Simon0362 | 16/03/2023 15:00:16 |
279 forum posts 91 photos | Posted by Martin Kyte on 16/03/2023 12:52:10:
You cannot have or cut a 59 and1/2 tooth wheel. You can however have and cut a 59 and 1/2 gap wheel. 🥴 Strictly I have a wheel with 58 teeth and an uncut part of the wheel that is less than the width required. If I had made that last cut I would have had 59 fully formed teeth and a 60th one that had been part machined on one side. For the purposes of this thread, I suggest that constitutes 59 1/2, others may differ, as is their prerogative... |
duncan webster | 16/03/2023 15:06:00 |
5307 forum posts 83 photos | Posted by SillyOldDuffer on 16/03/2023 10:03:51:
Posted by Howard Lewis on 16/03/2023 09:31:47:...
If all fails, read the instructions! Howardd Skipping over the instructions, or not bothering to read them at all, might be the most common human mistake of all! Admittedly instructions often feel like a perverse intelligence test, but admitting defeat far too quickly and then trusting to luck seems a universal fault! Faced with the irksome job of reading a 300 page manual, I apparently believe I'm clever enough to pick up a full understanding by randomly pressing buttons until something sensible happens... Dave Universal instruction book for use by women: press all the buttons at random, if that doesn't work ask a man. 😜 |
Martin Kyte | 16/03/2023 15:57:08 |
![]() 3445 forum posts 62 photos | Posted by Simon0362 on 16/03/2023 15:00:16:
Posted by Martin Kyte on 16/03/2023 12:52:10:
You cannot have or cut a 59 and1/2 tooth wheel. You can however have and cut a 59 and 1/2 gap wheel. 🥴 Strictly I have a wheel with 58 teeth and an uncut part of the wheel that is less than the width required. If I had made that last cut I would have had 59 fully formed teeth and a 60th one that had been part machined on one side. For the purposes of this thread, I suggest that constitutes 59 1/2, others may differ, as is their prerogative... ‘‘Twas only a tongue in cheek comment that we only cut gaps. 😵💫 |
Simon0362 | 16/03/2023 16:43:16 |
279 forum posts 91 photos | ‘‘Twas only a tongue in cheek comment that we only cut gaps.
😵💫 Sorry, been a long day at the money generating site! Comment reviewed and appreciated - this time! |
Martin Kyte | 16/03/2023 17:30:24 |
![]() 3445 forum posts 62 photos | Posted by Simon0362 on 16/03/2023 16:43:16:
‘‘Twas only a tongue in cheek comment that we only cut gaps.
😵💫 Sorry, been a long day at the money generating site! Comment reviewed and appreciated - this time! We have all done it. That was my reason for building a digital dividing head. regards Martin |
daveb | 16/03/2023 17:49:40 |
631 forum posts 14 photos | I very carefully screwcut a replacement part for for my dividing attachment. A superb job, I was pleased with it. Until I found it was out by 1 TPI. This was how I discovered that the selector on my gearbox doesn't quite line up with the label. Well yes, of course I blamed the tool, miles out innit! |
Zan | 16/03/2023 18:57:42 |
356 forum posts 25 photos | When making my dividing head. I was so so proud of the worm, first I had made , many many cuts and a lot of time, Because for me the thread was deep and the tool was wide. The shaft was spot on giving a precision running fit on the housing It was perfect. Smooth flanks polished crests. I was so proud, that is, until I fitted it and found it was the wrong hand….. That was in 1988 never throw things out. It’s now built into my loco building ( made 30 years later) stand and nicely rotates my small 7 1/4 loco Edited By Zan on 16/03/2023 18:59:24 |
Hopper | 17/03/2023 10:16:50 |
![]() 7881 forum posts 397 photos | In 1975, at the extremely knowledgeable age of about 18, I bought a brand new Triumph Trident 750cc three-cylinder motorbike. Being a typically smart 18 year old and now a third year apprentice I decided to do my own service after the first two free services by the dealer. This including adjusting the tappet clearances via the usual threaded adjusters on the ends of the rocker arms. These were located under a long narrow flat alloy cast rocker box cover secured by a small bolt at each end and two larger bolts in the middle. Started the bike up to hear a loud clattering noise. OH OH! Must have set a tappet wrong. Took the rocker covers off and checked. All good. Nothing wrong. Put the covers back on. Started it up. Same result. OH DEAR. Must have stuffed something up. So, off with the rocker boxes. Nothing to see here. So off with the head. Nothing to see here. Off to the dealer to buy new gaskets and then I put it all back together a day or two later. Managed to snap one of the