Hi All,
Warning! there are images of off piste British quality machine tools on this thread.
I had decided to put together a compensator shaft assembly for a Vintage Bentley of the 1920`s. In my opinion the WO Bentley design for this fully compensated mechanical brake compensator is the best design that i`ve ever seen for a mechanical brake system and it works!
![Click image for larger version.
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Above is a partial image of a layout of the Bentley compensator taken from an original Bentley factory drawing. The basis of the design involves three whiffle tree sets of levers which compensate the braking force from side to side and front to rear.
![Click image for larger version.
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Above is shown the kit of parts that i`d assembled several years ago. The levers had been cast in steel by means of the lost wax process instead of being forged from steel ingots because the original forging moulds had been lost or scrapped when the company went into liquidation in 1931. I`d already had the parts machined that were beyond the capacity of the machines in my workshop by my friendly machinists in Coventry. There was still a lot of machining to be done on the levers and that was the work that I started off with.
![Click image for larger version.
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Above my gorgeous little ex school workshop Raglan vertical milling machine which was built by Myford when they bought out the Raglan machine tool company in the 1960`s. The design has the unique feature that the column is cast in aluminium and the dovetail for the vertical movement of the slide is bolted onto the front of the column. You may think that this is a bit suspect, but no, the large column which houses the variable drive pulley system is actually a very rigid structure having a very favourable moment of inertia and perfect for the job that it does on this small machine. (Ross please note that machines don`t have to be heavy to be rigid, It`s all in the design)
The boring bar is a beautifully made tool by precision engineers Arrand Engineering based in Leicestershire which I had bought from the factory during a visit there many years ago. Shown is the long lever being bored to within a few thou of the required diameter to be finished off to size later with a David Brown adjustable reamer.
![Click image for larger version.
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Above, another ex school machine that had seen a lot of action, my Boxford VSL 10 inch swing lathe, this was the top model of this generation of Boxford precision lathes, It no longer warrants the "precision" label but is still ok for general machining. Here we can see the lathe roughing out a lever ready for boring.
![Click image for larger version.
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Above, some of the parts that have roughed out and the super quality David Brown adjustable reamer that was to be damaged later!
That`s my five images used up so that i`ll have to continue in the next post, stick with this thread as I promise that it has an interesting and useful conclusion.
Alan
Warning! there are images of off piste British quality machine tools on this thread.
I had decided to put together a compensator shaft assembly for a Vintage Bentley of the 1920`s. In my opinion the WO Bentley design for this fully compensated mechanical brake compensator is the best design that i`ve ever seen for a mechanical brake system and it works!
Above is a partial image of a layout of the Bentley compensator taken from an original Bentley factory drawing. The basis of the design involves three whiffle tree sets of levers which compensate the braking force from side to side and front to rear.
Above is shown the kit of parts that i`d assembled several years ago. The levers had been cast in steel by means of the lost wax process instead of being forged from steel ingots because the original forging moulds had been lost or scrapped when the company went into liquidation in 1931. I`d already had the parts machined that were beyond the capacity of the machines in my workshop by my friendly machinists in Coventry. There was still a lot of machining to be done on the levers and that was the work that I started off with.
Above my gorgeous little ex school workshop Raglan vertical milling machine which was built by Myford when they bought out the Raglan machine tool company in the 1960`s. The design has the unique feature that the column is cast in aluminium and the dovetail for the vertical movement of the slide is bolted onto the front of the column. You may think that this is a bit suspect, but no, the large column which houses the variable drive pulley system is actually a very rigid structure having a very favourable moment of inertia and perfect for the job that it does on this small machine. (Ross please note that machines don`t have to be heavy to be rigid, It`s all in the design)
The boring bar is a beautifully made tool by precision engineers Arrand Engineering based in Leicestershire which I had bought from the factory during a visit there many years ago. Shown is the long lever being bored to within a few thou of the required diameter to be finished off to size later with a David Brown adjustable reamer.
Above, another ex school machine that had seen a lot of action, my Boxford VSL 10 inch swing lathe, this was the top model of this generation of Boxford precision lathes, It no longer warrants the "precision" label but is still ok for general machining. Here we can see the lathe roughing out a lever ready for boring.
Above, some of the parts that have roughed out and the super quality David Brown adjustable reamer that was to be damaged later!
That`s my five images used up so that i`ll have to continue in the next post, stick with this thread as I promise that it has an interesting and useful conclusion.
Alan