Drilling driveshaft flange

[LandCruzrNY]

Working with a friend on his cruiser. He bought some double cardan driveshafts. Probably the wrong ones but he says they're right. He's stuck with them at this point.

Anyhow, the flange holes are too small. So I'm trying to drill them larger. Not easy so far.

Dewalt and Milwaukee titanium carbide won't touch it. Just gets hot. What's the right drill bit for doing that?

Found this but just because it's expensive doesn't mean it's going to work. Thoughts on better bit?

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[mudgudgeon]

Expensive experiment.

Drilling a hole only slightly larger often chips the corner of the cutting edge of drill bits because all the force is focused right on the corner.

If you're gonna spend $100 on one drill bit, do some research so you understand how best to use it.

My thoughts would be, slow drill speed, lots of downward pressure, and cutting lube. That's coming from a carpenter/ jack of all trades, not a metal worker

Too much drill speed, it's easy to overheat the drill bit, which means you lose the tempering in the tool steel, and lose the cutting edge, if you haven't already chipped it off. And/or you harden the material you're drilling through

 

[Rifleman]

If you are using drill bits from Lowes, or Home Depot take my advive and stop wasting your money, Just as an FYI, titanium carbide is just a coating that has been applyed to the drill bits your using, they are in fact not solid carbide,

The problem with the drill bit you listed from McMaster Carr, solid Carbide is VERY HARD, and will easily drill hardened steel, but it is also VERY BRITTLE like glass,

So if you're trying to drill those holes with a hand drill, that expensive drill bit you just spent 100 bucks on will more than likely chip off one, or both of it's cutting flutes, or worst it could shatter into pieces,

Best bet would be to spend that 100 bucks with a local machine shop that has the right equipment to drill hardened steel and have them enlarge those holes for you,

How do i know all this, i use to own and run my own machine shop so you can take my advise, or not,

 

[Kernal]

^^^This^^^

Sometimes it's easier/cheaper with less headaches to just pay the man.

 

[1973Guppie]

Take it to a driveshaft shop......

 

[thatcabledude]

Who are the driveshafts from?

 

[LandCruzrNY]

He bought them from a driveshaft shop in Clearwater, they said they would fix his issues. They holes don't match the bolts. I think it's better to have them take it back and drill the correct sized holes. Having one side or the other have any play can't be good.

 

[LandCruzrNY]

If you are using drill bits from Lowes, or Home Depot take my advive and stop wasting your money, Just as an FYI, titanium carbide is just a coating that has been applyed to the drill bits your using, they are in fact not solid carbide,

The problem with the drill bit you listed from McMaster Carr, solid Carbide is VERY HARD, and will easily drill hardened steel, but it is also VERY BRITTLE like glass,

So if you're trying to drill those holes with a hand drill, that expensive drill bit you just spent 100 bucks on will more than likely chip off one, or both of it's cutting flutes, or worst it could shatter into pieces,

Best bet would be to spend that 100 bucks with a local machine shop that has the right equipment to drill hardened steel and have them enlarge those holes for you,

How do i know all this, i use to own and run my own machine shop so you can take my advise, or not,

I think we were going about it all the wrong way. He was using a dewalt drill, high speed, and it just burned the bit up I think. Looking around on the floor, there are tiny pieces that look like they were part of the drill bit vs. what the flange. The machine shop or the driveshaft shop is probably the right place. I never really gave it much thought, figured faster drilling was probably better, but what you're saying makes perfect sense.

 

[Rifleman]

I think we were going about it all the wrong way. He was using a dewalt drill, high speed, and it just burned the bit up I think. Looking around on the floor, there are tiny pieces that look like they were part of the drill bit vs. what the flange. The machine shop or the driveshaft shop is probably the right place. I never really gave it much thought, figured faster drilling was probably better, but what you're saying makes perfect sense.

Depending on the material you're trying to drill, will in fact dictate the feed speed (how fast you feed the drill bit into your work piece), and the speed (RPM) that you turn the drill bit at,

Turning a drill bit at too high a speed, and holding it against a work piece for to long, can in fact work harden that material, and take the cutting edge right off of your drill bit,

When drilling an item you'll also want to remember to use some type of cutting fluid, even something as simple as WD40 can make a big difference in cutting performance,

Last but not least, if you want a good set of "all around" drill bits, buy a quality made in American set, like Chicago Latrobe, Greenfield, or Cleveland,

Get a set of Jobber length High Speed Steel drill bits, and if you've got the extra money step up and buy a set made out of Cobalt steel instead of High Speed Steel,

Cobalt works better and the cutting edge lasts longer on stainless steel and high carbon steel,

Set of HSS drill bits

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Set of cobalt

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[LandCruzrNY]

It's the price of doing business I suppose. Both are ordered and will be here on Friday. Thank you for the great information. I feel like I learned something.

 

[Rifleman]

It's the price of doing business I suppose. Both are ordered and will be here on Friday. Thank you for the great information. I feel like I learned something.