small rocker box studs by tightening it up to the same torque setting as the main head studs. Got it out, off to the dealer for a new stud. Reassembled a few more days later. Started it up. Same result. Clatter clatter clatter. WHAT THE ??? Good old Dad comes down the shed after hearing days of swearing emanating thence. I pull the rocker covers off. He takes one look at them and says "What's that mark there?", on the inside of the long flat rocker cover, right above the centre exhaust tapped adjuster screw. I had only over-tightened the centre bolt in the cover, bowing the whole thing down far enough to contact the tappet adjuster on the end of the rocker arm. Hence loud clattering every time the tappet adjuster hit it. A five minute job to lay the cover on the concrete floor and belt it out flat with a soft hammer and restore the required bee's whisker of clearance. Reinstalled and hey presto! Clatter all gone. Doh! But once I had broken the factory seal on those rocker box bases, cylinder head gasket and pushrod tube seals, I never ever could get them oil-tight for any length of time again. |
John Doe 2 | 17/03/2023 10:34:59 |
![]() 441 forum posts 29 photos | My central heating is working at last !! Faults were: Boiler overheating and tripping the overheat cut-out. Air leak in the positive pressure sensing system in the boiler, preventing it from firing up. Blockage in another part of the air pressure sensing system, ditto. Damaged flue gasket. Main board failure - re soldered all connections, but that did not fix it. No circuit diagrams or even schematics available and did not have the time to trace the circuit out myself. New main board. No restrictor fitted to the hot water loop, so if HW was selected on as well as the CH, the HW would steal the hot water from the boiler and the radiators would stay cold. Magnetite detected, (with a magnet), in some pipe junctions. This caused blockages which were preventing fill water from the expansion tank in the loft getting into the system, and restricting the flow of water through the system. Cut out the affected pipework and fitted new pipe, including fitting a restrictor valve in the hot water loop. All back together, with cleaner fluid circulating and radiators all balanced. A warm house after 2 weeks of very low temperatures in the house - down to 8°C at one point. Total cost, about £100 for a new control board and cleaning solution. BUT.........on clearing up, the sheet I had carefully put down on the carpet by the airing cupboard before starting work turned out to be porous and the light coloured carpet is stained. So another £100 to have the carpet cleaned. Those dust sheets are absolutely useless - they do not prevent contamination getting through.
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DMB | 17/03/2023 11:27:10 |
1585 forum posts 1 photos | I recently ordered small black plastic balls for a project and upon receipt, were found to be too small, so put on one side and ordered bigger balls! Unfortunately forgot to put a note in plastic bag of the small ones, of thread size. Another small project recently, called for a small ball. Raked out the tiddlers (about 25mm dia.) and quick measure suggested 1/4" BSF or 6mm thread. Gently tried taps in the brass thread but neither seemed OK. Next, short scrap of 1/4"dia. steel was threaded differently each end and one fitted quite well but I thought not perfect. Used the best fitting thread on the project and screwed knob on tight. Success! A balls - up turned good! John Edited By DMB on 17/03/2023 11:29:12 |
Tim Hammond | 17/03/2023 11:39:41 |
89 forum posts | Loved your account of your Triumph Trident travails, Hopper, as I bought a brand new one in 1976 from a London dealer at a cut price. It was difficult to return the machine to the dealer for servicing, so after the first (free ) service, I did them myself. Nothing particularly difficult and all went well until I rode the thing to Woodham's loco. scrapyard in South Wales (I was involved with the restoration of Urie S15 506 at the time, since you ask ); a few miles from my destination the engine started making horrendous clattering noises and was well down on power. Quick investigation at the yard showed that the noise was coming from the rocker cover, so I checked the rocker arm clearances and bingo! one of the gaps was way out. If you remember, there was a steel ball fitted to the tip of the rocker arm with a flat ground on it, this flat contacted the valve tip, and somehow, when I adjusted the clearance on that one valve I'd managed to rotate the ball in the socket, so that the clearance was between the spherical surface of the ball and the valve stem tip. This was OK until the ball self-rotated to its correct position after the engine had run for some time, with the resulting increase in clearance. Doh! Readjusted and all was well. I had all sorts of problems with that bike and finished up with a holed centre piston after fitting a Lucas RITA electronic ignition system. Found out 20 years later from a Trident enthusiast that they were noted for this. The clue was in the name "Lucas" - I should have known. Gave up after that, sold the bike and bought a BMW R60/6. |
