Hints and tips

[chris stephensParticipant @chrisstephens63393]

My fellow Model Engineers,

I thought it was time we started offering answers, to unasked questions, i.e hints and tips.

So, to start the ball rolling, how.about, put a sheet of brown “kraft” paper on your mill table, poke holes for the vice bolts. The aim is to a, stop all those bits of swarf going in the tee slots, which makes cleaning up easier. b, if you spread oil on the paper it helps to stop condensation and rust, c, helps to stop small drills or milling cutters getting lost in tee slots, turning you table into a table I can imagine someone who shall remain nameless but you know who you are, will say something like “what about fire risk or you should not leave things on the table ‘cos they might fall on your foot “or some such, well phooey.

Another tip thinking of the mill vice, if you have one of those swivelling vices, like the Vertex K series, and you find it a bit of a pain-in-the-you-know-what to set true after cutting at an angle, the simple fix is to drill two diametrically opposite holes ( about 3-4mm should do) in the vice to base flange, (after squaring the vice) then ream with a taper pin reamer and fit two taper pins. You need to use two pins because of the play on the central pivot, one pin allows some movement. Don’t ask me how I know, I just do! 

Still thinking of the mill vice, I got fed up with the cranked handle that come with the thing. Always falling off if you forgot to remove it. Well on the MIT videos , I saw a mill vice with a swivelling handle, and thought A-Ha (eureka moment not Norwegian beat combo) so I made one and boy what a difference. If you have never tried one you don’t know what you are missing.

Well that’s enough from me, hope someone will take up the reins and offer some other tips. 

Well folks that’s all,  back to the Asylum. 

chris stephens

[chris stephensParticipant @chrisstephens63393]

Slight change of tack, offering instead of asking

[keithmartParticipant @keithmart]

Hi

Here is a very simple and easy to do tip;

Do you find that when you drop something in the workshop it disappears under a bench and you spend hours looking for it?

Try placing a piece of 3 X 3 wood in the gap. Things will bounce back into the open, and are easy to find.

It works for me!

Regards

Keith

Leeds UK

 

Edited By keithmart on 09/11/2009 19:26:00

[David Clark 13Participant @davidclark13]

Hi There

A very useful vice handle is a ring spanner.

 

You can do it up lightly or a bit harder and there are many positions to put it onto the vice.

 

If you cut a short length off a ring spanner you can use it to spin the jaws up tight (or out) quickly.

 

I have just bought some roasting tins from Tesco. They are very cheap at the moment, can’t think why?

 

I have two, one for each side of the tray on my Tom Senior mill to stop objects falling down the coolant holes.

I have another one for use on the machine table to hold the tools and spanners etc,  I need to drill a hole in this to bolt it down. (I feel a tip in the magazine coming on.)

 

I have 2 more, one for under the bed near the headstock on each lathe to collect swarf and for easy removal to find lost components.

 

Finally, I am about to fit a TV bracket to the wall above the lathe. No, not for a TV but for the quick change tool holders. I think I will bolt a tray to that as well.

regards David

 

[NilochParticipant @niloch]

Mr Stephens et al, your notion of a hints and tips thread is most laudable.  Your wish to promulgate your expertise should be welcomed by most especially by beginners like myself.

 

I don’t wish to detract from your ‘fire-power’ but I have recently discovered the articles by Geometer and Artificer in the digital archive and thoroughly recommend them.

 

David C: I would have thought that publication of the Geometer series in book form would be a worthwhile exercise.

 

Meanwhile tipsters, if you have a moment or two, please address the following related queries:

(a) I have a second-hand Griptru chuck and despite having the original instructions I’m finding it difficult to adjust so that material runs truly;

 

(b) I have similar problems in adjusting a 4-jaw to hold round work truly; and

 

(c) in Tubal Cain’s book Building the Overcrank Engine Georgina the following advice appears  regarding chucking a flywheel (p.19), “Set up in the 4-jaw gripping by the inside and adjust till true in the usual way with chalk and patience”.

 

Please excuse me if the answers to my queries appear in the very archival information that I am recommending  –  I haven’t read all of them by any manner of means just yet.

 

Any elucidation would be most welcome.  Thank you.

Edited By Niloch on 12/11/2009 15:36:14

[chris stephensParticipant @chrisstephens63393]

Hi Niloch,

As you can see by the overwhelming number of posts, this idea is a non-starter. Such apathy is surely why our Editor has to virtually plead for material to publish. 

