Need tips on drilling a long thin through hole

Got it figured out ?
 
tjb said:
That's a good idea which I had considered, but I'm only starting with 5/8" stock. I've been pondering this today and thought about using some 3/4" stock I have available. We'll see what we come up with.

Regards,
Terry
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I just mentioned a half inch hole as an example. You could use a smaller head Allen head bolt.

Also if needed you could chuck up an Allen head bolt in your lathe and take the head diameter down a bit to fit a smaller hole if needed. Just put 3 or 4 nuts on the bolt and tighten them so the hex sides match. Chuck that up and make the head smaller.
 
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Cadillac STS said:
I just mentioned a half inch hole as an example. You could use a smaller head Allen head bolt.

Also if needed you could chuck up an Allen head bolt in your lathe and take the head diameter down a bit to fit a smaller hole if needed. Just put 3 or 4 nuts on the bolt and tighten them so the hex sides match. Chuck that up and make the head smaller.
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That's a good idea. I mentioned 3/4 stock after looking at Mr. Whoopee's photo. Looks like he used 3/4 or maybe even 1 inch. I'll study it some more tomorrow. Thanks for the input.

Regards,
Terry
 
tjb said:
That's a good idea. I mentioned 3/4 stock after looking at Mr. Whoopee's photo. Looks like he used 3/4 or maybe even 1 inch. I'll study it some more tomorrow. Thanks for the input.

Regards,
Terry
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I used 1x6 stock to replace the original cast tailpiece that covers the crossfeed screw and connects to the taper attachment. It provided a flat surface for mounting the scale for the DRO.
 
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Could you mill long pockets on the underside of the extension leaving 1/2 inch of solid aluminum at each end then drill from each side followed by a reamer from one side to ensure alignment. Or use a long drill from one side? The pocket would remove most of the "wandering" I would think and the 1/2 inch would be more than strong enough to hold everything without flexing much. I'm still a nuub but might work.

John in Minnesota


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I would drill from both sides. Because location is important I would drill undersize then bore to .1875 as deep as your tooling will permit. The undersized hole should be just a bit deeper than you can bore. The bored portion of the hole will act as a drill bushing to keep the hole on location.
 
Success on Step 1!!!

Milled my piece of 5/8" aluminum with cutouts similar to Mr. Whoopee's and it fits perfectly. Sorry, no pix tonight, but I'll post some tomorrow. The most challenging part was drilling for the tapped holes in the end of the cross slide. Fortunately, I have an 8" angle plate that I mounted and indicated on my mill, but it took almost all the tolerance I had to mount the cross slide standing on end. Clamped it to the angle plate, drilled and tapped the holes and it matched up perfectly.

I suppose in the grand scheme of things, there's a silver lining to my asking an abbreviated question instead of giving a full-blown description of my objective. Having never drilled a long, skinny hole, I was not aware of the complications associated with such an effort. Now I know. Hopefully, some of our other rookies were able to learn from this as well.

Now on to the big challenge - cutting the glass scale. At the moment, I'm considering the best course of action is to reassemble the cross slide with the extension plate on it, and go through some exercises to determine optimal length.

To be continued...

Regards,
Terry
 
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