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: Lathe Drilling|
As stated ,using drills chuck etc which perform ok in an identical lathe then there is nothing wrong with the drills or methods, try to see your tailstock will fit your fathers lathe and se if you get good or bad results,if the results are good then your tailstock should also be good ,then try your fathers tailstock in your lathe and see what the results are,if good then its your tailstock at fault.When trying the above experiments use the same length of material on both lathes to rule a material problem. another test would be to get some steel or brass bar ,using your fathers lathe drill say a 12 mm drill hole to about 10 mm deep,then take the barand set up in your lathe and using a single point boring tool bore the hole out to be a good fit on a 13 mm drill, then using a 13 mm drill continue drilling to a reasonable depth and just see what happens, if it still makes wanders and make the 13 mm hole oversize then it must be an alignment problem or a problem with the headstock spindle. Curiously I have some cold rolled bearing bronze 7/8 dia which I bought from a respected supplier about 30 years ago,if I drill this to make a bush say a small end bush the drilled hole will be oversize and visibly off centre,same results on both my S7 and Colchester master, cannot see any faults in the material,as its good bronze and valuable I get over it by drilling well undersize and then boring to size, I put it down to an inherrent fault in the material due to rolling procees though the bronze does make good bearing bushes. I mentioned this to emphasize if you do compare the two lathes use the same piece of material.
|Thread: Boiler Formers|
I used .5 and .75 aluminium plate for my Allchin TE boiler and tender formers, they were also loaned out to another Allchin builder, The aluminium plate came as off cuts which were free,
|Thread: Collets for Myford tailstock|
I have always used a Jacobs chuck to hold taps in the myford s7 its ok with small taps but larger taps are more difficult to stop spinning in the chuck ,not having reverse I release the jacobs chuck and then reverse out the tap with a tap wrench.Er collet chucks,have a really positive grip so can cause tap breakages or worse still spin the morse taper shank in the tailstock barrel and damage the internal morse taper,after the s7 is a cente lathe and the taper in the tailstock must be kept in good condition. To get over the risk of damaging the taper or the keyway in the tailstock,it is reaonably easy to make an attachement for holding taper shanked tooling on the cross slide,any strain then goes onto the saddle,drills can also be power fed,taper sockets can be obtained which have ground parallel outside diameter,its the just acase of mounting this in a suitable block and boling ut to the cross slide. For my Colchester Master I have a cross slide mounted 4 mt sleeve so with a ER 40 collet holder I have tapped up to 1.125 whit with no tap slip in mild steel and the reversing motor clutch allows reversing the tap out easily,and no strain on the tail stock,plus I can drill under power feed up to 2inch dia. Small tap holders with a slipping friction clutch like the Archer are ok but take time to set the clutch and while setting there is the risk of tape breakage,ok if there are say 200 holes to tap. I have an Archer tap holder,brand new a gift from a friend but as soon as I had ER collets its never been used since.
|Thread: Myford ml7 "parting off"and "max working size"|
ML7 and S7 Part off ok though better results are obtained with hand ground parting tools than commercial tools, hand ground tools can have side clearance so they dont jam in the slot, I was taught during my apprenticeship that a good guide for parting off was to use a spindle speed which is HALF usual turning speed for normal turning a lot of amateur users always seem to want everything done immediately and use far too high a speed, we never used power feed on for parting off on any size of lathe,even on the capstan lathes,you were expected to be able to operate the feedby hand at a steady speed, I agree that quick change tooling is not the best system for parting off ,most lathes in my early days had 4 way toolposts, a lot more rigid but requiring lots of packing to adjust tool height.Dont be cruel to a small lathe. Parting off is a skill which takes time to learn and lots off practice,when on a capstan lathe an operator might part off 400 or so parts in a day,though a centre lathe turner would not part off so much as sawn blanks were preferred. our model engineers lathes have to be multi purpose and there are problems with belt slip,tool breakage ,jamming of tool in the cut ,etc its not the lathes fault.
|Thread: Quill feed milling machine|
For the average model engineer the quill type spindle is the most useful,look for a mill with a useable amount of clearance between spindle nose and table,so that a drill can be held by a chuck in the spindle and there is enough space to allow for the height for a vice and workpiece,most quill heads can be tilted in one direction,mills like a Bridgeport can tilt in both directions ,some mills only tilt to 45 degrees, tilting heads have to be regularly checked to ensure that they have not tited accidentally due to side pressure on a cutter when milling,know as tramming.Go for a mill that has plenty of x,y,and z travel ,its all too easy to set up a job on a small machine and run out of travel or table space.
