Member postings for Peter G. Shaw

Here is a list of all the postings Peter G. Shaw has made in our forums. Click on a thread name to jump to the thread.

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Thread: End mills in lathe chuck
19/10/2010 12:01:03
I'd just like to add my two pennorth, not that I'm any sort of expert, but through experience on my lathe.
 
I have tried to use the 3 jaw chuck to hold a milling cutter. It wasn't particularly good with much vibration. It did do it though - eventually. I think I also experienced the dreaded walk out of the cutter, ie where due to the vibration, the cutter slowly works it's way out of the chuck.
 
Using a direct MT3 collet and drawbar, cutting was much better and smoother.
 
The drawbar is inserted into the lathe mandrel from the opposite end to the collet, and is used to force (by pulling) the collet further into the taper in the mandrel. This in turn causes the slightly flexible parts of the collet to clamp down even tighter onto the cutter thus hopefully preventing any further movement. I think as well, by using the collet, I reduced the overhang away from the mandrel bearings thus stiffening up everything. Finally, the collet is likely to be more accurate than the 3 jaw chuck, thus reducing out of balance forces.
 
Now, I use a milling machine!
 
Regards,
 
Peter G. Shaw
Thread: Change gears for my lathe
12/10/2010 13:50:53
Hi Nick,
 
Your chart cuts off at 40tpi and is labelled Fig 16. Mine goes down to 72 tpi, and is labelled Fig 8.
 
As regards the formula for tpi, I had picked up that there was a discrepancy therein, and had found that eliminating the "0035" figure made it more accurate. (Decimal point is  deliberately not shown.) This still gives errors of a few hundredths.
 
However, adding 0.0035 to 28, as you have shown, then gives dead accurate figures for tpi, accurate to 15 decimal places according to my spreadsheet. 
 
Which suggests to me that Mashstroy, have deliberately chosen ratios to give an exact conversion, in which case, the fact that one wheel is 63T, and is not quite 127/2, is for us irrelevant.
 
It is of course possible then to simplify the formula even more, and I get this:
 
                177.8            Z2            Z4    
 tpi =     -----------   x    ----    x    -----     x    Z6  
              896.112          Z3           Z5
 
This takes into account all the fixed values and the fraction values are exact. Calculating 177.8 / 896.112 gives an indeterminate number, hence leaving as a fraction.
 
For those who are wondering, Z1 is always 32, hence can be incorporated into the fraction.
 
Regards,
 
Peter G. Shaw

Edited By Peter G. Shaw on 12/10/2010 13:53:08

Edited By Peter G. Shaw on 12/10/2010 13:54:26

11/10/2010 16:40:42
Hi jomac/John,
 
To be perfectly honest, all this about gear size has only arisen as a sideshow to the main event! Which was: why do my largest changewheels show a different M number to the other wheels? This has now been satisfactorily answered in that it looks like incorrect stamping, especially as Nick states that all his changewheels are marked M1.5.
 
I personally have no worries about whether it is 63T, 64T or 127T for metric/imperial threadcutting: any slight discrepancies over a short distance will be unimportant, and I ain't about to try screwcutting 500mm of thread! For one thing, my arm won't be upto it (power screwcutting is possible, but rather hair raising even at 125rpm, plus there is no way to stop the power at the correct point, hence it's all manual using a mandrel handle).
 
FWIW, I've not yet had to cut a Module thread, metric and imperial yes, but not Module.
 
So, thanks to one and all for their valued interest and contributions, but let's park it for now, shall we? As I said, the original query has been answered to my satisfaction, and I am concerned that we seem to be going off at a tangent.
 
Regards,
 
Peter G. Shaw 
10/10/2010 21:12:46
Hi Nick,
 
My manual is an original C210T manual, printed on coarse paper on a dot matrix printer and complete with a number of misspellings. I agree with you that the 61T is only required for Module threads, but I'm surprised you haven't got it as it appears to be standard. Interestingly, Mashstroy's website suggests 15 gears are needed for the full range of Module threads, yet my manual only shows 9. Makes me wonder if Mashstroy has come up with other combinations to give the same range, but not using the 61T.
 
Thanks for the confirmation of the gear wheel markings - it's now obvious that mine are incorrectly marked.

Bogs,
 
I notice from my gearing chart that the 63T is only used on imperial threads - this lathe has a metric leadscrew. 
 