Come on chaps and chapettes, if every one of you submitted just one hint or tip there would be a new ME special to publish. 

Hint on four jaw work centring, if you are contemplating much truing, as surely you must if accuracy is your aim, make yourself a tool post mounted DTI holder. Despite what most of the books show, even from the most famous old timers, mount your DTI horizontally and on centre height, not vertically on the cross slide. The obvious benefit is that you have a very easy to use and precise rough set facility.

Put your work in a four jaw or grip-tru and you can bring the DTI into near contact and then spin the chuck, if it is still clear move the cross slide in till it touchs the point of the work that is nearest to it, then turn chuck again. If the the clearance is within the movement  of the plunger, move the DTI in till you have used about half the plunger movement. You are now ready to start centring the work. 

Rotate the chuck till the plunger is far in the DTI as it wants go whilst in alignment with one of the jaws, say this jaws is #1, slacken the jaw opposite (#3) and then tighten #1,  Rotate chuck till another high point is shown on the DTI and repeat process, perhaps it is #4 this time, well slacken the opposite one (#2) and tighten #4. Repeat the process till you have about 2 thou of movement on the DTI when the chuck is turned. Now we come to the bit that seems to confuse beginners, I don’t know why but it does. Turn the chuck and move the cross slide till the average reading is zero, that means the hand moves an equal amount either side of zero, now the point of an average is that it is in the middle, so any movement towards it is getting nearer to centre, if you follow my drift. So now you turn the chuck till one of the jaws shows the highest reading and tighten that one, how hard you tighten it is a matter of judgement learnt from experience (although as a side note I once made a torque wrench type chuck key for this purpose, but we wont go in to that too deeply).

There is usually about half to one thou of “slop” in the jaw adjusters, so watch the dial and tighten till you get a reading of near or at  zero. Turn the chuck till the next highest jaw is aligned and tighten that one to get at or near zero. Rotate the chuck a few times and see what happens, if there is a steady rise and fall of the DTI hand with each rotation, repeat the last process. If you can’t reasonably tighten the jaws any more , just slacken the opposite one a bit less than a tad, but a bit more than a gnat’s doings., and tighten the first one again. Don’t be surprized if things show more than one rise and fall with each rotation, even ground stock is not always round, although it is of one diameter (a consequence of centre less grinding, but that’s another story)

It is because of this not round round stock that you can only really check the run out at  each of the four jaws, otherwise you will be chasing an accuracy that is unobtainable.

All of the above sounds long winded and difficult, it really isn’t and once you have done it a few times I assure you that you will be able to true up work in less than a minute, possibly even square stock, It is a skill that is better demonstrated than written about, but if you remember to only work on two opposite jaws at a time and aim to only tighten jaws not loosen, it will soon come to you. 

On your Grip-tru if it has four adjusting screws then follow the above and it should work just as well.

Perhaps this should be a regular demo on the SMEE stand at MEXs, as part of their beginners training? 

chris stephens

PS please remember if the above doesn’t make a lot of sense that Gibberish is my native tongue not English,  That’s my excuse, go find your own.

[Michael Cox 1Participant @michaelcox1]

Hi Niloch,

I agree that the Geometer and Artificer articles are very interesting.

I cannot help with your problem with the Griptru chuck but perhaps the following helps in respect of your other questions.

To set up a piece running true in a 4 jaw I use the procedure given on http://www.littlemachineshop.com . This works for me.

In Tubal Cain’s engine I suspect that the flywheel is supply as a casting. This is gripped with the inside jaws of a 4 jaw and then spun slowly. Then approach the wheel rim slowly with a piece of chalk. The point furthest from the centre then gets chalked. Adjust the chuck to move this point closer to the centre. Repeat this procedure until the whole of the rim is chalked. This procedure is good for castings because they are so rough that a normal DTI would flicker all over the place.

Mike

[NilochParticipant @niloch]

Chris & Michael,

I thought I’d wait until there were a few more responses before expressing my thanks especially to you Chris (no offence Michael) but I had a little difficulty navigating to the ‘littlemachineshop’ article so here is the url in case the convenience of finding it makes it even more useful for other beginners.

Chris – thanks again for your considerable help, a regular demo at the SMEE stand – yes please!

Michael – thanks also for addressing the chalk issue.

