Author Topic: How I drill a hole in this or thread  (Read 4355 times)

Offline wongster

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How I drill a hole in this or thread
« on: September 15, 2010, 07:26:14 PM »
I'm trying to fix up a snap bolt to a 8mm stainless steel rod for a friend.  Wanted to turned down the end for threading but couldn't find a way to mount it on the lathe.  So I decided to drill a hole at the end of it.

Setting the part up in the vise on the drill press was frustrating.  I couldn't seem to be able to get it perpendicular to the drill.  Everytime when the drill touches the surface, it shifted.

Can anyone suggest ways I can try to either put a hole at the end of the snap bolt or mount it in the lathe to turn it down for threading?

Regards,
Wong






Offline Lew_Merrick_PE

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Re: How I drill a hole in this or thread
« Reply #1 on: September 15, 2010, 11:25:24 PM »
Wong,

I can't really tell from the picture, but I would assume that the shackle itself tapers along the length.  Thus, when you grip it in the vise, you only get a line of contact with the vise jaws which makes it easy for it to tip this way and that.  That is compounded by the swing-latch closure riveted on (which I am sure you do not want to remove.)  Were you to scribe lines a given distance apart approximately perpendicular to the ring line, you could measure the thicknesses and find the included angle.  Halve that and make a tapered shim set.  You should then be able to clamp it in your vise.

It may be an optical illusion, but the top photo appears to show a "dimple" on the end of the swivel-ring base.  That does not appear in the middle photo (and not visible one way or the other in the bottom photo).  If that is there, it should help you center up your drill bit.  If not you will want to use a centerdrill or a spotting drill to start your hole.  A regular drill bit wll do its best to "walk" on such a surface.  If you have access to a milling machine, that would help as: (A) you can dial in to center on the base of the shackle and (B) the spindles are many times more rigid than is common for drill presses.

I hope this helps.

Offline wongster

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Re: How I drill a hole in this or thread
« Reply #2 on: September 16, 2010, 12:43:32 AM »
Thanks Merrick.

The dimple was from my attempts to drill. That's the deepest I can go with the work being shifted in the vise. I would prefer to turn it in the lathe. I'll try to of a way to do up a jig for this.

Regards,
Wong

Offline Stilldrillin

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Re: How I drill a hole in this or thread
« Reply #3 on: September 16, 2010, 02:24:57 AM »
Wong,

2nd pic..... A piece of cardboard between the  shackle and the jaws may be all you need.......  :thumbup:

David D
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline wongster

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Re: How I drill a hole in this or thread
« Reply #4 on: September 16, 2010, 02:51:31 AM »
That's a good idea.  :thumbup:

How do I square up the drill to the surface of the work?

Regards,
Wong

Offline wongster

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Re: How I drill a hole in this or thread
« Reply #5 on: September 23, 2010, 06:37:33 AM »
Anyone can suggest a way to hold the snap bolt in the 3 or 4 jaw chuck to turn down the thick part of the stem for threading?

Regards,
Wong

Offline AdeV

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Re: How I drill a hole in this or thread
« Reply #6 on: September 23, 2010, 06:53:22 AM »
If your 4-jaw has independent jaws, you should be able to clamp the piece fairly tightly on the two sides (i.e. the flat edges).

For the other two jaws (I'm assuming the back edge isn't parallel with the locking pin), I'd make up two triangular pieces out of aluminium, the idea being you can tighten up the other two jaws - you don't need them murder tight, just enough to stop the piece deflecting under the pressure of turning & threading (if you're single-point threading - if you're using a die, then it's only turning forces you need to worry about).

In order to not damage the clip, I think you'll have to have quite a lot of it sticking out of the chuck, so you'll be wanting to take only light cuts...

Cheers!
Ade.
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Offline djc

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Re: How I drill a hole in this or thread
« Reply #7 on: September 23, 2010, 03:14:28 PM »
...Can anyone suggest ways I can try to either put a hole at the end of the snap bolt or mount it in the lathe to turn it down for threading?

Rectangular plate with a hole in it the same diameter as the waisted parallel part of the snap bolt. Cut in half. Grip the two halves with the bolt in between them in the vise.