lathe radius tools

[T0rnado69]

so ive been trying to find someone who sells these.
but i need a smaller radius one like 4 to 5mm
just cant seem to find anyone that sells these type of cutters anymore.
anyone know of a place that does? cheers.

 

[123hotchef]

cant you just grind your own

 

[Hood]

You can get radius milling cutter, they should work if you made up a holder.

 

[6ply]

How uniform do you need the radius? If all you need to do is round an edge over it should be easy enough to shape HSS on an off hand grinder.

There is a small chance I may have some carbide radius cutters in a box somewhere, but I believe they will be a larger radius. What shank size do you need?

 

[Agroshield]

can't you just grind your own

Carbide will cut HSS no problem, so milling might be an option as well.

If he needs 4mm & 5mm radius, that is 8mm and 10mm diameter and carbide end mills are cheap.

Angle the stick of HSS just a little to give some clearance and don't worry about top rake.

Technically, it will not be an arc of a circle but it will be close enough.

As an alternative to Hood's radius milling cutter, carbide-tipped roundover router cutters are worth a try (but affordable ones only come in imperial dimensions, 5/16" or 3/8" radius). On aluminium, they will work well, steel just abourt, stainless, no.

 

[Hopefuldave]

Cheat, buy a carbide router roundover bit, unbraze one of the inserts (if they're separate, the whole thing if not) and braze it onto a bit of key-stock/ground bar etc.?

 

[T0rnado69]

cant you just grind your own

ermm ive never tried to grind HSS before or even make any type of cutter before.

You can get radius milling cutter, they should work if you made up a holder.

hmm il do a search on that cheers,

How uniform do you need the radius? If all you need to do is round an edge over it should be easy enough to shape HSS on an off hand grinder.

There is a small chance I may have some carbide radius cutters in a box somewhere, but I believe they will be a larger radius. What shank size do you need?

well ild like it to be fairly good of a radius. not sure what the one above is. might well be 1//2" radius.
bit too big for trying to put nice ends on some 10mm bar. as for the cutters i can use any between 6mm to 16mm. think the one above is 12mm

Cheat, buy a carbide router roundover bit, unbraze one of the inserts (if they're separate, the whole thing if not) and braze it onto a bit of key-stock/ground bar etc.?

i do have a few of these but i use them in my routers for woodworking, dont really wanna mess one up for this little job.
seems very strange that places are not selling these anymore.

unless i get a radius turner/ball turner for my lathe. something to look at i guess.


thanks everyone for your replies.

 

[Hood]

....
seems very strange that places are not selling these anymore.
....

CNC has basically done away with the need for them.

 

[frank horton]

plenty of ball turners on utuuube....
mind there was few on the beach last week when I had to drive by.........

 

[Johnnybravo]

Easy to grind and easy to polish. No fancy tools required. Turn a piece of aluminium to the required radius. Mark your radius on a piece of HSS with a sharpie and grind it to shape on a bench grinder making sure to cool it frequently that the HSS does get too hot. When you are grinding it, hold your HSS at a bit of an angle so you get some cutting clearance. Cover your slideways on the lathe, put some valve grinding compound on your aluminium mandrel and polish the radius you just ground. It’s easy to see where the high points are now. Bear in mind you don’t need to polish the whole tool, only the first couple of millimetres of the profile. Again, when you are lapping/ polishing on the aluminium, don’t hold the HSS square to the mandrel, again, at an angle to maintain the cutting clearance.

 

[iNf]

You can also use a piece of silver steel/ gauge plate which is easy to turn/mill/file/grind then harden

 

[T0rnado69]

CNC has basically done away with the need for them.

yes true i guess.

plenty of ball turners on utuuube....
mind there was few on the beach last week when I had to drive by.........

i mean i guess i could make one but its the time factor, if i can buy one that will fit. i might just do that. as it will be a handy tool to add to the lathe.
otherwise it means making one at a later date i guess

Easy to grind and easy to polish. No fancy tools required. Turn a piece of aluminium to the required radius. Mark your radius on a piece of HSS with a sharpie and grind it to shape on a bench grinder making sure to cool it frequently that the HSS does get too hot. When you are grinding it, hold your HSS at a bit of an angle so you get some cutting clearance. Cover your slideways on the lathe, put some valve grinding compound on your aluminium mandrel and polish the radius you just ground. It’s easy to see where the high points are now. Bear in mind you don’t need to polish the whole tool, only the first couple of millimetres of the profile. Again, when you are lapping/ polishing on the aluminium, don’t hold the HSS square to the mandrel, again, at an angle to maintain the cutting clearance.

its something ive never done or tried before.. would need to get some tool steel i guess and give it a try, i guess it wouldn't hurt to try. i mean i can only mess it up LOL
il have to search for some HSS

You can also use a piece of silver steel/ gauge plate which is easy to turn/mill/file/grind then harden

true enough i guess.

 

[Hood]

Another option would be to buy an insert for a milling tool and make a holder up, you could then get different rads later on if required. Then again buying a ball turning attachment may be the cheaper option in the long term.

Inserts | Protool Ltd

www.protool-ltd.co.uk

 

[addjunkie]

SAGD Convex Radius Turning System - Multifunctional Lathe Tools - Lathe Tools Cutwel Ltd

Cutwel is one of the UK's leading engineering cutting tool suppliers. With over 25,000 products stocked, we are unbeatable on quality & value. Buy Now.

www.cutwel.co.uk

bit small for your needs

 

[iNf]

il have to search for some HSS

Broken centre drill/milling cutter...easy to make a holder for

 

[6ply]

SAGD Convex Radius Turning System - Multifunctional Lathe Tools - Lathe Tools Cutwel Ltd

Cutwel is one of the UK's leading engineering cutting tool suppliers. With over 25,000 products stocked, we are unbeatable on quality & value. Buy Now.

www.cutwel.co.uk

bit small for your needs

But look at the prices!

@T0rnado69 just get yourself a bench grinder and some HSS and give it a go!

 

[T0rnado69]

yer i see what you mean.

already got two bench grinders., just need some HSS and knowledge on what to do lol

 

[Seadog]

Just mount a rounding over cutter in you toolpost. No need to destroy it. Set one cutting edge horizontally and away you go. I've done it a couple of times.

 

[T0rnado69]

Just mount a rounding over cutter in you toolpost. No need to destroy it. Set one cutting edge horizontally and away you go. I've done it a couple of times.

il take a look and see what size ones they are. dont remember off hand. might have one that has a small radius.

though i just took the tool block off and pulled the compound apart, as i want to get a new quick change post.
and needed to take measurements and find out bolt hole size etc.

 

[RichardM]

I just grind HSS to shape and finish the cutting edge with a round diamond file.