Perfectus Airscrews for Silver Biplanes

Nico – no ‘levering off’ unless you want to do yourself some damage. Tools are placed on a tool rest and wood is pared (shaved) off. 

Oracal, thank you for the id on the tool. Nicko, no need to log on to another, just leaving some breadcrumbs for a future lurker in case they want to follow the topic on a more detailed and specialist site. The dH108 could only be improved with a fixed pitch timber prop, but some would disagree! 

Thanks Oracal. So I gather the operator uses the chunky blunt bit to lever off to get some pressure on to the cutting tooth.

I suppose, Ed, that if propellers were one of my core interests I would already have a log-in for that forum: shame about having to have yet another log-in to view pictures!

The q. re the Zenford item. It’s a lathe cutting tool for working wood.

Prop glueing bench and clamps

Updates on this subject are posted on the woodenpropellor.com site under Design. Does anybody know what this tool is used for? 

Very large and very small hub tooling. Some hubs are readily identifiable ‘Bristol 10 hole’ for RAAF and airliner Bristol Jupiter applications like dH 66 Hercules, Westland Wapiti and Bristol Bulldog, some need to be matched to engine candidates such as Gypsy Major or AS Genet and AS Cheetah, all in good time. 

After sandblasting, dimensional information  and tolerances reveal themselves

Blade profile checking templates for ‘Gypsy III’ 

what an excellent discovery of early aviation manufacturing artefacts

Oracal, a fantastic document, thank you. The apparatus seems functional for a simple blade of fixed aerofoil section, but not sure how it would handle twist or varied aerofoil sections, which were evolved by the 30’s and for 40’s aluminium blades. I could do a Fairey-Reed type, prior to giving it a twist. A great document to see. The journey was not done on a whim, but a bhim, which is a combination of bet and whim, based on probability and confluence of domestic duties and geography. I had to take the kids to a rural camp, so this was a Dad treat – diversion on the way back. The skill of combining domestic duties with treasure hunting is sadly under appreciated as an Olympic sport, but most effective aerophiliacs would be up there on the podium, I reckon. 

Ed, was the journey of discovery done on a whim?

Time to share the contents of AP 472 / Air 10/487 at TNA.

Fantastic!

Absolutely fascinating!

These are the arms from a suspected 4 bladed test club marked ‘Bristol Hercules’. Each arm is approximately 5 foot high and as thick as an elephant’s leg. It would make a huge test club, worthy of a 1,000 HP test rig. Perhaps it could be used for the current craze for indoor sky diving centres. The evidence of Kestrel hub drilling jigs and a Bristol Hercules test club suggests the ‘Ellis-o-Matic’ was capable of duplicating very large propellors, as much as for more modest applications like the Tiger Moth or Avro Cadet used for training. This contraption is currently in pieces, and as the months go by I will try and share progress with its reconstruction. One day, there I will be, smiling, with bloody stumps for hands! 

Rust to some, but hub holding and drilling jigs to others. The holding tool fits in an old Hawker Demon propellor, and the drilling jig matched the Hawker Demon hub plate. From 1935 to 1943, the RAAF operated Demons as part of the Empire Air Training Scheme, and the typical photo from the period is a Demon nosed over, with smashed propellor. The reduction gearbox mounting flange on the Rolls Royce Kestrel engine block is typically bent back on Australian Kestrel engines, as the aircraft were patched up and passed onto the next hopeful trainee. The Shuttleworth Hind flew on a donated Australian powerbank with this feature, as an antipodean giveaway. Perfectus would have been busy making countless replacement blades. 

‘Ellis-o-matic’ duplicating blanks. The ‘half’ was enough, as the ‘work’ could be turned around to cut the other side. Some of these are Tiger Moth and Gypsy Moth, with hints at pitch and dimensional variations. That these survived is a minor miracle. 

