So, I drill bowling balls. I have two sets of bits. All the way from like 5/16 to 1-1/2. All sizes in between. Today it appears that one of my 31/32 straight shank bits has expanded to 63/64. How do I fix that? I work for a University and have an amazing machinist. How can he fix this?
>>964537
grind it down 1/64?
people can tell 0.015" diff in a bowling ball?
>>964537
Grind it down or if you really wanted to get crazy I guess you could chuck it up in a lathe and turn it down.
Personally I would just buy a new one from MSc or grainger. They aren't that expensive anon
>>964553
Bowler here. Not really. 1/32" difference is about the limit. Exception being the hole being just _barely_ too small, but even then it's not really going to matter whether you add another 1/64" or 1/32".
In any event, a lathe with a grinding attachment (or even just a simple jig and a bench grinder) could fix it, or rather, fix most of it. You'd still have to re-do the relief angles after it's brought down to size.
>>964537
>Today it appears that one of my 31/32 straight shank bits has expanded to 63/64.
I would check your measurements again, I've never heard of any drill expanding from use.
how are you measuring this? by the drill bit or diameter of the hole?
>>964537
>drill bit expanded
let it cool down a bit then measure it again
>>964553
Plenty of people can tell the difference between a 7/64" and a 1/8" drill just by looking at it
>>964705
I know I can, because one says "7/64" on the shank, the other "1/8".
How the hell do you claps work with these insane units, anyway?
Why aren't they marked "7/64" and "8/64"?
How long does it take you to put a socket set back if you knock it over?
>>964744
It's like 4th grade math.
Do you have trouble putting your shoes on in the morning too?
>>964760
Do I have to solve a math problem every time I want to know how many shoelaces I have?
What's wrong with numbering them 5, 6, 7, 8, 9, 10, 11... ?
If you just standardised on whatever denominator the set comes in, then:
- you'd immediately know what sizes were available
- you'd never have to calculate a fucking GCD just to know what the next size up is called.
>>964772
> trying to explain common sense to yanks
Check out AWG (American wire gauge), the sizes are all backwards, 64 is tiny and 0 is huge. What's bigger than 0? 00. You can't make this shit up.
>>964776
SWG is the same way, just offset by 2 gauge.
>>964744
8/64ths? What kind of normie are you? You must made 47/64ths of this board go
>REEEEEEEEEEE!!!!!!!!
>>964705
Yeah, if they're side by side and relatively small in diameter to begin with. 1/8" to 7/64" is nearly a 13% difference in size.
Much more difficult to tell when, like in OP's case, you're going from 63/64" to 31/32" (less than 1.6% difference) and you only have one of them.
>>964772
>What's wrong with numbering them 5, 6, 7, 8, 9, 10, 11... ?
There are plenty of things numbered like that. Pretty much anything ending in "gauge".
And it's almost always a fucking nightmare to figure out what size they actually are. Moreover, most drill sets don't go down to 64th increments, unless they're specifically geared toward machinists. 32" is much more typical, since that's fine for the vast majority of work.
In related events, OP should probably measure again. Drills don't just randomly expand on their own. It'd be the opposite, if anything...
>>964592
Its for grip inserts. Like for Vise and Turbo Grips. 31/32 is the OD for those. If it is 63/64 then the grip doesn't fit in the hole right, and the size feels off for the grips.
>>964781
it was replaced in the 80's and no, it wasn't the same, it was based on actual measurements of the cable rather than the american system of interpolating like 39 sizes between drawings?
>>964861
Huh. Kinda surprised those don't go by 16ths.
OP. I'd say your problem isn't your bit, it's the runout on the chuck/spindle on whatever you are using to drill the holes with. Get a better drill press friend.
>>964744
>visiting friends in burgerland and doing some touristy shit
>have half a day to kill and friend asks if I can help do some odd jobs around the house like replace a few decking boards and shit
>okay.jpg
>he gives me some of his tools and I go to measure a length of decking plank
>open his tape measure
>Jesus Christ how horrifying
How you burgers use your retarded system in daily use is totally beyond me.