Regards,
 
Peter G. Shaw
09/10/2010 17:00:26
Wheeltapper,
 
I've had the lathe from new, about 16 years now. All wheels are present and correct (in respect of no. of teeth) as specified by Mashstroy. I've actually been aware of this discrepancy for a long time, but only just got round to asking  because a) I'm doing a major strip down, clean, lubricate, re-assemble and setup; and b) because of the availability of this forum.
 
Keith,
Agree with your last sentence so I'll leave as is for now. When all said and done, there's only me uses the lathe; it's not worth a great deal now, so will probably be disposed of for song when I peg out; and it's now in my head about the discrepancy. I could, indeed have, put a note in the manual on the relevant page.
 
Regards,
 
Peter G. Shaw
09/10/2010 15:42:16
Hi Keith & Pete,
 
Many thanks for your reply.
 
I have now measured the od of each gear, and calculated the module by, if you like, reversing Pete's formula. The results are that three wheels (20T, 26T & 38T) are mod 1.49, whilst the remainder are all mod 1.5. The three at 1.49 are obviously slight measurement errors.
 
So, all gears from 20 to 61 appear to be correctly marked at M1.5, whilst the 63T & 64T wheels marked at M1.75 & M2.0 respectively appear to be incorrectly marked - unless there is another explanation.
 
Regards,
 
Peter G. Shaw
09/10/2010 14:39:41
Hi folks,
 
A little query which someone may be able to answer - I hope!
 
All my changewheels are marked Z x M y where x is one of the following numbers: 20, 25, 26, 30, 35, 36, 38, 40, 44, 45, 48, 50, 60, 61, 63 or 64; and y is 1.5 for all wheels up to 61, 1.75 for 63 and 2.0 for 64.
 
Eg: Z61M1.5,  Z63M1.75, Z64M2.0
 
The x number is the number of teeth on the wheel. I assume that y is the relevant module number, eg 1.5, 1.75 or 2.0. There is no restriction on which wheels may be meshed together (other than that of physically mounting them - some combinations can't be done), but this doesn't make sense to me as I thought that wheels of differing module cannot, or perhaps should not, be meshed together.
 
Can anyone explain what's going on? Could it be that the actual difference between mod1.5 and mod 2.0 is sufficiently small to be insignificant?
 
The lathe is a Mashstroy C210T rebadged as Warco 220 and originating in Bulgaria.
 
MTIA
 
Peter G. Shaw
 
Thread: Shine a Light
03/10/2010 22:23:34
Norman,
The only lathe I got to see all those years ago was a Portas (3½"?). Craftwork was taught by the art teacher. I suppose there is actually a connection there. It wasn't until I built a 00 gauge model railway and realised that one loco needed new wheels that I started on the Model Engineering caper.
 
You are quite correct in that most of my colleagues seemed able to, and capable of, turning their hand to just about anything. Which in turn led to a very useful situation when I could usually find someone who knew something about whatever problem I was having. And best of all, advice and info was freely given, a bit like these boards really. And that is something I still miss after 15 years of early retirement.
 
Like you, I think I was lucky in having the job I did, and yes I would do it again, but with one difference - with the confidence I now have, I would do a lot more off-the-cuff stuff. Unfortunately though, those days are long gone and although I do sometimes feel somewhat sad that my skills are now obsolete, today's telecomm world is much better, I mean, could you imagine tone dialling into Strowger? Or even TXE2. And let's face it, with the routing controls they now have, the days of running into congestion have also long gone.
 
Ok, end of reminiscing, other than to say: I had a good life, a good job, and now a decent pension, something which I cannot see my children getting.
 
Actually there is just one thing extra I will say, and this may not necessarily be applicable to ex-BT people, so other thoughts would be welcome. As Norman and I have said, we were capable of doing a wide variety of jobs,  not just at work, but in the wider field as well. I have two sons, one is 34 and a teacher, whilst the other is 21 having just got a Physics degree. Neither seem to have the same wide-ranging skill base that I had at the same age. Is this because people are becoming more specialized and hence more narrow in their abilities? Or is there something else, eg "stuff" in general is becoming more complex such that any one individual just cannot hope to become conversant with anything outside their training?  
 
Regards,
 
Peter G. Shaw
03/10/2010 16:07:47
I have to say that although I had the grammar school education, I don't think I benefited from it. Probably couldn't see the reason why, wasn't interested in most subjects, and probably lazy. So I left school at 16.
 
It was recommended by the Schools Careers Officer (wrong title, can't remember the correct one) who recommended in order: CEGB, YEB (our local electricity board), and finally the GPO, on the basis that the CEGB offered the best training whilst the GPO offered very good but narrow training. The YEB wouldn't have me, CEGB said yes as long as I got 4 'O' levels (I got 3!) and the GPO didn't care about 'O' levels as they had their own entrance examination and training scheme. So I ended up as an apprentice telecomm technician.
 
