Entry posted by MinerChris
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This blog entry starts with the entirely predictable “Has it really been six month since I last wrote something,” comment. Well yes it has. Real life it seems has a way of getting in the way of modelling time, that and commuting into London on Mr Branson's 1:1 train set every day.
In that awkward time between graduating and starting the first proper job, I did manage to get some modelling done. This was in the form of one of Mr Higg's excellent replacement chassis for commercial bodies. The body that was donated was a 14xx in lined green livery picked up off an popular auction site. I chose the 14xx in particular as it fitted in nicely with my scenario for Congdon's Shop and it would be useful for the branch service on St Ruth, whilst also making up for the lack of steam on the layout. It also lacks outside pistons which I don't want to tackle just quite yet a I foresee it as another area of problems. I had meant to write something up earlier about the construction of this from an absolute beginner’s point of view but consequently I haven't got around to it.
The chassis at one point was running quite well, albeit on a pure smoothed 12VDC supply and with two white-metal cars bluetac'ed on to give some traction.
A number of things were changed from this early rendition. Firstly the cars were removed as they wouldn't fit under the body. I also changed the way the motor was mounted, replacing the bracket at the front of the motor with brass rod soldered onto the terminals at the rear. From memory I think the chassis went for 4 rebuilds, mainly due to issues with delaminating PCB. I can't remember how many times the wheels were quartered, but it was probably in the tens of times.
You may gather from the title of this entry that the final result wasn't all together successful. I did manage to get the chassis “running,” and the body “fitted,” before St Ruth went to TINGS and consequently it made its show debut there.
Needless to say when the Autotank and Autocoach appeared from the branch, it was promptly followed by the “finger of god,” or an “earthquake,” knock from below the baseboard. Even when the loco was moving the juddering was so violent that at one point it lost its Autocoach. This is the reason why the designation “Vomit Comet,” was applied. The Autotank combination then limped back, disgraced by its builder, to the fiddleyard, where it was replaced by one of these newfangled diseasel thingbob’s. Not exactly a good advertisement of the better running qualities of 2mmFS. It was so bad that I even forgot to get a picture of it on the layout.
The combination has had one other outing of note, to the AGM in Bedford where it accompanied South Yard. It here that Mr Higg's himself looked at it, along with Rich Brummitt and gave me some pointers as to how to improve the running. After this, it has sat in a box whilst I oohed and arred as to what to do with it. Eventually, after was over Christmas, I decided that I had better stop dithering and start to go through some of these suggestions.
I should reiterate that I am not a loco builder, and these practices are probably questionable at best. Those with much more experience would do things differently the first time around. Most of these points seem to have been debated quite thoroughly on the 14 page forum entry.
1. Too much time I spent drinking beer rather than building the engine. Especially a 0-4-2 as a first try, where there is little to no weight.
Well... this isn't going to change now.
2. Rusty Wheels.
Rich's suggestion was to polish the wheels off with Autosol metal polish. I can definitely see the benefit of this as the steel tyres on the association wheels rust extremely quickly, which is catastrophic for the pick-up on this very light engine. Thus the coupling rods were removed and the drivers pulled off the muffs. The sideframes were then un-soldered from the body, (damaging them in the process 
,) revealing the pony wheels to also take off.
The wheels were then placed in a mini drill and the polish put on using a cotton bud, at the same time that the Manor's wheels were done. Now the wheels are safely put away in a re-sealable bag away from moisture until they are needed once again.
3. Bent Chassis.
This really where the tale of woe begins. Once the wheels and sideframes were taken off the chassis, something caught my eye. The chassis wasn't lying flat on the workbench.... a check with a ruler confirmed my fears.
I'm not sure how or where this happened or how, but I am fairly certain that it either happened when the wheel were pressed on the muffs using the bench vice or perhaps an error was made when building the soldering jig.
Worse than this, when the spacers were un-soldered it was found that the etched sides were also as bent as a banana. Surely this was the sign to start again from scratch...
