Thanks John, your comments about the quick change toolholder have probably encouraged me more than the fact that you have made the grinding rest. This because the rest is very popular whilst to my memory you are only the second person I know who has made them. I have been thinking of making a video of it being used to publicise it more.

Having come from the electrical control systems industry, particularly employing large variable speed drives, I have been used to change , and often. Even going back over 60 years I saw the changes happening. Ariving at metalworking I soon learnt that the metalworking individual was far less likely to look for other ways for doing things. In many cases, a 2014 vice is probably not much different to a 1914 vice.

I probably get away with my grinding rests as there is nothing like it commercially, to my knowledge, the options being a fully fledged tool and cutter grinder or one of the simpler rests mainly aimed at the wood working fraternaty.

Unfortunately, I do not want to end up as Harold Hall, the man who designed the cutter grinding rest, but I will not be here to know.

If there is anyone reading this and saying, what "Quick change toolholder", look here- **LINK**

Harold

Well done John, you have made a fine example of the rest, certainly better than mine! My excuse though is that I would have been in a hurry to get it off to the magazine for publication. This particularly as it was part of a series and I never sent a series off to the editor until it was fully complete. Seriously though, with all the time in the world I doubt if I would have produced such a pristine result as yourself. I do particularly like your modified locking handles.

I assume from the photographs that you still have to make the accessories, some of which are essential to get the best from the device. However, with them complete you may like to look at my web site for the pages on using it. Whilst there are others the following two will help you for starters, as they will for others who have made the rest or the simpler rest which I have had published.

Shaping and Sharpening High Speed Steel Boring Tools at- **LINK**

Tool and Cutter Sharpening at- **LINK**

Perhaps these pages will also encourage others to make either of my two rests, both working in much the same way and using the same accessories.

Grinding Rest Basic at- http://www.homews.co.uk/page146.html

And Grinding Rest advanced at- http://www.homews.co.uk/page145.html

Harold

I have been promoted to start adding to my web site the non metalworking contributions to the MEW magazine I made over the 20 years. Typically, Electrical, Mathematics, Timber characteristics, and Photography.

The prompt was because of a contribution to this forum where a question was being asked about the resulting value of placing capacitors in parallel and in series.

So far I have added two items, Basic DC theory and Basic AC theory.

Unfortunately, even basic AC theory is not that simple but I did want to emphasise the fact that Volts times Amps does not give the power consumed (unless a resistive load), an error that I have seen made a number of times when the workshop owner is trying to determine the size of a motor required for a machine.

For those whose understanding of AC theory does not warrant visiting my site but still may like to see some actual values these are for my lathe.

Running just the lathes countershaft

4.28 Amps 360 Watts

Taking a cut of 1.5mm deep at 600 rpm and feed rate of 0.06mm

4.60Amps 662 Watts

That is a 7% increase in current but an 84% increase in power.

My web site also gives the results for running the mandrel but without the cut being taken, Also giving the Power Factor for the three tests.

Harold

Chris

I know nothing about the lathe you have but is there any possibilty that the tailstock is not parallel with the lathe's axis, but at an angle. If it is not, then you could set it on centre at one point, but more or less extension of the barrel, longer or shorter drills would result in an error, Just a thought.

Harold

I see Jack that you mentioned an "internal depth stop" which you intend to make from one of my books. I think perhaps you are referring to what is normally called a "Back Stop". If so, then you may be interested in the improved version, complete with drawings, etc., which can be found on my web site here. **LINK** The pages also detail the reason for the update to the design.

Harold

As my comments regarding my index moved down the list rather rapidly I am making this comment to bring it to the top again to give those who missed it another chance a noting the fact that the index is up to date again. Will only do this this once.

Harold

Thanks Jack for purchasing the book, I do hope you will find it useful.

Regarding the gauges, I would not suggest they serve no purpose but as far as the book is concerned they are there to provide exercises in working to very close diameters and lengths.

For me, I only used the hole gauges very occasionally, that is when I need to get a hole diameter as close as I can to the gauge diameter. To do this, I set my top slide at about half a degree off of parallel with the lathes axis so that a 10 thou feed of the top slide will result in radial movement (depth of cut) of nominally 1/10th of a thou.

By this method I can take very shallow cuts as I arrive near to the required diameter for the bore, doing this until the gauge just enters the hole. Of course the tool has to be honed to a very fine edge for these depths of cut to be taken. You do also need to clean the hole completely to make the test.

This is basically the method I use in the book to arrive at very precise diameters and lengths. The following, scanned from the book, shows a round nose tool that has become magnetised and producing swarf almost like grinding dust. It shows a hole gauge being made with a chamfered leading edge to give early warning that one is approaching the required diameter and then a very slightly reduced diameter to show you are very close.

The distance gauges however I make considerable use of, typically for setting my saddle stop as can be seen by photos 1 and 2 here

Harold

If you have visited my MEW index web site in recent months you may have become disillusioned with it as it became around six issues out of date. Pleased to say now that it is up to date again.

I have also subdivided some sections, Miscellaneous typically, which have become too large.

For those who do not know my index it can be found here **LINK**

Harold

Again I would suggest a look at my web pages on using a fixed steady, as per David's method. Look here for the appropriate page,

Harold

You may find Kenneth my web pages on using fixed and travelling steadies useful. This can be found here

Incidentally, if you need to support a part quite close to the chuck then a three jaw chuck is unlikely to be accurate enough. This, especially at larger diameters and in particular if the reverse jaws have to be used. My web pages cover this and many other aspects of using steadies. The reason for this is that the workpiece is likely to walk out of the chuck jaws, and quite quickly if the error is too large.

Also, unless the workpiece is supported by the tailstock centre, then Clive's method is essential in my opinion.