The SCO was proved dead right in that I ended up working on telephone exchanges, and that's all I knew. There is, however, quite a lot of other stuff in the telecomm world: power, line plant - everything from copper wires in the ground to microwaves and later optical, international communications, telex etc. None of which I know much about. As a result, all of my training, both at Technical College and in house was purely based around exchanges, however, in later years I was able to self-teach about transistor and CMOS design and usage producing a few one-off designs along the way.
 
But, one of my colleagues about 25 years ago hit the nail smack dead centre with an off-the-cuff remark: "You learn now because you want to, and not because someone tells you to do it!"  I've never forgotten that.
 
Regards,
 
ten0rman
29/09/2010 21:01:34
Hi Andrew,
 
Despite failing English all those years ago, I mean decades, er just over ½century ago, I must have learned something, because about 5 or 6 years ago, I got complimented by a PhD in English Literature no less who said, following a letter published in our Choral Society magazine, "This person knows how to write!". She did not, initially, believe me when I explained my (lack of" success in languages.
 
There is one thing though about Latin which I do like. Some of the music we sing is in Latin, and some of the words are absolutely wonderful, and make a lovely sound when all the consonants are used. Mind you, I still haven't a clue what I'm singing about!
 
Regards,
 
Peter G. Shaw
28/09/2010 12:00:48
I too went to a grammar school, and like Andrew went down hill with languages attaining the dubious distinction of English Language (Fail), English Literature (Fail), French (Fail) and Latin (dropped after two years). Neverthe less I do remember something from my Latin days:
 
Latin is a dead, dead language,
As dead as it can be.
It killed the ancient Romans,
And now it's killing me!
 
Regards,
 
Peter G. Shaw
Thread: What are you building?
20/09/2010 16:26:22
Not building anything, just trying to improve the machines, make my own tooling, and improve my personal skills and knowledge. On reflection, I think the knowledge should come first, followed by the personal skills, and then everything else.
 
Like others, time is limited, eg going singing, taking the caravan 100miles for servicing, then taking the memsahib off in it (actually to see if a place we saw on the telly is where we think it is!) , mending a door (when it arrives!) for my daughter, and all sorts of other things keep cropping up. And funnily, having this am been to the doctors, been told that he would expect me to still be feeling tired and weak for another two months following an operation early July (true actually, but am improving). In other words, engineering has to come at the bottom of the pile.
 
Nevertheless, it still holds my interest.
 
Regards,to one and all,
 
Peter G. Shaw
Thread: Bending HSS
19/09/2010 20:25:45
Ooh, what a lot of suggestions. Many thanks. I'll not use names - instead I'll just talk generally. Does that make sense? I know what I mean, even iff you don't!
 
TCT.
I quite agree that TCT does have some advantages, but for me generally it's usefullness is outweighed by the need to spend a lot of time honing etc to get back to an unbroken tip. In any case, TCT cannot have a sharp corner which means HSS/carbon for that purpose alone. I did have two parting off tools - one broke the first time I used it (the tip parted company from the parent metal), whilst the other created so much chatter it was useless. I also cannot easily get a fine finish, due I suspect, to the lack of a broad enough tip, although my grandson the first time he used TCT produced a perfect finish! Anyway, enough of that - I've tried it, and now I want to go back to HSS/carbon.
 
Lathe stiffness.
I have had some concerns about this for a while, and now that I have found that the lathe is not turning parallel, I have decided to do a full overhaul/lubrication, adjustment and setting up of the machine. This should improve matters. 
 
Bending, or not, of HSS.
To be honest, I had forgotten that HSS can be silver soldered - which is a bit remiss of me since I already have a bit of HSS silver soldered onto an angled  mild steel shank & ground up for aluminium cutting. This, I think, is the way I shall go especially as it will enable me to get the cutting edge nearer the centre line without recourse to loads of packing . 
 
Tool Holders.
Sounds good, but here I would like to make my own rather than buy.
 
Tangential Toolholder.
Yes, could have a go at that.
 
There is one thing I would like to say. And that is that my interest is in making the tools wherever possible myself. Which is why I have a couple of large scrap files waiting to be cut, cleaned, and reground. Also why I have some square "silver" steel waiting to be used. Trouble is, as some of you will have realised, I have no engineering training as such, hence a lot of what I want to do is learning by experiment, ie am I able to do it.
 
