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Member postings for Bill Pudney

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

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Thread: Building lathe/mill in cast of concrete?
08/04/2011 23:12:47
We seem to have wandered off the thread a bit.
Rather than concrete I would have thought that an epoxy based polymer would be the way to go. Hardinges use has already been mentioned, but there are several others.
There has even been a couple of articles in MEW about using an epoxy based vibration damper in Chinese mills. This would be a start in reading.
 
About the Mulberry harbour stuff up, I gave up guessing when I got married 36 years ago, so come on who was it????
cheers
Bill Pudney
Thread: Made me chuckle
23/02/2011 01:11:58
Back in the '60's I used to read Motor Sport magazine. One of the few concessions to humour was a photo on the back page. The one that has stuck in my mind was a photo of a sign on a windswept moor in, it was claimed Yorkshire. The only wording on the sign was
 
"Do not throw stones at this sign, signed Borough Clerk of wherever"
 
Dopey officialdom is not a modern thing
cheers
Bill Pudney
Adelaide, Australia
Thread: Dickson Tool Post . - can it be drilled ?
11/01/2011 21:22:57
On "upside down" parting off tools.  I recently completed a QCTP set up for my Sieg C3.  Amongst the changes I included a pair of upside down toolholders. 
Despite all the prophets of doom they work extremely well.  Where parting off used to generate considerable stress, it's now a relarively calm procedure.
There are some photos in the Gallery, look for "QCTP"
 
cheers
Bill Pudney
Adelaide, Australia
Thread: Aircraft General Discussion
25/12/2010 21:57:43
I've just watched all the TSR2 clips, it makes you want to weep!!  A couple of aviation tales tinted with politics.
 
Prior to the infamous "No more manned aircraft"  decision in 1957, the UK Minister of Defence was visited by his equivalent  from the USA, who managed to convince the Brit that there would be "no more manned aircraft".  Then within a day or so of the announcement in Parliament representatives  of Lockheed  appear in Hayes, where the Fairey Aviation establishment was based.  They certainly wern't there for the good of their health, they were there to recruit the design team of the FD2, which they largely did.  Coincidence, I don't think so.
Harold Wilson and his gang of Bandits....The announcement was made at 3pm that TSR2 was to be cancelled.  When we arrived at work THE NEXT DAY the wreckers were in cutting up the jigs and fixtures .  I am usually saddened when somebody dies, but when I heard that Harold Wilson had shuffled off his mortal coil, I'm afraid I stood up and applauded.
There is little doubt that the British Aircraft industry needed sorting out, but obliterating it wasn't the way.
 
Happy New Year
Bill Pudney
Thread: HSS tool inserts
21/12/2010 06:29:58
I use the HSS indexable tips from LMS, yes they are expensive but they are pretty good....certainly better than my attempts at sharpening some tools!!
A R Warner is the company that makes them.
 
For what its worth I'd get them again if I had to.
 
cheers
Bill Pudney
Thread: Harold Hall QTCP, MEW 50, any one using it?
17/12/2010 21:34:33
After my last post I went and had a look at the Albums section here.  Amazingly I managed to set up an album, I simply had been doing it incorrectly before......
Anyway have a look........
cheers
Bill Pudney
17/12/2010 21:08:06
Clive wrote....
 
"..........as a DIY design a solid block with grooves and clamps to carry either the standard parting HSS blade or the modern insert holder blade."
 
Like this you mean??  (scroll down).  I got the idea from GHT's book, Model Engineers Workshop Manual
 
http://madmodder.net/index.php?topic=3823.0
 
Sorry but for some reason I cannot include photos here.
 
