building custom chopper frame

[Chris Stevens]

I guess robots are a step up from old hearth brazed ERW Brit frames, with the lugs held in place with nails? Seriously though, Jap frames may not look pretty, but do seem to work relatively well.........................

 

[normspanners]

Interesting I thought they were all 531.

The Featherbed name[edit]
Harold Daniell was a successful Isle of Man TT racer with three victories and several placings in the Tourist Trophy races and the Manx Grand Prix.[10] After testing the new Norton frame in 1950 he declared that it was like "riding on a featherbed" compared with riding the "garden gate[11]" — and it has been called the featherbed frame ever since.[12]

The term feather bed was used in the 1933 to 1938 Brough Superior catalogs in their press section. As printed in the 1933 Brough Superior catalog:

The "Brough Superior" Rear Spring Frame, to quote "Castor" of "Motor Cycling," renders "pitching or wobble non-existent, impossible. A feather bed could scarcely be safer" -- and this in relating his experience on a Special "Brough Superior" S.S. 100, on which he did 106 m.p.h. in second gear on the road ![13]

Racing success[edit]
Further testing took place at Montlhery race track with four motorcycles running flat-out for two days. The new frame stood up well to tests and saw its UK launch at Blandford Camp in Dorset in April 1950. Geoff Duke had won the Senior Clubmans TT and the Senior Manx Grand Prix in 1949 on the earlier type Nortons, so was a clear choice for Norton to really put the new Featherbed-framed race bikes to the test. Duke won the race on the new design and several racing successes followed with Norton winning first three places in the 1950 Senior and Junior TT's.[8] In the Friday Senior TT Duke set a new lap record of 93.33mph and also broke the overall race record, finishing in two hours, 51 minutes and 45 seconds; he had previously finished second to Artie Bell (Norton) in Monday's Junior TT. (Harold Daniell's Norton was third.) When it came to the bends on the twisting Island course the new frame gave the Nortons a distinct advantage.[7]

Featherbed frames were also successfully modified for use in off road racing or motorcycle scrambling.[14]

Featherbed variants[edit]
Manx racer in Reynolds 531[edit]
Weight and strength were key factors in the design of the featherbed frame for the Norton racing team's Manx. 16- Gauge Reynolds 531, a high-tensile manganese-molybdenum steel alloy, was used as it allowed the frame tubes to be made thinner for the same strength, as well as making for a more responsive frame. All the joints were Sifbronze welded,[15][16] – a relatively low-temperature flame-braze – except for the sub frame which was initially bolted-on but welded in later versions.[17]

Norton International[edit]
In 1953 the Norton International was relaunched with a new version of the Featherbed frame made from grade A mild steel.[18]

Single and Twin cylinder roadsters in Featherbeds[edit]
Having earlier installed the Dominator twin-cylinder engine of 500 cc and 600 cc, in 1959 Norton put the old single cylinder Model 50 (350 cc) and the ES2 (500 cc) into the Featherbed frame to rationalise production. Using grade A mild steel, the size of this engine determined the space between the top and bottom rails of the full duplex cradle. In 1960 the top rails were installed at the rear of the tank.[19] Riders complained that these wideline Featherbed frames were uncomfortably wide at 11.5 inches (29 cm) but it was not until 1960 that the top runs of the frame were narrowed towards the front of the seat, with corresponding overall styling changes including tank and seat to create the slimline frame.

The slimline was used until the last of the vertical twin cylinder models in the late 1960s, the Norton Mercury, a limited-production run of single carburettor 650 cc machines based on the Dominator;[20][21] the Norton Commando with its new frame design and angled-forward engine having been launched at the Earls Court show in 1967 took over as the 750 cc range-topper, later enlarged to 830 cc, but badged as '850'.

 

[normspanners]

Does anybody remember Mike Hailwood fitting the 500 honda 4 in a featherbed coz the honda frame couldnt handle the power.
But honda stopped him coz it was bad for their image.

 

[ronan]

Honda 500 ? pah ! I raise you Rover v8 !

 

[slim_boy_fat]

^^ That must be one of the worst YT videos ever......

 

[Robotstar5]

^^ That must be one of the worst YT videos ever......

I just got the usual black square as Firefox won't install flash player

 

[ronan]

^^ That must be one of the worst YT videos ever......

I posted it slim-boy and i agree with you, its shocking, but the only vid i could find with the river lump in the featherbed frame. I do have pictures of a hillman imp engine in the featherbed and it is sweet. Will post them later.

 

[Robotstar5]

In that case I would assume the robot gets programed by a competent welder and that the welds are inspected periodically as part of a QA system to ensure standards stay high.

Most modern robot welding systems will monitor the welds and flag an alarm or stop when it detects an out of parameter weld. When I was involved in automotive welding each assembly/sub-assembly would be visually checked and welds would be routinely macro tested, results have to be kept for quite a few years for trace-ability. Most modern auto manufacturers and suppliers work to TS16949 not sure if motorcycle manufacturers have their own version.

I did a robot welding thread here should give you an idea how they work.

 

[normspanners]

river lump in the featherbed frame.