|Thread: Seal selection|
When I rode in trials on uk two strokes 60 years ago,the sealed wheel bearings did not last very long,some of current riders in pre 65 trials have added an extra neopriene seal out board of the bearing with some success, and if memory serves me correctly I believe that my 69 Bultaco had seals between hub and a bush on the spindle to help keep the water out,a mag does not get that much mud but will get a lot of rainwater and 3000rpm is an awful lot faster than a motor cycle wheel. If the ht leads are "live" then there should be a rubber cap which is a tight fit on the lead and the pick up to keep out of the mag,I found some of these rubber caps on a web site selling BTH mag spares,I required one to keep any rain water from the mag of a restored stationary engine. In those days it was difficult to keep water out of Villiers engine electrics and carbs with cut up inner tubes and plastacine,lot easier nowadays with modern sealants.
|Thread: Hi all, newbie with first lathe, rare one i think.|
I would be looking at a minimum of a two HP motor to drive your lathe ,thats a big headstock to drive,plus cut metal,the multiple drive pulley indicates that it originally had a good size motor.I would not try to get a high spindle speed,if it is ww2 ,a spindle speed would not been much over 750 rpm. In the 1950s a 8inch Wilson lathe i worked on had a top speed of 440 rpm and a 41/2 Boxford was only 1450 rpm.
|Thread: Vfd and motor efficiency|
on my Elliott 00 omnimill I changed the vertical head motor from 0.75 hp to 1.5 hp with inverter drive,big improvement I would say that for a milling head with a 3mt spindle and a high top speedof over 3000 rpm 1.5 hp is a minimum. I considered a 2 hp motor but being larger it would foul the round overarm.
|Thread: t-bar material advice|
All my tommy bars for,toolmakers clamps,tailstock die holders,box spanners, etc are made from silver steel,just as it comes no further heat treatment. just cut to length and face off and then turn a small rad,each end,to save your hands, Currently restorng a Ruston Hornsby stationary engine and doing the water cooling plumbing in 3/4 in bsp steel pipe, threading with a 3/4 bsp die in a large tail stock dieholder ,tommy bar for that is 12 mm silver steel.One curious thing I found with tommy bars was the pair of M&W toolmakers clamps I bought during my apprenticeshiop would not take 1/8 in dia silver in the tommy bar hole,and we only used imperial silver steel in those days,later on I found that the holes took 3mm s/steel, and metric steel was in stock a couple of job later, why in those imperial days were M&W making tools that had metric tommy bar holes, 3/32 ins the readily available size down bent easily so 1/8 dia was reduced in dia to fit.
|Thread: Model of an epicyclic gear made by apprentices|
Reading about Blackstone engines,and crankcase explosions I am glad that my two Blackstones are open crank,
|Thread: Gas engine|
I run 2 Gardner engines an no 0 and a no 1 on propane and a small National ,I use a two regulator set up one for the engine ,the other for the hot tube. each regulator has a pressure gauge,I find 3/4 to 11/2 psi works, the burner uses gas pressure of about 3 psi.the gas air mixture is critical ,too rich or too weak and then the mixture will not fire,unlike a petrol engine which will run with a rich or weak air fuel mixture though with lots of smoke or pops and bangs. The separate gas supply for the burner is used as the induction stroke from the engine can drain the gas supply and extinguish the tube burner. most gas engines run on three valves ,air inlet, gas inlet,and exhaust the governing being on the operation of the gas valve ie hit and miss, my wifes Stuart 600 was designed to run on gas or petrol ,it has the usual 3 valves for operation on gas,the governor hit and missing on the gas inlet valve,when running on pertrol the governor control to the gas inlet valve is disconnected and the governor operates the carburreter slide.Be careful with very thin hot tubes they can burst so dont look directly down the tube chimney, I have seen a tube burst ,hot bits of chimney hit the shed ceiling when a friend operated his 1/2 size model and a no 0 . tough he did make very thin tubes which do run better.
|Thread: Crankshaft Factory|
Despite all the modern manufacturing tecniques ,L/R Discovery 6 cylinder diesel crankshafts break all to often , new engines are well over £10k,
|Thread: Old rule divisions twelfs etc|
some of my older steel rules, have eigths,sixteenths on one edge and the opposite edge is divided into twelfs ,twenty forths and 48 ths, one of these rules is dated 1959 ( ex WD) what was measured in twelfs etc I have never seen a dwg using these fractions what industries used these fractions.printing is a possibility.
|Thread: Chatter/finish problem|
Have a look at the workholding ,is the bar held firmly in the chuck jaws? From the photo the new chuck appears to be a self centering 4 jaw chuck, not the best way to hold work, I would never dream of using this type of chuck they are ok for woodturners. Never seen one used in a trade shop. And do not assume that a new chuck has perfect jaws to grip the work along the length of the jaws, I have seen a new european made 6 inch 3 jaw chuck where the jaws were bellmouthed ,due to poor manufacture. The tool looks suitable for brass ,though is there sufficient front and side clearance plus tools for brass turning must be sharp and honed with an India oil stone,some grades of brass can be difficult to turn and get a good finish, try going fast in top speed and take cuts of around 5 thou.The very rough cuts look as though they have been taken at very slow speed with tool set to take a far too great a depth of cut, like screw cutting to full depth at one cut only worse,that will not do the lathe much good.