So, there we are, question duly answered (Yes, HSS can be bent), but as I initially said, it was just a wild idea and I knew there were other possibilities. At least I now know the answer even if I don't do it.
 
Many thanks to one and all,
 
Regards,
 
Peter G. Shaw
18/09/2010 21:07:18
Hi folks, this is just an idea!!
 
Ok, I don't like TCT. Sometimes it's ok, and other times it seems to chip even before it's touched the work! But ok, I understand it's probably best for getting underneath the skin on cast iron, but....
 
So I'm thinking about, no definitely am, doing back to HSS, and even carbon steel, even to the extent of converting an old file or two. (I've already used an old 4" file to make a parting off blade!)
 
Now, I'd like a bent tool in order to get closer to the chuck jaws, and it struck me that I might possibly be able to use the blowlamp with a fine flame, heat up where I want a bend, and then bend it. So can I actually do it? And is it likely to have a negative effect on the hardness of the tool.
 
I stress this is just an idea, a wild thought even, because the easier and alternative method is to cant it within the tool holder and also twist the toolholder round slightly, but I did wonder.
 
I have actually found that Amadeal has some square HSS going fairly cheap and I'd wondered about experimenting a bit, but if it's a no-no before I even start, then there ain't much point in experimenting.
 
Many thanks in anticipation.
 
Peter G. Shaw
Thread: How do you use indexable cutting tools.
13/09/2010 13:09:16
Well, assuming that the insert actually has a cutting edge, then is the height correct, ie not too high? That's all I can think of.
 
Regards,
 
Peter G. Shaw
Thread: Another 'What Mill' Question
12/09/2010 16:02:49
Well done Clive. Now makeMcLatchie's adaptor, and don't tighten up too far in future.
 
Regards,
 
Peter G. shaw
Thread: Is this hobby dying?
11/09/2010 17:38:46
Which is absolutely fine Neil, but what happens when the equipment fails to work? Those people with NO practical knowledge won't have a clue what to do whereas those with some practical experience may at least be able to have an intelligent guess - I mean, it could something as simple as a fuse blown!
 
I've not put the above very well. I hope you understand what I'm fumbling towards.
 
Regards,
 
Peter G. Shaw
Thread: help with seeing
11/09/2010 17:31:49
Alan, I think I may have spoken to my optician about varifocals, but is was a long time ago if I did. Perhaps next time I'll see what he says.
 
Know all about floaters & jagged lines & iritis& hence the importance of getting urgent medical treatment. Trouble is that on one occasion, I pressed the panic button on a Good Friday only to be told by the emergency doctor that he couldn't see it! The following Friday I ended up with an emergency appointment with the consultant! 
 
Ian. Like it, but what would be the cost? And could people actually cope with it? Anyway, let's not get bogged down on that one.
 
Regards,
 
Peter G. Shaw
Thread: Is this hobby dying?
11/09/2010 17:22:16
John, that's good news indeed, but what AGE are they? I have a friend through my choir who has taken up the hobby. He has also just retired! And that is what seems to be the brunt of a lot of the earlier posts.
 
We need to encourage the younger end and preferably before they get infected with the "want it, and want it now" syndrome so that they do realise that there is an alternative way of doing things. This is why I let my grandson loose and to hell with any breakages.
 
Regards,
 
Peter G. Shaw
Thread: Another 'What Mill' Question
11/09/2010 17:16:42
Just another point. The Warco MiniMill DOES indeed have plastic gears internally. There are metal replacement gears available from Arc Euro Trade (usual disclaimer) but will be found under the C3 lathe spare parts list where they will be found as C3/X2 parts (the MiniMill is basically an upgraded X2).
 
As far as using it is concerned, there is a lot, indeed a heck of a lot, of play in the various handles, but the usual idea of going well back to take up the slop, and then come forwards seems to work. A new machine really requires a strip down, clean, grease and reassembly when delivered. I've seen two machines now and both required this doing to them.
 
Accuracy? Don't know. I haven't done much machining with them, and frankly, I'm not sure that my personal skills are good enough yet. Having said that, it has done all that I asked of it - except when I smashed the gears in the early days. (And a friend smashed his gears in less time than I did - he now has metal gears whilst I am still on my second set of plastic gears witha metal set waiting for the inevitable.)
 
I have to say that I do find milling a darn sight easier than on the lathe, but as I've never used a miller before, that's not really a recommendation. 
 
I haven't yet used it as a drill because I do have bench drill, not particularly accurate, but nevertheless a drilling machine, and until I need to do some accurate drilling, it will suffice.

Regards,
 
Peter G. Shaw
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