Cheers
Bill Pudney
15/12/2010 01:03:08
Now I know, I've seen and used those, I just never associated them with "Armstrong".  One of the reasons for doing what I did was to reduce overhang, both of parting off and cutting tools.  The Sieg C3 is not the most rigid of lathes and anything to help increase rigidity is welcome.
cheers
Bill Pudney
10/12/2010 21:51:21
Whats an "Armstrong type holder"
A picture  speaks a thousand words
Bill Pudney
09/12/2010 01:31:28
Hi Terry
I almost made the height adjustment as you suggested, what stopped me was the "sticky up bits" as John described them getting wrapped up with swarf, exactly the same rationale as John in fact.
There were several compromises in what I did, like...
1  Not using a dovetail design, because of the anticipated difficulty in generating the dovetails.  I would have used a similar, but smaller set up to that described by John.
2  Using socket fasteners throughout, as appropriate square headed fasteners and screws would  be hardish to make, whereas decent quality socket fasteners are available off the shelf.  Yes I know that its tedious getting swarf out of the sockets.
3  Originally the clamping mechanism was intended to be a single M8 screw.  When the 50mm x 50mm toolholder size was selected, an M8 fastener was simply too big, so 2 x M6 fasteners were used.  This obviously mean't double the drilling and tapping, which was made worse because I chose to use as long a thread as possible, to minimise any problems...wear etc.  Drilling and tapping all those holes was a major part of the whole.  The advantage is that with two screws, the clamping effect is very good.  Being a pedantic barsteward I'm going to measure the torque required to achieve a secure set up. 
4  The use of a 35mm diameter pillar, rather than the more usual 25mm.  This was to achieve the greatest possible clamping area, and therefore the greatest resistance to inadvertent movement, despite the extra work involved in boring a 35mm accurate hole.
What I'm trying to say is even with a basic concept (i.e. "pillar and clamp on toolholders") even the most minor details should be thought through, and it should be understood that all detail design will require some compromise.  It seems important to me to make those compromises to suit the user (in our case the designer and manufacturer).  Hopefully whatever is made will be in use for a long time, so any minor irrits during manufacture will be acceptable.....classic "Design for Manufacture" scenario!!  I suppose that this is the major area of compromise.    As an ex draftsman, I enjoy lots of conceptual doodling as well!!
 cheers
Bill Pudney
 
08/12/2010 21:45:36
Hi Terry
Just behind the cutter slot and at 90 degrees to it (parallel axis to the 35mm central bore) is a tapped hole.  In the tapped hole is a set screw (metric grub screw) with a brass end pad Loctited to the screw.  When the toolholder is loosely located on the pillar, by screwing the brass tipped set screw up and/or down the height of the cutter can be changed.  Once the correct cutter height is established then the clamping screws (2 x M6 SHCS) can be tightened.
The point in having 12 available toolholders is so that it is not required to do a lot of cutter changing whilst making any particular part, or series of parts.  Twelve toolholders permits me to have most, if not all of my commonly used tools set up and ready to go.
It seems to me to be a bit futile to have a QCTP with (say) two toolholders!!
Even though currently I don't really know what I'd use them for, apart from maybe a tangential toolholder, and a specific boring bar holder, I'm thinking about getting some more 50mm x 50mm x 25mm bits of S1214 with my next material order.
My next little project is a tool setting gauge.
cheers
Bill Pudney

08/12/2010 09:20:59
Hi Terry,
Not once a cutter/toolholder assembly is set up.  If the cutter is removed from the toolholder and changed for another cutter then the height would have to be reset.  Thats why I made 12 toolholders and 2 parting off toolholders.
 Since I've been pratting about with the 0.040" parting toolholder (taking photos, taking it all apart etc) then I will have to set the height on that one.
So far it all works really well.
08/12/2010 01:24:28
To clarify the parting toolholder construction I've just added some photos here............
http://madmodder.net/index.php?topic=3823.0
cheers
Bill Pudney
05/12/2010 22:53:01
The toolholder rotates on the post, 360 degrees!!  This is from choice, as I have removed the small spring loaded detent pin in the compound slide, which enabled indexing to some degree.  It wouldn't be a problem to reinstate it should that be required.  I do take great care to make sure that the parting blade is perpendicular to the spindle axis though.
cheers
Bill
05/12/2010 03:17:57
I started off deciding what was required.  My lathe is a Sieg C3.  The major  requirements turned out to be:-
1/ 12 toolholders, plus 2 for parting off blades (I use 0.040" x 1/2" and 1/16" x 1/2" blades from LMS)
2/  Keep everything as small and stiff as possible, to reduce vibration and chatter.  This mean't using steel rather than al. alloy as is sometimes seen.
3/  Reduce overhang from the compound slide.  The original toolholders overhung by up to 25/30mm for the parting toolholders.
4/  With the quantity of toolholders required, reduce machining as far as possible.
 
