Angle of the Toolpost

[Hog-Rider]

Hi all I own a Myford Super 7 Lathe, Had it a few years now but only use it occasionally.My Question I have always kept the toolpost on the crossslide set at the zero degrease marks unless I need to cut a small taper on workpiece,However when I look at utube videos of people using lathes there toolpost seems to be set about 30 to 40 degrease angle on the crossslide why is this ?

 

[addjunkie]

I really only use the top slide occassionally, and set an angle if a job has tapers bigish champhers, or for screw cutting, at half the thread angle. Once done it often stays there.

 

[Hopefuldave]

For screwcutting, set at half the thread included angle less a half-degree, so it cuts on one side of the tool (and you get more uniform forces to take up backlash etc.) and barely shaves the other, also it gets the topslide handle out of the way of the cross-feed when feeding by hand?

Dave H. (the other one)

 

[grim_d]

You may find often that the compound is set at an angle for clearance.

On my Harrison for example if set at zero degrees it's easy to bang the tailstock into the handwheel.

 

[frank horton]

makes no differance if ur turning parallel to the bed.......as above it depends on what clearance is needed.....tail stock can get in the way...
I have a Super 7 and a Colchester Student and I norm run at Zero degrees depending on the last job was.......
PS what tool holder do u have on the S7.......the standard horse shoe type wasnt very good.....
I use the Dickenson quick change tool holder, it all helps with ease of use.......
if u want further info P.M.me......no probs.......

 

[Hog-Rider]

Thanks guys ,Hi Frank, I have tried a number of tool holders but use the Swiss quick change type. I getting an Idea now that its probably just personal preference .At the moment I am also trying to think of a way of Indexing the fixing plate on the rear of the chuck.

 

[grim_d]

Some will also use specific angles so super precise advancements can be using the compound rather than the cross slide.

Lyle Peterson has a good YouTube video about it which I'm struggling to find at the moment.

Edit: here's an alternative (haven't watched it)

 

[Pete.]

My compound slide fouls the cross slide when turning small parts with the tailstock centre. so I have to keep it turned. 6 degrees is a good one to use, then 10 thou on the compound gives you 1 thou straight in. Good for taking tiny cuts if you have a sharp enough tool.

 

[Maker]

Mine's just at whatever angle I last used it at, usually 62.5 degrees from threading.

 

[graffian]

My compound is nearly always at an eyeballed 27 degree or 29-1/2degree.
The toopost is always set perpendicular to the spindle.
Of course there are times I need to move one or other.

I use a dial gauge to set toolpost angle, and set tools in their holders with a dial gauge, but that
is for threading tools I set them by eye unless I need a specific angle.
I did verify the compound scale by checking when I had set the compound and I was around .15degree out, so close enough.

 

[Tangledfeet]

Some will also use specific angles so super precise advancements can be using the compound rather than the cross slide.

Lyle Peterson has a good YouTube video about it which I'm struggling to find at the moment.

Edit: here's an alternative (haven't watched it)

This Old Tony did an excellent explanation (even I could understand it!) on the sine bar and how the compound slide can be set for added accuracy - the whole video is superb but this bit starts at 17mins in:

 

[grim_d]

Good shout Andrew, I forgot ToT had covered it in that video!

 

[Turbo]

That's something I always wondered as well, I keep mine on 0 degrees but turning it round a but would help clearance on the tailstock.

The first time I used the lathe after fitting a newly painted tailstock I promptly slid it up the bed into the handle for the top slide, chipping the paint! The air turned blue for a few minutes!

The down side would be losing the ability to remove an exact amount off the length of a bar using the top slide dial. I'm guessing that if you set it to 45 degrees it should take off half the amount indicated?

 

[earthman]

Good shout Andrew, I forgot ToT had covered it in that video!

He's one of the best on YouTube I'd say, I can imagine that every video he makes takes ages what with editing/special effects.

 

[eLuSiVeMiTe]

That's something I always wondered as well, I keep mine on 0 degrees but turning it round a but would help clearance on the tailstock.

The first time I used the lathe after fitting a newly painted tailstock I promptly slid it up the bed into the handle for the top slide, chipping the paint! The air turned blue for a few minutes!

The down side would be losing the ability to remove an exact amount off the length of a bar using the top slide dial. I'm guessing that if you set it to 45 degrees it should take off half the amount indicated?

Yup but move it into he work the same amount.
Mine lives at zero. As long as my handle has the counterbalance forward it clears the tailstock.

Edit. See below

 

[Maker]

I'm guessing that if you set it to 45 degrees it should take off half the amount indicated?

No, that would be 30 degrees, 45 degrees would take off 0.707 times the amount you wind it in.

 

[eLuSiVeMiTe]

No, that would be 30 degrees, 45 degrees would take off 0.707 times the amount you wind it in.

Learn something every day never thought to try it out.

 

[grim_d]

Learn something every day never thought to try it out.

Unfortunately we were supposed to learn trigonometry at school...

 

[eLuSiVeMiTe]

Unfortunately we were supposed to learn trigonometry at school...

And I probably would have done if they related the lessons to the real world.
Doesnt stop me hand cutting a roof mind.

 

[Seadog]

This is "The Real World," though. If only you'd paid attention At the time you can never imagine a use for certain things you should have learned. Mind you, most the stuff I learned is well and truly forgotten