Jamming T nuts

…”now I know what this hole is for” said the bishop to the actress…

So do I. More on that later.

Since the last post, I’ve not been here. We’re training new pilots like they’re going out of fashion, so I’ve been in the simulator almost all this time. I must say it’s fun to be training again. These kids are the brightest of the bright. They’re like huge empty vessels and one just pours knowledge in to them. The ones I did last month are already flying The Line. Very satisfying.

Although Big Bad’s been somewhat tamed, he has an insidious wee friend who creeps up on you. This is the wee git who jams up your devices when you’re in a hurry, so that you run out of time and have to go without. He’s so stealthy, one never sees him coming. And he doesn’t have a name, even.

Intending to do posts whilst away last week, Big Bad arranged that I would leave the transfer of photos to iPad until the last minute before leaving for the airport. That transfer process has always gone well before, so why wouldn’t it be easy this time? TED’s fiendish wee pal caused the iMac to shut itself down in the middle of the iPad sync. Not enough time to do it all again. Walked right into that one. So no photos. No photos, no posts. Unless you’d be happy reading ramblings? No, thought not.

Anyway, about this Top Slide…

Fettling was similar to the Cross Slide but took less time. Found a metal rod which happened to be just the right size to get into bores…

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This is the engraved angle scale on the edge of the body…

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There’s a scored line on the top surface of the Cross Slide to reference against this. This is the Tool Post Stud back in place…

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The Micrometer Dial cleaned and reassembled…

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Gib Adjusting Screws…

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Both body parts back together, showing Gib Strip and Feed Nut…

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The completed Top Slide Assembly…

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Here’s a picture showing Good News and Bad News…

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First the Bad News (although, as Bad News goes, it’s not really…)
The picture shows the T nuts in place as far as they would go. They jammed in the positions you can see and would slide in no further. Clearly annoying.
The Good News is that it dawned on me what the Hole and The Thing in it is for.

The T nuts were jamming because they were not made very well. They don’t seem to be originals as they differ from the ones shown on the diagram. When I measured them with the Calipers, they are not evenly machined from one end to the other. Also, I examined the slots in the Cross Slide into which the T nuts engage and found those to be roughly machined.

So I took a large Smooth Cut file to the Cross Slide T slots…

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With safe edge downwards…

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…as opposed to cutting edge…

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…I applied pressure only within the slot, starting like this…

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…and finishing like this…

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I also smoothed out the T nuts themselves a bit more. The result was a good fit…

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By the way, always clean your files after, otherwise rust can take hold in the filings. Use a File Brush. This photo shows the brush and a half cleaned file…

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Finally, The Hole. Turns out to be the pivot connection between the Cross Slide and the Top Slide. There’s a little two diameter plug which connects the two. Here it is dropped in to the Cross Slide…

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You can see the problem. The small diameter is below the top surface, so will not engage into the corresponding hole in the underside of the Top Slide. Here I put it in place in the Top Slide, holding the Top Slide upside down…

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…but, when I turn it the right way up, it drops out. So I punched dents at four point around the smaller diameter…

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This spreads enough metal to get a tight fit, as you can see here…

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So, at last, the Top Slide is in place…

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Of course, just when you think you’re finished…

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