# Pop quiz, spot what the issue is... and the fix



## Ttrees (12 Jun 2022)

I got a bit enthusiastic whilst drilling some holes for this vise installation.
However I only made my mind up that I would prefer these nuts to be flush
I might likely make them a bit skinnier with the *bench grinder *and some filing.
Could even *lap* them if I wanted on a lap, or on my cheap diamond hones, as would make a nice job of the nuts, but won't be polishing them.

Plenty of suitable drill bits I have, both *really cheap* ones like that wide bit, and dear ones,
but only drilled the holes to accept M10 thread, 
all went well with the drilling with no breakout or anything,
_But.. _for a few minuets, I was not happy!

Luckily the fix exists, well I hope so at least, and if not, likely will be great with a little work.
I'll be making a timber spacer for this soon, it's not got anything to do with the job.

What did I do wrong?
What is the fix evident in the photos?


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## Ttrees (12 Jun 2022)

Anyone?
Perhaps some more clues might do the trick


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## Terrytpot (12 Jun 2022)

The only issue evident is a spade bit isn’t much use at enlarging an existing drilled hole as it can no longer align itself with the centre of the hole as it’s not there anymore…which if you’re wanting to have the nuts flush “ish” presents an issue if that 20mm spade bit is the only one you have capable of enlarging a hole for accepting the nut in a recess.


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## Ttrees (12 Jun 2022)

@Terrytpot
The sleeves I was pleased to have found, is the fix for the existing drilled holes.


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## Terrytpot (12 Jun 2022)

Ttrees said:


> @Terrytpot
> The sleeves I was pleased to have found, is the fix for the existing drilled holes.


Taping a thread in them?


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## Ttrees (12 Jun 2022)

Maybe this might give it away.
The M10 threaded bar and fixings shown are the only thing involved,
and you are correct on the nuts being flush (which I might slim down on the ginder and maybe a tack with the welder)
Though the relative depth isn't important, although the fact that it can be done fairly nicely.


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## Ttrees (12 Jun 2022)

Perhaps I need to show the results that it makes?


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## Ttrees (15 Jun 2022)

Will this explain it?


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## Ttrees (15 Jun 2022)

On a different note...
One way of getting a good result cutting threadbar


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## Ttrees (15 Jun 2022)

I think you'll agree, an outstanding result from a wonky poundshop spade bit.





Left a burr on this lab countertop, but leaves clean holes in timber.
Could think about some sort of depth stop as its a trial and error thing, and easy to over do it,
so one must be careful!


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## --Tom-- (15 Jun 2022)

Guessing the error was drilling the hole for the thread before the hole for the nuts?


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## Ttrees (15 Jun 2022)

@--Tom-- Kinda, but the sleeve/bushing was the fix for that, which was improved with a bit of insulation tape for a tighter fit.


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## throbscottle (15 Jun 2022)

I'm really confused about what has happened here, please help me understand!
So what I see is, you drilled holes in a metal table, which then turns out to be plastic (can't tell from 1st pic)
You realised you needed to counterbore the holes so some nuts could be hidden in them
Fitted a sleeve to the shank of the wonky poundshop spade bit, then fitted a sleeve in the holes you drilled
Then magically, the counterbores appear! How the heck did that happen? Is it that the sleeve just fits the spur of the bit? Is it? is it????? (gnashes fingernails from the stress of not knowing...)

Potentially you could alternatively grind a wonky poundshop spade bit into a wonky poundshop counterbore spade bit, so instead of a spur it has a long wide section that fits in the pre-existing hole, and the blades could be ground level so you don't get a hump in the hole. Though it might need a half-round dowel gluing to either side for stability.

Now I have to get some wonky poundshop spade bits to try the experiment!

Nice job anyway. I've made the same mistake a few times myself - well done!


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## Ttrees (15 Jun 2022)

@throbscottle the spur of the spade bit isn't involved!,
and no sort of plug was used to drill the wider holes.
The sleeve was only the fix for my numpty move of drilling to final size before thinking, 
Must say though possibly a likely improvement for something thinner than say an inch.