[mgjParticipant @mgj]

If perhaps one could elaborate on Chris Stephens setting up a 4 jaw.

 

1. Make a mandrel turning handle. 

2. Paint one pair of opposite jaw key holes on the 4 jaw. I have red and yellow, so 1& 3 are red and 2 &4 are yellow. (I think – but its opposites that matter)

 

2. Set the clock so it is at the BACK of the lathe bearing on whatever needs to be centred. I use a magnetic base.

 

3. Turn mandrel to the highest point indicated on the clock.

 

4 You SLACKEN the jaw nearest you – note colour.

 

5. Turn chuck til the opposite jaw, same colour, comes up, and tighten.

 

Continue till accurately set using the halving method suggested.  – I find the colours very helpful, and setting the clock up on the far side means its facing you so clockwise is “higher”. So you turn to fully clockwise, slacken this side, rotate, tighten the far side, and it is quick easy and painless.

 

 

Griptru is equally simple. 

 

1. slacken the 3 backplate mounting screws, and just nip up.

 

2. Slacken the Griptru adjusters.

 

3. Put whatever it is into the chuck. and adjust using a clock.

 

When you finish, lock up the backplate screws. Note also that like a 4 jaw, you can’t just keep on tightening the griptrus – they drive wedges into place between body and backplate. So you have to loosen one before tightening others. If you don’t the chuck cannot move because it is wedged solid.   

 

Edited By meyrick griffith-jones on 12/11/2009 18:14:29

[chris stephensParticipant @chrisstephens63393]

Hi Meyrick,

Your method is as valid as any other that works, as a old friend of mine would say,”there are more ways of killing a cat than stuffing cream buns up its as*e” The important thing is that you can do it, not how you do it. If we all did things in one way only, we would not be in a democracy, which we are, aren’t we?

Volunteering for the SMEE stand, perhaps? They can sign you up on the spot, being voted in, at the next meeting, would only be a formality.

chris stephens

[David Clark 13Participant @davidclark13]

Hi There

New section in Model engineers’ Workshop 159.

Tool Tips.

Useful ideas to make life easier in the workshop.

regards david

[mgjParticipant @mgj]

I wouldn’t mind trying for the SMEE. I’m not sure I’m that expert, but it would be nice..

 

You are quite right about setting up in 4 jaws or whatever. These things are all just variations on themes. I’ve just evolved one approach and it suits me, but it would be most unwise to suggest its the only way, or even that it was original. 

 

Everyone can look and cherry pick what suits them. 

 

Castings I often set up with a surface gauge, but that’s no better (or worse) than using a mounted tool point as a reference.

[David Clark 13Participant @davidclark13]

Hi There

Quick method of trueing a casting up in a 4 jaw chuck.

Put a tool into the toolpost.

Put the job in the chuck.

Wind the tool up to the job in line with a jaw.

Zero the tool.

Wind out a turn.

Rotate chuck 180 degrees.

Wind tool in to see how far out work is.
Undo one jaw and move job in required direction

Tighten up jaws.

Continue till true (use both pairs of jaws)..

If extreme accuracy is required, finish with test indicator.

 

Note, at no time should the lathe be running.

 

regards David

 

[chris stephensParticipant @chrisstephens63393]

Hi Meyrick,

You will be glad to hear that there are no entry qualifications to join SMEE, it is open to everyone. There is a popular myth that “I would be out of place” or “They are all hyper-experts” this is completely and utterly false. If this were not the case, why would they run courses for beginners?

Just because the best and most famous model engineers seem to join, does not mean that they alone can join. Join and find out for yourself. 

I only joined on the assumption that knowledge flows downhill, from greater knowledge to lesser, I always want to know more.

One phrase I use is “I know enough to do what I do, but the more I know the more I can do.” A few schools could indoctrinate their pupils with this philosophy to some benefit, me thinks!

If there were to be an entry qualification, your ownership of a Grip-Tru would, alone, surely be enough.

chris stephens

[mgjParticipant @mgj]

Then I will apply this MEX.

 

We have to disagree about 1 thing – tightening 4 jaws.

 

I forget what the leverage of a thread is – something mighty. The point is that it is quite easy with a 4 jaw to squeeze the job rather than move it. So you do have to slacken 1 jaw to move the opposite. Within reason .. but one must be careful they  don’t end up deforming the work.

 

Depends on the nature of the work too, of course.

