Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Lifeboats => Topic started by: dpbarry on December 10, 2017, 07:32:53 pm
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Hi guys.
What the best way to convert bolthead sizes to scale?
On the Mersey lifeboat, the engine hatch covers are 17mm bolts and looking to convert them to 12th scale.
I’ve looked at a couple of conversion tools and read Alan Robinson’s excellent article on his Mersey build (courtesy of Gregk9)
Alan mentions 12BA nuts and pins - Not sure why he didn’t go with the actual bolt though. Mind you, the article was 13 years ago.
Any assistance greatly appreciated
Declan
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17 divided by 12 =1.416mm ?
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No such thing as a 17mm bolt. 17mm refers to the measurment across the flats - AF.
So 17 ÷ 12 = 1.4mm, therefore, 1.4mm AF = 16BA.
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I’ll check the bolts tomorrow night when up at station. I just did a rough measurement using a ruler across the flats so assumed it was a 17mm bolt(probably describing it old style by spanner size)
Having read up a bit more I gather its an M10 bolt wich uses a 17mm spanner. Will check better tomorrow night. ok2
Declan
No such thing as a 17mm bolt. 17mm refers to the measurment across the flats - AF.
So 17 ÷ 12 = 1.4mm, therefore, 1.4mm AF = 16BA.
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don't confuse the bloke AF (American size) has nothing to do with metric 17mm =slightly over 5/8AF
David
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Don't confuse the bloke.
17mm =slightly over 5/8AF
??????????????
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If we really want to confuse him, we can start quoting either ISO and ANSI bolt sizes, or Japanese sizes which are all different from the normal standard DIN, which is what we commonly use.
4mm dia = 7mm spanner size
5mm dia = 8mm spanner size
6mm dia = 10mm spanner size
8mm dia = 13mm spanner size
10mm dia = 17mm spanner size
12mm dia = 19mm spanner size
16mm dia = 24mm spanner size
Substituted AF (across flats) to spanner size to avoid confusion.
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{-) {-)
I'll just take my trusty roll of spanners up with me tonight and see which one fits then sort the conversion out.
I thought model making was supposed to relieve stress.. not add to it! :} :}
Declan
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I use stainless steel pins as screw heads at 1/12, just file a line across the top for the slot then drill 0.8mm hole - insert pin.
metric bolts- the diameter of the head across the points is twice the thread diameter.
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You will find that it is 1.8 not 2.
Declan, pop a spanner on, divide by 12 and you will get your scale size, it is as simple as that. Hardest part will be finding stockist of that size.
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Cheers.. :-))
Will do. Heading up to Station later on so will let you know how I get on. Have spoken to Adrian from Speedline models to see if he has any of the dummy bolt heads.
Declan
You will find that it is 1.8 not 2.
Declan, pop a spanner on, divide by 12 and you will get your scale size, it is as simple as that. Hardest part will be finding stockist of that size.
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Hi,
Has anyone resolved the issue whether the 1/12th Mersey model are what model BA or mm bolt sizes? for the main superstructure access patches?
Regards,
Rich
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If we really want to confuse him,
Substituted AF (across flats) to spanner size to avoid confusion.
why wish to confuse people, I always like to find things as simple as can be.
also, I always thought and was taught that AF stood for American Fine...........has it been reassigned as an acronym since my school days.
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AF = across flats, always has been always will be.
Spanners marked with AF on, are used on UNC/UNF, UNified Course/UNified Fine........American threads.
Now that is simple.
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https://model-motorcars.myshopify.com/collections/small-parts-hardware/bolts
Well worth a look through their websites, with models like this.
https://www.modelmotorcars.com/whats-new/the-duchess/
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Some great info but we still haven't nailed the original question even though it might be lost in transmission. {:-{
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Digging this chestnut up again cus i'd like to check defore i commit to purchase
As mentioned, 17mm across flats at 1/12 scale comes out at roughly 1.4mm
Applying this to:
https://knupfer.info/shop/index.php/deutsch/modellschrauben-messing/messing-hoher-kopf/301-10-05.html
Is this roughly the right size of bolt i should purchase?
