Lathe Tools

[Trebor]

The last time I used a lathe was at school so looking at the lists of bits n pieces is starting to confuse me. I have an old Myford lathe s7 with rotating tool post. Just looking to learn how to cut internal and external threads and be able to part off. Been looking at RDG tools and mainly wanting to machine stainless would I be better of getting indexable tools due to not having a grinding wheel. I havent got much in the way of tooling and I really dont want to waste any money. Am I better of getting 8,10,12mm shank holders ?? Help please 

[Pete.]

That picture is chuffin huge - can you re-size it to 800x600 please?

What grade of stainless are you cutting? Some of it is hard on lathe tools.

[Trebor]

Hows that ?  Stainless grade about 316 but could go harder.

[dsquire]

Trebor

I was going to offer to fix that photo up for you but you beat me to it, good for you.   

That is a 100% improvement. With the original size you had posted a lot of members tend to just look at the thumbnail which doesn't show any detail. Have a look at some of the posts by Rob Wilson. They are a good example of the perfect size of photo to post in these forums.

I will leave the rest of the questions for someone more qualified than myself. 

Cheers

Don

[Rob.Wilson]

Photo is spot on now Trebor 

In a Myford 4 way tool holder can only use up to 6mm / 1/4" shank tooling , the quick change tool holders made for the Myford will take 8 mm shank tooling .

I use these 6mm ones on my Myford . Set of 6mm Glanze Mini Indexable Turning Tools XC50  (Ref: 777101.)

http://www.chronos.ltd.uk/acatalog/Glanze_Boxed_Sets_of_CCMT_Turning_Tools.html

You get more use from your tips with the set as you can make use of all four corners on the tips for cutting .

I use them on SS and a range of other materials , shots below using same lathe as yours .
Machining a Stainless steel spindle . 





work fine for me


Rob

Edit , above tools can be bought individually

[Trebor]

Thanks for that, I will have a look later on.

[Trebor]

So you could not use 8mm shanks in the 4 way tool holder ? only Ive just looked at one I got with it and it measures 8mm.

[Rob.Wilson]

Put the 8 mm tool in the holder , is the tip on centre height ?


Rob

[Trebor]

I'm pretty sure it's under centres will double check when I can get out there ! What's the ideal hight ?

[doubleboost]

Photo is spot on now Trebor 

In a Myford 4 way tool holder can only use up to 6mm / 1/4" shank tooling , the quick change tool holders made for the Myford will take 8 mm shank tooling .

I use these 6mm ones on my Myford . Set of 6mm Glanze Mini Indexable Turning Tools XC50  (Ref: 777101.)

http://www.chronos.ltd.uk/acatalog/Glanze_Boxed_Sets_of_CCMT_Turning_Tools.html

You get more use from your tips with the set as you can make use of all four corners on the tips for cutting .

I use them on SS and a range of other materials , shots below using same lathe as yours .
Machining a Stainless steel spindle . 





work fine for me


Rob

Edit , above tools can be bought individually

I use the same tool set but in 12mm
Rob what tool will you be using to get a good finish lol
John

[kayz1]

It's that fancy camera of his John that does it..

[paulmo101]

Hi Trebor

As a rule the tip ( cutting area) of the lathe tool needs to be as close as possible to the centre height of the lathe.  An easy way to set yopur tool to this height is to put a centre in either the tailstock or headstock and set your tool so the cutting tip is at the same height as the point on the centre.  If you dont have a quick change tool post ( sorry not looked at your photo) and your tool is below centre height you can correct this by putting packing pieces under the tool in the tool post.  However if it is above centre height you would need to use a smaller section tool.
I recently bought a QCTP and I find it a lot easier but they do cost a bit to get started and extra toolholders are not cheap.

If you do need a few packers I may have some in my garage in a few thicknesses from about 0.6mm up to about 3mm.

Hope the above helps.

Cheers

Paul

[tekfab]

What's the ideal hight ?

STOP !   Me thinks you should maybe purchase one of the many lathe books that are available and work your way up to cutting threads. Asking what is the ideal height makes me think your a tad "rusty" and should have a read and a bit of practice before attempting single point thread cutting on s/s , just an idea ? When you do feel comfortable there's plenty of folk here who will help.

Mike

[John Rudd]

Rob what tool will you be using to get a good finish lol
John

Nowt wrong with his finish DB....Shudda gon to specsavers....  

He's a real master dont ya think........?

[Trebor]

Thanks for the advise, some memories are starting to come back from school and my college days but I will start of with brass first. I got a few problems with the lathe, made a coolant feed with pump and fitted new belts. The lathe has had work done to it before by the look of it. There is a later apron fitted on it and I'm having a job figuring out what's going on with the micrometer dials on the cross and top slides. It doesn't appear to be metric or imperial as there way out, I might have a mixture of parts fitted on here. Starting to think I'd be better off with a new one made in china. 

[paulmo101]

Hi Trebor

I`ve never used a myford so Im not sure how the dials are marked and in what divisions but on some lathes the cross slide measures the actual movement of the cross slide in either mm or thou`s of an inch and therefore this would result in a cut of twice that size.  I.E moving the cross slide .5mm in ( towards the bar being cut) using the dial would result in a cut of 1.00mm.
Hope that helps

Cheers

Paul

[Jonny]

Decent machines namely better British, winding cross slide in X amount marked will reduce diameter that amount. ie  winding in 0.1mm it reduces diameter 0.1mm.

[Rob.Wilson]

Hi Trebor

invest in this book http://www.amazon.co.uk/Amateurs-Lathe-Lawrence-H-Sparey/dp/0852422881 

Rob

[DavidA]

The cross slide on my main lathe moves 0.098" to a full turn. It does this at any position along it's travel.  Doesn't seem to be worn.  In fact it is in almost new condition. Guess it was made that way.
No problem as long as you allow for it.

