D869

2 hours ago, t-b-g said:

The Dean Goods took much fiddling about to get it to run

You've got the hang of it now so the next loco will be easier.

Nice job BTW.

14 hours ago, Ian Morgan said:

 

The Transport Library webpage says Newport MPD in the 1930's.

 

https://thetransportlibrary.co.uk/index.php?route=product/product&product_id=153387&search=A1+isle+of+wight&page=3

 

The Medina Wharf, just north of Newport, seemed to be mainly for the receiving of coal. St Helen's Quay or Wharf seemed to be used for more general goods traffic.

 

 

Cheers Ian.

It's a fascinating bit of traffic. Begs all kind of questions... like how they dealt with maintenance of such a tiny and specialised set of wagons. Maybe they brought people in... or maybe they swapped the tanks with fresh ones from the mainland when they became due for overhaul.

On 07/08/2021 at 22:51, Ian Morgan said:

... the only other private owner wagons on the island that I know of were a small number of tank wagons used to transport paraffin. At Freshwater, there were a pair of storage tanks supplied by these wagons. The traffic was important enough for plans to be prepared for two more storage tanks, although I do not think they were actually installed.

Interesting... and news to me. Any idea where the paraffin tank traffic originated? I'd hazard a guess at a coaster from Fawley (Esso had several coasters) and then offloaded at one of the island ports and pumped into railtanks. Just a guess though.

Do you have any details for the prototype photo? ... like location and year maybe?

Good luck with the new job Steve, Love the cameos - very creative.

1 hour ago, Valentin said:

 

Thanks, Julia, it was easy to remove the bearings.

 

It seems I need to purchase a pair of 17mm spanners to tight the collet. I tried by hand but I couldn't get the nut nowhere near enough to even slightly grip a 1.5mm drill bit in the 1-1.5 ER11 collet. Is this expected?

Are you using the collet and nut correctly? - you need to clip the collet into the nut before putting the nut onto the collet holder. ER collets have a groove that engages with the nut. It doesn't work if you put the collet into the holder and then put the nut on.

My collets (ER16, not ER11) are stamped with a decreasing range, e.g. 7-6mm . The nominal size (the one you choose when ordering) is the higher number. When inserting drills etc that match the nominal size they are a close fit and sometimes won't go in unless I first unscrew the nut a bit to release the collet properly. You should be able to tighten the nut by hand and get a noticeable grip... but don't try to cut metal like that - tighten it properly.

Going all the way to the lower end of the range will need more effort (and probably a spanner) and is not the best way to use collets anyway.

On 21/05/2021 at 15:10, Ian Morgan said:

I think you will find many loco chassis end up with the motor off-centre. Provided the weight distribution puts the centre of gravity near the middle you should be fine.

Modern coreless motors are not very heavy - their main factor in weight distribution is the room they take up without adding any useful weight. I suspect that with those bonnets full of lead the motor won't be a factor in weight distribution.

22 hours ago, Valentin said:

Regarding the milling cutters I understand that the 'uncoated' ones are for machining non-ferrous materials. There are mainly two types: HSS and solid carbide, the latter being approx. twice the price. Apart from having a longer life, are there any other advantages of a carbide cutter, when used to mill small brass rods and bars?

Carbide needs a rigid machine and high speeds to deliver its benefits. The MF70 is hardly the most rigid thing in the world but I think that up to 3mm it handles carbide OK. If you plan to put bigger cutters in your ER11 spindle then you need to reassess the question. Sorry I don't have any simple answers.

For my lathe I am now using HSS cutters (6mm and 10mm) and they work very well. I did manage to snap a tooth off a carbide cutter in the lathe when it dug into the work. I've also snapped a 3mm carbide cutter in the MF70 - I think it was too much vibration and an overhanging workpiece that caused it.

I tend to keep my cuts light but I gather there is another issue called 'rubbing' that relates to running milling cutters without enough cutting demand on them.

Fun isn't it?

+1 for mounting on the bogies although with your half length coach you might get away with it. I did try mounting on the buffer beam on some bogie diesels a long time ago. I soon changed.

