Hello everyone, I've enjoyed reading this forum in the year or so since I've been a member and learning from everyone. I was hoping someone might have some advice on my current predicament as I've run out of ideas!
I have a Bachmann Mainline Hunslet with tender, a blue Linda. I'm trying to get the body off to fit a DCC chip (as I have previously successfully managed with a tender-less Blanche). Unfortunately, one of the retaining screws is just rotating in place without coming out of the hole. To be clear, the screwdriver is definitely "biting", I can see that the head of the screw is rotating, it's just not coming out of the hole, nor showing any signs of going back in when I turn it the other direction. I wasn't aware that the screw needed any more force than any of the others, I just turned it then noticed it didn't come out after a few seconds like all the others. The screw in question is (as you look at the loco from the top down with it facing forwards away from you) at the front right of the cab, nestled next to some details representing brass pipes.
I've not managed to get anything under the head of the screw as it is still slightly below the level of the hole. The body is definitely being held by that screw, it will not budge there while there is a bit of "give" everywhere else. Has anyone else had this problem or have any special tricks? A long shot I know, but the next stage will be trying to drill the screw out which is obviously a last resort. Either that or return to Bachmann (I bought it from them directly via their spares website) but I neither want the argument over whether I broke the screw nor to deal with the trying to organise a customs refund (I live in Germany).
Thanks all!
Matthew
It sounds as if the thread might be stripped. As you suggest, getting something under the head to provide a little bit of 'lift' as you unscrew instead of the downward force of the screwdriver might be a way to remove it. I've done that, but not when a screw is completely countersunk in its hole.
I imagine that to drill it out it might first need to be glued in to prevent it just spinning as you try to drill.
I wonder if it might be worth trying to glue something to the head of the screw so that you can apply a little tension as you try to unscrew it? Avoiding gluing the screw in at the same time could be difficult, but a tiny drop of epoxy resin might give just enough grip?
If the screw is very loose and made of a ferrous metal then possibly a very strong magnet on the screwdriver blade might be enough to enable it to engage with the slot and unscrew without applying downward pressure.
On the other hand I may have got it completely wrong and instead of a stripped plastic hole thread the screw engages with a captive nut and has a actually 'let go' but the screw is not coming out. A magnetised screwdriver might help here too.
Thanks Graeme, some good suggestions to try. I'm sure I have some neodymium magnets somewhere, so that might be a place to start before moving onto more potentially destructive methods. I'm not too bothered about destroying the screw or fitting if I really have to: if this one screw is capable of holding the body on this securely I'm sure the other 5 screws that I did manage to remove at the cab end can cope without it!
I'd suggest trying something very fine - tip of a new scalpel blade for example - under the head of the screw to provide a bit of upward thrust whilst turning it with the screwdriver might help.
Trouble is that you may need more than 2 hands to do this without an accident with the blade, so be careful (and get help to hold the loco at least).