After quiet a lot of thought I decided to use a pillar and clamp on toolholder type.  The pillar was made as large as possible, this turned out to be 35mm diameter.  The toolholders were 25mm slices of 50mm x 50mm square S1214 steel, freeish machining steel(35mm slices for the 2 parting toolholders).  The 35mm diameter bore was a challenge, quotes for watercutting and laser cutting were obtained and dismissed as being too expensive.  A bi-metal holesaw was tried but didn't work for me.  So they ended up being drilled and red in the 4 jaw.
 It was all a fair amount of work, but so far I'm really pleased with the result.  there are some photo's at........
 
http://madmodder.net/index.php?topic=3823.0
 
I hope I haven't broken any protocols by adding a link to another web page....
cheers
Bill Pudney
Adelade, Australia
 
 
 
04/12/2010 21:00:20
When I was researching my recently completed QCTP upgrade I came across this one.  I obviously admire and respect Harold Halls work generally, but in the case of this QCTP it seems over complicated and unfinished as presented. 
 
I can see what he is trying to do, but the pad seems to me to be unnecessary, if the whole thing was dimensioned differently, and better; and the location bar, the one with a flat on it, could be replaced with a square or rectangular bar.
 
Its very interesting though, shows there's more than one way to skin a cat!!

Or am I missing something??  I often do.
 
cheers
Bill Pudney
Adelaide, Australia
Thread: Brake Discs
04/12/2010 05:57:16
Mr Jones, how formal!!  You wrote....
"Stainless brake disks were introduced on japanese motorcycles to remove the ugliness of rusted disks on otherwise neat motorcycles."
 
Isn't that what I said??
 
So no arguments from me really, but the first 750 Honda that I inspected, closely, in March or April 1970 had a stainless steel disc, with no holes or grooves.  This was before the bike was on sale in the UK. 
The first bike that I had, with a disc brake was a 500/4 Honda in 1973, it also had a stainless disc with no drainage mechanisms; also it wouldn't run in the rain, it even misfired in the fog!!  The undertank lightning display was a sight to behold, but that's another story.  Maybe it was Hondas way of making sure that you couldn't go fast enough to cause any damage in the wet, knowing that the brakes wouldn't work.
The Japanese manufacturers have certainly  got their act together now, and whilst they may not use cast iron in their discs, it's not the same material that they used in the early '70's.  Yes the pad material has changed and improved as well.
cheers
Bill Pudney
04/12/2010 00:24:45
When the Japanese introduced disc brakes on motorcycles in the late '60's early '70's they used plain stainless steel.  We surmised at the time that this was because all the development was done in Southern California where as we all know, it never rains.  The problem was when they started being used in the UK, where as we know its always raining, they were terrifying.  At low speeds, when the water wouldn't be flung off, there was a lag of about one wheel revolution whilst the pads wiped off the water.  This one wheel revolution would be around two meters with no braking effect.  Within a short time there was a large aftermarket trade in drilling holes and cutting grooves in the discs.  The real solution was cast iron discs.
cheers
Bill Pudney
Adelaide, Australia
Thread: Chinese lathes
27/11/2010 01:15:41
About the cost of high quality lathes.  A friend has three Schaublin 70s which he bought new.  They are all well equipped and professionally used to make dental implants.  Each lathe cost in the order of A$27,000, thats about GBP16,200 at the moment. 
They are exquisite machines which are expertly used and since he bought the first one about 7 years ago, they have all paid for themselves several times over. 
 
He also has a small CNC swiss type lathe to do high quantity parts
 
Have you seen the cost of dental implants??  Which helps to explain the machine selection rationale.
 
They are VERY expensive,  but they work..............
cheers
Bill Pudney
Thread: Why is everything you buy such rubbish!!
22/11/2010 01:14:03
A quick comment to those who believe that in days of yore, machine shops were full of highly skilled machinists.....they were'nt.  Where I did my apprenticeship in the late '60's they had a row of about a dozen capstans, all operated by "semi skilled" people.  The only time a highly skilled individual was anywhere near the machines was during the set up of a new part and the breaking down of the set up of an "old" part.  The skilled person would set up the new part, run the required quantity of first offs, wait for inspection, and then the semi skilled bod would take over, with little real knowledge of what was going on.  The training for a semi skilled lathe operator amounted to seeing if they could read and interpret a very explicit set of instructions.  From memory the Machine shop had about 100 people working two shifts, of those there were only about 15 or 20 skilled people.
 Incidentally the capstans were all German made during WW2 and considered as war reparation, whilst making a guard for one of them, I spent some time underneath it, with the manufacturers plate about an inch away from my eyes.  Can't remember who the maker was though!!
cheers
Bill Pudney

Edited By Bill Pudney on 22/11/2010 01:15:18

Edited By Bill Pudney on 22/11/2010 01:16:15

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