I moved to QCad myself. There is a fully functioning free version. There is also a paid version with more bells and whistles.

Other free options are available. I thought there was a pinned topic comparing CAD tools on here but maybe I imagined that?

1 hour ago, Caley Jim said:

Thought : is this why the 6ft always looks, to my eye at least, too wide in 'N', in order to allow for this?

In case the terminology is not clear outside of this island... the 'six foot' is the space between double tracks (between adjacent rails, not track centre lines). The 'four foot' is the space between the running rails of a track. They are not exact measurements... the four foot one being particularly inexact.

And then there is Brunel's broad gauge.

Hi, you should probably ask in an 'N' gauge forum to reach those with more up to date knowledge of Peco track but let's not worry about that just now.

There are a couple of issues with tight radii...

1. They don't look very much like the real thing (unless you are modelling a dockside or industrial scene). There are exceptions but most rural railways had plenty of space so tended not to need to resort to tight radii within station limits. Some were lightly built (often the later ones built under light railway orders) and followed the contours closely so their running lines could be somewhat twisty and limited to low speeds.

2. They do create clearance issues - bogie coaches and long locos can foul bridges and platforms, both at the ends (outside the curve) and in the centre (inside the curve). Increasing clearances on bridges etc is probably not a big issue but definitely avoid tightly curved platforms because otherwise your passengers will need to be olympic athletes to jump the gap. The clearance issues extend to rolling stock too with compromises needed to allow bogies to swing, bigger gaps between vehicles etc.

In many cases the compromises needed to allow stock to run on tight curves will be 'baked in' to RTR stock already but I suspect that some of the more recent RTR stuff may not work on 9 inch radius Settrack curves - I'm thinking mainly of main line tender locos though but it would be worth checking things like 2-6-2 tanks to make sure that the pony trucks can clear the cylinders on tight radii.

FYI, the folks in this forum work to 2mm Finescale (2FS) on a track gauge of 9.42mm. What Peco call Finescale is a different thing - it's still 9mm gauge and I think pluggable into their coarse scale track. Many of us are reformed 'N' gaugers and in many cases we run converted 'N' scale locos and stock so we do know a bit but RTR compatibility with tight radii is not something we are typically experts on.

Of course should you wish to convert to the true path then you will find a lot of support here

Hopefully this link will work...

Every now and again something interesting turns up on the 'Nostalgic Hayle' Facebook group. This is an interesting shot of the weighbridge showing just how close the point switch blades were. More interesting still... the deck was still mixed gauge. No date posted with the pic but the Steam Packet Inn in the background makes it mid 60s or earlier. The weighbridge deck must have been replaced after this because it only had two rails when I saw it... which was before it was removed and reconstructed further along North Quay.

https://www.facebook.com/groups/1389945024615259/permalink/2917566338519779/

... that just showed as a link. This one seems better...

52 minutes ago, jonas said:

Well, I’ve finally taken the plunge and converted my first loco - thanks to association drop in wheelsets, an absolute doddle!

 

Awaiting for my easitrac delivery (including a pegged turnout kit) and one of sample packs 16 tonners to have a bash at next!

Nice work. Bash is probaby a good verb for a 16 tonner of this era so good luck with that.

2 hours ago, Bryn said:

The first of many for Colwyn Bay Goods. A TTB 45T tanker made from the Stephen Harris kit.

Nice job. I have had one in the gloat box for ages. Must track down my stock of round tuits.

I'd suggest taking a pencil rubbing of what you have, perhaps with some extra entry and exit rails temporarily soldered into place. Scan it and then overlay it with track in Templot. Then you'll get to see which arrangement works best. I did this when trying to devise a new crossover to fit some pre-existing curvy track on St Ruth. You don't necessarily need to go the whole hog - just do enough to answer your question.