So only the spade bit and the sleeve was used, and nothing else involved in the process of countersinking these holes apart from the hole drilled previously.
The sleeve is the giveaway.
One might even question why these bits aren't made like this in the first place?


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## xy mosian (15 Jun 2022)

Did you 'sharpen' the rear end, shoulders, of the flat bit? Passing that through the sleeve in the hole before chucking in the drill. It would be tempting to assume a need to dun the drill backwards, but the bit could be sharpened to cut when run in reverse.
gf


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## Ttrees (15 Jun 2022)

Spot on @xy mosian 
Not being sure of what direction was best, but I filed the bevels right or wrong, so
as the cut was in reverse as it just seemed more suiting 

These cheap ones cut like butter with a hacksaw, although you want an aggressive file for
shaping, as in double cut and not a single cut as it will skate about.



















I didn't come up with the idea, Frank Ford of frets.com is where it came from, 
which somehow hasn't been popularized as it works great.


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## Setch (15 Jun 2022)

Everyone should should read frets.com. Even if you have no interest in instrument repair Frank is a master at practical problem solving.


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## xy mosian (15 Jun 2022)

Those flat bits are very useful. Want a small tapered hole, re-file a flat bit, need an odd sized hole, re-file a flat bit. I have converted a flat bit to a tap in the past, not a quick job but quicker than trying to find a suitable tap, and much cheaper for a job of one or two threaded holes.
geoff.


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## Dave Moore (16 Jun 2022)

Ttrees said:


> On a different note...
> One way of getting a good result cutting threadbar
> View attachment 137719


Better to cut the other side of the nut, wind the nut on a little after the cut an either file or grind a small chamfer on the end to take off the sharp edge. Then wind the nut off and the nut will cut any burr off leaving it easy to get nut on or off.


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## Ttrees (16 Jun 2022)

@Dave Moore Don't know how you're doing it, but I have yet to see a better way for short fixings
which is as easy to get everything the same.
i.e the section in the vise is cut to length, not the rest to the left which I presume you were referring to.
Edit: it does look that way in my picture, as it might appear that I'm a left handed sawer!
here is a previous one, the difference in the above one is the nut can be set for the depth of cut, so one can cut where they want rather than
picking a thread.
You kinda still have to, but the fact the rod can be rotated with left hand means you can still cut where you want to.






All the best
Tom


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## okeydokey (16 Jun 2022)

I'm a bit confused so I need to read it again again - could you have got the same result by filling the previously drilled holes with a some dowel then just re drill with the flat bit to get the countersunk portion then drill the rest through with a standard drill bit?


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## Ttrees (16 Jun 2022)

Only possibly so if it were timber and in this particular case.
Say one wants a really clean hole, likely would be better getting a forstner bit rather than afancy spade.
and then you have a peck hole, which if not using an M10 bolt and an M6 or M8 would be a sloppy affair, and on thin material a bit weaker.
If I wasn't so close to the edge, I might have chosen a wider spade bit to make the job look more proportional.
(I was toying with the idea of making these bolts into cheese heads, but I don't think it's possible to make them round and not be too small looking)
The beauty of this method is that it is guided, so some cheap spade bits make sense to have around.
Ps I tried hammering the shank flat, but this stuff is rather tough compared to mild steel.

Tom


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## Ttrees (16 Jun 2022)

This might explain better about the sloppy hole from the pecking if using for narrower fixings.
Here's another spade bit I ground and filed down to what I think is possibly an M6 thread,
(if so, illustrates the point of the guided element of the tool, should one need be grinding one of these in somewhat of a hurry)

Looking back, I see that I have a little missing of the edge of one side, and yet it still worked very well.
Nice to have something which in my opinion is rather dependable, should you not drill too deep!
You get pretty fast at taking the bit out to check the fit of the bolt head,
and I've never had an any issue starting the cut again.

Works well in timber also, having done this with bolt on guitar neck conversion,
didn't have a lot of tools back then, and not even sure if I filed bevels onto the bottom,
I do recall some light burning, so am guessing I didn't have any bevels filed onto them.
They must play a good part in regards to timber, as every spade bit I've seen has them.


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