Chamfering on the lathe

[Oompa LumpaParticipant @oompalumpa34302]

Posted by Neil Wyatt on 24/05/2014 19:31:10:

Ian,

So, it seems there are files designed for safer use on the lathe:

"Designed for smooth finish lathe work on either hard or soft metals, this file has the teeth cut on a long angle. Both edges safe (uncut) to permit working next to a shoulder without injury to it. Also used for finish filing of aluminum. Files are single cut. Opposed direction of the cut on the front and back side forces the file away from the chuck during lathe work, improving safety."

**LINK**

Neil

This Article confirms that (as I recall) Single Cut Mill Files are the best for use on the lathe. I think the Pferd file you linked to might be just that type, the main difference i believe are the number of safe edges. That and the fact that you keep on pointing out all of these really nice tools that are readily available to you – if you live in the US 

graham.

Edited By Oompa Lumpa on 25/05/2014 08:15:18

[JasonBModerator @jasonb]

Bit of a shame they only list Bastard cut, may be a bit heavy for some of our work

Bills point about holding the file at an angle is quite true, I find the metal particularly non ferrous peels off much faster when the file is angled.

I do prefer a cutting edge though, handy for items with a number of small/short steps in dia where you would not get a wide file in.

I suppose this just scrapes in as chamfering on the lathe, a boring bar in the boring head that will chamfer internal and external corners.

J

[Ian S CParticipant @iansc]

If you look at an ordinary single cut file, the cut is at about 30*, on a long angle lathe file the angle of the cut is around 60*. I'll have a go at a photo at some stage, I'v actually picked up three of them, one at the rubbish dump over 40 years ago, second one at an auction when I bought a pair of V blocks ex a NZ Army mobile workshop, The thrird one at the local second hand shop, cost $NZ2 brand new. Ian S C

[Alan HopwoodParticipant @alanhopwood63369]

If you have a Stihl chain-saw dealer in your area try one of their flat files for adjusting the raker teeth. The files are about 8" long and have two safe edges. With the available wooden handles there are at least three of them living in various tool trays. BTW I know it is not PC, but for fighting for the odd tenth on a fit they are brilliant when flooded with straight cutting oil.

Regards, Alan.

[Colin HeseltineParticipant @colinheseltine48622]

Hugh,

Thanks for the photo and the size info. Looks as though I need to invest (again). Will look out on Ebay for T2 QCTP. Would also like a QCTP for my Cowells.

Colin

[Nigel McBurney 1Participant @nigelmcburney1]

Chamfer tools as per the 90 degree pointed tool shown above with no top rake are ok for brass or cast iron ,to get a good finish on steel or bronze a chamfer tool cuts better with top rake, I use a Dickson toolpost and have a 6 inch long ,half inch square HSS tool bit permanently fitted in a toolholder , looking at the tool holder from the top,it is set parallel to the cross slide ,the toolbit has a 45degree angle ground right across the tool and top ground onto it, in this position small edgebreaks to wide chamfers can be machined on outside diameters. Now to machine chamfers on bores the toolholder is positioned parallel with the lathe bed ,the other end of the toolbit now protrudes towards the chuck this end also has a 45 degree chamfer with top rake,though more clearance on the front face has to be ground as it is boring type tool,so say a tube can have its outer edge and bore chamferred by just indexing the tool post through 90 degrees, The toolholder is marked with yellow tape so that it can quickly identified from the other dozen or so toolholders. I have used this method for twenty odd years on my Colchesters and it is quick and convenient particularly when earning a living at it.

When I trained as an instrument maker ,the use of files for breaking edges was more common than using a graver,the files were classed as super smooth and were either 6 inch and or long narrow 8 inch pillar files the tooth angle was normal . On the other hand a turner in a machine shop would not use a file ,he would be expected to achieve finish and size by turning , When I moved to a small toolroom cum model shop,it was noticeable that my colleague trained as a fitter and turner never used a file on a lathe but always used the power feed whereas I being an instrument maker nearly always fed by hand on mill and lathe on the smaller work,and even now rarely use power feed on my ton and a half mill if the travel to machine a job is less than 6 or 8 inches,you can feel what the cutter is doing and I cannot see why so many modellers want x,y power feed on small mills. z feed on the knee would be far more usefull but is rarely fitted

[V8EngParticipant @v8eng]

If I remember rightly PFERD tools have a UK arm, might be worth asking them about machinists files.

 

Edited By V8Eng on 27/05/2014 16:58:11

[Ian S CParticipant @iansc]

Here's a look at the long angle lathe files, One coarse, one fine. Ian S C

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