Tales from a sporadic modeller.

[adrian]

Things have been ticking along but it's all the small details so I don't seem to have much to show for my efforts this week.

I've moved onto the boiler and as mentioned this is a resin/plastic casting. It needed a little fettling around the splashers but overall it was nice and square and fitted very well.



Once I was happy with the fit I moved onto the detailing as some improvements were in order. The washout plugs were lost-wax brass castings, whilst reasonable they were quite shallow and they would need a bit of filing to get flush I decided to make my own instead.

I drilled a series of 1/16" holes in a bit of brass strip and then cut out in to squares. A short length of 1/16" brass rod was soldered in. With the base being square it was a few moments works with a 6" file to file the rod square. The bottom 4 in this photo have been squared off, the height is such that they can be inserted and glued from the rear of the firebox.



The other item that needed drastic action was the ejector (?) on the side of the boiler. First look it didn't look right for some reason and it took a little while to decide what need fixing. Basically it was too long, the 3F has quite a short smokebox and the front part of the ejector on the smokebox should line up with the chimney centre line, but this then placed the main body too far back. Measuring up from the drawing it should be about 2' 8" in length (full size!) whereas I measured up the supplied casting as 3' 7" so nearly a scale foot too long.

There are plenty of spares components in the kit and I think from all the photos I have seen the 3F always had the ejector on the right hand side but in the kit there is a lefthand ejector and a right hand ejector. So the photo below shows the cut and shut right hand ejector (bottom) verses the supplied left hand ejector (top). It wasn't a simple cut and shut either it needed 2 slices removing either side of the union joint half way down so make sure that was in the right place.



Once that was done a few other fittings, hand rails etc were fitted so this is the current status. The pipework at the rear of the firebox has been left over length at the moment. The next job being sorting out out drilling the cab spectacle sheet for pipes and hand rails.





My thanks to @Thirtysecond for the recommendation for glue
An amazing adhesive

I have used this for sticking everything to the boiler and I'm very happy with it. It seems to work well on the plastic, I know the recommendation was application of activator on both surfaces and then glue on both surfaces. I did it slightly differently, for example the handrail knobs I would use a cocktail stick to fill the drilled hole with the glue, I would then spray the handrail knob with the activator and then push it into place, it took about 15 - 20 seconds to go off so it was a nice little bit of wriggle time to make sure it was in the right place and not too long that it was no problem just holding it in place with fingers whilst the glue went off.

 

[adrian]

Still ticking along with the build. Just been slowly adding details as supplied so the loco body is now more or less complete. The beading around the spectacle plate is the second attempt. I let my guard down and didn't check the dimensions. I added the beading before adding the boiler and the two above the firebox were just fitted over the holes etched in the spectacle plate. Big mistake as they were too low and the boiler/firebox would no longer fit. They had to be removed and soldered on about 1.5 mm higher up to allow the firebox to fit. The other details include the reversing rod, pipework, curved plate in-front of the smokebox, dome, chimney, steps etc. There are just a couple of details left, vac pipes and injector behind the steps with pipe work and cab detailing. However effort is now switching to getting the chassis running.

 

[adrian]

So the motivation to just get this finished rapidly evaporated when I switched back to sorting out the chassis. When everything fits properly and is accurate the work just flows nicely. Unfortunately when it doesn't fit and doesn't work I seem to hit a wall and just struggle to find the enthusiasm. Well that was has happened with here when tackling the inside motion. So it's been slowly chipping away at it a little at a time.

So the inside motion - where to start? This is the JLTRT supplied inside motion. The first thing to note is that it's just a set of eccentrics to slip over an axle. Whilst a nice idea so you don't have to modify the axle it does have one major drawback. The piston stroke on the real thing is 26" with this motion and eccentrics we get all of just over 3mm of movement so barely 6". So even when all fitted correctly it will barely waggle the crosshead which meant I struggled with any enthusiasm for it.

Once the eccentrics had been cleaned up I moved on to the connecting rods and eccentric rods. They all needed a reasonable amount of work to clean up, some were twisted, some were oval rather than round. After a lot of work I managed to get them all revolving freely around the crank axle.

I then fitted the expansion links to the eccentric rods which is when everything stopped working again. There was twist in the eccentric rods which when attached to the expansion links meant everything stiffened up again. I hadn't even fitted it to the chassis at this moment! I sorted that out and then fitted it to the chassis. When I attached the connecting rods to the crossheads any free movement evaporated again. Got that sorted and then fitted the expansion link to the piston rods - and yes you've guessed it, it all locked up again!!

