K3s progress 2011
Now the wheels and axles are all in place the spring gear became the next priority.
Spotting the bolt holes in a block of mild steel for a pair of spring hanger brackets.
The K3 was actually done first but this photo is the H4.
Drill the holes
The next series of photos shows the sequence of milling the block to produce a pair of hanger brackets.
A pair of K3 brackets after all the milling work was finished
The inner face of the bracket needs a stiffener attached and one is seen in the vice being prepared.
The stiffener passes to both the sides of the top of the bracket and a slot was carefully cut with a saw and finished by filing
The stiffener has been fitted to the bracket and fluxed for silver soldering
Silver soldering in process
After soldering and cleaning
A pair of K3 brackets finished ready for fitting to the frames
The brackets in position each side of a horn gap
The fixing hole drilling jig attached to the frame for drilling the holes.
Note the pegs for locating the jig in the horn gap
A pair of brackets bolted in place.
The next 2 photos show two pairs of H4 brackets after silver soldering the inner stiffeners. The later engines had different brackets as they were built with longer springs. The original brackets had the fixing bolts each side of the bracket but the later engines had the bolts only on the outside of the bracket as there was insufficient space to use the original brackets with the longer springs.
A pair of brackets during finishing
A pair of brackets after soldering with a pair of finished brackets for the H4
The H4 frames being jig drilled
The frames with the bolt holes completed ready to receive the brackets on one side with brackets fixed on the other and
a similar shot of the K3 with all the brackets fixed shows the differences between the early and later engines.
Some of the K3 brackets helped provide extra rigidity for the frame by having an angle tie bolted to them.
A tied pair in position.
The leaf spring for the locomotives were made in the same way as the tender springs.
The top leaves are different and this shows them for both locos before the addition of the hanger location ribs
This photo shows the method of providing the ribs by silver soldering a split pin to the leaf (left) and trimming to make the bar (right)
Next job was to make the buckles and here six are having the slot milled. Note the paper between the material and the vice jaws to take up variations in the thickness of the stock material used.
Six buckle blanks
The buckles are completed by silver soldering the bottom in to the machined blank.
All the holes are then drilled in the blank including those to form the bottom of the shackle.
The tops were rounded in pairs in the mill.
The sides of the shackle were milled
The shackle was slotted and here are six complete buckles
A completed spring for the H4 temporarily held together with a 5ba bolt.
They will be riveted in the end when I've decided if they really need heat treatment.
May 2011 and the two locos were again exhibited at Harrogate on the TSMEE stand.
Having done a lot of repetitive work on the K3s and finding it was becoming a little tedious, I decided to set them to one side for a while and do something different. Construction of this 21T coal hopper from a kit was supposed to take six months but it actually took nine, but that's another story.
The next instalment on the K3s will start with the swing link pony truck.