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: Cutting BSPT threads with a die|
looking at some Machinerys publications, the flanks of tapered pipe threads are normal to the pipe axis not the taper with exception of gas fittings. Any way if you are making a couple of fittings for a radiator thread the form in relation to the pipe or the machined taper does not matter in practice, Use the die so that the tapered lead of the cutting teeth help produce a taper,then when getting close to size, and the thread is still tight in the mating hole,tighten up the die and only cut halfway down the thread so the first part fits and the rest is tight,and use loctite pipe thread sealer or boss white and hemp or ptfe tape. When I make steam fittings for full size I do use a taper turning attachment its just knowing when to adjust the thread by fiddling and when to do it correctly.
|Thread: Help required with Colchester lathe|
Thanks for the info,I have just drained the Triumph saddle, oil was murkey and a couple of blobs of coolant, I last drained it about 22 years ago when I bought it,I will leave the oil to settle in the tin and see if there is any water in it.The lathe generally is in very good condition,I bought it at a government auction and it was ex Royal navy, The 3 jaw chuck was used but not worn, the four jaw was new and still greased,the face plate was in its box,the centres ,sleeves drill chuck were still in the crocell goo not used,no steadies,plus a new spare cross slide nut ,new worm gear for the feed shaft and some springs. The address of a small naval station along the south coast was on the face plate box, so why all the new kit,I have often wondered if all the loose equipment had been stolen or lost ,and all the very expensive new parts were replacements. An why does the feed clutch slip on a lathe that has not seen much use,no doubt I will find out. I have also just drained the apron on my Master 2500 the oil was clean,no sign of soluble oil ,though the master gets far more use and the oil is topped up alot more often than the triumph. When I bought the master at another government sale about 12 years ago,it had seen a bit more use,I stripped the cross slide at the time of purchase as it did not feel right , the feed screw was corroded having sat in a pool of corosive liquid in the trough in the saddle, A call to Colchester was made enquiring the price of screw and nut ,oh dear £ 400 plus vat ,a bit too expensive so I made a new cross slide screw on my other lathe and used the existing nut as it was not too worn, I could not find a drain hole in the saddle trough so I drilled one, and from the good condition of the oil it must be working,though my master is a bit newer than the Triumph and may have some seals fitted. I will have to wait a bit before working on the triumph until my backs better, At least the Triumph is free standing and easy to get at ,the master is hard against the shed wall and difficult to get at ,dont put big lathes against a wall,learn from my mistake.
|Thread: Toolpost holders with morse tapers|
My 2mt Dickson holder came with my first Colchester,it is useful to be able to drill off the saddle when working on large batches of tough material,I also mount an old tapping head in the 2 mt holder, the tapping head with its ability to grip taps without slippage makes tapping easy and also it reduces the use of the tailstock,a lot of lathes are ruined by worn out tailstocks, Some precision toolroom lathes eg Holbrook had precise saddle attachments for drilling and a plate on the tailstock engraved " do not drill from the tail stock" A lot of precision plain lathes have relatively small tapers in the tail stock,to prevent the tailstocks being ruined by the use of large drills .
|Thread: Clarkson Autolock chucks 40int are they worth selling|
Collets sell for about £10 to £20 each metric being dearest, a clarkson s type autolock with a set of collets will sell for between £60 and £100, they are still the best way of securely holding threaded shank cutters,they CANNOT get dragged out of the collet when cutting tough materials,
|Thread: Mercer or John Bull?|
John bull indicators were very good,though not as common as a Mercer, John Bull were the first British made dial indicator to get a British Standards Kite mark, around 1960. I would advise keep all of them its very easy to drop or damage indicators.
|Thread: Help required with Colchester lathe|
Thank you for the information,I will try when I get over this cold,how do you get a cold in this beautiful weather plus I am recovering from a bad back and as I have to drop the apron I will try a bit later.
|Thread: Colour inside of frames|
In the days when locos were cleaned,I understand that frames and other components were painted red as it is easier to see any cracks in the steel.
|Thread: Help required with Colchester lathe|
I have a Colchester Triumph 2000 Square head type,generally in good condition. The apron feed lever is raised to engage the feeds,as soon as it is raised it drops down and stops the feed. I have tried the adjuster for the clutch,from tight to slack,this does not work , the feed works if I manually hold the lever up, so either the clutch is worn or out of internal adjustment, I have found the manual on the web but as usual does not cover faults. I intend to hold the apron assembly in position with wooden blocks remove the cap screws which hold the saddle to the apron,then if possible slide the saddle to one side down the bed to get at the apron internals, has anyone tried to slide a Colchester saddle away from the apron?
