thin wall cutter for head studs

[jbuckl]

Tonight I started to make a thin wall cutter for cutting corrosion around head studs....to assist head removal.

Bore of 11.4mm seems to clear a new stud so the cutter was drilled 11.4mm

But the outside diameter target size is a lottery.

The reference head I have has various stud diameter holes that vary from diameter 12.5mm to 11.6mm, so now I'm unsure what the best size is to turn the outside diameter to... any advice in terms of any other reference heads out there?

I'm thinking of trying 12.3 diameter...what says you?

Thanks for any useful sizes.

Julian

[stag8manod]

Hi Julian, I would err on the side of caution and plum for the middle road of 12mm. If you are able to get this cutter to full depth it will leave a clear channel and the inner diameter on or close to the stud will guide it true and not cut into the head. Hope this helps.
Cheers Ian A

[mole42]

Hi Julian,
ISTR the Sykes-Pickavant tool wall thickness was about 0.5mm, so if you had an 11.5mm bore with an o/d of 12mm that sounds about right.
However, I'd be surprised if it's metric - Triumph was an imperial company, I might have expected a 7/16" stud in a 1/2" hole, but stranger things have happened!! Then the S-P tool would probably have a 1/32" wall thickness.

[LAMBRETTLAD]

Julian

Your not far from me ,may I have a look at what your doing and offer you any. Help I might be ?

[jbuckl]

Ok thanks, PM sent

Julian

Your not far from me ,may I have a look at what your doing and offer you any. Help I might be ?

[jbuckl]

Thanks Richard, the 0.5 wall sounds sensible, but 12.0mm - 11.5mm = 0.25mm wall, which might not cut for long I was thinking / worrying about, even if i can make it that thin, which is by no means certain yet!!
The parts are being made with metric equipment / tooling / instruments & only 0.5 of a brain (the other 1/2 is still imperial)

Hi Julian,
ISTR the Sykes-Pickavant tool wall thickness was about 0.5mm, so if you had an 11.5mm bore with an o/d of 12mm that sounds about right.
However, I'd be surprised if it's metric - Triumph was an imperial company, I might have expected a 7/16" stud in a 1/2" hole, but stranger things have happened!! Then the S-P tool would probably have a 1/32" wall thickness.

[jleyton]

Thanks Richard, the 0.5 wall sounds sensible, but 12.0mm - 11.5mm = 0.25mm wall, which might not cut for long I was thinking / worrying about, even if i can make it that thin, which is by no means certain yet!!

I hate to hear myself saying this but I wonder whether you could aim for quantity more than quality. Ie If you could make lots cheaply then, even if they don't last long you could discard it and use a fresh one ?

Cheers

Julian

[mole42]

the 0.5 wall sounds sensible, but 12.0mm - 11.5mm = 0.25mm wall

I think it's me that's using the 1/2 a brain......

[jbuckl]

The bar stock is iirc thickwall tube 15mm o.d & 10mm i.d. which means that for me at least, its about a 3 hour job to make, at least the 1st one anyway, slow drilling & turning & hardening. Also, for me & the 1973 machine its on, the 125mm long sub half mm wall is 'quite high quality' in terms of concentricity over length; even more so if it goes down to 0.25mm wall

I have enough tube to make 3 or so more though & some other tube that might work too, so i probably will end up making more than 1.

However, making lots cheaply isn't really possible with the equipment & time I have.

I'll post more info as it develops....first trial might be this thursday evening.

I hate to hear myself saying this but I wonder whether you could aim for quantity more than quality. Ie If you could make lots cheaply then, even if they don't last long you could discard it and use a fresh one ?

Cheers

Julian

[Lokisdad]

Julian (jbuckl). If you are able to make a number of them I'm sure there will be a market for them in the club. I know one person who is in need of one. ( No not me - yet!!!)

Harvey

[Paul Roberts]

I think one problem, for whatever cutter, is the material through which it is cutting, Julian(s) both.

If the cutter bore clears the stud (notionally 11.5mm) then, in an all new components situation, it would only be required to cut through aluminium (any part of the cylinder head obstructing its' passage). However, in the real world scenario, where corrosion (galvanic action) has occurred, the product of corrosion will be in a form of aluminium oxide. This material is extremely hard (it being utilised as an abrasive - amongst many other things) that will, almost instantly, dull the cutting edge of many cutting tools - especially a low-grade version.

How about using the diamond cutting industry approach; a soft tool (copper tube?) dipped in (industrial) diamond dust?

[mole42]

My aged memory tells me that the old ones were blue spring steel but maybe they didn't last too long. They weren't designed for Stag head studs but rather diesel injector removal.

[jleyton]

I'll post more info as it develops....first trial might be this thursday evening.

Ok Julian, I understand. Good luck with your work and, as Harvey has said, maybe you could make yourself a small fortune if you can find a way to make more . I know next to nothing about metallurgy and tooling but Paul's diamond dust idea sounds interesting.

Cheers

Julian

[pagan]

Another thought
Are you going to reuse the head studs/bolts?

If not, then shaving a millimeter off the bolt diameter wouldn't matter.

[milothedog]

Another thought
Are you going to reuse the head studs/bolts?

If not, then shaving a millimeter off the bolt diameter wouldn't matter.

I think the point of the exercise is to cut through the softer materials (corrosion) to cut the stud you would have to harden the teeth on the tool.