I had drilled the eccentric and axle to use a 1/16" taper pin to lock them together. At this point I was seriously tempted to leave the pin out and just have static inside motion! Still I persevered and continued with the reversing links, again this was not without it's problems as the eccentric rods seemed to be fouling on the balance weights. This is when I worked out that the expansion link was too long, on the 3F they are quite short between the eccentric rod attachment points, as supplied they were a good 2mm too long. The other fix I wanted to do was to be able to remove the reversing rod so that I could remove the inside motion. I have no idea what JLTRT used to cast the reversing rod and weights but it was an absolute nightmare. It was more like gunmetal/bronze rather than brass. I wanted to drill the ends so I could tap it 10BA but it resisted all attempts to drill a hole, I heat treated it but nothing. Fortunately I had a set of balance weights from Ragstone which were a better geometry and the cast weights were a better size (smaller) so helped the clearance. These were soldered to a piece of nickel-silver rod which I could tap 10BA.





So this is where I'm up to. I fitted the CSB spring wire and coupling rods and the chassis ran smoothly although there is still a slight bind when I lock the inside motion to the axle.

I test fitted the loco body to keep the enthusiasm going and also to double check my calculations on ride height matched the tender - which it did much to my relief! There's still a fair bit to do, guard irons, brakes, pickup, motor/gearbox, sanding boxes and pipes etc. but I finally feel like I'm making progress again.

 

[john lewsey]

Nice Adrian

 

[adrian]

Just spent the evening sorting out all the bits needed for the chassis and this is what I ended up with. I then started to work out what would fit and what would need fettling and it wasn't encouraging or conducive to getting it finished.



So from left to right the components are.

- Balance weights for the wheels, cleaning up the etching cusp and they should fit fine and seem to be the right length. (+)
- Dummy springs, one set etched and one set whitemetal castings. The whitemetal casting are pretty reasonable in size and shape so I'll use them rather than the etched version. I'll probably stick them on which will mean that the axleboxes can't be removed but not too much f a problem with the slaters wheels.
- Sand boxes - again whitemetal castings of the right size and shape so can be used. Unfortunately at the bottom there should be a sand trap casting which is not present in the kit so will have to be made, as will the connector for the steam pipe.
- Then the brakes - these will need plenty of work - more of which below.
- Finally the guard irons, the wrong shape and too short. As fitted they will end up floating about a scale 9" above the rail rather than the required scale 3".
​

Not included because I've not made them yet - the pickups. Following a couple of suggestions I will probably try some hand made plunger pickups.

So back to the brakes - the biggest hurdle to getting this finished. There are holes etched in the chassis to fit the brakes and this is the setup. The brakes end up a country mile away from the wheels. They are also too short/high. The brass angle across the wheels show the location where the brake tie rods should be, as shown in the photo the bottom of the brake hangers is about 3mm higher than it should be, close to hitting on the eccentrics on the centre axle! The brake shoes are brass so current plans are to replace them with a plastic insulating version in a similar way to those I fitted to the tender.



Now I just have to muster the enthusiasm for the final push to getting it finished!

 

[AJC]

Blimey Adrian. Knowing JLTRT's rep' for artistic interpretation of parts lists (packing errors), are you quite sure these are the intended brake hanger/shoe fittings for this loco? They strike me as being about the right size for a Jinty (I'm assuming that a 3F has 5' something or other wheels - is that right?). Ditto the guard irons, though plenty of designers seem to have a blind spot for making these theright length. Not being my scale, I've no idea if SLTRT do a kit for anything like...

Courage!

Adam

 

[adrian]

They strike me as being about the right size for a Jinty (I'm assuming that a 3F has 5' something or other wheels - is that right?). Ditto the guard irons, though plenty of designers seem to have a blind spot for making these theright length. Not being my scale, I've no idea if SLTRT do a kit for anything like...

They don't do a Jinty but they do a MR 2F - as you say packing errors have been known. Despite being marked as the 3500gal tender version on the box it was supplied with a 2750gal resin body from the 2F! Sorting a replacement wasn't a problem at all but as I'll be replacing the brake shoes with plastic versions I'm happy to work with what I've got.

 

[adrian]

A quick update, there was small diversion helping out operating St. Ruth (2mmFS) at the Manchester exhibition and whilst I having been doing a bit more 2mmFS stuff I've kept going with the 3F as the finish line is tantalisingly close.

Work on the chassis has continued so a couple of photos to show some progress. I started with the sandboxes and pipework. Despite all the castings in the box I couldn't find anything resembling the sand trap casting for the bottom of the sandboxes. So I used a little bit of copper tubing soldered together with the pipework to give the impression of the sand trap. The brackets holding the bottom of the pipe was made from a bit of scrap etch, a bit of copper pipe again and a 16BA nut drill out to form the steam in casting.