I've tried it without too - 20 years ago I ended up with some very dodgy geometry when trying to 'ad lib' a three way in a tight using space paper templates and hand drawn track

7 hours ago, richbrummitt said:

Andy, I think your perseverance is rewarding you. I really dislike soldering brass; finding that it seems difficult to get sufficient heat for the solder to take. Apparently the real problem is getting the brass properly clean enough and I'm told by those more experienced that 12% phosphoric acid flux is the silver bullet. I've also read that Viakal (even neat) is the best option for cleaning up a tarnished etch (and all the brass etches I have stored need a clean) before starting. I haven't tried either yet but thought that you might benefit from trying these ideas.

Cheers Rich. I use Carrs Green Label which I think is phosphoric acid. That seems to do the trick pretty nicely (after a quick rub with the fibreglass brush). I don't think that muck, tarnish or whatever are a big problem for me.

The main issue is getting enough heat to where it's wanted as the amount of metal increases - brass conducts heat away much more quickly than N/S. My solution has been to reach for a bigger soldering iron but the bit is not ideal for delicate work.

Cleaning for painting is another matter. I've seen it said that tarnished brass provides better paint adhesion than clean brass... not sure if I'm brave enough to try it though.

Work on the O2 continues but progress still feels slow. Partly I think it's because I'm now doing fairly small details that don't have a big impact on the whole picture, partly because some of those jobs are the ones I've been putting off and partly for fear of screwing the job up at such a late stage. There seems to be a fair backlog of photos to talk about here so I guess I must be making some progress.  Anyway, here goes...

The driving wheels have been off the muffs to have the balance weights epoxied into place. While the wheels were off I also had another go at filing the coupling rods. They are thinner now and I think improved so I decided to stop filing. I may or may not have another round of filing.

There was no obvious way to attach a coupling to the front so a milling cutter was deployed to turn the previous curvy bottom edge of the spacer into something more amenable and a 12BA fixing hole drilled and tapped...

Boiler handrails... definitely a job I've been putting off but it could be delayed no longer. I'm using Albion Alloys 0.2mm N/S rod. Step 1 was to use a vee block and progressively smaller drills to form the curve over the smokebox door. I think I ended up around 4.5 to 5mm but the curve radius is not quite so small.

Then some sharp bends were added either side of the curve to take the handrails out past the corner of the smokebox. After offering up to the boiler, the bends were made to send the handrails back towards the cab. Amazingly I managed to get a decent result at the first attempt. I was definitely not expecting that. The two handrail knobs on the front of the smokebox are soldered to the handrail. The split pins were threaded on and the handrail loosely fitted...

Then the pins were put one by one into their drilled holes and soldered to the handrail. One hole is nice and deep. The other was pretty shallow so I tried with a 0.3mm drill to make it deeper. No joy... deployed a brand new drill... snap. Finally I remembered that a drill had disintegrated inside the hole when I originally drilled it several months ago so now that handrail knob will have a shorter tail.

The two knobs on the sides of the smokebox were unsatisfactory. The right hand one is an odd one out on the real loco, perhaps it is a join. I'd left this as a plain bit of 0.5mm brass rod soldered into the hole in the smokebox but this had no positive way to hold the handrail. I experimented with filing a vee but this wasn't much better. Finally I decided to bite the bullet and try to solder a short length of 0.2mm bore brass tube into the vee. I used another length of handrail rod through the other knobs and coated this with marker pen... the extra thickness of which made it hard to thread back into the tube. After three attempts with Carrs 188 which all came adrift as soon as I tried to remove the handrail rod I resorted to my usual electrical solder and finally managed to get a solid joint without soldering it to the handrail rod. The clack valves also put in a rare appearance during this test assembly...

The left hand handrail knob is a normal split pin but being in the smokebox had resisted all attempts to solder it into place from inside so it was wobbly. I had several more attempts to get enough heat onto it from inside the boiler before giving up. I decided that the only option was to solder it from outside. After pulling it into alignment with tweezers I applied a fairly generous amount of flux and solder which finally made it stay put... and filled up the hole... and left a messy solder blob...

Nothing that couldn't be rectified by some careful scraping and a very rare outing for a 0.2mm drill which I am usually far too scared to use.