|Thread: vertical slide|
When I started in the 1960s I had a Myford seven and a Fobco drill, I then bought a Myford swivelling vertical slide ,and a myford vice ,with these I was able to machine all the parts for an Allchin 1 1/2 in TE I was fortunate to have changed jobs to a company who provided all hand tools required so I was able to keep all my own tools at home bought via the tool club during my apprenticeship. I went for the swivelling slide as it had a larger slide table. Being myford everything fiitted easily and was square and true,I found it easy to make parts ,thats where the Myford design is so good it gives one the maximum capacity available for a relatively small machine,I would point out that swivel function of the slide is useful when using the myford dividing head. Later on after I had left my parents home,with more room I did buy a Tom Senior M1 mill with vertical head, as I had started on restoring stationary engines,now there is a machine very well built but with limited space under the vertical spindle ,and forever running out of room when setting up jobs, I think size for size a Harrison would be a better buy. When I bought the Myford I was working in a two man toolroom with some very good all new machinery ,including a Deckel fp3 now there is toolmaking mill,accuracy approaching a jig borer, possibly the best small mill ever made,it cost the price of seven new Bridgeports in 1967.but at home I was well satisfied with my Myford.
|Thread: What have i bought??|
The low centre height possibly indicates it was intended for the German/swiss type precision toolmaking mills,used for making punches,milling cutters etc and could be mounted on the table or the front face of the machine,with swivel table removed,google LATHES UK and then go to THIEL under the list of milling machines which shows an example of this type of dividing head with index plate on top. bit of very expensive kit in its day.
|Thread: Lathe holding|
workholding using a wooden chuck and glue,is a very old tecnique,mainly for machining very small thin parts or small instrument castings,I would not fancy holding a lump of 12 mm plate by glueing and then trepanning a wide groove, recipe for disaster and dangerous, Just hold the plate in the four jaw and set the front face true ,preferably with a surface gauge or an old DTI ,I would not use a good DTI on a bit of rough black plate,on a piece of plate this size there is no need to set two jaws one way ie external and two internal ,,set them all the same way and just true up by tapping the work with the time honoured way by using a lead mallet or a copper one , grip on about 10 mm of the thickness leaving 2 mm protruding so that a light clean up cut can be taken if required, One method or machining a groove in black plate,is to use a 3mm /4mm wide parting shape tool with a full radius ground on the tip,more clearance is required on one side to clear the rad (similar to a boring tool clearance) plunge in carefully say half a mm then face to nearly the full width of the groove, carry on until full depth is achieved,the use narrow right and left hand tools to clear out the groove to get sharp corners and finish width on the groove,all this carried out at about 150 rpm,go slow and careful, black plate is not the easiest material to machine,
|Thread: What did you do today (2015)|
Core plane memories,that takes me back to 1967,I was involved maintaining the equipment to feed the X,Y wires through the cores and weld them to the frames,the ferrite cores broke very easily and the pieces got every where in the machines mainly shorting out relays ,we had a suggestion scheme and I got enough suggestions approved for improving the machines that I was able to purchase a new Fobco drill which is still going strong.I was then a procurement engineer on winchester drives and large systems. Only a few MB from large disks ,thousands of punched cards, large systems that required water cooling,that was interesting,especially the traveling around the country working on the problems at foundries and machine shops and sheet metal workshops.When I took early retirement small hard drives had got up to 800 meg around the end of the 1980s ,nowadays its in terra bytes.incredable progress .
My Super 7 motor started making clicking noises,then the clicking got worse within a few minutes,stopped the motor ,restarted all quiet,stopped and started again it was noisy again, of course the lathe is against the wall,so lot of effort to remove motor. Soon found the cause,the internal plastic cooling fan was no longer gripping the shaft it was not sloppy just a sliding fit and was sliding along the shaft by about 3mm, I tightened the socket grub screw and its now ok, The motor is 40 years old and and its taken all this time for the screw to loose its grip, probably due to creep in the plastic.
Years ago I worked on hard drives, torx screws replaced the use of skt hd screws as the hex drive bits produced minute particles of stainless which contaminated the reading heads, torx bits gripped the screwheads better,reducing the risk of contamination .At the time you could buy cheap all plastic verniers, one of the design engineers aquired one ,he used it for checking dims on rare earth magnets,simple!! in those days the magnets were massive and it was not wise to use steel measurment tools.
