Here is a list of all the postings Nigel McBurney 1 has made in our forums. Click on a thread name to jump to the thread.
|Thread: DIY Bed Gap|
in the past I have skimmed discs because I am mean,I have a blank of cast iron which has numerous tapped holes so that various dics will fit ,each time the blank is mounted in the chuck I skim the face of the cast blank ,absolute minimum,to ensure it is running dead true ,then make sure the mounting face of the disc has no burrs or dings and the car hub is clean and likewise free from burrs, clean off the disc,with wire brush and and use angle grinder to clean the o/dia where the pads do not touch. if after cleaning and grinding the disc brakes really do need skimming the bolt the disc to the iron blank this gets them really true,then skim to the desired finish,if the lathe is big and the disc small,there the possibilty of skimming both sides at one setting.I had one volvo that covered120000 miles without changing the discs,the o/dia was just cleaned with an angle grinder, one thing I did learn from a specialist volvo mechanic was always use genuine volve pads,I was using ferodo pads at the time and they squeaked and despite using all the well known remedies they still squeaked ,changed to genuine pads and the problem disapeared.My wife had a peugot 306 from new,ran it for 21 years and never replaced or skimmed the front discs ,again only the rusty outer o/dia was cleaned off occasionally. Our cars are always garaged which does help stop the corrosion.
|Thread: Viceroy AEW|
I had many years ago a Tom senior with the standard vertical head,no room under spindle,head has to be removed to use the horizontal spindle,and 2MT spindle ,this size of spindle and tooling is too light for general work,I moved onto a full size turret mill and a universal mill with 40 int spindles,I have now downsized my workshop and now just have an Elliot 00 Omnimill which has 3 mt vertical and horizontal spindles ,it is easy and quick to change from vert to horizontal just by swinging the whole vert head assembly to one sde,no lifting involved.and lots of space under the spindle. It was fitted with a 3000 rpm 3/4 hp single phase motor by a previous owner far too fast ,and even with a 1450 rpm motor bottom speed was too high for me at 200 rpm,too high for large slitting saws on tough materials,now improved with Newton tesla inverter pack with 1 1/2 hp motor(80mm frame) It has quill feed and head swivels.When using heavy cuts on steel I have made a quick fit steady plate to stiffen the vertical head.photo on my album.When milling always go for the larger spindle .The 3mt vert spindle allows the mill to be used a heavy duty drilling machine,though I dont use it as I have a 10 speed Meddings floor standing drill which is a very good machine.
|Thread: Notre Dame|
building & restoration work again the probable cause of the fire,and accidents keep on happening, and it will happen again because people involved are careless and there do not appear to be any one constantly checking buidings after work for the day has finished,lot cheaper than total disaster. Watching the news last night,one view along one side of the building only showed one hose on a hydraulic tower ,whats the use of one jet of water on a fire that size,look back on any film of the London blitz and the large numbers of hoses in use and the streets filled with hoses all pumping water,noawadays there appears to be just like the local councils ,ten firemen and their bosses looking on and just one bloke with a hose. My old man was in the brigade after the war,and it was usually two appliances and ten men and they put fires out ,on the dailly news it now takes an awful lot more me and they never appear to get stuck in,I expect half the time is taken up with risk assesments.
And why spend all that money on rebuild on something that is of no real practical use.
|Thread: Using magnets|
Dont get them near to bank cards or other cards as they will wipe the magnetic stripes. I worked for a long time with hard drives,I was working onnce with an actuator engineer who held an actuator up close to his chest to show me some details and promptly wiped out the magnetic stripe on his security pass.
|Thread: What Did You Do Today 2019|
I tried motor cycle clutch bowden cable on my strimmer,it just comes apart and shreads,though I must admit my strimmers on wheels with a 6 hp engine,
|Thread: Looking to purchase a new 4 jaw chuck|
Hi I have dealt with Rotagrip for around 30 years and found them to be a good supplier,in this time I had 2 X 8 inch,3 jaw chucks both eastern european manufacture ,and various backplates ,soft jaws ,and other tooling .all have given good service.The advantage of this copy of the Burnerd is that the chuck has good overall proportions,less overhang and jaws are narrower and not so clumsy as some of oriental ones.
