage behind the combination levers:

 

 

At this point, I needed to separate the cylinder block from the motion bracket to thread the radius rods into place. Having these parts joined together earlier was very helpful for aligning the valve spindle crosshead guide brackets, however.

 

Here you can see how there needs to be room for the combination lever to fit behind the guide bracket and in front of the slide bars... ideally without having to crank the combination lever in and out. The left hand bits of valve gear have been slotted into place temporarily for checking.

 

 

This view from above shows the gap on the right hand side, and also the filed back brass cylinder mountings for the spindle guides:

 

 

The rear end of the valve gear "chain" - comprising the expansion link, return rod and crank were assembled, then joined to the radius rod as it was threaded through the motion bracket.

After that, it could be "hung" from the bracket by the expansion link pivot.

 

For the expansion links themselves, I used the Black 5 ones. They're identical in size and shape to the Jubilee ones, but have the bonus of a second 0.3mm hole being etched into them, which I used to pivot them to the radius rods. I also added a layer of 5 thou shim over the top part of the expansion links, to give the pivot at the bottom the appearance of being recessed.

 

Once all the pivot joints were made, the slidebars and motion bracket were joined back together:

 

 

I had previously drilled holes in the main frames to accept a 0.5mm weigh shaft. (The middle spacer was in the way of this, and had to be filed by slightly along its front edge.)

With the weight shaft fitted, I could measure the distance from it to the slot in the radius rod, so that I was able to fabricate a pair of lifting arms.

These needed to be longer than the ones included in the Black 5 kit.

I cut some tube to slide over the weigh shaft to space the lifting arms accurately from the frames, and give them something to rest firmly against to ensure they ended up nice and square.

The front end of the lifting arms have a short 0.3mm pin with engages in the radius rod slot.

 

This is the left hand side completed:

 

 

And the right hand side:

 

 

After cleaning, the valve gear was lubricated and tested under power. Here's a tiny video showing "proof of life":

 

 

[Yorkshire Square]

I do so enjoy throwing a bit of flock around! Having formed the groundwork around the new factory, the terrace and the drainage ditch, I dug the electrostatic sieve out and made a start on the grass. The basic  covering is in, now for some weeds and brambles and bushes.

 

 

 

[Donw]

It does strart bringing it to life

 

Don

[DavidLong]

11 hours ago, Yorkshire Square said:

I do so enjoy throwing a bit of flock around! Having formed the groundwork around the new factory, the terrace and the drainage ditch, I dug the electrostatic sieve out and made a start on the grass. The basic  covering is in, now for some weeds and brambles and bushes.

 

 

 

 

Looking good, Tony. It's really starting to come together.

 

David

[AWright]

Hi, first time posting on RM Web I've been working on a NBR mineral wagon, 9' wheelbase which is 3d resin printed except for the axle sets (2mm association). Does any one know who produces transfers for this type of rollingstock?

[richbrummitt]

22 hours ago, Yorkshire Square said:

 

I do so enjoy throwing a bit of flock around!

 

I agree with the comments above regarding the change in appearance.
Before ballasting though? I’m curious - having only got to such a stage on one serious layout ever - as to your reasoning. I’d presumed to paint the track and cross then ballast to ‘finish’ that area before working more widely to complete the surrounding landscape. 

[Yorkshire Square]

41 minutes ago, richbrummitt said:

I agree with the comments above regarding the change in appearance.
Before ballasting though? I’m curious - having only got to such a stage on one serious layout ever - as to your reasoning. I’d presumed to paint the track and cross then ballast to ‘finish’ that area before working more widely to complete the surrounding landscape. 

 

Well that's probably the conventional way, but I tend to be pretty erratic and nonconformist when I'm modelmaking. Sometimes it works, sometimes it doesn't! I'm full of admiration for those modellers who produce neat models, but occasionally I feel they're a bit clinical. Just my opinion of course.

 

I'll probably end up redoing some of the ground cover and to be fair, I don't really know how I want to do the ballast yet. I sort of do things as they take my fancy and depending on how I feel. And, of course, it's only a train set. 🙂

[GER_Jon]

18 hours ago, AWright said:

Hi, first time posting on RM Web I've been working on a NBR mineral wagon, 9' wheelbase which is 3d resin printed except for the axle sets (2mm association). Does any one know who produces transfers for this type of rollingstock?

Shop 2 or railtec do them.