30.7.09

Hint's 'n Tip's (and a few obscure thoughts!) #1

Hint 1

Don't ever let your work space get to this state! I spend more time looking for bits and pieces due to this chaos than for any other reason. If you look under the desk, directly below the belly up 38, you will see a portal to another dimension, yeah that big dark space that you're staring at. It's either a dimensional portal, a worm hole or a black hole (are the last two one in the same ?). It has to be, because every time a little part, and the odd large one, enters it's dark maw (that should read "that I drop") it usually disappears of the face of the planet never to be seen again - it's true, really it is.

I have sent my son on many search and rescue missions into this dark abyss, purely as a last resort of course, (mainly because his eyes and back are about 25 years younger than mine) some have been successful, others, well, there may be children reading..............!?


Tip 1 (This one is actually useful, I promise)

Detail parts such as these white metal marker lamps, for the front of the 32, are not cast with any locating sprue or spigot. Even if it were, on a part this size a fine white metal locating sprue would be fairly useless and probably break off at the first nudge, or shunting mishap! These little fellas' have been modified to make them more likely to survive actually being used in service as opposed to sitting in a display cabinet or a dark box somewhere. Particularly if you were take your pride and joy on the exhibition circuit for others to marvel at. The casting sprue for these is the square bit at the bottom which represents the 'handle' to change them from red to white. It looks a bit chunky at this resolution but you can only go so small with white metal and get the bit out of the mold in one piece. This highlights the reason that some casters go to the trouble of 'lost wax' casting in brass (which these really should have been) as the detail would have been much finer, and more expensive of course. I may have a go at filing these down a bit and see what happens.
The first step in this mod requires a 12v drill, or a 240v one with speed control, a 10 or 15 mm piece of 0.5 mm brass wire, a 0.5 mm (#76) drill bit and good quality cyanoacrylate, thats boffin speak for superglue.
Drill a hole, you knew that was coming didn't you, at slow speed or you will find that your drill bit may 'skin' with white metal if it gets too hot, right through the side of the casting, as 'square off' to the casting as possible, and out the other side. Ease out the hole a bit, ie wiggle the drill bit around a bit, to make some room for the glue. No you cant really use the 'next size up bit' as this, in my opinion, is too sloppy a fit. There is also a very high tech and expensive drilling lubricant you can apply if you wish - spit, seriously, it works. No, not a 'lumps and all' golly, just a bit of unadulterated saliva. Not recommended straight after eating!

Don't stress if it's not exactly square, the next step will fix that. Take your piece of wire and check that it fits through the hole ok. This will probably be when you discover if your hole has been bored square or not, if it's an easy fit then take it out and apply a bit of super glue to the wire and shove it back in the casting until the other end is flush with the outer edge of the casting. If you went to the trouble of filing the end of you bit of wire flat, I'm yet to find a pair of cutters that give a true square cut, then you will have a nice neat appearance on the outer face of the casting. If not, then leave the wire a bit proud of the hole and touch it up with a file or some fine emery on a hard flat surface.

Once the glue has gone off, adjust your new sprue to square it off if necessary. Drill a receiving hole where the part has to go, using the same technique and bit, trim the new sprue to about 5 mm, test fit, because this hole may not be quite square either, adjust if needed, apply glue and in it goes. Repeat the process with the other lamp but don't forget that, in this case, being a pair, that they are 'handed' right and left. I you glue the wire in the wrong way you will not get it out again once the glue goes off. You can avoid this possible error by only drilling part the way through each casting on the correct side first. The end result may not be quite as strong.

You will have noticed I repeated the term 'square off' a couple 'a three times. Take the time to do this or your installed detail part will look crap, simple as that. I employ this method to any detail bit with a locating sprue around 1 mm dia or less. I use Zap CA glue and find it lasts for years if you keep it in the fridge (not with eye drops!) and don't let it sit on the work bench with the lid off. If the nozzle starts to look a bit ferral, give it a gentle squeeze with a pair pliers and the offending bits should come off. If its blocked just drill it out, it works.




2 comments:

  1. Hey Gary, it's tidier than my desk/workspace (6" square? sorry, 150mm square) and you should know, you've seen it often enough... ;-)

    Ray

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  2. I recently came accross your blog and have been reading along. I thought I would leave my first comment. I dont know what to

    say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often.


    Patricia

    http://lioneltrains.info

    ReplyDelete