Lathe tooling - worth a punt

[SVB]

Hello.

Bit of newbie advice requested.

I've just bought a small lathe (ML7) to make fitmemts / mounting items for my wood projects but am struggling to get a decent finish on the items I'm turning.

I've had a got at grinding HSS tools after reading up / watching YT but suspect I'm going wrong. Problem I think is a lack of understanding how metal cuts (I know how wood cuts, fibres sliced with bevel support etc but have no mental model of what I'm trying to physically do to the metal). Anyway, Picture attached of the tool I've ground that seems to look like examples with the 3 angles as good as I can get them.

To take this hassle out of the equation I'm thinking of buying some inset tooling and seen these, do they look worth a try of too cheap to be any good?

https://www.ebay.co.uk/itm/302073262947

Thanks in advance

Simon

 

[TFrench]

I bought my dad a set of the insert cutters from RDG tools, he says they're brilliant.

 

[SVB]

I bought my dad a set of the insert cutters from RDG tools, he says they're brilliant.

Do you know which ones, they have quite a range?

Thanks
Simon

 

[novocaine]

it's very hard to see in your pictures, but it looks like you have negative or no rake on the forward face. could be wrong though.

is the tip of the tool lined up with the centre? either you've been really lucky or the lack of shims under the tool suggests it isn't. that's the first thing to look at.
then it's feeds and speeds. what are you trying to cut? there are plenty of charts out there (and most likely a set in the back of the book for your lathe) to give you an indication, you might find you are way out, again this will make a massive difference to cut quality. if you are feeding in by hand this can also have a similar detrimental effect if you aren't used to doing it, but it should still be passable.

you've got a few other issues, like stick out could be a bit long on the tool so you are getting chatter (especially if that face isn't right), and only 2 bolts locking it down (it isn't critical but it's best to use all 3 lockdown bolts if you can).

hopefully that'll get you started. don't just jump to insert tooling, whilst it is a great tool, it won't fix other issues. like most tools, you need to learn how one works before you jump to the next (think like not using hand tools at all, you miss out the basics by just jumping straight to power tools)

It's been recommended on here before but "the amateurs lathe" is worth reading.

also look here https://store.lathes.co.uk/

and although it isn't for your lathe (or make for that matter), boxfords "know you lathe" is good too for a basic insight in to setting up and turning. (note, I have a boxford hence I know about it) http://www.pulse-jets.com/boxford/boxfo ... _lathe.pdf

edit to add, pictures of the work would be useful, easier to see what's wrong from that than guessing.

 

[woodpig]

If you're having problems grinding your own tools then these two should sort you out.

http://www.jbcuttingtools.com/epages/es ... 10%2011%22

http://www.eccentricengineering.com.au/ ... &Itemid=17

I use both and they cover 99% of the turning I do.

https://youtu.be/Q___K61iKdI

 

[novocaine]

don't know if anybody on here watches this chap, but it's worth a look in.
HSS tooling
https://www.youtube.com/watch?v=__A2xtLF0AU

Carbide
https://www.youtube.com/watch?v=rsFFWYo8ugw

bear in mind that most small lathes can't go fast enough for carbide as such (although it still works)

 

[hawkeyefxr]

I have the opposite trouble to you, metal turning is second nature to me where as wood i am just learning, emphasis on just,

To describe the angles is quite hard in that i have to get across to the the angles and what they do.
If you are standing in front of the lathe with the tool bit at 90 degrees to a line between the chuck and the tail stock with a round bar in the chuck.
The face of the tool bit that faces the lathe chuck should be ground from top to bottom, more should be ground away at the bottom, this is side clearance.
The face of the tool bit that faces the the work piece should be ground from left to right so that as the tool bit approaches the work piece the left side of the bit should touch the work before the right side, this is front clearance.
The top of the tool bit should also be ground left to right with the edge that faces the chuck should be higher than the right side, the is the rake.
The point of the tool you have ground should be at the centre of the rotating axis to get a nice clean face finish on the work piece.
All three angles want to be about the same, this is a very basic starting point. As with wood turning there are many different and for different types of turning for example brass would use a lot less rake.
The way i have described will leave the tool with a very sharp point, if you mad a small radius instead of a point you will get a better finish.

Hope this helps and can be understood.

 

[chaoticbob]

Simon, I was in a similar situation some years ago when I took up metal-mangling. The old hands always advise grinding your own tools, and they're right - but it's not that easy if you haven't got anything but YouTube and diagrams to go on.
I suspect that if you go for the cheap insert tooling, and it doesn't work out you'll still be asking yourself if it's your technique, the lathe, or the tool that's at fault.

Arc Euro Trade do a set of 8 HSS tools at the same sort of price - I've no experience of those particular tools, but they look very similar to the Proxxon set I bought (at 3x the price) when I started out. The cutting edges are hollow ground, which would be difficult to replicate in a home workshop, but they give an idea of the angles involved and I expect they would give better results than a first go at grinding your own.
If you decide to go for indexable insert tooling you might want to to look at CCGT inserts . They're designed for cutting non-ferrous, but in my experience they work well with mild steel as well, if you dont push them too hard.
Rob

 

[marcros]

is it possible to get his inserts to use with non ferrous or plastics?

 

[woodpig]

Yes, you can get inserts for light alloys and plastics. Polished ones like this work well and can even be used on wood.

https://www.shop-apt.co.uk/carbide-tips ... -tips.html

 

[marcros]

thanks. but can you get hss ones, that can be touched up using normal sharpening methods, rather than carbide?

 

[Inspector]

HSS inserts are available from the US.
http://www.arwarnerco.com

Pete