Tool tips

[David Clark 13Participant @davidclark13]

Various tips to make life easier in the workshop

[David Clark 13Participant @davidclark13]

To find out the exact centre height of your lathe headstock, turn a bit of bar to a known diameter.

Say the bar is 0.500 and the measured distance from the lathe bed to the top of the bar is 3.745in.

The exact centre height is 3.745 minus half the bar diameter = 0.250in. so the centre height is 3.495in.

This is a very useful dimension when setting tools to centre height.

regards David

 

[keithmartParticipant @keithmart]

Hi

What about setting the tool as near as possible by eye, facing off a piece of bar, and using the centre pip left on the bar to set the exact tool height?

regards

Keith

Leeds UK

[Ian AbbottParticipant @ianabbott31222]

Keith wrote:

What about setting the tool as near as possible by eye, facing off a piece of bar, and using the centre pip left on the bar to set the exact tool height?

 

Funny, I thought that I was doing it that way because I’m lazy to do it properly. 

 

Ian 

[David Clark 13Participant @davidclark13]

Hi There

Great idea.

I will try the pip idea next time I set a boring bar.

regards David

 

[Sam StonesParticipant @samstones42903]

Hi David,

 

I think it’ll take forever and you’ll become really bored just before it gives you the pip.

 

Best regards,

 

Sam

[AndyBParticipant @andyb47186]

Hi all,

 

To set a tool at centre height I just swivel the topslide around and match the tool to a nice sharp centre in the tailstock.

 

It is easier to feel the level if the eyes are starting to clap out, but just as easy to see for  the younger members.

 

I keep a pile of old, very worn (so not to have the teeth upset the measurements) hacksaw blades broken off into short sections as shims if I am using tools of different thicknesses.

 

Works every time and takes about 30 seconds. Once set, you can take what time you like to set the angle of your topslide.

 

Andy

 

 

[Anonymous]

Paah, the whole centre height thing is a pipsqueak!

 

Regards,

 

Andrew

[adyParticipant @ady]

Just make a tool which sits on top of the toolholder and hangs down to the correct centre height.

 

A hex wrench shape, like a gooseneck/elephants foot, hold long bit flat on toolholder with thumb and position the cutting tool to touch the bit which overhangs.

 

easy peasy lemon squeazy

Edited By ady on 17/10/2010 21:51:28

[Steve GarnettParticipant @stevegarnett62550]

If your lathe is level, you could always use one of these, or even make one pretty easily:

 

 

 

[chris stephensParticipant @chrisstephens63393]

Very interesting, does this video define the expression “overkill”?

chriStephens

PS next time i get bored might have a go at making one, I have little space left in my box marked “sounded like a good idea at the time but in reality never used” 

[WALLACEParticipant @wallace]

The problem with the pip method is that it’s dead easy to take the end of a carbide tool  .  .  . no prizes for guessing how I know.

 

There was a tool described in MEW a few years ago using a lump of perspex with a couple of lines scribbed on it to avoid paralex errors – I always thought this was a  very clever idea – but still haven’t found the time to knock one up !

 

W.

 

 

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

The Editor touches on a subject of interest in measuring the exact centre height
of his lathe . A real engineer when presented with a new machine of any kind
will spend a little time getting to know it and part of this familiarisation process is

finding out what the primary machine datums are for future reference. On a lathe such as a Myford the useful datum measurements are bed to centre , top of crossslide to centre , top of topslide to centre and top of tool post mounting face (if of four toll turret type ) to centre . With these measurements available from the start all setting up of work and tools becomes an exact process . Setting up any loose tooling just requires you to measure the height of the tool itself and the simple arithmetic gives you the exact thickness of packing needed – similarly for setting up a job for boring on the cross slide .

 

 

[Howard JonesParticipant @howardjones35282]

I put a center in the morse taper of my headstock. then another centre in the tailstock.

bought the two up together with a razor blade between them. the blade sat perpendicular to the bed confirming that the heights of both centers were the same.

 

thereafter I just put the metabo keyless chuck in the tailstock. I have a 2mm chinese drill that I murdered by breaking the flutes off and grinding to a precise point. this gets set in the chuck (which is accurate). the tool is then placed against the pin point and adjusted to be a tad below centre to prevent rubbing.

 

If I ever doubt the accuracy I put the centre in the headstock and check the height of the pin.

been ok so far.

works with boring bars, armstrong tool holders and hacksaw shimmed quarterinch hss tooling.