Hopper | 17/03/2023 12:15:02 |
![]() 7881 forum posts 397 photos | Posted by Tim Hammond on 17/03/2023 11:39:41:
Loved your account of your Triumph Trident travails, Hopper, as I bought a brand new one in 1976 from a London dealer at a cut price. ... etc Tim, it was the T150's same "elephant foot" tappet adjuster holding the ball bearing with flat ground on it that flummoxed me. I was convinced I had done exactly what you had done and rotated one of the balls inadvertently and that was coming around and rattling. But no sign of it on checking so concluded something terrible was amiss. So I learned at a tender age to always check the simple stuff first when troubleshooting. Could have saved days of anguish and permanent oil leaks if I had looked at that tappet cover the way the old man did -- instantly. Had a good run out of that Trident otherwise. Other than wearing out top ends in about 15,000 miles. But it only had one speed in the hands of an 18 year old, including wheelstands off the stop lights regularly and being revved out to 8500rpm every Friday night trying to keep up with the Kawa 900s at the front of the pack. So it may not have been the bike's fault! Traded it in on a Harley Sportster in 1977 and still have that bike today. Agricultural enough to be resilient in the hands of the ham-fisted. Edited By Hopper on 17/03/2023 12:20:39 |
Mike Poole | 17/03/2023 12:42:10 |
![]() 3676 forum posts 82 photos | The rocker covers on the Trident are barely adequate, the web’s supposed to reinforce the holes for the sleeve nuts crack at the slightest hint of over tightening. Norman Hyde used to supply a much heavier replacement cover as this problem was common. A top end rebuild for gasket replacement was a regular event but even though I would say I have mechanical sympathy the threads in the soft aluminium give up with repeated assembly so I just helicoiled all the 1/4” threads before they gave up. I must find the enthusiasm to get it back on the road, I have now owned it for 45 years. Mike |
Mike Poole | 17/03/2023 13:33:25 |
![]() 3676 forum posts 82 photos | One of my memorable machining mistakes was during a turning phase test when I was an apprentice. I was cutting a thread when the instructor informed me that it will never fit the other part. A quick check around and I realised I had set the screwcutting gearbox incorrecty, to give me a chance at completing the test I had to remake the part for which he gave me a one hour extension to the test. As the rest of the group finished their test they were setting up other lathes to save me having to do chuck changes, thanks again lads. Despite having to hurry I got 10/10 for my test, the instructor John Hopkin didn’t mark me down for the mistake. Mike |
Nigel Graham 2 | 17/03/2023 15:17:41 |
3293 forum posts 112 photos | Mike- Perhaps in your favour was that having made the mistake, you soon identified it. I have seen very experienced people tie themselves in utter knots by missing a very simple error, because they cannot imagine they'd make such basic errors. ''''' A Cautionary - or Exemplary - Tale of Two Instructions... From my sister Sarah, who is skilled in the creative-arts traditionally associated with the distaff side, so whom I would trust to Do Practical Things Correctly. Her daughter and son-in-law bought a "Garden Room" (big fancy shed ideal for a cosy model-engineering workshop, if given a solid floor and not used an office / guest-bedroom). It arrived of course as a self-assembly kit. Hubby and S-in-L, with occasional "hold this" help from the others, managed to turn the huge pile of machined timber eventually into a sufficiently effective Big Fancy Shed, but only by a lot of bodging, straining and mis-matching; and not as the manufacturers had intended. I gather S-in-L had tried to approach it in the logical way but was rather sidelined by Hubby's more impetuous nature. Meanwhile, Sarah proudly told me having narrated the above, she and Michelle had engaged themselves indoors, assembling a flat-pack book-case (Ikea probably). Sarah described