The castings were stuck to the chassis and pipe work fitted. Other jobs done - wheels blackened. Unfortunately it doesn't work on the nickel-silver balance weights - next time I think I might try to make the balance weights from steel sheet so when the wheels are blackened the balance weights get done as well and don't require painting! Also fitted the front guard irons - this again was a job that was harder than it needed to be. The shape of the chassis frame is wrong so I couldn't add the guard irons in the correct place. They are not immediately behind the buffer beam but a 1ft or so behind the buffer beam mounted at a lower position. So I had to scab on a little filler piece in the chassis to be able to mount the guard irons.





So work is now progressing on the pick ups and brakes.

 

[adrian]

As all the Christmas preparations are sorted, kids presents wrapped etc. and the Christmas spirit in hand. I can spare a few moments to report progress on the pickups.

As they are Slater's wheels some form of rim pickup was required. There has been a thread on the Gauge O Guild forum (for those with access http://www.gauge0guildarchive.com/xenforo/index.php?threads/let’s-talk-pick-ups.505/ ). A multitude of options seemed to be used but for simplicity and unobtrusive then @Ian@StEnochs solution seemed interesting so I have blatantly copied it!

So the photo below shows the various stages in making the pickup.

At the bottom all the components, a short length of 3/32" brass tube drilled 1/16" for the white plastic rod. A couple of metal takes made from some scrap etch in the kit. A couple of insulating bushes, I had no plastic rod of suitable size so I just used a bit of scrap sprue from a couple of Parkside wagons I have in stock! A length of 0.7mm brass wire and a couple of springs. Having opted for the continuous springy beams method it means that I have a small stock of slaters springs spare which were ideal for the job.

Above that shows the pickup set soldered together. Unfortunately the 1/16" diameter plastic rod from Evergreen was more oval than circular so the tube needed drilling out a little to get a smooth sliding fit.

The chassis shows the pickup fitted to the leading driving wheel (left hand set). The black plastic bush is glued to the chassis. There was no problem fitting it and the pressure seems light yet continuous as it seems equalised on both sides. The position of the etched holes in the chassis for the centre axle doesn't work with the inside motion as it will interfere with this arrangement, so a new location will be needed.

 

[Scale7JB]

Marvellous !

JB,

 

[3 LINK]

Hi Adrian,

I must agree with JB, Marvellous,

A question, those small insulating bushes did you make them or are they available from a supplier?

Merry Christmas,

Martyn.

 

[adrian]

The black insulating bushes? I made them, it was a fairly easy job if you have a lathe but I dare say it could be done with a mini-drill and a file if needs be.

 

[3 LINK]

Thanks Adrian,

That type of small unobtrusive pickup will come in very handy on my next build, certainly food for thought.

I will have to fire the lathe up and give it a go. My lathe was built in 1947 so it might need warming up first, a bit like me as there is no heating in the playroom at present....

Martyn.

 

[adrian]

My lathe was built in 1947 so it might need warming up first,

As it happens the lathe I used was a 1947 vintage Coronet Diamond
Coronet Diamond, Jewel, Ruby and Tiara lathes

 

[michael080]

morning,

just in case someone doesn't have an antique lathe available, these thingies are used to isolate power semiconductors. http://uk.farnell.com/multicomp/31-...ey=http:en-GB/Element14_United_Kingdom/search . They are available in many (mostily metric) sizes.

Michael

 

[3 LINK]

This is my little beauty, and that is not dust from lack of use, just saw dust as I didn't notice that I had placed it under my saw table.....

It was made by a firm called Grindturn Engineering of Shrewsbury, I have no other info.

Martyn.

 

[simond]

What a beast!

Best
Simon

 

[adrian]

It was made by a firm called Grindturn Engineering of Shrewsbury, I have no other info.

As always Tony Griffith's site has plenty for you
Haighton & Grindtrun Lathes

Seems like a good solid unit - although the grinding wheel seems to have moved to the motor shaft. On the publicity stuff it shows the grinding wheel on the left hand side of the headstock which as Tony mentions on his site was not a particularly inspired decision.

 

[3 LINK]

Thanks Adrian,

That was an interesting read, I thought that maybe the previous owner might of installed that grinding wheel himself, so you learn something new everyday.

I haven’t got a 4 jaw chuck with mine, but I have got a vast range of collets instead which has so far catered for what I need.

All the best,

Martyn.

 

[adrian]

I haven’t got a 4 jaw chuck with mine, but I have got a vast range of collets instead which has so far catered for what I need.

I got a nice range of collets with mine as well and use them almost exclusively, especially for the finer detailed turning. Although the stand they came in was falling to bits so I made a new one. I can do a set of parts for a collet stand if you would find it useful, the holes in the top are 9mm diameter but I could adjust them if required.