>yeah mate if you can cut it to 3ft and 8 and 17/64 inches that would be great
As opposed to
>cut that shit at 1050
>>965124
>>965136
He's right though, when you are talking about 63/64ths of an inch...just use fucking mm. I understand that the country you live in is based around the imperial system, but it doesn't men you can't learn both systems and use the easiest method needed at the time.
>>965148
>based around the imperial system
The sad thing is that science/engineering do use metric. You can never have to many standards right? How many types of imperial thread do you guys have again? Absolute lunacy
>>964942
>OP. I'd say your problem isn't your bit, it's the runout on the chuck/spindle on whatever you are using to drill the holes with. Get a better drill press friend.
That would be a heck of a lot more likely than "the drill bit expanding",,,,
I didn't know jack about bowling ball drill bits so I looked them up: they are usually HSS twist bits with an overcutting carbide spade point. ????
That spade point is NOT going to expand, at all. The drill bit HAS NOT expanded.....
>>964537
you mean the hole size it makes has exanded? that's just poor sharpening
>>965500
This guy.
Are you measuring the drill or the hole? A drill can't grow metal. If it's a really cheap Chinese drill it could possibly deform, but they usually just nuke themselves rather than get slightly weird.
If it has been resharpened the lips may not be equal, this will give an oversized hole as the drill pivots on the off center land and the longer lip cuts oversize.
Your amazing machinist should have a decent drill sharpener, or be able to do one this size freehand and keep it close.
But honestly, if you're looking for .015" precision out of a drill this size you need really good drills and really good procedure, and should be looking at reaming to final size.
OP here. I drilled a few holes with the table Zeroed out. Used a pitch gauge to confirm 0x and 0y. Turns out the vacuum jig (that holds the ball) creeped over and it was 1/128-1/64 off. So pitches were not exactly correct. My X axis was barely off. Now, that does not consider run out. There was run out. There must have been a piece of debris stuck on the straight shank of the bit. With other bits it is fine. Operator error. Fuck me.
Stick drill bit in pooper.
And I fucked up. Drill bit is fine after checking again. Just had heard of people back in the day talking about bits expanding. And the table was just barely off. But that would cause a different pitch, and it did, but not run out causing a larger outer diameter hole. Operator error. I have about 40 bits and they get sharpened every year or two. Not all of them ever get used, only common sizes. So yeah, after 5 years of doing this, I let a small piece of resin get on the straight shank and tossed it into the chuck. And fucked up. Not a big deal at all. Their equipment is fixed now. Was barely off on the x axis From between 1/128-1/64 of an inch. And btw, the pitches and x and y values of the table to deal with bowling balls is a little odd. My digis can read standard, metric, fractions and decimals, but the industry standard is to use the standard fractions. Not what I chose, but its the Industry Standard all across the world.
So, here is one of the devices to find pitch. The pitch is the angle the hole is angled at from the surface. But is measured at how many fractions of an inch it is pointing away from the exact center of the ball. So, 3/8 side pitch means that the tip of the bit is going into the ball at an angle that if it went down to the very center of a ball, it would be 3/8s of an inch away. That's lateral, forward and reverse consider the same nonsense. Forward is towards the center of the palm and towards the center of the ball. Reverse is away from the center of the palm, and away from the center of the ball.
>>964942
There was something on the straight shank, debris from the coverstock/filler/core of the previous ball, I didn't clean it off. Shank didn't seat right, caused run out. You are correct sir.
>>965148
Well, I used to have machines from the 1960's. The new ones are less than a year old. And guess what... I have to adjust everything within 2-3mm! And every nut, bolt, and gap is measured in MM! So there has been progress in this industry to convert to metric. And that's fine with me, tolerances are kept tighter, and i don't have to worry about people in the past slapping on new 3rd party hardware that I have no documentation of what parts were used. Everything is slowly going to metric, don't you worry.
>>966021
I'm pretty sure most Imperial hardware, at least that which comes from the east, is manufactured to metric tolerances.
>>966005
>Just had heard of people back in the day talking about bits expanding
Depending on what you're drilling and how they can expand from heat, but only a quite small percentage of the drill diameter. Gets fun in titanium for example.
