Alan Gibson crankpin nuts

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Captain Kernow
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Alan Gibson crankpin nuts

Postby Captain Kernow » Wed Jun 03, 2020 9:38 am

Although I've had my fair share of experience of using Alan Gibson wheels and their associated crankpin nuts, I've always found them awkward and time-consuming to fit and (especially) to remove.

I am currently fault-finding (and hopefully repairing) an 0-6-0 owned by a friend (and built by someone else), which will probably require the rods to be removed.

Before I go back in there with my pair of flattish jawed pliers, I was just wondering if others had a better suggestion or knew of some other, easier method?

Many thanks.
Tim M
Member of the Devon Riviera Area Group.

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zebedeesknees
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Re: Alan Gibson crankpin nuts

Postby zebedeesknees » Wed Jun 03, 2020 10:16 am

Like several of us it seems, I've been doing quite a lot of this lately.. I use flat jawed Mauns to take them and the softer brass Ultrascale ones off with no visible damage. To get them on, I use a wooden kebab skewer with a blob of Blu Tack on a cut end, and a final tightening twist with the Mauns. As soon as the wheel moves with the pliers - stop!

Ted.

philchudley
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Re: Alan Gibson crankpin nuts

Postby philchudley » Wed Jun 03, 2020 10:23 am

I am trying out Markits de-luxe crankpins on my latest project, a Manning Wardle "I" Class

The are fitted from the front of the wheel and the crankpin has a 10BA thread, which attaches to the boss of the wheel which can be tapped accordingly, The crankpin nuts appear to be the same as Alan Gibson.

Both the crank pin and the crank pin nuts, which also act as the bushes are fitted / removed with the Markits nut screw driver (the one with a BA nut attachements) I have so far found these much easier to use than the Alan Gibson and easier t get at 90 degrees to the wheel.

On mine, they did project a little through the back of the wheel, but easily fixed with a file.

The crankpin nuts / bushes are all on one length roughly the same length as the longer crankpin bush by Alan Gibson

I got my crankpin nuts and screwdriver etc from RoxeyMoldings and I received them within a week, despite the lockdown.

Phil

DougN
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Re: Alan Gibson crankpin nuts

Postby DougN » Wed Jun 03, 2020 11:04 am

The easiest way to deal with the crankpin nuts I have found is a clutch pencil. This has 4 jaw arrangement to hold the graphite which is about 2mm in diameter similar to a pacer propelling pencil but a lot larger in size. A decent stationers may have them but a architects drafting supplies should have them. I have 2 of these pencils now, one is a staedler that I use for the crankpin nuts. The easiest way to "grab" the nut is to have it flat on the desk and then with the jaws fully extended capture the nut. https://www.draftex.com.au/product/draf ... pencil-2mm
The above link is to one supplier of the pencils.

They are a lot cheaper than when I bought one for uni all those years ago and I think I have used it more as a crankpin nut spanner than as a pencil!
Doug
Still not doing enough modelling

FCA
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Re: Alan Gibson crankpin nuts

Postby FCA » Wed Jun 03, 2020 11:27 am

I use a pin vice of suitable capacity.Hold the nut on a reamer and grip with the pin vice parallel to the face.

Richard

Enigma
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Re: Alan Gibson crankpin nuts

Postby Enigma » Wed Jun 03, 2020 12:07 pm

I use the pin chuck method or occasionally a toothpick, slightly blunted, with a dried out bit of Evostick on the end, sufficiently sticky enough to hold it through the hole while starting the thread. I don't tighten the nuts fully as I find that this locks the bush to tightly. I allow a (very small!) bit of slack so that the bush can rotate somewhat with the rod and help to prevent tight spots. A dab of sticky nail varnish secures it but allows removal in future should this be necessary. Probably I will now be frowned upon - but it works for me!

I have found that some crankpin nuts from AG appear to not have the tapped hole drilled centrally. This probably doesn't matter much under 'normal' usage but, for instance, if you're recessing a nut into a rod behind slide bars etc. then it can have an effect.

shipbadger
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Re: Alan Gibson crankpin nuts

Postby shipbadger » Wed Jun 03, 2020 12:14 pm

I have a set of home made nut runners for small hexagon nuts. The 'working part' consists of a socket cap screw. Most of them have been neatened and fitted to aluminium handles but a few are just the screw chucked in to the plastic drawer containing the nuts. Years ago I had a chart (probably from Model Engineers Workshop magazine) which gave you which skt cap screw fitted which nut. Nowadays I just hunt through the odds and sods box.

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David Thorpe
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Re: Alan Gibson crankpin nuts

Postby David Thorpe » Wed Jun 03, 2020 12:15 pm

I've always, rather hopefully, used my fingers first to get the nut started. That sometimes works, sometimes not. In the latter case, a small set of flat nosed pliers works, not first time, not second time, but probably a few goes after that. I usually secure the nut with a very small amount of weak strength Loctite threadlocker. To get the nut off, it's the flat nosed pliers every time. Yes, it's a bit awkward, but not so awkward that it makes me spend money on anything else to do the job.

DT

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David B
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Re: Alan Gibson crankpin nuts

Postby David B » Wed Jun 03, 2020 1:28 pm

Like Doug, I have a small (2mm) scratch brush which holds the glass fibre bundle in clutch jaws, the same as a clutch pencil. I take out the scratch bit and use the jaws to hold the nut. This works for many small bits. Easier putting items on so you might need to loosen the nut first with pliers before using the clutch gadget to remove the nut.

See here on Eileen's site for the type of scratch brush I am referring to.

CeeJay60
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Re: Alan Gibson crankpin nuts

Postby CeeJay60 » Wed Jun 03, 2020 4:10 pm

I've got 14BA nuts on some of my crank pins, and I need to look really closely to spot which ones!