how they laid all the parts out neatly on the lounge floor, patiently identified each by the diagrams and numbers right down to the legendary Allen key, and carefully but quite rapidly put it all together with no problems at all, and just as it was made to do. . Moral? Well, we mere males are said to use the Instructions only as a desperate Last Resort; and for some that is certainly so! ++++ Though it was only after I had crossed Mr, Griffiths' palm with plastic in return for the facsimile Operation & Servicing Manual, that I could make my Harrison L5 Lathe cut threads the change-wheels told me they'd be! Or rather, let us be fair to the still gallantly effective old gal, that I can now cut threads matching my wheels sums. (This lathe follows the change-wheels with a 2-speed-&-direct gearbox serving both feed-shaft and lead-screw; and I had not understood it...) I still can't knit lathe-cosies though. |
Nigel McBurney 1 | 17/03/2023 15:28:56 |
![]() 1101 forum posts 3 photos | Part of my apprenticeship was 6 months turning on a Ward 2a capstan lathe,the work was components for scientific instruments small batches from 20 to 1000 components,after brief instruction on setting you had to do the setting up as well as the work,wich was mainly i brass ,nickel silver ,aluminium,and a few small steel jobs,one day I was setting up for a run of around 1000 brass parts for microscope eye pieces ,which had fine threads for lens locking rings and where the eyepiece screwed into a microscope, threads cut with ordinary taps and dies,I set myself the task of seeing if I could complete the batch without adjusting or resharpening any of the cutting tools,so took a bit of time with the set up and then got going ,while setting up I "lost" 3 parts as they were not good enough,the company was fairly small so the owner spent a fair time in the works,well he came round to see how I was doing ,he saw the the 3 scrap parts in the swarf tray and told me off for wasting the brass (1.5 inch bar ) , though during the week he came back after looking at the time sheets and asked how I managed to get the usual component time down from 41/4 minutes to 31/2 minutes,the fastest that it had been done, my reply was I took a lot of care in the setting up to see if it was possible to avoid stoppages and resharpening ,If I remember it was only the die that needed adjusting,all HSS tooling had not required attention,The main lesson I learnt from this was sod being honest,if in future I have to part off parts that I was not satified with ,dont part off just machine it off to swarf leave no evidence. I still have one of the parts in my tool cabinet drawer 60 years later as a reminder. It was a good example of what can be done with HSS tools and toolbits,if they are ground correctly no need for carbide, and no power feeds . |
Martin Kyte | 17/03/2023 15:34:00 |
![]() 3445 forum posts 62 photos | Absolutely, they can’t touch you if they can’t find the body!! regards Martin |
Martin Kyte | 17/03/2023 15:37:31 |
![]() 3445 forum posts 62 photos | My absolute favourite was the bloke who drilled a small dimple in the brand new milling machine table. Brilliant. regards Martin Edited By Martin Kyte on 17/03/2023 15:49:43 |
Bazyle | 17/03/2023 15:59:18 |
![]() 6956 forum posts 229 photos | Posted by Martin Kyte on 17/03/2023 15:34:00:
Absolutely, they can’t touch you if they can’t find the body!! regards Martin Off topic but anyone reminded of an episode of a detective series in which the murder weapon, an aluminium crutch, was turned to swarf on the Myford the weird murderer had in his living room. The scriptwriter obviously had something against model engineers. |
Phil Lingham | 17/03/2023 18:51:40 |
16 forum posts 14 photos | Not one of mine but rather amusing anyway. Back in the early 1990's we were having a number of special purpose automated machines made by Philips in Holland. One of the engineers I was working with told me a they had one designer / draughtsman who was particularly arrogant and claimed never to make mistakes. We were still working with manual drawings in those days and said chap had transposed the dimensions of a bore and an outside diameter. The machinist making the part presented him with tongue firmly in cheek with a cardboard box of swarf and said here's the part you asked me to make. Obviously he was asked why he had brought a box of swarf to which he replied that he knew the draughtsman never made a mistake and that is exactly what the drawing specified! Whether the portion of humble pie he was force fed had any effect I never found out. |
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