Published Commando frame dimensions

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I have been asked to produce a drawing of a Norton Commando for a friend. It will be a direct side view rather like an engineering drawing. I looked on t'internet and found a number of Commando frame drawings purporting to be from a Norton manual for checking a frame for distortion. It has a few dimensions that I thought would be very useful.
However , having created a CAD drawing these dimensions make no sense.
Has anyone verified the source or their accuracy?
Here is said drawing from this forum.
 
I have been asked to produce a drawing of a Norton Commando for a friend. It will be a direct side view rather like an engineering drawing. I looked on t'internet and found a number of Commando frame drawings purporting to be from a Norton manual for checking a frame for distortion. It has a few dimensions that I thought would be very useful.
However , having created a CAD drawing these dimensions make no sense.
Has anyone verified the source or their accuracy?
Here is said drawing from this forum.

Could you be a little more specific than "these dimensions make no sense"?

Ken
 
I'm also a bit puzzled by the question. The frame checking drawings allow you to position the iso mounts relative to each other, & the headstock & frame lower loop.
The missing fabrication dimensions will have to be estimated of measured from a physical example.
 
Apologies if my query was unclear.
The frame drawing proportions look correct but using the printed dimensions produces a much different looking frame. e.g. the 248.92 dimension is proportionally smaller than the 189.2 dimension to the rear suspension top mount position. When drawn to these dimensions the frame is clearly incorrect. I will publish the resulting frame drawing when I have completed it today and I hope you understand my concern.
This would not be the first time I have found "manufacturers" drawings published on the internet to be inaccurate, BSA unit singles drawings are too.
 
The frame drawing proportions look correct but using the printed dimensions produces a much different looking frame. e.g. the 248.92 dimension is proportionally smaller than the 189.2 dimension to the rear suspension top mount position.

The 248.92mm dimension is wrong on the first drawing in the previous thread you quoted because 248.92mm should be to the Iso. mounting hole, as below, not the rear plate hole.
Published Commando frame dimensions


Wrong on the 850 Mk3 drawing:
Published Commando frame dimensions
 
I am unable to load a .jpg image of the drawing. Simple copy and paste does not work.......................help!
 
I posted my plea for help before I'd read L.A.Bs reply. Many thanks for the clarification. It now makes sense.
 
I am unable to load a .jpg image of the drawing. Simple copy and paste does not work.......................help!

Only VIP members can directly upload images, etc.

Non-VIPs must use an image hosting website.
 
I am unable to load a .jpg image of the drawing. Simple copy and paste does not work.......................help!
You either have to host your picture on a separate website, or become a VIP member to paste in a photo directly.
 
The 248.92mm dimension is wrong on the first drawing in the previous thread you quoted because 248.92mm should be to the Iso. mounting hole, as below, not the rear plate hole.
Published Commando frame dimensions


Wrong on the 850 Mk3 drawing:
Published Commando frame dimensions
Thanks to Les' help, I've corrected that error in my edit of the Mk III Workshop Manual. FYI, I found that drawing F4 [this frame drawing] is best obtained from the French version of the earlier workshop manuals. It does not contain most of the errors.
 
IF ONE IS PONCING ABOUT WITH THE FRAME , AS SUCH .

Steel Rods fed through the holes , at least a metre long ( you gettem from the scrap at Alumn. Supplies , silver steel , and other sources )

10 mm for a 'free '3/8 in. hole maybe ? Check First !

This alows you to check for PARRALLEL , lonzenging , radial dislocation ( viewd head on ) and other awsome factors .

Stiff Rods , eyeballing , and ' The Gap '' ( use a stick & shim / wedge ( Scrap bin at buildrs supplies , or the affluent can buy 'ex stock ' )
3/8 or 1/2 Sq even grained straight sticks ! be selective !

The DIAGONELS also are a reqisette . Corner to Corner should match , at the lugs .

Commando Frames are pretty soft . And often not entirely aligned . Len Perry had a Large rubber sledge Hammer . "Just Hold This " ( Commando Frame )
while I 'Align ' it .
The ' S P R O N G 'had me worried about the teeth and other parts , as it tended to react elastically . There are other better ways .
Large Wooden Levers . 6 or 8 foot 4 x 2 s ! ! ! wedgeing , clamping , ropeing the frame to a surface , tree , trees , flat bed truck deck ,
solid door frame or whatevers handy , so long as its sufficently RIDGID . With soft wood ( pine ) packers & pads , one can do wonders.
With patiance & forethought . Unhurridly . Generally its reverse the order of deformation , if its not to healthy .

They're just mild steel tube . Some Italian even .
 
It would be handy to have a frame jig to check all the holes as it is persuaded back or into where they should be
 
This is the frame jig I use for straightening and/or modifying frames. A friend made it, and I just borrow it when necessary. We've used it for a variety of different frames, just making suitable brackets and stands to suit them. I do some of the work right in the jit, and others by clamping the frame to the steel table.

Published Commando frame dimensions


This is a shot of the way I clamp it to the table and do some of straightening, using heat, levers, clamps, and pullers.

Published Commando frame dimensions


Ken
 
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