Drilling the output shaft.

[Jaydee]

As my engine started knocking , I thought I swap engines. The old one was a mk.2 bottom with a gsxr 11K top end, new one a stock bandit mk.1. 

As I wanted to keep the mk.2 loom and digital k5 bandit clocks, I had to drill the output shaft.  After 2 hours with a box of high quality carbide drill bits I was only 4 or 5mm in. 

I decided to have a break and search the forum for an answer. Same results, everyone having a go, most giving up as case hardened steel is a right bastard to drill. 

Went back out to the shed and was getting any further after an hour. I was about to give up when I had a brainwave. Why not try a 6mm spear tip glass drill bit?

It cut like fucking butter! Just kept swapping between the 6mm glass drill bit and a 7.5mm carbide. I did 3 times as much drilling in ten minutes than I did in  the first 3 hours!

Just passing on my experience as it might help others in the future.

[TonyGee]

f,b,o,b has done this a few times. 

[Jaydee]

1 hour ago, TonyGee said:

f,b,o,b has done this a few times. 

I know. But when I did a search he was one of very few who had success. And that's as far as the info goes. His drilling technique is not mentioned, just he's been successful. There were many who gave up going by half a dozen threads I was reading. 

I've done milling and turning courses in the past and know about drills and rev rates but drilling case hardened stuff is always a pain.

The 6mm glass drill bit was far more effective the any other drill bit I have at breaking through the hardened outer surface into the softer center.

I'm just passing on the info of what worked for me as it may help the next guy doing it and save him all the hours I wasted.

[Arttu]

Carbide end mill bits can also do wonders sometimes. Once I had to enlarge a hole in a hardened steel bushing. A cobalt drill couldn't do anything to it and I was almost giving up but then thought to give a try for a mill bit. And for my surprise it went like into butter.

[Blue]

Nice one jaydee  did you go in dry or use lubricant?

[Jaydee]

1 hour ago, Blue said:

Nice one jaydee  did you go in dry or use lubricant?

Used a cutting fluid and short bursts to keep the heat down. Short bursts is all I needed, instant swarf!  Engine was on its side so the output shaft was facing up. Easier to keep the cutting fluid in the hole. 

[Maggotbreath]

Very cool, thx.  I've had good results drilling harded steel with masonary impact bits. Old mechanic told me to sarpen them on a greenstone grider wheel.  Worked ace.

[fatblokeonbandit]

Ive done 3, they have all been case hardened, not made from hardened steel.

 

I've been told several time its impossible and one bloke called me a liar and said I hadn't done it!! 

 

Its not rocket science, use good quality sharp drills and go up in stages, use the correct speed and off you go.

I started this one with a centre drill then 3,4 and 5mm.  they cut so well i didn't even use any cutting fluid.

 

 

 

 

[Kamikaze]

excuse my ignorance, but why would u want to drill the shaft, is it only for fixing a lock nut to hold the sprocket nut on...? or does it serve another purpose

[Joseph]

That little extra bit allows easy fitment of an Electronic speedo on old oil cooled bikes that no longer have the cable drive

It's the mk2 bandit pick up, that has a magnet sensor on the sprocket cover

[gray711]

Not that I’ve tried it yet but certain Kwakasaki’s (I think some zx10’s) have the castle bit of the pick up built in to the actual sprocket nut 

[Dezza]

 

4 hours ago, fatblokeonbandit said:

Ive done 3, they have all been case hardened, not made from hardened steel.

 

I've been told several time its impossible and one bloke called me a liar and said I hadn't done it!! 

 

Its not rocket science, use good quality sharp drills and go up in stages, use the correct speed and off you go.

I started this one with a centre drill then 3,4 and 5mm.  they cut so well i didn't even use any cutting fluid.

 

 

 

 

Precisely what type and brand of drills do you use and what speed was the drill set to? In my limited knowledge of engineering, different make drill bits make a world of difference ranging from total disaster to total success and happiness .

Edited February 21, 2022 by Dezza

[Dezza]

Slabbies also have the output shaft drilled and tapped at the factory to accommodate the large washer that goes on as OEM fitment.

