Further facinating progress in the build of Eddie Gibbons K3 and H4
A last machining operation on the axleboxes was to profile the bottoms Set of six axleboxes on a copy of the working drawing
A driving box in place in the guide A temporary axle was made to check the alignment of the axlebox pairs when
fitted in the guides. A bit of careful filing and scraping corrected the fit
Both sets of frames with the axleboxes in place A coupled axle in the lathe between centres for rough machining
A toolmakers clamp on the lathe bed provides a back stop whilst reducing the centre of the axle, The head end of the machine has a saddle stop.
A journal being finish machined A pair of axleboxes on an axle
Coupled axles in place on the frames A crank web bored for the axle and crank pin and the keyways broached
The axle drawing with revisions over several years as the project developed on paper. Roughed out driving axle ends ready for machining of the keyways
Keyway machining Axle stub with finished keyway
Axle stubs and crank web blanks Machining a pair of crank webs (1)
Machining a pair of crank webs (2) Machining a pair of crank webs (3)
Machining a pair of crank webs (4) Machining a pair of crank webs (5)
Finished crank webs ready to receive axles and crank pins Crank web with axle end pressed in after facing off
Crank axle being Drilled for dowels Keyways to crank pins being machined
Crank pins with keyways ready for finishing and final assembly by pressing into webs Crank pin after pressing in to web
Assembled crank axle Crank axle set up on rotary table for drilling dowels
Assembled and dowelled crank axles ready for finish machining A crank axle set up between centres for final machining.
Note the wheel seats are left oversize until the wheels are bored.
As these are a taper fit, once the machine is set to cut the tapers the wheel seats
and the wheel bores are finally machined to the same taper setting.
A driving wheel casting set up for facing the back Facing in progress
A wheel set up for boring. The centre is located by measurement from the inside of the wheel rim.
As this may not be truly circular some judgement is required on determination of the best location.
Starting the bore Drilling the bore Boring in progress
Once all the wheels are carefully bored to the same diameter a mandrel is made to fit in in the lathe spindle taper and used to set up the wheels for all further machining operations in the lathe and on the rotary table on the milling machine. A wheel is seen set up for facing.
Facing the tyre Facing and profiling the centre
Machining the inside edge of the tyre.
Note at this stage there was no intent to fit steel tyres. That came later. Machining the groove at the balance weight
Chamfering the edge of the balance weight Rough machining of the tyre profile. Final profiling should be done after
the wheels are pressed on to the axles to correct any run out that may develop
Back in the milling machine for rounding the back of the spokes. The wheels were reversed and the front of the spokes were also machined with a radius cutter. The spokes as cast were not perfectly regular in spacing and thickness and had some casting defects. Whilst time consuming the end result is a great improvement on the original cast.
The final operation was to finish the spokes by hand with a round file. A typical casting fault in a spoke
An epoxy metal filler was used to finish the wheels where machining had not completely removed the defects.
After curing the filler is easily smoothed by hand with a file
The wheels were then returned to the lathe, trued using a dial test indicator on the tyre and bored to a taper of 2 thousandths of an inch in the wheel thickness.
Once the wheels were bored the axles were returned to the machine and the wheel seats were machine to the same taper such that
the axle would enter the wheel bore by a third of the length of the seat.
When the wheel was pressed home this gave an interference fit of 1.5 thousands of an inch, a little over the recommended thou per inch.
An offset mandrel was made and fitted to the face plate for boring and reaming the crank pin holes.
The holes were started with a centre before drilling And finished with a reamer.
A jig was made up to hold the broaching guides for the crank webs and this was modified
and reused for the wheels to ensure the axle keyway was exactly in line with the crank pin centre.
A setting block was used to align the broach guides The wheel press was used to drive the broach for the keyway
The coupled wheel crank pins ready to be for pressing in to the wheels. The driving crank pins were made as a pair and one is seen having the
keyways cut using a between centres set up in the milling machine.
The rotary table was used to set the angle for machining the square for the
return crank, accuracy being essential for correct operation of the valve gear. The crank pins machined and ready to be separated
The same between centres set up in the milling machine was used to cut the keyways in the axles.
These needed to be accurately machined at 120 degrees so the cranks would be "quartered" as the wheels were pressed on.
Cutting an axle keyway The other end after rotating the axle 120 degrees
The wheels are fitted to the axles with the keys on place and put in the wheel press. They should press on equally confirming the press fits are the same.
The crank axles need setting up carefully in order to get the correct relationship between the centre and outside cranks.
The wheel sets all complete save final profiling of the tyres and fitted in the frames.
Making the wheel sets took until November 2010, about 9 months from starting.