And a spanner or nut spinner on a hexagonal nut is easier and quicker than the round ones and pliers ... ;)
Cheers,
Colin

I promise I'll get some of it right some of the time!

nigelcliffe
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Re: Alan Gibson crankpin nuts

Postby nigelcliffe » Wed Jun 03, 2020 4:37 pm

CeeJay60 wrote:I've got 14BA nuts on some of my crank pins, and I need to look really closely to spot which ones!

And a spanner or nut spinner on a hexagonal nut is easier and quicker than the round ones and pliers ... ;)


You can also cheat the nut a little - round off two of the points (opposite ones) with a file, and the nut will look round with two flats. Less visually obvious than a hexagon, but still fitting a spanner.

- Nigel

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Flymo748
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Re: Alan Gibson crankpin nuts

Postby Flymo748 » Wed Jun 03, 2020 4:58 pm

I'm surprised that no one has mentioned the GW nut spinners yet.

IMG_6818[1].JPG


Cheers
Flymo
Beware of Trains - occasional modelling in progress!
www.5522models.co.uk

shipbadger
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Re: Alan Gibson crankpin nuts

Postby shipbadger » Wed Jun 03, 2020 5:20 pm

Posh versions of my home made ones :-)

Philip Hall
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Re: Alan Gibson crankpin nuts

Postby Philip Hall » Wed Jun 03, 2020 5:51 pm

I too have a set of nut runners, but that doesn’t don’t help our OP, whose problem related to Alan Gibson (round) crankpin nuts!

I do as David does, small flat nose pliers to fivallg tighten or to remove, and a touch of thread locker to help secure them once all adjustments are made.

Philip

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grovenor-2685
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Re: Alan Gibson crankpin nuts

Postby grovenor-2685 » Wed Jun 03, 2020 5:58 pm

To be fair the OP did not say whether he meant the round ones or the hex ones and about half the replies have been aimed at hex ones. For round ones I usually try with a pin vice.
Regards
Keith
Grovenor Sidings

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Captain Kernow
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Re: Alan Gibson crankpin nuts

Postby Captain Kernow » Wed Jun 03, 2020 6:37 pm

Hello again all. Thanks for all the helpful comments.

These are the round nuts. I will probably use the flat jawed pliers to get them off and when the rods go back on, it will either be with some hexagonal nuts (slightly rounded off or otherwise!) or perhaps replacement with Markits crankpins, with the wheels having been tapped in the meantime.

All this has only arisen because I thought I would give the loco a quick test run to confirm that it still ran OK yesterday!
Tim M
Member of the Devon Riviera Area Group.

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Will L
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Re: Alan Gibson crankpin nuts

Postby Will L » Thu Jun 04, 2020 11:44 am

For round ones I'm in the pin chuck camp too, for both fitting and removing. The narrow section of the nut will fit nicely in the right chuck* and you can tighten it down so you have a good grip. They then stay gripped until you let them go, so sacrifices to the Great Carpet God are avoided. You will be able to tighten them down enough against the bush that they don't need gluing to the crankpin to keep them there, and still be able to remove them easily when required. To pick up a nut you just need it face up on a flat surface. All in all make a very fiddly job much easier.

*The right Pin Chuck. Not all pin chucks will do. To do this it must be a able to easily accept and then grip something with a diameter of 1.5mm. Many will not. Metal jaws are better than plastic too.

For 14ba hex nuts, one of the GW nut spinners is an absolute god send, and again tends to avoid unintentional sacrifices. Having acquired one I swiftly returned to pick up it 10 and 12ba brothers.

Dave Holt
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Re: Alan Gibson crankpin nuts

Postby Dave Holt » Thu Jun 04, 2020 1:32 pm

On the Gibson round nuts, I file two flats on the smaller diameter portion, trying to keep them opposite and parallel. The flats help pliers grip without slipping round whilst not squeezing too hard.
I also pick up these and hex nuts in a suitable sized pin chuck. Recently, for hex nuts, I've been using 16 BA drilled and tapped out to 14 BA and also thinned down a bit. They look more to scale than a straight forward 14 BA nut, to my eyes.
Fitting recessed front nut is still a pain, often leading to a lengthy carpet search!
Dave.

Philip Hall
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Re: Alan Gibson crankpin nuts

Postby Philip Hall » Thu Jun 04, 2020 3:51 pm

grovenor-2685 wrote:To be fair the OP did not say whether he meant the round ones or the hex ones and about half the replies have been aimed at hex ones. For round ones I usually try with a pin vice.


True, but since Alan Gibson doesn't - as far as I recall - make hexagonal crankpin nuts I thought I was on safe ground...

Enigma's comments about AG nuts not being drilled in the middle also prompts me to say that I have had a few where the tapped hole is too big and doesn't lock on the crankpin screw. The AG screw is M1, and although a 14BA nut will go down for a few threads, probably enough for us, (I regularly use Ultrascale flush nuts on an AG screw) it will seize at some point. I have also had crankpin bushes where the hole is clearly not in the middle, or a very loose fit on the screw. None of this is much of a problem as long as you are aware of the possibilties.

Philip

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Captain Kernow
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Re: Alan Gibson crankpin nuts

Postby Captain Kernow » Wed Jun 10, 2020 3:40 pm

Well, the flat jawed pliers removed two of the nuts today and none were lost to the carpet!
Tim M
Member of the Devon Riviera Area Group.

DougN
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Re: Alan Gibson crankpin nuts

Postby DougN » Wed Jun 10, 2020 10:56 pm

You have done better than I did... sheared the pin and then the other side decided to unscrew out of the wheel... locking everything solid!

any how I have beaten it into submission! new crankpin and nut!
Doug
Still not doing enough modelling


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