|Thread: How to get 89 divisions from a dividing head|
I never understood why dividing heads were made either right of left handed, I first used a dividing head on a Victoria universal mill and that was mounted onto the left of the table and thats always seemed the most convenient way,after all lathes have the headstock to the left of the bed. Cincinnati mills mounted their heads on the right,and they must have been made in their thousands, their main competitor was probably Browne and Sharpe and who I believe were the first to make the dividing head as we know it ,mounted on the left so there may have been patent problems at the time forcing competition to have a different mounting position,. Also I have wondered why dividing head spindle have screw threads ,milling in the "wrong"direction can loosen the chuck,particularly when left hand spiral milling. My Hofmann universal dividing head has a tapered spigot and three tapped holes so that the chuck and driving plate are rigidly bolted to the spindle, the spindle is also tapered for centres and tapered mandrels. The photo of the mill with l/h div head mounted on the right is asking for trouble,you need the dividing plate facing the operator. Regarding a horizontal mill with vertical head not having enough space for the div head to be set vertical, set the vertical head at 90 degrees, with the dividing positioned at the end of the table,this gives more room, lack of height was the reason why I sold my Tom Senior and bought an Elliot milmor with 18 inches from table to spindle.
|Thread: Shipping knee, saddle and table to grinder...advice on palletising|
I would extend the pallet by a few inches so that is longer than the table,and with the weight of three components I would suggest stiffening the pallet, by screwing 19 mm shuttering ply onto the top of the pallet, pallet delivery companies are not very careful. Though I do think that three heavy precision items on one pallet is asking a bit too much from a timber pallet. I had a tonne of steam coal delivered, the load of 25 kilo bags had shifted and were very close to falling off the pallet,The operator only just managed to get the load onto the tail lift, and I lucky had a tractor with forks to remove the pallet from the tail lift, two other pallet loads of thin wooden flooring had gone over and dumped the whole load over the truck floor, total write off . Ensure your goods are insured. When I had my 6 inch traction engine wheels vulcanised I took them a long way up to Yorkshire on my trailer,ii anything went wrong at least it would be my fault.
|Thread: A New Dividing Plate for my Dividing Head|
Reading back through this topic,which is quite old ,one post mentioned a straight tooth gear slipping and producing a thin tooth, gear slippage on the mandrel can be caused by a cutter being sharper on side, than the other. Usually caused by the cutter rubbing on a hard spot on a previous job (,a lot of cutters used today second hand bought from auction or other sources ,most are good but some can be damaged,) the blunt side pushes away from the work and the sharp side cuts deeper, a can move the workpiece particularly if the gear is on maximum capacity of the dividing head. It does pay to mark the first tooth ,and check the gear when finished ,a gear tooth vernier is ideal for his task. Very often an awful lot is discussed about theory of dividing methods and accuracy ,but very little about the work set up accuracy ie mandrels and work holding ,correct cutter sharpening,and checking of the finished product.
|Thread: How to use a die?|
When I stated that the solid dies were rubbish,and then a contributor stated I was talking cobblers,Well I had in mind the sets of c--p cheap taps and dies usually oil blacked all over and available from auto jumbles,motor trade distributors,cheap retail outlets etc. I have been around a long time and I have nothing against carbon dies /taps I bought a lot of me/brass size taps/dies from Stuart Turner 50 years ago,they were by good known English manufactures and they are still in good conditition, I also have a 9/16 to 1 inch whitworth tap and die set ex WD dated 1940 superb English quality ,all carbon steel ,guided die holders and really good tap wrench .The problem nowadays is finding threading tools of the same quality, The English manufacturers have gone ,and it is difficult to find good reliable suppliers,known names on tools nowadays can be misleading ,they can be made anywhere in the world and somebody possibly bought the company name. I have an unused (until I got them)pairof molegrips,possibly 60 years old and made in Birmingham thats before they went to Wales, I also aquired a pair that were made in spain ,I think after Stanley aquired the brand name,not very good compared with the old ones.
Sorry these circular dies which are not split are rubbish,(cheap foreign imports) their only possible use is for cleaning up a burred or damaged thread, dustbins the best place for them. On tough materials like stainless,use a split die opened up with the pointed screw in the die holder,the other two screws should be just finger tight at first,lubricate the die with oil Motor oil is ok for one offs, if used lot then a Rocol or similar threading lubricant should be used.When opened up a good die will cut an oversize thread ,thread to the length required ,then close the die a little and thread the work again,with stainless the die must be cutting and not polishing as it will work harden, adjust the die until the correct size of thread is reached. The difficult part is keeping the die square to the work,it takes practice,get some practice by cutting some threads on some scrap brass and mild steel rod first.
|Thread: Dissembling an old machine vice|
Get a manual impact driver,hit it with a big hammer type ,they really work. I bought mine many years ago as many leyland/BMC cars secured their brake drums with 2 countersunk screws ,pigs to get out if rusted,the impact driver always got them out.
|Thread: Choice of Steel Grade?|
If I was intending to bolt a rear tool post on a Myford and do it up tight ,I would be more worried about the load on the Tee slot and the risk of breaking the slot out. I suggest making a long tee nut ,to spread the load, tap it and use a stud made from a long bolt. Why does the nut require to be so tight,a shallow tenon would stop the toolpost rotating, Any stud material stronger than en8 would be a waste of material.
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