Another Stripped Counter shaft :(

[daviee]

looks good i would go with cobalt drills  as the shaft will be hardened

[Bretty]

Yes it'll be hard as foc. And you'll want a few bits as you might need to start small and work up in sizes.

[unfazed]

Circlip looks fine. :thumbup
I used a very high quality HSS bit, but with slow speed with a variable speed drill.
The shaft is case hardened and using a slow speed it will get through the case hardening.
If the speed is to high it will over heats and destroy the bit.

[Drezza]

All reassuring to hear thanks guys!


I have ordered a 3.5 cobalt drill bit so hopefully that will work, I'd imagine once I've broken through the case hardened surface then it should be much easier. (touch wood). 


Will keep you updated.

[daviee]

should once you get past it slowly slowly catchy monkey lol

[Drezza]

So... I've just tried the Cobalt bit and it won't touch it either!


How the hell did you do it? Feeling like a might need some sort of diamond tipped bit now  :lol

[fazersharp]

So... I've just tried the Cobalt bit and it won't touch it either!


How the hell did you do it? Feeling like a might need some sort of diamond tipped bit now  :lol

Not having to drill it myself but also wondered when people have drilled out studs and so on where do they get the high quality drill bits from and what is a high quality drill bit - not one from Wilkinsons I expect

[red98]

Also depends what power drill your using aswell......you want lots of power but a slow speed....bit like a blue thou  :lol

[daviee]

could try a tile drill to  start it the are  industrial  diamond once you break through then us the cobalt

[Drezza]

I'm using a Heller (German) Cobalt bit, so would have thought the quality would be fine?


http://www.ebay.co.uk/itm/191884884799?_...EBIDX%3AIT


However I am using a 12v hand drill which is possibly not the best? Would have though a drill is a drill, as long as it turns what more can it do  :\


I'm very tempted to put some lock-wire through the holes of the circlip and leave it at that at this point  :lol

[fazersharp]

I'm using a Heller (German) Cobalt bit, so would have thought the quality would be fine?


http://www.ebay.co.uk/itm/191884884799?_...EBIDX%3AIT


However I am using a 12v hand drill which is possibly not the best? Would have though a drill is a drill, as long as it turns what more can it do  :\


I'm very tempted to put some lock-wire through the holes of the circlip and leave it at that at this point  :lol

Ive got those I have this set - http://www.toolstation.com/shop/p94153?table=no
My problen when drilling anything other that wood is that they are all blunt now.----------- Next question
(I will start a new thread in the general section as not to de-rail this one )

[Drezza]

Managed to drill the hole 5mm diameter 22mm deep, had to use carbide drill bits in the end, cobalt were useless!


Now I've tried tapping the hole and having no luck again, the taps are HSS to I've got a feeling I'd need carbide taps too (if they even exist??)...




How on earth did you do it Unfazed??

[Bretty]

I've no idea what to suggest mate as I've never done this. Although I don't think I've ever found a metal so hard that a tapered tap won't cut it?!

[unfazed]

Managed to drill the hole 5mm diameter 22mm deep, had to use carbide drill bits in the end, cobalt were useless!


Now I've tried tapping the hole and having no luck again, the taps are HSS to I've got a feeling I'd need carbide taps too (if they even exist??)...


How on earth did you do it Unfazed??

You will need to ensure they are tapered taps as Drezza said. I got very high quality tapered taps from a local tool shop. I will check this evening as to what type/make they are.

[Drezza]

Fantastic, thanks Unfazed. Would be a shame to have to weld it now I've done half the work.


I thought about filing away the entrance to the hole so the threads don't start on the case hardened part of the shaft.



Bretty - I've been doing some research and it seems standard taps are only designed for use in metals with a hardness of up to 45HRC, whereas I think this shaft is about 60HRC to a depth of 1.5mm if it's case hardened.

[unfazed]

The taps I used were "Apex UK High Speed Steel Ground Thread Tap" M6 x1

If you cannot get them let me know.

[Drezza]

Thanks Unfazed, will try to find some


I've just looked up tap sizes for 5mm diameter holes, and it appears for an m6 tap, you need a 5.2mm hole. I'm wondering if this is the issue since I'm trying to tap a 5mm hole.

[unfazed]

Don't think it would make much difference and it was a 5mm HSS bit I used.

The tap was an intermediate taper one.

[Drezza]

Don't think it would make much difference and it was a 5mm HSS bit I used.

The tap was an intermediate taper one.

Tried again with the intermediate tap and it worked a charm! Cheers Unfazed, lifesaver....


Done about 20 miles on it and nothings fallen off yet (touch wood), so just in time for summer. 

[unfazed]

:thumbup