Dynamo screws
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Dynamo screws
Could anyone tell me what size the screws are that fit the end of a Lucas dynamo, they hold on a triangular shaped plate (with rounded corners) on the end of the dynamo between it and the inner primary, there are three and countersunk, they look as if they may be 1 or 2 ba ? thanks
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Re: Dynamo screws
Hi
Thread dimensions here if you have the means to measure the thread:
https://britishfasteners.com/threads/
1BA is rather an uncommon size whereas 2BA is very common.
This chap is very helpful if you need replacements:
http://www.ba-bolts.co.uk/index.html
Regards Mick
Thread dimensions here if you have the means to measure the thread:
https://britishfasteners.com/threads/
1BA is rather an uncommon size whereas 2BA is very common.
This chap is very helpful if you need replacements:
http://www.ba-bolts.co.uk/index.html
Regards Mick
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Re: Dynamo screws
They are 5BA for the bearing retainer plate, or should be if original Matchbart.
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Re: Dynamo screws
Thanks everyone, 5ba ? that`s tiny isnt`t it ?
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Re: Dynamo screws
Hi
5BA has a thread diameter of about 1/8"
Regards Mick
5BA has a thread diameter of about 1/8"
Regards Mick
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Re: Dynamo screws
apparently i don`t have a matchless dynamo fitted, so until i get it off and inspect properly i can`t really check the size, many thanks for your help anyway..
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Re: Dynamo screws
Pretty small yup.
There are those with a 2BA (much fatter) draw stud also in the same area (dynamos for our twins, or dynamos fitted to magdynamos for example) but the screws that hold the retainer plate for the drive end bearing on Lucas 3" dynamos should be 5BA as standard.
Unlikely for there to be other than a Lucas dynamo on there I'd have thought. Might not be the exact model as per catalogue, but the variants that will go on a Matchie single are all much the same at the drive end.
An idle query - but do you know you're missing some screws Matchbart? Or do you just want to have everything to hand in case you find you are when you get things apart? (These screws are usually present, although the threads in the alloy end of the dynamo are sometimes a bit knackered. More typically absent are the very specific fixings to ensure the sprocket stays on and can't fall off in the primary chaincase . . .)
There are those with a 2BA (much fatter) draw stud also in the same area (dynamos for our twins, or dynamos fitted to magdynamos for example) but the screws that hold the retainer plate for the drive end bearing on Lucas 3" dynamos should be 5BA as standard.
Unlikely for there to be other than a Lucas dynamo on there I'd have thought. Might not be the exact model as per catalogue, but the variants that will go on a Matchie single are all much the same at the drive end.
An idle query - but do you know you're missing some screws Matchbart? Or do you just want to have everything to hand in case you find you are when you get things apart? (These screws are usually present, although the threads in the alloy end of the dynamo are sometimes a bit knackered. More typically absent are the very specific fixings to ensure the sprocket stays on and can't fall off in the primary chaincase . . .)
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Re: Dynamo screws
there is only one screw left in and its doing its best to escape, i am doing the Beamish Reliability run on sunday and don`t have time to strip and repair before then, so for now it`s bodged and wedged to hold in place,,, it might last it might not, i did 160 miles at the weekend and it was loose for the last 100, fingers crossed, also, i think your right about the alloy /threads being knackered, they may need re tapping , ta
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Re: Dynamo screws
Aah! It can happen ... esp if the female threads are mullered. 5BA insert kits are hard to get I think - but you could go out to 4BA (or a close equiv in metric might be easier) and solve it that way, there's enough monkey metal there.
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Re: Dynamo screws
Where are you in the North East I have BA taps and dies, can't recall the sizes but will take a look.
I did the Beamish a couple of times years ago and it was a load of fun. Does it still stop at Allenheads?
Johnny B
I did the Beamish a couple of times years ago and it was a load of fun. Does it still stop at Allenheads?
Johnny B