|Thread: What new lathe?|
Nice lathe,especially as it has the long bed,which does allow the tailstock to be pushed back out of the way,We all all have space problems,but rear access to the coolant tank and motor is adviseable,my Colchester master 2500 is back against the wall so the lathe has to be moved to get access to motor and tank.lack of regular cleaning of the tank led to corrosion and leaking of the tank,modern coolants go off quicker and bacteria form which turns the coolant into corrosive liquid.My Master has a 5 HP motor running off a converter and I certainly do not end up with 5 hp so get a good converter with more than adequate power,Though I have no personal experience perhaps some form of digital conversion to 3 phase may even be better,and worth investigating,no point in having a really good lathe which is underpowered.
|Thread: R8 instead of MT3|
I did have a big turret mill with int30 spindle, good for holding clarkson and bristol ericson collet holders and the four tapped holes were great for bolting fly cutters direct to spindle face with minimum overhang.Abosolute pain in the backside with 3 mt adaptor, the adaptor had to be removed from the spindle taper to get at the extractor slot,to get over this I turned down a few taper shank drills to a parallei slot and held them in the collet chuck though only really suitable for light work, On the larger mills (50 inch table) 30 int is really too small,I should have looked for a machine with 40 int, there is not much 30 int tooling on the second hand market whereas there was/is lots of 40 int, so in the end I bought a Meddings 3 mt pillar drill 100 to 3500 rpm very good machine. to back up the mill for heavy drilling Regarding a choice of 3mmt and R8 one should look to the future,should you wish to upgrade to another machine I think a machine with R8 would command a better price. I have now downsized to an Elliott 00 omnimill (a gift from a neighbour) vert and horizontal spindle,this is the early version with 3 mt spindles ,on later machines the horizontal spindle was updated to 30 int, I suppose this gave a better drive for horizontal spindles and still allowed the use of 3 mt drills in the vertical spindle as there is a lot of daylight under the vertical spindle nose, A 3mt horizontal spindle nowadays (55years after the machine was made) makes thing difficult as availability of s/hand long arbours is virtually non existant,so if buying an older machine with horizontal MT spindle make sure it has a at least one arbour, with collars if so it will probably be for one inch cutters.And make sure the bearing collar which runs in the overarm support fits,.
|Thread: How Are Letter / Hallmark Punches Made?|
If any reader has a set of number/letter stamps in a blue plastic case,with the name Imperial they were made by the Imperial typewriter company of Leicester and Hull, I worked for a subsidary company making early automated tywriters and other electronic office equipment (punched tape driven) and I saw some of the punch making process,the punches were made from square bar held in square collets in auto lathes where the taper was machined and parted off, sizes of stamp ranged from 1/16 to at least 1/2 inch,this was back in 1965 so memory is a bit hazy,the punches were then cold stamped with dies held in presses,I can remember there was quite a lot "flash" left around the impression though cannot remember how this was cleaned off,possibly by a clipping tool. Imperial also made a lot of very precise steel ink stamps for the stamping of government and GPO documents so security was very high to prevent theft. These stamps had the impression rolled on them ,the largest rolling machine was a giant modified Cincinatti horizontal mill,most of the guts and table drive had been removed and the table had a large rack bolted to the table this rack engaged with a gear on the horizontal spindle the table was pushed along by a hydraulic ram,and in doing so the spindle rotated, also mounted on the spindle was a really heavy steel cylinder which held a number of dies mounted on the o/d The blanks for the stamps were held in a row in a massive fixture on the table,so as the table was pushed along the spindle rotated forcing the dies onto the blanks, as the table moved along a fair number of stamps were made.One of those that you see and never tend to forget was the table to over arm support,instead of the usual cast support tying the over arm to the knee of the mill it was a steel support cut from steel plate and about 3 inches thick, it was needed to stop deflection during the rolling action..
|Thread: Cast Iron stress relieving|
Its the slow cooling thats important,to avoid cracking, Suggest machine the mounting feet,then place the casting feet down on a surface plate check that the feet are flat and the casting does not rock,to get a good job scrape it flat with scrape rand engineers blue.Then rough machine the long top surface and then put the casting aside ,store it the garden shed for at least a month so daily temp range will help to remove any further internal stress.Check the feet again with blue and surface plate to ensure the feet are still flat,then machine the top surface and sides if required, then check flatness against a good surface place and scrape in if necessary or take somewhere to get it surface ground.