Dave.

[Trebor]

Hi Trebor

invest in this book http://www.amazon.co.uk/Amateurs-Lathe-Lawrence-H-Sparey/dp/0852422881 

Rob

This might be a good idea    I need to get a few things like a dial guage and a live center etc Also thinking about converting to metric.

[DMIOM]

The cross slide on my main lathe moves 0.098" to a full turn. It does this at any position along it's travel.  Doesn't seem to be worn.  In fact it is in almost new condition. Guess it was made that way.
No problem as long as you allow for it.

Dave.

Dave - I suspect that maybe one of these where the maker has thought - our lathe has a metric leadcrew 2.5mm pitch but we'll make an "imperial" version by just calling it 100 thou per revolution   

Dave (IOM)

[garym]

DavidA:
The cross slide on my Sieg C3 which is metric is marked 0.025 mm per division. It is also marked 0.001" which are obviously not equal. I suspect DaveIOM is correct, it is a 2.5 mm pitch leadscrew thread. Treat it as 2.5 mm per turn.

Gary

[DavidA]

You're both probably right.  With 2.5 mm being 98.425 thou  it would make sense. 
At the moment I have an imperial clock fit up to measure my cross slide travel.  Works well, but tends to get in the way.

 So,  I need to make a 2.5 mm dial.


Damn,  there's always something.

Dave,

[tekfab]

Where about in Britain are you ?  maybe one of the guys that lives close-ish could pop round and have a quick look and see if they can guide you a bit ?

Mike

[bp]

When I got my C3 lathe and X2 mill, I was getting in all sorts of trouble with the leadscrews.....all of them.  So I took my dial gauge + magnetic doofa, stuck it appropriately so each slide could be slid.  In turn each leadscrew was turned one turn and the amount moved noted.  As a result I have the following engraved in my mind.....
C3 Compound 1.0mm pitch
C3 Cross Slide 1.0mm pitch
etc etc
It took about 10 minutes, doesn't require super accurate gear, and its with you for a long time

On my metric C3 with the same dial markings as Gary, there are 40 divisions per turn of the dial, 40 x 0.025mm = 1.0mm

Although I consider myself "bilingual" between metric and imperial, I made the conscious decision to not swap between metric and imperial and to stick to metric.  It avoids a whole lot of confusion.

cheers
Bill

[Pete.]

DavidA:
The cross slide on my Sieg C3 which is metric is marked 0.025 mm per division. It is also marked 0.001" which are obviously not equal. I suspect DaveIOM is correct, it is a 2.5 mm pitch leadscrew thread. Treat it as 2.5 mm per turn.

Gary

Mine is the same. The difference in a full turn is not even 2 thou, so rough it close and then measure for your final cut. To make things even more weird, the cross-slide thread on my lathe is specified on the drawing as an imperial OD but metric pitch

[DavidA]

Pete,

That is more or less what I do.  Here is a picture of my set up.  It's probably more accurate that using a dial.




Dave.

[Trebor]

Just found out that I have a mixture of metric and imperial dials and feed screws on my carriage so at the moment I haven't a chance in hell of sorting it out without spending more money. 

[Pete.]

Just found out that I have a mixture of metric and imperial dials and feed screws on my carriage so at the moment I haven't a chance in hell of sorting it out without spending more money. 

Shouldn't be too hard to fix. Do you know what pitch the screw is, exactly? I put a dial gauge on my cross-slide and measured mine over 1, 2 and 5 turns.

[Trebor]

I did find out that my feed screws and dial for 1 rotation move tool 2mm metric / 1/8 imp. Tested mine and its already been converted apart from the top dial is imperial. So it's turned out a cheap fix.
Why is my coolant rusting my bed ? That's the next topic !!! lol

[Pete.]

I did find out that my feed screws and dial for 1 rotation move tool 2mm metric / 1/8 imp. Tested mine and its already been converted apart from the top dial is imperial. So it's turned out a cheap fix.
Why is my coolant rusting my bed ? That's the next topic !!! lol

Doesn't make sense. 2mm pitch and 8tpi are nowhere near the same.

[DavidA]

Trebor,

Got to agree with Pete. Something wrong there.

RE the rust.  Your coolant mix is probably too weak.

Dave.

[Trebor]

Well the metric dials are 0 to 40 and imp 0 to 100. I have feed screws that move tool post 2mm on full turn. I did check this before speaking to Myford. I have metric cross feed dial and feed screw, metric top feed screw and imperial dial.

[Trebor]

sorry about the pictures this is the only site I have trouble loading pictures on !! just got to get used to it.

[DavidA]

How far does the topslide actually move for 1 full turn of the dial.  Measures with a dial gauge ?

Dave.

[Trebor]

I only have a vernier gauge but on 1 full turn it moves 2mm.

[DavidA]

Then if that 40 on the dial was read as 4.0 it would seem to indicate the amount of reduction on the diameter per revolution.  I.e 2 x 2

Anyone agree ?

Dave.

[Pete.]

Yep, direct-reading dial, 2mm travel is 4mm off the OD.

[Pete.]

Trebor is the compound slide also 2mm pitch? If it is, for now all you have to do is put some masking tape around the dial and double all the numbers with a felt pen.

[Trebor]

Trebor is the compound slide also 2mm pitch? If it is, for now all you have to do is put some masking tape around the dial and double all the numbers with a felt pen.

You have lost me now I'm a novice chap. Both the cross and top slides have the same feed.

[garym]

Hi Trebor,

Compound slide = top slide on most lathes. Does this help?

Gary

[Trebor]

Cheers I've learnt something else today