Harold

I do not know the sharpener you mention Gordon but you must have placed the drill into the device with the cutting edge wrongly orientated. The same will happen with the jig being discussed here. If the cutting edge is not upright the point will take on a curved shape, becoming more extreme the greater the error in placing the drill. See Sk6 here **LINK**

Still, it goes to show that things are not as critical as often unfortunately implied, something I try to avoid doing.

Harold

Cannot comment Jason regarding carbide drills as I have none to see if the flute has a different shape to those on a high speed drill. However, where HSS drills are concerned they are made with a differing helix for different tasks. If these are ground at the wrong angle then the cutting edge will become curved, convex if too pointed for the drill being sharpened and concave if too flat.

See Photo 6 here (left hand drill) and the associated text on that and the following page. **LINK**

Harold

I agree Neil that there is much to be desired with the very common drill grinding jig but in my estimation 90% of the failings are in the instructions received. It has been mentioned on this forum, and I have receieved similar comments by mail, that the contributor has had one stored away for years having found it impossible to achieve adequate results. However, having read my article in MEW, or on my website, have rescued it, tried to use it once more, achieving acceptable results.

I do though agree that there is room for improvement in the device itself, having made one of my own. I do though particularly like Graham's superior pivot arrangement and will endeavour to find time (unlikely) to make the modification to my jig. However, I must go back and read Graham's explanations as I am unsure as to the reason for the tapered packing under the jig's base, is it to correct an error in the angle being ground?

Should anyone like to take a look at my pages on drill sharpening, including using the common drill grinding jig for the purpose. It can be found here **LINK**

Harold

Thanks Michael for giving my website a mention. For an unbiased recommendation, see what Russell Eberhardt said here about the pages on drill sharpening **LINK**

Harold

I would point out Chris that, at the start of the paragraph detailing the speeds, I say "As a starter I would make the following recommendation;" Whilst a few lines further down, having detailed the speeds, I say "With experience you will no doubt be happy to increase these values, probably quite substantially "

Harold

Have a look Bob at picture 53 here **LINK**

Harold

On my thread "Account Closing" **LINK** Ian S C suggested I should, on leaving the forum, place a link to my website here.

The following are a few of the more useful pages

Home Page **LINK**

Metalworking Home Page **LINK**

My Workshop **LINK**

Index to the metalworking pages **LINK**

Other interests, includes model making **LINK**

For those not conversant with my website it presently has about 550 page, mostly metalworking.

Harold

Thanks Andrew for your explanations and must admit I had not taken into consideration that a single CNC setup could carry out what would need many setups if done manually. I still feel that for the workshop owner who wishes to take the CNC route some manual experience would be preferable. In industry a newcomer to the process would surely have some more experienced programmers to guide him or her.

As to the emergency stop I suppose it is my lifetime in control systems that condition me to ask this question. I assume it is a nice large button somewhere rather than a key on the key board and stopping the motions as well as the cutter drive motor.

Whilst involved in large paper making machines and newspaper presses stop circuits were always done using relays as electronics could not be made fail safe, other than using triplicate systems, very expensive. I have seen in the magazines stop buttons feeding electronic controls being normally open. What happens, I ask, if a wire to it becomes loose or the contacts become dirty, you cannot stop the machine. In a typical newspaper press I have known there to be over 500 closed contacts in a series circuit, any failed contact or connection will then stop the machine. It is almost always better for a machine to stop, or not start, without operator action than to not stop when a stop button is pressed, especially is someone's arm is being drawn into the machine.

I agree John, there is a lot of satisfaction in producing a control program and seeing it working when the button is eventually pressed. A point I tried to make earlier relating to using CNC for the clock I made.

I think now I should fade out of the picture, nice to have been involved and thanks to all who have been reading my comments over recent years. See here **LINK** I will though continue to read the threads for another week or two.

Harold

I have disposed of the magazines I referred to, to make my skeleton clock, so am not totally sure, but have looked at the ME index and think the article "Finishing a Gold Medal Clock" in ME issue 4325 (2008) is the one I found it very useful.

Rather than using lacquerer I used a Carnauba wax polish from one of the suppliers to the clock maker, Again, have not kept the invoices so am not sure which one. If you are making the John Parslow skeleton clock it is one he listed.

Harold

Andrew's suggestion that a digital only magazine is interesting and could revolutionise contributing with no need to go through an editor, or ask approval. However, how long would they be available as there are many reasons why they may not. As Bazyle says, the details could easily disappear with the failure of the company holding it at the time. Paper copies are still available of the magazine published some 100 years ago and with careful storage would be in another 100. OK, they would unlikely be very relevant but would be interesting historically.

At a much lower level I often wonder what will eventually happen to my website, and with that in mind have considered offering it on a DVD but then who will be able to use DVD in say 20 years time, people will probably say, what is a DVD. I am though reluctant to make the offer as the site is still being developed but then it may become too late.

I find Peter's comments regarding CNC interesting as I have always considered that it would be difficult, but not impossible, if not dangerous, to use a CNC without learning the basics manually. With a manual machine you can stop winding the handle immediately should a problem arise, or even better still, just before it gets out of hand. Does a CNC control system have an emergency stop button.

With regard to your suggestion for an article on workpiece holding I have done a number but if I did another it would probably be considered as unnecessary repetition. All is not lost though as you can see the article on my website here **LINK**

Also, my latest addition may be of help. I have started a gallery of machine setups and the first is setups using the angle plate. See here for this **LINK**

Incidentally, how soon is too soon for a repeat article. My article on updating a drilling vice which had a large part in starting this thread was in issue 110 (2005) and was actually part of a series on milling on the lathe. Its purpose, primarily, to illustrate just what could be achieved if only a lathe were available.

Harold