I know they dont have a 1.4mm. They have either a 1.3 or a 1.5mm
https://knupfer.info/shop/index.php/deutsch/modellschrauben-messing/messing-hoher-kopf/301-08-06.html
Declan
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Declan......Knupfer are great people to deal with & have what you want O0
From the page you show, click on Brass Low Head .......amazing........1.4mm brass hex bolts.....check the AF size, the when you look for 1.4mm hex nuts try Model Sizes
There you will find the correct AF sized nuts....
[Knupfer probably term AF [across the flats] as SW which I assume is a German Technical word :o for the same measurement]
Merry Christmas
Derek
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Cornwall sell the Amati ones, including M1.4, and they also do an M1. See attached www.cornwallmodelboats.co.uk/cgi-bin/sh000001.pl?WD=bolts&PN=Amati-Brass-Bolt-with-Nut-A4960_10.html#SID=1317 :-))
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Hi Derek.
I think that is where I'm getting a little confused.
The 1.4 has a SW (AF?) of 2mm whereas the 1.0 has an SW (AF?) of 1.5mm (0.8mm give an SW of 1.3mm)
In order to keep with the 12th scale of 17mm/12 to give a 1.4mm (AF), should I be looking at the 0.8mm or 1.0mm bolts at knufper.info to get the 1.4mm scale?
Declan
p.s. Merry Christmas to you and everyone else :-))
[size=78%]g706571#msg706571 date=1607306795][/size][/font]
Declan......Knupfer are great people to deal with & have what you want O0
From the page you show, click on Brass Low Head .......amazing........1.4mm brass hex bolts.....check the AF size, the when you look for 1.4mm hex nuts try Model Sizes
There you will find the correct AF sized nuts....
[Knupfer probably term AF [across the flats] as SW which I assume is a German Technical word :o for the same measurement][size=78%]
Merry Christmas
Derek[/size]
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Cheers TonyH
As per my last post to Derek, just trying to work out which is the correct bolt.
Seems like the M1.4 refers to the thickness of the threaded part and not the head size. As per their website details, it refers to the wrench size as being 2mm whereas the M1.0 refers to a wrench size of 1.5mm. The M0.8 refers to a wrench size of 1.3mm :-))
Declan
Cornwall sell the Amati ones, including M1.4, and they also do an M1. See attached www.cornwallmodelboats.co.uk/cgi-bin/sh000001.pl?WD=bolts&PN=Amati-Brass-Bolt-with-Nut-A4960_10.html#SID=1317 (http://www.cornwallmodelboats.co.uk/cgi-bin/sh000001.pl?WD=bolts&PN=Amati-Brass-Bolt-with-Nut-A4960_10.html#SID=1317) :-))
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Roymech lists common bolt dimensions amongst HEAPS of other engineering stuff. I guess you'd just divide by scale then find the closest size from available stock that gives an OK hex size for you? You may end up with a very small Mx size...
https://roymech.org/Useful_Tables/Screws/Hex_Screws.html
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Hi Declan,
you are right: M1.4 refers to the thickness of the threaded part, not to the head size. SW in German means ‚Schluesselweite‘ which is AF in English (across flats).
Hope this helps, Knupfer have good quality products and deliver fast, but not cheap.... I have ordered a lot of times from them.
Kindest regards from Germany,
Arno
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Cheers Arno. :-))
Declan
Hi Declan,
you are right: M1.4 refers to the thickness of the threaded part, not to the head size. SW in German means ‚Schluesselweite‘ which is AF in English (across flats).
Hope this helps, Knupfer have good quality products and deliver fast, but not cheap.... I have ordered a lot of times from them.
Kindest regards from Germany,
Arno
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don't confuse the AF (American size) has nothing to do with metric 17mm =slightly over 5/8AF
David