Magneto Taper

A_HRD

Well Known and Active Forum User
VOC Member
Grateful if anyone can enlighten me please as to the angle of the Lucas magneto taper? And a related question, is the dynamo taper the same? Assume Lucas K1F/KVF and E3L/Miller D6.

Thanks in anticipation,

Peter B
Bristol, UK
 

Magnetoman

Well Known and Active Forum User
VOC Member
Which according to my maths is about 5.71 degrees, right?
Others beat me to it. Yes, arctan(0.1) = 5.7105932... degrees. The same 1:10 taper was retained for the points cams on "modern" BSAs, Triumphs, etc. For machining it actually makes more sense to set up a taper in this way (i.e. a rise over a run) rather than as an angle.
 

A_HRD

Well Known and Active Forum User
VOC Member
Thanks to all above. Fast and efficient answers and a sharing of knowledge which is typical of this great forum.

Peter B
Bristol, UK.
 

passenger0_0

Well Known and Active Forum User
Non-VOC Member
Others beat me to it. Yes, arctan(0.1) = 5.7105932... degrees. The same 1:10 taper was retained for the points cams on "modern" BSAs, Triumphs, etc. For machining it actually makes more sense to set up a taper in this way (i.e. a rise over a run) rather than as an angle.
Agree.
Another point to note: Please don't use the lathe cross-slide to machine this taper as getting the angle right is next to impossible. Also, it tends to wobble about given the clearance in the dovetail guides. Better to use a taper turning attachment if you can.
 

chankly bore

Well Known and Active Forum User
Non-VOC Member
If you are turning the male taper, make it a freep larger, then lap in with fine grinding paste. Check with blue. If you do this, lemur strength on the spanner-rather than that of any larger or more fractious primate will ensure perfect tightness.
 
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