Building a ModelWorks 5700 Pannier Tank Engine in 5" Gauge
The reason for the modification is to make it easier to remove the front cylinder covers in order to replace the piston rings. Good modification, it’s a shame however that an addendum sheet was not retrospectively added to Kit 2 for those building on a monthly basis.
The actual assembly was quite easy and straight forward. I have however used some technology for future reference and maintenance. Due to the lack of detailed and dimensioned drawings, before fitting “O” rings and gaskets, I first measured them and using my PC, scanned them. Therefore, should I need to make my own gaskets in the future; I can print the scans and use these as a template.
The bolts supplied for the Piston Rod Glands were too long and had to be shortened. I also discovered during the assembly of the Slide Bars that a couple of M3 x 25mm counter sunk screws were missing. Perhaps we should have counted all the nuts and bolts during our Parts List check?
Now a problem; where in Hertfordshire do I find a shop selling nuts and bolts? Not as easy to find as you might think. Along with ModelWorks and Phoenix I have now discovered my third friendly/helpful supplier:
Like many Model Engineering suppliers they do not carry a full stock of metric nuts and bolts but could in this instance supply 5BA screws and nuts which were suitable. In compensation to the missing screws its worth noting that often an over supply nuts & bolts is not uncommon, providing a nice supply of spares.
Once I had bolted the Slide Bars to the Motion Plate my first real problem was noted. Both Cross Heads became tight towards the Motion Plate. On close examination and the use of tools that had not seen the light of day for many years (verniers and micrometers etc), it was discovered that the top Slide Bars were too tight at the motion plate end by 0.3mm. This was relatively simple to resolve; I hand filed 0.3mm off the top rear edge of the top Slide Bars. I would recommend that if you are uncertain of your skills, then these would need to be machined on a milling machine.
Having resolved the fit of the Cross Heads at the Motion Plate, I then discovered that the Cross Heads were a little tight towards the cylinders. The Slide Bars are easily adjusted using shims between the Slide Bars and Cylinder Covers.
I had a concern with the security of the Piston Rods where they screw into the Cross Heads, not wanting then to loosen during use! Because in the future I will need to remove the Pistons and Rods for maintenance, therefore the use of Loctite is not recommended. I therefore, carried out a small modification to the Cross Heads after having spoken first with Ian from ModelWorks. The modification is the addition of a 3mm grub screw in each Cross Head that secures the treaded end of the Piston Rod firmly (but without damage to the thread).
A note on the Documentation
In principle a good format for such a document. However, at this point I found that sometimes the parts lists are not always correct. Problems found include incorrect part numbers, duplicate part numbers and not all parts required listed.
These issues do not affect every sub assembly procedure, and usually by cross referencing against the full parts list and or drawings, which part/s to use is relatively easy to resolve.
One improvement that would help would be to list at this point which and how many nuts & bolts are required etc. The sub assembly procedures also tend to be quite “wordy”; I recommend the use of a highlighter pen to avoid continually rereading the same sentence.
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