If you have driven for miles, neglecting hamburger stops and even the sideways glances of the dog as promising opportunities to sniff and mark new territory flash by, you get reasonably to the point at the destination. It is not my policy to ‘nickel and dime’ custodians of treasure. I respect the overheads and alienation of capital incurred by holding stock and probably resisting sudden weaknesses like the urge of scrapping and burning slow moving merchandise. If a bloke has protected something, he should know what has been saved. He should be reasonably rewarded, beyond the satisfaction of being a matchmaker, and seeing a form of love flourish, that is understood without being spoken of, that makes one man’s rusty junk another’s glad mistress. And so I directly asked if he was holding the key to the treasure chamber of Perfectus, and the immediate answer was ‘Yes’. As in all these worthwhile things, the custodian knows exactly what he has, and exactly where every scattered part is shoved and hidden. In fact he had tried to buy it in the 90’s, but it eluded him, as a cashed up dentist took a shine to making ornamental display propellors, and had more wherewithal back then to transact. This was good, at least. There were no mad chimpanzees smashing Perfectus into matchwood and loading scrap bins when the factory closed. Each piece was taken carefully away. The ornamental propellors never happened and the dentist passed on to where all milk teeth go, but at least Perfectus remained, somewhere, waiting. The current custodian came serendipitously upon it when the dentist era ended, and had the reward of getting what he could not get then, like a frustrated schoolyard romance finding its second legs in a divorcee date club. He had loaded it all up and brought it to its rural rest, where it was known and tended for, and became the stuff or shifting plans and gathering dust, but never at risk of loss. And so a new custody was arranged, from one tired old knight to fresh blood, understanding the awful responsibility of custody, but keen to get things done. So here I will share the cataloguing of what was in the tomb, and, over time, its careful burnishing and reconstruction, God willing, to see the light of day. I am fascinated to reconstruct the ‘Ellis-o-Matic’, as I call it, the custom duplicating machine. It has, I now know, a bloodthirsty, unguarded router at its core, guaranteed to slice the hands off a Millenial, unaccustomed to steam age things. It is a crime to hide these things. Folks must know how things were done. Each treasure lost in grim, dark storage is a victory for those who might rant at an internal combustion engine as a thing melting glaciers and suffocating helpless penguin chicks in petroleum vapours. We must get this stuff out and working, give a whole new generation a chance to swing a prop and feel the wind against their cheek. Make the connection to even grimmer times, of fascist armageddon, when just ‘getting on with it’ and imaginative enterprise saved the day. It is duty. 

Now there is a little country town in Australia that barely deserves the description of a town. It is loathed by tough cattlemen because it does not even have a pub, and there is nothing to suggest to the driver lost from the closest main road that there is anything to stop for. Just a decrepit flash of rusty, weedy buildings that might house suspicious country folk with guns, and lost willows gripping yabby holed, eroded creek banks teeming with hungry snakes. And it was into this rural idyll that Australia’s pre-eminent diviner of lost aeronautica drove into, perchance, and being equipped with more eyes than a fly spotted an old sign suggesting an antiques store. Prudent folk would not stop. To preserve the mystique, we shall call him ‘The Baker’. Now the Baker followed the sign, like some doomed sailor in thrall of sharp toothed Sirens, following an unpromising, dusty track to a building that might sustain a conspiracy to dismember lost strangers.  First appearances can be unfair. For inside was a most courteous proprietor, with a treasure trove of delightful, quality merchandise, procured from quality foraging. “Do you have any aeroplane stuff?” the Baker asked, after preliminarily courtesies were fulfilled. “Yes”. And so the Baker became Howard Carter, and so the old shed became the tomb of Tutankhamun, for those concerned with the matter of Perfectus. Like all treasure tombs it was not obvious, in the first gloom and dishevelled debris of old tin cans, matronly furniture and rabbit traps, that pure gold lay in careless abundance, but it was enough for the instincts of the Baker to be aroused. There were old timber propellors stacked on a dusty shelf. Not propellors, mind you, half propellors, awkward and disappointing for a ditzy interior designer to display as a conversation piece on a wall, but obvious to the Baker that they were patterns, from some forgotten atelier’s workshop. The Baker is more of a WW2 variable pitch prop kind of guy, but sufficiently tutored to make accurate, scientific observations, and connect these with a network of grasping, desperate collectors like me, as individual bias of the client base suggests itself. In the analogy of Egyptology it was a tomb, but of a Prince or pauper, to the Baker, unknown. The Baker, as is the method, safely returned, and later conveyed this information to me, and the hairs stood on my neck. By gentle compliment, then pleading, then threat, then begging, the coordinates were given to me, and I instantly mounted an expedition, as by context of history, geography and faint pencil sketch, this could only be Perfectus, or at least some equally promising interloper, like a Larkin or 1960’s clearout of a hitherto unknown artist. I have been in the game long enough to know that each slender rumour must be followed through, because for every dozen disappointments, there are crowning peaks of discovery to be made, that reward astonishingly, and turn the foolish expedition into the sublime moment. So the dog and I loaded ourselves into the ute, and set out on the road.