Edited By meyrick griffith-jones on 12/11/2009 23:04:29

[Flying FiferParticipant @flyingfifer]

Niloch,

when Chris says “SPIN” the chuck he means by hand & NOT with power switched on! Otherwise you`ll better get a tin hat & suit of armour. So when you are centering in this manner make sure to motor is OFF.

 

Moderator. Geometer & Artificer articles were great stuff when I ws a young lad & taught me making things. So how about that other great series “Lathe Lore” written by L.C.Mason in Model Maker. I`m sure a lot of Newbies & Old codgers (bodgers!) like me would appreciate them.

 

Regards Alan 

[chris stephensParticipant @chrisstephens63393]

Hi Alan,

My knight in shining armour coming to a maidens rescue, (just joshing about the maiden bit, if you saw my beard you would be in no doubt. although come to think of it there were freak shows….)

Of course I never intended to suggest or imply running the lathe under power, that would be silly. When I centre, I put the headstock gearbox into neutral, so there is less drag from the motor and the power is OFF

Hi Meyrick,

I had thought I was reasonably clear on this point, for solid material the 1/2 to 1 thou tightening gives about the right grip, as i said I made a torque wrench  key for the 4 jaw to overcome this issue, but with limited success. 

There is no real  substitute for experience and feel. As I said it is much easier to show rather than tell, this is where videos would be better than words, but still not as good as real life. I know we would agree if we were doing it live.

 For tubular stock the tightening must be less but if you over tighten you can see the deformation on the DTI!

chris stephens

[chris stephensParticipant @chrisstephens63393]

Further to my last, 

You will be welcomed with open arms., as would any others who wish to join the best model engineering society in the known world. Any dissenters can join me in the asylum.

 I just had a thought, if you didn’t think you were eligible due to abilities, don’t talk to a certain member from Switzerland, I think he would make Einstein feel inadequate. 

I am of course kidding, he is quite approachable. Wasn’t kidding about Einstein though, well maybe just a little.

chris stephens

[Ian S CParticipant @iansc]

One idea I thought of some time ago,a competion at club or what ever-setting a bar in a four jaw chuck ie how fast,how accurate,perhaps two groups,beginers and experts.Could be either with or without a DTI.IAN S C

[David Clark 13Participant @davidclark13]

Hi There

Model Maker is on our hit list.

Not for a while but as we own the magazine, we can eventually put PDF’s up onto the web site.

They will have to be complete magazines or we are up against the copyright problem again.

regards David

 

[mgjParticipant @mgj]

Overtightening. Yes but what if you start with a thickwall bit of tube and thin it down some?

 

Not a big point, just something one needs to watch.

[chris stephensParticipant @chrisstephens63393]

Yes, indeed, but this is where practice and experience takeover to form that indescribable quality called “Feel”. 

Some people are born with Feel, some people are made to have Feel, and some people have Feel thrust upon them, to paraphrase that old saying.

Well folks that’s all, back to the Asylum. Goodbye.

chris stephens

PS you can tell it is too cold wet and miserable out there to do any real work. Which is why i am in here in the warm ranting.

[Tony Pratt 1Participant @tonypratt1]

Tapping tip, although taps come in sets of three, taper, second & plug you rarely need to use all of them. Just use the taper tap, remove the swarf produced by any means at your disposal and then finish the hole with the plug tap again cleaning the hole to finish.

Also always countersink the hole before tapping, or drill a couple of threads deep with a clearance drill [which is my prefered method] so the threads start below the work surface.

 

Tony

[chris stephensParticipant @chrisstephens63393]

Hi Tony,

At last someone else has chimed in with a H&T. 

You are quite right of course, but have you tried Spiral flute taps, you can drive these in without having to stop and clear the flutes. The swarf comes out of the thread all by itself in three “strings”. Great for machine or hand  tapping on blind holes, but work just as well on through ones too.

chris stephens

[Tony Pratt 1Participant @tonypratt1]

Hi Chris, spiral taps, oh, happy memories! In a previous life I used spiral flute taps [always M6] to tap literally 1000’s of holes in HSS tool blanks whilst my Wire Eroder was cutting on generally long cycle times. I had forgotten about them but as you say they are great to use and the swarf comes out in strings.

I will go and have a look in my toolbox to see if I still have a couple of these good old tools left which I can bring out of “retirement”

 

Tony

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