[Joseph]

49 minutes ago, gray711 said:

Not that I’ve tried it yet but certain Kwakasaki’s (I think some zx10’s) have the castle bit of the pick up built in to the actual sprocket nut 

W650 1999-2006
W800 2011-2016
ZX6R 1998-2005
ZR750 2004-2006
ZX9R 1998-2003
ZX10R 2004-2005

[fatblokeonbandit]

I used new Dormer HSS drill, I “ Borrowed”: them from work, but they aren’t expensive.

as to speed, I don’t know what rpm, all you need to do is use a variable speed drill and slowly sped it up until it started cutting correctly.. 

In a pillar drill or lathe, small drills should spin at 3000 I think,  up to 6 mm if I remember correctly, I did try and find my Zeus table but it’s gone AWOL

[Kamikaze]

4 hours ago, Joseph said:

That little extra bit allows easy fitment of an Electronic speedo on old oil cooled bikes that no longer have the cable drive

It's the mk2 bandit pick up, that has a magnet sensor on the sprocket cover

Ahhhh gotcha. so it can be adapted to use a speedo sensor. nice idea

[Gixer1460]

As to correct speeds - it varies depending on drill material, material to be drilled, cutting oil etc, but here's good 'assumption' chart for guidance. If the hole being drilled is 4x and greater than the diameter of the bit then i'd reduce speeds quoted by half. Too slow is bad, slow - medium is good - too fast is bad also

[Jaydee]

Drills have a feed rate. The circumference multiplied by  revolutions =feed rate

The smaller the drill bit, the faster the revolutions.

There is a general rev chart for drill bit sizes that you cross reference for correct speed.

With special drill bits like carbide or cobalt, there rev range will differ and  have their own rev chart which can be found usually by contacting the manufacturer.

In the real world there are exceptions to the rule. For instance,  if I was to drill the output shaft at too quick a speed, the excess heat can help temper further an already hard surface which is the last thing you want. Big difference between that and working it on a lathe with flowing coolant where you can achieve the correct drilling speed.

[no class]

…….aaaand since it’s a hand held power drill …. feedrates and drill size formulas are out the window ….. Fbob’s method seems to be the way to go if one choses this route . 

[Fazz711]

Guhnrig cobalt drill set are superb. 

Set 1mm to 10.5incuding tapping drill sizes are about £60 and well worth it. 

I got mine from MSC direct

[Dezza]

Maybe there is variation in the case hardening on these shafts so sometimes they drill and sometimes they don't. I did not try a spear-head glass drill, but did try several other drill types (new) that all failed. I tried brand new cobalt bits (Bosch) and at least these were not instantly blunted in 30 seconds like all the others. Different speeds, bits, different drills and made pricisely zero progress. The only swarf I saw was when the 4.5mm drill bit was reduced in size to 4mm, the same size as the hole in there from the off. I gave up

Edited May 7, 2022 by Dezza

[Jaydee]

34 minutes ago, Dezza said:

Maybe there is variation in the case hardening on these shafts so sometimes they drill and sometimes they don't

I wasn't getting anywhere with drilling the shaft (for hours!) till I changed over to the spear tipped m6 glass drill. Then it was swarf city once I did.

[Dezza]

19 hours ago, Jaydee said:

I wasn't getting anywhere with drilling the shaft (for hours!) till I changed over to the spear tipped m6 glass drill. Then it was swarf city once I did.

Ok, I will try a spear-head drill. Why did you use a 6mm and then go up to 7.5 mm? For an M8 thread? I thought only an M6 thread is required hence the final hole would be M5.

Also, what make/type spear-drill did you use? The market is flooded with cheap shite (as is usual) so it's difficult making the correct choice.

Edited May 8, 2022 by Dezza

[Jaydee]

13 minutes ago, Dezza said:

Ok, I will try a spear-head drill. Why did you use a 6mm and then go up to 7.5 mm? For an M8 thread? I thought only an M6 thread is required hence the final hole would be M5.

Also, what make/type spear-drill did you use? The market is flooded with cheap shite (as is usual) so it's difficult making the correct choice.

The bolt that holds the sensor wheel is an M8. I used the M6 spear tip as the next size up was M8 which was too big. The trick is to keep switching between the M6 spear tip and a 7.5mm carbide drill. When the 7.5mm carbide stops producing swarf, go back to the M6 spear tip to bore further in. As the spear tip has a different profile, it leaves something for the 7.5mm carbide to bite in to.

As for quality, it was cheap shite from Lydl. Glass is harder than case hardened steel so any M6 glass drill bit should do. Just go slow. Not the biggest problem if you break a spear tip down a hole as the flat piece can be fished out of a round hole easily.

[Dezza]

Ok, thanks for the info