This is the process that I learned during my time (1950s) making optical benches in lengths from 250 mm to two metres,Very few true fish belly types were made and these usually stood for over a year at the cold end of the factory,they were not annealed by heat treatment.
|Thread: Hardened Silver Steel Shattered - How to Avoid?|
I think some of the problem is due to the change in section of the job,a big mass of steel too close to the the fine cutting part,heat transfers to the mass so the red hot end of the tool starts to cool before it has a chance to get quenched, also if the tool is plunged into water sharp end first there is a tendency for an airlock as the tool has a blind hole ,(a centrally drilled hole through the tool wood get rid of trapped air),so may tend not to quench so well on the ID of the cutter. My first employer used a lot of silver steel tools mainly pin cutter and large counterbores on the capstan lathe as most the work was brass and nickel silver,hardening was primitive ,paraffin blowlamp,and a bucket of water ,and we were taught to plunge vertically and keep the lamp flame on the tool until the tool was close to the surface of the water to maintain heat,crude but it works,and the tools wood last for years on thousands of the lens retaining parts of microscope eyepieces, resharpening was done on a cutter grinder.Tempering was done by polishing the tool wth emery until it chaged to straw . I still use a calor torch and water for hardening at home.
In those days nearly everyone one used Stubbs Silver steel ,which was very good,and always marked with the stubbs name at one end,and it was drummed into us,always cut the piece you want off the unmarked end,so that you know that the piece left was marked silver steel,so there would be no errors by using the wrong material.
|Thread: Blacking engraved lines|
In my instrument making days.long ago,scales and verniers in brass or nickel silver were made on linear or circular dividing machine ,depth was approx 4 thou ,any slight burrs were removed with a water of Aire stone, the divisions were filled with black sealing wax applied hot, the excess scraped off with scrapers made from old hacksaw blades or when getting close to finishing ,aluminium scrapers then finishing up with extremely fine polishing grade emery paper,the finished scales were then sprayed with clear cellulose varnish, Engraving wax could not be used as the wax and varnish did not agree with each other. Items which required deeper marking ie nickel silver micrometer thimbles were filled with black engraving wax and just left polished.I aquired on of my old companies products a measuring microscope at least 55 years old and the engraving is still in good order.All sounds a bit laborious and rather trying,especially if a scale was scratched,it meant that the whole scale was machined to remove the markings and start again, batch quantities could be up to a hundred,with even more work on the circular scales of 100 batches of spectrometers.All a bit tedious and the reason why I moved on to get wider experience in other more interesting aspects of engineering .
|Thread: A gas engine question|
Regarding engine cooling,the water outlet must be from the top of the cylinder, then slope upwards the top of the cooling tank to ensure the thermo syphon operates effectively,when setting up an engine ,do not make a posh tank arrangement just try various size containers when an optimum size is achieved make a good tank of the same volume.old (non Diesel)stationary engines did not run on high compression ratios,lower ratios give nice slow running and do not produce so much waste heat. Now valve overlap,I have found ,even on early engines there is always some valve overlap,there was a comment that hit and miss engines would run hard and and not be allowed to hit and miss,which would allow air only to be drawn through the engine and help with cooling, there are numerous instances on work where the engine does idle then pick up again, instance log sawing the engine idles when the operator has to pick up the next length of wood,but you must wait for the engine to fire before pushing the wood into the saw otherwise it will stall. Throtle governing was used on petrol /paraffin engines to keep the cylinder head /vapouriser hot to ensure the fuel was vaporised. Most owners of full size gas engine prefer to use propane set at about 3/4 to 1 pound per square inch read on a gauge mounted close to the gas cylinder regulator and then a gas bag in the fuel pipe,setting up and adjusting the air gas fuel ratio can be difficult,unlike petrol ,gas will not run weak or rich so a petrol set up is far easier, i have 3 gardners,two are gas with hot tube ignition and the other is petrol and magneto ignition,the early 1906 gas engines runs beautifully but the lamp for the hot tube can easily get blown out on a windy rallyfield,the petrol engine keeps running if its blowing a gale,and it is noticeable that the 1910 petrol Gardner has a higher compression ratio and a lot more power.
|Thread: Myford 33t and 34t gears for metric threads|
I trained and worked for six years as a scientific instrument maker and I never saw anyone screwcut a BA thread or indeed later in my life of engineering ,thousands of BA threads were cut using split dies and they did not wobble,provided a sliding die holder was used,I can recall ,that in our works some 60 years ago only one job ,a steel 1 BA screw was produced in batches of 2k that used the self opening dieholder. on a Ward 2A capstan, I can never understand why BA was ever thought of though I gather that it was instigated by a commitee and we well know the rubbish committees invent. In the smaller tooth sizes I do not see any problems with running mixed tooth angles together at slow speeds and relative short running time.
