comet cowl

[karl johnson]

hi all.
can sombody please confirm i have got the right part.
the thread on my cowl ( for the bolt that goes through the tab) has stripped.the bolt looks wrong anyway to me. to be sure i have ordered a new bolt by the part no number 589/1ss . on my parts list it is plainly 589 is this correct ? before i send my cowl away for a thread insert repair to match the bolt.. thanks

 

[BigEd]

hi all.
can sombody please confirm i have got the right part.
the thread on my cowl ( for the bolt that goes through the tab) has stripped.the bolt looks wrong anyway to me. to be sure i have ordered a new bolt by the part no number 589/1ss . on my parts list it is plainly 589 is this correct ? before i send my cowl away for a thread insert repair to match the bolt.. thanks

You will usually find that an item in the original spares list has been renumbered with a /1 added to indicate a revision. The revision in this case is /1ss to indicate it is the same part (589) now made in stainless steel.

 

[Bazlerker]

Mine stripped a few years ago..a whitworth helicoil provides for a repair that's better than new..install the helicoil with a healthy buttering of red loctite

 

[A_HRD]

Karl,

There might be some confusion if you are looking at the VOC Spares Co listing. 589 is a 1/4BSF x 5/8 long hex setscrew (which has a thread all the way to the head). The description is correct, however, the photo shows it (wrongly) as a bolt. This 589 hex setscrew is the one you want. But you could also use 572 which is 1/8th longer and will likely give you extra thread engagement.

589/1 is the same dimension except that it is a bolt (i.e. it has a plain shank near the head). It is the preferred item to use when fixing the rear sprocket to the drum (10 off) - and also use 413 (1/4 shake-proof washers) under the associated nuts; they were used by the factory for good reason (but missing from the printed Spares List). Personally, I continue to use 589 in this application made from cold-forged 304 stainless which has a higher tensile and shear strength than the EN58BM (303) which tends to be used, by some, to make the 589/1 bolts.

All that said, for your alloy Comet Mag Cowl, a wiser engineering solution would be to do what Bob says and have it helicoiled with a 1/4 BSW thread which is coarser and deeper, hence more suited to use in alloy. In which case, a 279 would be perfect! All those part numbers mentioned have an ss suffix meaning they are made from stainless steel.

I know, I should remove my anorak and get out more…..!!!

Peter B
Bristol, UK.
STILL WANTED: Series A Front Frame

 

[clevtrev]

Makes no difference if you use Whit or BSF, the load is now on the helicoil, not the alloy.

 

[karl johnson]

thanks for reply again guys your,e all