 

measurements have errors. this method has none.

 

but!!!! you go on doing what works for you. I’ll do likewise. none of the techniques are wrong but how do you know your measurement is being made exactly vertical?

 

[WALLACEParticipant @wallace]

How about one of those laser thing’s held in the chuck ? (or better still a collet ?)

 

I suppose it depends on how wide the beam is to how accurate the height would be set  .. .

 

w.

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

I can set a newly ground tool to centre height with an error of less than one thou in under twenty seconds from picking up the tool bit to locking down in the toolpost and I can do it time and time again with no subjectivity and no drifting errors .  

 

Obtaining a true measurement of the separation of two components requires a complete assessment and preferably nullification of all error components . The off true angle would have to be several degrees before it had any significant effect and in any case it is just as easy to do it right in the first place .

 

There are  right and wrong ways of doing any task . As far as  tool height setting in the home workshop is concerned the only methods which have any real credibility are :

 

(1) Accurate measurement based methods .

(2) Fast trial and error methods like setting to a fresh turned pip .

 

Within the above there are certainly different ways of actually doing the job but the details do not change the fundamental nature of the process .

 

Lasers are in common use in industry for the accurate setting up of machine tools and , at great expense , there are companies that will come and set your tools for you !  Serously lasers are usually used for the primary setting up machines – tool setting is more often than not still done with dial gauges and comparators .

[Richard ParsonsParticipant @richardparsons61721]

 

My eyes are not as good as they were. So I made this little Gizmo.  It works you get a coconut every time   I have written it up and posted it to the editor as a contribution.

[Sam StonesParticipant @samstones42903]

When I was a lad in’t toolroom (c1950), there was one toolmaker who did most of the intricate turning. However, his eyesight was so poor that he wore glasses so thick they were like the proverbial beer-bottle bottoms.

For really intricate work, especially when there was a need to locate a `tight’ spot, he used a simple flash-lamp battery and bulb arrangement. The cutting tool was electrically insulated from the body of the machine, which thus became the `earth’ return.

Richard, I hope this doesn’t read like a “Me Too!”.

Your photograph appears to show a Super 7 with a Bernard `Grip-True’ three-jaw chuck.

Fond memories for me!

Sam

[Richard ParsonsParticipant @richardparsons61721]

It is but it uses two LEDS culled from broken lighters. The cheapo light is insulated (with masking tape. A Super 7 bought in 1975 with a body threaded Griptrue.

Thanks for the tip about insulating the tool The next lighter I find with a torch I will look at that idea.

Must go as I have to repair a shower bath, Hungarians seem to be able to break anything

Edited By Richard Parsons on 19/10/2010 09:22:47

[David Clark 13Participant @davidclark13]

Hi There

I too worked with a turner who appeard to have bad eyes.

Did super work but kept getting his head too close to the chuck.

Boss told him to get his eyes checked.

Two weeks later he was seen wandering around with a white stick.

He was almost totally blind.

We wondered how he had driven to work every day.

regards David

 

[BogstandardParticipant @bogstandard]

Setting centre height

 

 

Bogs

[KWILParticipant @kwil]

I use a old fashioned double edge razor blade (thin, hard material) for this, it also works when aligning two centres, try it between your spindle and the tailstock sometime.

[Howard JonesParticipant @howardjones35282]

michael williams old sausage you have a lot to learn. (which is good because life will be interesting)

the old dodges used by turners of old have a lot going for them. they tend to be less error prone when the user is in the faded stage before being aware of fatigue and packing it in for the night.

the method I described also has the advantage of alerting you to a positional error in the tailstock well before relying on the accuracy for a drilling job.

also I would make the point that methods that work on the myford with it’s flat bedways often cant be used on a hercus or southbend because they use V ways.

the method I described doesnt use batteries, pencil , paper or a calculator. It uses the inherent accuracy of the machine tool.

 

Bogs your ruler method will come unstuck on the first piece of irregular shaped bar that you try it on. on the stuff I seem to turn it would never work until a truing cut was made.

 

I hope you all live long enough to have David tell stories about you and your accuracy.

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

One of us is obviously an idiot so lets find out who – open invitation to all contributors to this site to say which of us is right about fundamental issue of accuracy and how to achieve it .

[David Clark 13Participant @davidclark13]

Hi There

Can we calm down?

We can all use whatever method we like to set height.

Does not matter.

Razor blades at dawn are not required.

regards David

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