In an effort to save £15, the etched sides were clamped on the baseboard, and lengths of brass rod were soldered onto the sides in a truss like pattern. These are strategically placed in order to avoid the uprights of the soldering jig. The hope is that these brass rods will both straighten the chassis out and make it stiffer so that it doesn't occur again.
Once the soldering jig had been straightened using an set square, the sides were placed in once again, (MK5 remember...) The sides were checked for square-ness by using long lengths of axle steel (~1')
Initially pieces of brass were used to “tack,” the sides together, which allowed for the sides to be removed from the jig. It was then possible to check the straightness again using the ruler before placing the sides back in the jig and soldering the spacer’s onto these. Initially I had used the wider 7mm PCB spacer, however I reverted to the 6.4mm wide spacer. I think that using the wider PCB had caused the ends to splay on the sides due to my ropey soldering.
The narrower strip certainly left much more “tolerance.”
In an effort to reduce the amount of delaminations, I decided to solder the flat spacers in place and then cut the insulation gaps afterwards using a razor saw.
This immensely improved the success rate, possibly as it spreads the heat over a relatively larger area. The downside to this is that there is only one isolation gap rather than doubling up. The vertical spacers were similarly treated however an isolation gap was placed down the middle before emplacement due to the difficulties of putting a razor saw into the chassis.
4. Bearings and Simpson spring's
As I was aware that electrical pick-up was going to be a problem with a light, 6 wheeled engine. I decided to follow the recommendation to fit Simpson springs and completed these to the letter. This basically involved reaming the bearings out to 1.6mm and using the straightened spring wire from couplers. I found this wire extremely fiddly to use, and when the wheels were fitted the wire had lost its springiness and had already bent into the wrong shape. I had replaced this with DG wire which worked well, however to keep the friction low I only fitted these onto each side. I have now replaced these with slightly finer wire, fitted these on all 6 wheels and used a longer length to try and reduce the friction whilst maintaining the springiness.
I have also replaced the bearings on the driving wheels. I know that this shouldn't make any difference under the tolerances of 2mm, however I think that under my loose tolerances it didn't help the quartering.
5. Sideframe Repairs.
The sideframes that cover the rear pony truck are folded up from the etch material and then soldered on, and hence not the strongest construction. The etched spacers were replaced with lumps of brass, cut and filed square before being soldered to the main body. The sideframes will be fixed in place with glue once the pony wheels are positioned and fitted, to avoid damaging the paintwork.
6. Motor Mounting.
Fitting the motor was the subject of many trials and iterations. I chose the flat can motor to use a recommended by Chris. Others that I have spoken to would recommend shelling out for a coreless motor. I am however told that this could be risky with AMR, PWM controllers around.
Perhaps my first mistake was to chop off the wrong end of the spindle as this left the holes for the bolts in the gearbox end of the motor. After trying several different mount configurations I couldn't make one accurately enough to use and maintain electrical isolation. This would definitely be a lot easier if the motor was the other way around.
In the end I have opted to use a solution similar to what was used before. The problem with this is that after painting the chassis, the motor has to be soldered into position. I have probably been lucky once already no to get paint in the motor after soldering it on before spray painting it.
To solve this problem, I have used brass tube soldered to the end of the chassis attached to the side-frame spacer brass. Into this brass tube, appropriately sized brass rod is inserted which is in turn soldered to the motor terminals which creates a socket. Overall this configuration isn't perfect as there is a lot of strain placed on the solder joints on the terminals, however for the occasional fitting and removal this shouldn't be much of a problem. The other problem is that an old bit of rail ticket also provides the insulation between the chassis and the motor body, perhaps not the most elegant engineering solution.
Originally I had used both sides of the gearbox, however I think that this may have been causing an bind in the gear chain. As a lot of other people have done, I chopped the nearside off. With the other end of the motor still supported, there isn’t too much problem with the Motor moving around.
This brings it up to date so far. I think that I am now at the point of having to wait for the weather to break to do some painting, and possibly waiting further to use that etching primer that my dad was using for his manor. There is still much more to do, but I will have to save that for the next entry. Unfortunately that will probably be another 6 months away. 
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