|Thread: Cast Iron Straight Edge|
Natural "weathering ' iron castings was a very good way of stress relieving iron castings there was the daily temperature cycle and then the annual cycle from winter to summer temperature cycle,this produced very stable casting in good quality iron and was quite common practice 50 years ago, the very best makers of precision tools would leave them out longer,iwas informed jig borer makers would leave them up to 3 years, its no good telling the buyer of a very expensive tool expected to be accurate to within 2 tenths of a thou over the capacity of the machine that its not as accurate as specified because the accountants did not like the slow procees,I once was in technical contact with a swiss jig boring company,their machines had a normal life of 40 years before reconditioning was reqired ,when a borer table was machined and scaped in a minimum of 3 millimeters was machined from the table as it was found that a stress was built up in the surface of the table dues to years of clamping work to the table and they found that it was essential to remove a least 3mm to remove this local stress.The company where I did my training made a range of optical benches up to 2 metere long and these castings spent a long time in the stores prior to machining and were used in a first in first out arrangement. The problem with car cylinder blocks is that the bores tend to go out of round as the motor industry did very little in in stabilising the castings in the 1960s it was found that if the cylinder head of one popular car was removed for say a decoke ,some of the engines would tend to burn oil,and it was believed at the time that the removal of the head removed a clamping force ,the block relaxed and the internal stresses released tended to cause bore ovality.When of a visit to Massey Fergusson at Coventry I found that there was no stress relieving of the iron castings,but on the other hand ,all steel bar material and steel forgings were stress relieved at red heat and there were massive chain bed furnaces which must have cost a fortune to run. Years later I was involved in machining LM25 gravity die castings which had recieved a very precise heat treatment and the metalurgy was strictly controlled,plus machining was under temperature control, I found that even with this control about one in a hundred castings distorted slightly when the clamps were released after machining,I would add that the clamps were not causing the distortion,eliminating distortion caused by internal stress be relieved during machining can be a problem,Perhaps with modern very accurate manufacture very few assemblies are dismantled during the life of a product and a bolted up assembly has no chance to distort,Cars for instanceare now rarely decoked or totally stripped.
|Thread: Progress No2 GS Pillar Drill|
I used to buy old drilling machines do a refurb and paint and sell them,I never found one with a double row race bearing,all were single row,the drill was no doubt intended for industrial use ie 8 hrs a day all week,for hobby use a single row ball race would be adequate just machine up some spacers to accomodate a smaller bearing,lot cheaper. To remove the chuck it needs a brickies club hammer ,the spindle resting on something big and heavy, like an anvil, with a strip of brass between anvil and spindle to prevent bruising then use a home made extractor wedge with about half the taper of a normal morse taper wedge,easiest way would be to modify an existing wedge with an angle grinder, also make sure the wedge is resting on top of the chuck tapered arbour and not on some small shoulder or burr in the extraction hole of the spindle,then give a hard single blow rather than a series of lighter blows, you get similar problems with extracting taper gib head keys from flywheels,take time in getting the key drift set up correct then give the drift one almighty blow, lighter taps or blows just have rivitting effect.
|Thread: Brass Hex Socket Set Screws|
Assuming you are using HSS toolbits these will not mark or burr when secured by socked head grub screws,should you be using hss steel butt welded to tough but unhardened shanks then steel grub screws will burr the shank,brass screws would be suitable for this securing method, one way would be to make up short lengths of round bronze which would be a push fit in the tapped hole and then insert hard steel skt head screws,so that the bronze is sandwiched between the tool and the screw.
|Thread: Cast Iron Straight Edge|
Better to get an old English made straight ,where the castings were allowed to "weather" to relieve the internal stress and were often rough machined and then left to stand for some time before final finishing,Using new "green" castings is not a good idea,Try the second hand tool dealers.
|Thread: Bending copper pipe|
For stationary engine work I use thick walled copper pipe which when annealed forms easily around a round steel of brass bar ,the pipe is available from ME suppliers who stock cu pipe ,tube and plate for loco boilers.
|Thread: First attempt at threading on a bantam - all didn't go well|
En1A leaded is even better, single phase motors do not like too many stop /starts or forward to reverse,most larger motor s have a rating of so many starts per hour,usually specified in the manufacturers literature but not on the motor plate.
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