Valve seat cutter

[John Rudd]

I need to make a valve seat cutter but have come across a slight problem..........

My original intent was to make the cutter from Silver Steel, profiled and hardened to suit...

I started making a mock up from some EN1a 1" diameter bar but found it was a tad too small...The SS needs to be ideally in the region of 1-1/4" but I cant source any.......

Back to drawing board....

EN1a is in plentiful supply but I'm not sure it can be hardened to perform as a cutter..

So, what else can I use along with the EN1a bar to make a cutter?  was thinking along the lines of some sort of carbide insert...but not sure how to go about this....?

Just to add the diameter of the valves are around the 7/8" mark...if this helps? and its for a small Villiers engine I'm renovating...

[philf]

John,

Silver Steel is equivalent to O1 tool steel or gauge plate. O1 is readily obtainable in most sizes.

EN1A can be case hardened but isn't suitable for a cutting tool.

Cheers.

Phil.

[Bluechip]

The SS needs to be ideally in the region of 1-1/4" but I cant source any.......

13" lengths are here. Download the supplies catalogue link.
 
Page 9.
 
http://www.livesteammodels.co.uk/suppliescat.html
 
Better to sit down first though ....£30 +vat ish .... not what you might call 'freeware' 
 
Dave BC

[sbwhart]

If you're cutting the seat in something soft like ally or brass you will get away with case hardening.

Stew

[awemawson]

Make a suitable EN1A cutter, but cut a pocket in it for an indexable insert

[vtsteam]

I think a fairly thick old automobile leaf spring under my shed might wake up in the morning to find a bit of its length missing in such a circumstance. 

[John Rudd]

Make a suitable EN1A cutter, but cut a pocket in it for an indexable insert

This is the alternative I'm considering after seeing a countersinking cutter on a Chinese tool website.....

Thanks for the ideas guys...

[philf]

Make a suitable EN1A cutter, but cut a pocket in it for an indexable insert

This is the alternative I'm considering after seeing a countersinking cutter on a Chinese tool website.....

Thanks for the ideas guys...

John,

You may probably already have considered this but there's one more thing to bear in mind - If you are going to use the tool either hand driven or via a power tool rather than in a milling or drilling machine you need to set a stop (possibly on the shaft which goes through the valve guide) so that it not only limits the depth of cut but, particularly when using a single insert cutter, to prevent you ending up with a spiral valve seat with a step where the cutter stops.

Cheers.

Phil.

[Jo]

Case hardened MS worked very well on my Cast Iron  R&B gas engine head. 
 
Jo

[John Rudd]

Case hardened MS worked very well on my Cast Iron  R&B gas engine head. 
 
Jo

Jo do you have any fabrication details  on your cutter please?

Saves 're-inventing the wheel' .....a couple of photos wouldl be great too if you have any ..

cheers

John

[NeoTech]

[rotorhead]

Hi John,

A very good supply can be found here.----- http://www.lawson-his.co.uk/stubs-r080a-silver-steel-imperial-1-1-4-x-p44342

That's just for 1-1/4" @ £18

Chris

[OKTomT]

John this is what I use its made by Neway. Its hand operated and very well.

[John Rudd]

John this is what I use its made by Neway. Its hand operated and very well.

Yeah ,I've seen the Neway offerings but they are very expensive.............Not quite within my budget.. 

[vtsteam]

Don't know how big your valves are but maybe this would be helpful to at least look at.

http://www.homemodelenginemachinist.com/f31/4-cylinder-ohv-engine-new-cylinder-head-work-progress-5529/index4.html#post62611