|Thread: Stuart engine paint colours|
Hi I painted my wifes Stuart 600 horizontal o/c petrol engine with navy blue enamel,looks very nice.
|Thread: Myford ML7 accuracy|
quite an attack on the S7,particularly it drive system,my S7 about 48 yrs old,has been an excellent machine,the motor pulleys and belts are original, the top speed is good at around 2000rpm,the Eglish made motor runs well and its swich gear, an even older MK 13 amp metal clad socket totally reliable, there is nothing wrong with a good tapered bronze bearing,some of the very best plain lathes use them, never experienced any spindleproblems or vibration, any machine tool needs to be looked after,its the ham fisted with no mechanical sense who wreck any tool or machine.For jewellry or instrument turning a Boxford is ok though the top speed is bit low and considerably cheaper,though when I bought my S7 a new Boxford was far far more expensive.Another option would be an used plain lathe, if required just to turn parts for jewellery,a Smart and Brown plain lathe can be bought quite cheaply and they are superb machines if you dont know what a plain lathe is look up Lathes UK website,they are often overlooked because they cannot screwcut but who wants screwcutting when making jewellery, the long top and cross slides with large handles which spin so easily in ones hands,nearly all will be 3 phase.
|Thread: What to drive a J & S with ?|
I had worked with J &S at work and they were fine and well respected machines,,I bought a used one at auction whena company went bust and had been in use and had an overhaul a little while before I bought it, I ran it off a rotary convertor,now this converter is still in use ,and has been used to drive a turret mill ,Meddings drill,A & S horizontal mill ,Do ALL bandsaw,S & B lathe,without problem, but I could never get a really good finish on the work. Then a friend called and advised that there was a good 540 for sale by a company he had sold the 540 very cheap,so I bought it and had similar problems with finish, also a Colchester 2000 did have finish problems on a separate static conveter,I jury rigged a temporary single phase motor to the 2000 and the finish improved.Health and down sizing saw the 2000,and the J & S sold, so I never solved the problem,just by chance I met someone last week end who has a good workshop including a 540 and he runs it with two vfds,bought from far east and programmed by him , the 540 runs well on the vfds, sp I think the VFD is the way to go. I now run a Elliott 00 and have fitted a Newton Tesla motor/vfd package and it has been a success,some of the problems may have been due to living in the sticks with supply by overhead lines. If a rotary converter is chosen,then I would recomend a Transwave unit,I have used ther makes of converter but consider the Transwave to be the best,
|Thread: Threading myth .... busted!|
According to early workshop practice,threads were cut with a tool with side rake and the cross slide set over,the thead was cut and then finished with a thread chaser,either hand held or clamped in the tool holder,These old chasers were carbon steel,so were all the cutting tools,and most dims were measured using fixed joint calipers and a rule,my neighbour over 50 years ago still owned the workshop where he and his father before him had a large shed which held a lot of machine tools plus capacity to keep four traction engines under cover and space to maintain others. ,the smallest lathe was 6 inch capacity with screw cutting by change wheels,and driven by belt from the overhead shafting or by a big treadle,the owner explained that the treadle was often used for small jobs as it saved all the hassle getting the big big electric motor going with the extensive line shafting. the lathes were really old ,the crosslide v ways were set below the level of the top of the saddle,possibly making it easier to mount jobs on the saddle for boring. the various features indicated build around 1880s .I have a carbon steel chaser with the name Joseph Whitworth stamped on the shank,chasers went back a long way. I myself being trained as an instrument maker where chasing direct without single point tools was the usual way for cutting threads, and I now have a good range of HSS machine chasers for screw cutting direct into brass and steel, though I have hss and carbide single point tools . Though you have to be quick and coordinated to withdraw the chaser and disengage the half nuts when working up to a shoulder.All the various methods of screwcutting have there use,it all depends on material,equipment available,and skill of the operator.
|Thread: Need some help/advice|
A 6 inch English Abwood vice is very heavy,depends on age nd fitness to lift it onto the mill, I use a 4 inch vice on my Elliott 00 omnimill.
|Thread: Scribing with verniers|
I started in the 1950s and am definitely old school and I dont see anyting wrong with that ,and why not most of the models we build are based on engines ,machinery etc which may have been made donkeys years ago and the castings and materials are nearly all similar, I would for a start never never use a vernier with pointed jaws for marking out, a scribed line needs some depth so that it can be felt bythe point of a prick punch (smaller than a centre punch) where the punch touches the point where two lines meet thats when you hit the punch or if you doing a very precise job check the position of the punch point with an eye glass. marking out machined parts and surfaces can be carried out with a surface gauge ,a more precise method is to use a vernier height gauge with a wide chisel like edge more modern ones have carbide scribing edge, marking out castings to establish datum lines and machining allowances use a surface gauge, to set the height make sure the rule is held vertical or use the square and rule from a combination set..like Andrew I prefer to measure accurate dims with a micrometer rather than a vernier, and still prefer non digital vernier and height gauge ,more reliable in the long term than digital.
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