8 Attachment(s)
Aveling I.C. Model Roller
G'Day All,
I started the build of this 1-1/2" scale Aveling model roller (designed by Edgar Westbury, circa 1938) early 2013. I found a set of copied original drawings from the Model Engineer magazine of the time, while looking for similar drawings for the Aussie built McDonald roller. The original drawings were drawn to be used with a set of castings that were available in the UK & apparently still are available.
I scaled up every sheet that had a drawn component on it & worked out a scale for each drawing from a dimensioned size. Then I drew a set of working drawings to enable all components to be either machined from solid stock or to be fabricated. This took three months to complete & finished up with 65, A4 pages of detail drawings.
As the camshaft is driven via two small spiral gears & this was the first problem to be sorted out. If I could not produce these gears the project would not proceed. Fortunately, I was able to make contact with a brilliant Canadian Modeller, Mr. Allan Suttie who steered me in the right direction as to how to make the two jigs required to enable the gears to be turned by plunging a formed HSS tool bit to depth, producing one tooth groove at a time.
This worked better than expected after a bit of trial & error.
To obtain a suitable tool profile a "hob" like cutter of 0.6 module was made to cut a spur gear to be used to grind the tool bit to a suitable profile.
Attachment 370468
The two jigs (one for 60˚ & one for 30˚) shown below are held in a chuck & presents the gear blank in a position that enables a groove to be cut around the gear blank surface at the correct angle. It's a rather strange motion that the blank rotates through but, it worked.
Attachment 370469Attachment 370470Attachment 370476
The final gears & a little jig to test run them.
Attachment 370473Attachment 370472
Once happy with the timing gears the crankcase/water jacket was started.
The material used for the crankcase was two pieces of 145 x 105 x 25, 6061 Aluminium. The internal cavities milled using both standard & bull nose end mills. A note here, all machining is manually done.
Attachment 370477 Attachment 370478
Regards & will continue,
Don.