You've made a wise investment in some quality tools that will serve you well for years to come,

 

[Outsane]

These stepped drill bits are great for this kind of thing.

https://amzn.to/3LCF3Zb

I have been enjoying this set, makes round holes in sheet metal instead of tri-lobal things

 

[Rifleman]

These stepped drill bits are great for this kind of thing.

https://amzn.to/3LCF3Zb

I have been enjoying this set, makes round holes in sheet metal instead of tri-lobal things

The set of drill bits you listed look like they will do a great job drilling holes in sheet metal, kind of like a Unibit that electricians use,

The only problem i see with them is the fact that they have that stepped cutting edge,

When they get dull, and need to be resharpened, that stepped cutting edge will be difficult to resharpen without a special grind fixture,

As for your problem of 2 flute twist drills making Tri lobed holes in sheet metal,

Here is the solution i use for that problem, most twist drills come with a 118 degree cutting angle, the problem with using that cutting angle on thin sheet metal, the tip of the drill breaks through the other side of the sheet metal before the outer cutting edges have a chance to started cutting,

Then because of the twist drills shape that causes the bit to want to catch, and be pulled or ripped through the sheet metal not allowing the outer edges to cut a clean round hole, there by ending up with as you called it, a tri lobe hole,

You can fix that problem by changing the 118 degree cutting angle to a flatter cutting angle of 140 degrees,

In most cases a 140 degree angle will allow the outer cutting edges of the drill bit to be engaged in cutting the sheet metal before, or just as the tip breaks through, thereby cutting a clean round hole and eliminating your tri lobe hole problem,

 

[Outsane]

These bits have been doing well in thicker metal also. I don't sharpen drill bits any more either.

 

[mudgudgeon]

These bits have been doing well in thicker metal also. I don't sharpen drill bits any more either.

If you pay $300 for a kit like the ones linked, sharpening them is a skill that pays for itself!!

I love a good step drill! So versatile.
Great in sheet metal, thin plastic, thin bar stock etc.
They drill a nice round hole, deburr, and chamfer in one.
Great for enlarging holes.
I find a small pilot hole helps most of the time.
Haven't had much success trying to resharpen them though

 

[Rifleman]

These bits have been doing well in thicker metal also. I don't sharpen drill bits any more either.

In my case I'm kind of forced to resharpen my drill bits, seeing as i have a whole draw full, But it's a lot easier for me to sharping my bits seeing as i have a drill sharping machine, see photos below,

 

[Marvelicious]

These stepped drill bits are great for this kind of thing.

https://amzn.to/3LCF3Zb

I have been enjoying this set, makes round holes in sheet metal instead of tri-lobal things

Norseman bits are excellent. I've got the big set of their regular HSS bits and they're excellent when I need a specific size. That said, I use the crap out of cheap HF unibits. They take all the abuse and I throw them away when they're dull. I'll sharpen the Norsemans though!

Not sure what was happening with the OP since I wasn't there, but my gut says the "operator error" factor was definitely in play. I wasn't under the impression that the flanges were quite THAT hard.

 

[mudgudgeon]

In my case I'm kind of forced to resharpen my drill bits, seeing as i have a whole draw full, But it's a lot easier for me to sharping my bits seeing as i have a drill sharping machine, see photos below,
View attachment 3686157
View attachment 3686159

I think you missed one on the left?

 

[CharlieS]

Every time I resharpen my drills I am amazed how much better they work. Proper speeds and cooling/lubricant make a big difference too. Step bits have a place, like making the 20mm hole for a LRA guage/switch in plastic, or enlarging the bilge pump hole in an aluminum boat hull a small amount. I use them sparingly though.

If the driveshaft doesn't have the right size holes, what are the odds the holes are at the right spacing?

In the OP case, I'd opt for the following in preference order:

1. return the ill fitting driveshaft and get one that fits correctly
2. take it to a machine shop to have them remachine the holes larger and on the correct spacing
3. drill it out on a drill press with a good quality drill, correct flute angle, correct speed for the material, and cutting fluid (and hope the spacing is right)
4. wing it freehand with a power tool, some wd40, work harden the material, swear a lot, destroy lots of cheap harbor freight drills, drink lots of beer, end up with oversize roughly hogged out holes, and call it close enough

 

[PIP]

Most everything above is pretty good advice- Slow it way down- HSS can't go slow enough. Good lubrication.

I realize the fancy drill bits have already been purchased, but the bits weren't the problem. The problem was just too much heat from too much RPM/SFM.

If this ever happens again. Stop what you're doing. Retouch the drill bit on any grinder. If you don't know how to sharpen a drill bit, I'm not joking, just stare at a good one for 10 seconds. make the dull one look like the good one. It's really basic to make a twist drill cut OK, no special machine required. Then go back to drilling, but run the drill as slow as possible with lots of pressure. Once you're cutting again- Through the hard spot you made- Stop and retouch that drill bit again. Because you just took the edge off again going through the hard spot.

Next January will be 20 years owning a machine shop for me. I like nice tools, but fancy drill bits don't make anyone better at drilling holes without a fair understanding of how a twist drill works. That is really all that is needed here.

And honestly, I have bought a number of the Lowes/HD/HF drill bits over the years when I needed a split point bit for hand drilling right now and I've found them to be pretty darn good drill bits most of the time.

My only drill bit suggestion that hasn't been mentioned here yet is if you need to buy twist drills from a real industrial supplier (like Mcmasters or MSC, whoever, don't buy Jobber drills. Jobber drills are almost never needed. Buy screw machine length drill bits. They are more controllable because they're shorter, cheaper, and something I notice is screw machine drills are generally higher quality than jobber drills at a given price point. Jobber drills are not used to actually make much. 99% of the time when you're buying a dozen drill bits for a real manufacturing process you're going to buy screw machine length drills because shorter is always better.