A1 Class crank pin problem

[Nokonium]

I have a problem with a crank pin that keeps coming out. If I tighten it right up the connecting rods won’t move and if I don’t it comes undone when running.

Logic suggests that I need to put a spot of some thread lock (one that allows you to unscrew it again if you have to) on the tip of the screw but before I do I thought that it would be best to ask here first, is that the best way to overcome my problem and can anyone suggest a suitable product?

Thank you

[Walkingthedog]

What make is it?

Was it new when you bought it?

[Steve M]

If you do want to 'lock' it in place try a very small drop of varnish or paint which will give way if you do need to undo it later.

[Walkingthedog]

It shouldn’t be possible to tighten the screw so much that it locks the connecting rods. It is either the wrong screw or a spacer is missing.

The maker of the loco would help.

[Nokonium]

The loco is a Bachmann 32-561 Class A1 60122 Curlew BR Express Blue Early Emblem bought new with DCC sound from Hattons in Jan 2018.

I thought about the possibility of a missing spacer, but the other side appears to be put together in the same way, without a spacer. Looking at the document that came with the loco I cannot tell what should be there.

The crank pin is the original one, it is the one on the middle drive wheel, the head fits into a recess on a rod whilst the thread screws into the top of a round pillar that has other rods fitting over it.

I have had another loose bolt problem on this loco, the head coming out far enough to cause a connecting rod to jam up, but that has tightened up OK and appears to be staying in place.

Contacting Bachmann sounds like a good idea.

Use lacquer, hmm my wife has a couple of bottles of that but what colour?

[Steve M]

Flamingo starburst?

[Walkingthedog]

That is very hard to get since you purchased most of it for yourself Steve. I have to use something different now.

[Nokonium]

Sunny pink is more my colour

[Nokonium]

I think that the sunny pink was just right, the crank pin came out again after the first attempt so I put it back in with more of the thread coated and test run it again. It appears to be holding.