Lamp brackets... hmm... I was expecting these to be a nightmare and so far they are proving me right. I'm mostly using the bits from the etch. The six on the rear of the bunker are now in place. Only the top one was at all straightforward. For the middle ones I used some pencil marks and a strip of card to get the two of them at the same height plus some more card to stop the top part welding itself to the bunker. My 25W iron could just about melt the solder but not make a convincing joint. The brackets would at least stay put after that so that I could pin them down with the end of a blade and apply the 80W iron to the bunker rear. It feels odd wielding such a big iron on such tiny parts. That got the joint made but the strip of card was not too happy about it.

The ones on the buffer beam were the worst, especially the two over the buffers. Several angles of attack and methods of packing were tried before I eventually arrived at the option in the photo - a bit of N/S etch waste wrapped in aluminium foil to prevent it being soldered to the loco. This had the advantage of being able to be held in place by the middle lamp bracket and leaving a bit of room to apply the rather large soldering iron bit to the lower corner of the bunker rear panel.

Inevitably the brackets are overscale. Sometimes it's better (and MUCH easier) to leave things off rather than doing an overscale rendition but then the bunker rear would look pretty naked. Anyway they are on now and they are staying. The soldering has undone some of my previous solder filling but I think some Milliput will be happening there. Cruel enlargement blah blah...

Now I've moved on to the front lamp brackets. The buffer beam ones were not too bad after doing the bunker rear. The three that attach to the smokebox front are putting up more of a fight and are still work in progress.

8 hours ago, Nig H said:

If the lamp irons are on the footplate above the buffers...

 

Thanks Nigel. It's a Southern loco so it has more lamp irons than your more northern railways had... so probably all of those variations will apply. Boiling flux and solder paste mucking up the joint are problems I'm very familiar with. I was trying to reduce heat input by making a joint with Carrs 188 yesterday. After it looked solid but then came adrift four times I used normal solder on the fifth try... then it stayed put. For my money, applying more heat and doing it quickly usually ends up being the answer... even if it requires a bit of a deep breath beforehand. Pencil marks on the bunker... simple... now why didn't I think of that?

Thanks both. I don't have an RSU - I think it will be a matter of using a big hot iron to get the heat where it's needed quickly and then get out again before it spreads far. Alignment and holding are the conundrums that are making me think. My own best guess is some strips of card with pencil marks along the top for alignment and to muddle through as best I can (same as always!) for holding. Will see how it goes and rethink if needed.

I need to solder a bunch of lamp irons to the back of the bunker on the O2. The irons themselves are from the N Brass etch so that part is hopefully sorted, but does anyone have a good way to get them neatly lined up and generally under control while being soldered?

The scattergun approach to modelling activity continues. This time I've been back working on the O2.

Before the hiatus I'd left the chassis in bits. I think the final straw was when one of the Simpson springs snapped so the first job was to fit a new one. These are bent into an 'L' and soldered into holes in the frames. The previous one broke at the 'L' bend. This does seem to be a bit of a weakness but space is very tight with the maximum amount of solid metal crammed in so I'll just have to hope that they will be less prone to breakage once I stop messing with the chassis.

Since restarting I've remembered that the chassis was taken to bits to fit the front guard irons. Again the lack of space was a factor - I milled a recess in the back of the frames to fit the guard irons into. The irons themselves are from the N Brass etch - nice to use a few more bits from it.

Putting the chassis back together and refitting to the loco proved that I hadn't finished some jobs before the hiatus because it now didn't fit. A good sesssion of filing was needed to sort out clearances behind the sandboxes but that's sorted now. The chassis has also had a prolonged round of fettling which has improved the running.

A pic of the loco in its current state. Progress feels slow and it's a challenge to spot the differences from the previous photo in this photo but there are some... buffers, guard irons, sand boxes, vacuum pipe under the footplate and brake cylinder on t'other side... plus it runs better and goes through pointwork better but you can't see that in the photo.

Balance weights have now been cut out on the MF70 and await fitting. I've used 5 thou brass, soldered to some scrap etch for milling. This needed more passes than expected because the 5 thou sheet was sitting less flat than expected.

'bout time I put something on here again. I haven't been idle but it would be fair to say that things have rather lacked focus, basically doing what takes my fancy rather than aiming to hit some sort of target like having an O2 running for the DJ Expo. The O2 will still happen though.

The last few days are a good example - the Hayle tractor currently has, effectively, 'skid steering'. I want to at least have a try to make the steering work... and consequently redesign the under baseboard drive system... which in turn may have a knock-on effect on the cutouts in the (so far non-existent) baseboard cross members.

I did a testbed 'tractor' ages ago with steering working along the lines of the Faller system with one magnet on a 'tiller'. It worked pretty well but what I hadn't realised was that it would only work when the tractor was moving in one direction.

One diversion last year was getting the Z axis drive built for my MF70 CNC. This is now working but I'm still learning how best to use it. I decided to put it to the test by using the CNC capability to make a part for the tractor that would be pretty impossible to do manually.

This is the new bit fresh off the machine - basically it should hold the steering king pins onto the chassis and provide the pivot for a balanced 'tiller' with a magnet at each end... hopefully without me needing to hack the existing chassis around too much... and without ruling out chickening out if it doesn't work. The alignment was not perfect between the drilling and milling ops, probably because I powered the whole thing down in between. The misalignment is probably about 0.15mm - this is quite an enlarged photo.

The original steering test tractor fabricated from the usual brass sections without the aid of a milling machine - the big upright king pins work fine but simply won't do appearance-wise. I could have put the rear tyre on straighter too. The tiller was not very robust and has been lost at some point.

The part finished tractor (old photo) for anyone who hasn't seen it elsewhere on here or at Tutbury in 2019 (seems so long ago... has something happened since then?)

The Z axis drive on the MF70. At the moment it's using an offcut of laminate flooring for the lower mounting plate. I promise to make a proper aluminium one . It doesn't really draw 3kA.

9 hours ago, Chris Higgs said:

Anyone worked out how to do the flare on a dome in OpenSCAD? I rather suspect it is beyond its capabilities.

 

Chris

First work out the geometry of the flare on a dome. That seems somewhat tricky on its own. I struggled to do it with a file and some brass, never mind telling software how to do it.

At the risk of diverging well off the OP's question... I suspect it's do-able - at any point when viewed in cross section it's probably not unlike a circular fillet but the radius is small on top of the boiler and a good deal larger at its lowest point. Not all flares are created equal - some seem to flare so that they end up almost tangential to the boiler cladding, others hardly seem to bother much and have a fairly noticeable angle where they join.

So it seems possible to generate circles of varying radii and position them around the base of the dome in a manner not unlike my tank filler skirt rivets. Joining them up as 3d objects might be trickier... generating lots of spheres and subtracting them from a 'fat' dome might be easier.

+1 for OpenSCAD (but you knew that already)

If you are happy getting your hands dirty with code then it's ideal - most of the tank barrel and rivets below were done with code - like spacing the rivets equally around the barrel and doing the 3d trig required for the rivets on the filler skirt. The top of the filler is a separate bit BTW. It's not all code - the vent and syphon bosses are rotated DXFs as are the domed ends on the barrel. Horses for courses.

I also use a lot of 'if' statements to allow me to do an assembly preview model pulling together DXFs from etch artwork with the 3d printed bits... and then use the same OpenSCAD model to render the parts (on sprues) for sending to the printers.

I suspect something similar is possible with Blender, Fusion 360 etc but once you know one tool there is less benefit in figuring out how to do the same things in another.

I do use a bit of Blender too - for posing views of rendered STLs and setting up lighting and camera angles to replicate prototype photos (and overlay the two for comparison). I find this a useful way to check dimensions when drawings are unavailable or don't fully answer the question. I have to refer back to my notes to remember how to work Blender every time though - I find it a pretty strange beast but its 'sweet spot' is more artistic 3d rendering, perhaps of organic shapes and also animation so perhaps it's no surprise that it's a bit odd to those of us more used to CAD tools.