Member postings for Chris Crew

My method of parting and grooving is with a good old fashioned J&S type holder with an Eclipse parting blade ground with about 5deg. front clearance and top rake (bottom rake as it's inverted) mounted up-side down in a rigid rear tool post very slightly above centre-height. Moderate speed, plenty of suds and a confident steady feed. Anyway, it works for me.

All good quality lathes are made to face very slightly concave, so even if the tool is set at 90deg. to the work it will always be at a very slight angle to the work. This doesn't stop you from parting off or grooving successfully but just be aware of this design feature.

"I blame the parents. My dad bought me a train-set..."

Yes, I had a trainset bought for me too but from that humble beginning I built a model railway layout, as I would think a lot of children of the 1950's & 60's did, but we always boarded a real train at a railway station.

But I kind of, like, sort of, take your point. It was like, sort of, kind of bound to be up-coming from someone. No worries!

'Our club is located next to a train line'

No, sorry, it is not. It is located next to a railway line that may have railway stations, not train stations, and the trains might be hauled by a locomotive and not a train engine. Please, lets not corrupt our wonderful language with the ignorance of 'yoof' that we seem to have to tolerate these days. Now, where's my tin hat?

I know these comments will be controversial to some but I use a cheap generically branded soluble oil which I bought from a local oil and grease merchant. I dilute it approx. 20-25:1 and add a squirt of Rocol bactericide which seems to keep the black grunge at bay. I accept that some people will not tolerate the idea of something containing water being used on their cherished machines but when I was an apprentice in a BREL training school we were ordered to swill down the lathes with the soluble oil, that was provided as a coolant and cutting lubricant, every Friday afternoon after a week's work. This is a practice I have continued ever since on my Colchester Student, which is the same model upon which I received instruction in the training school. It may not be considered acceptable, or even desirable, practice in these days of high-production rates on CNC machines but I am not in that business. I am simply making what amounts to trainee test pieces in a back-shed workshop and it works for me.

(BTW, I use the same fluid on a Harrison mill which is capable of taking some big bites out of noggins of steel when using 'sensibly guestimated' speeds and feeds). 

Edited By Chris Crew on 18/06/2023 21:43:33

I have had a nice Colchester Student (ex-St. Thomas' hospital), circa 1969, for the last thirty years but if I were to be starting again I think that it would be a no-brainer for me to opt for a similar sized Warco geared-head machine. The rational being that my lathe is now 54 years years old and although this particular machine has been relatively lightly used (it had never turned steel or had coolant fitted until it came to me) not many machines will have had such an easy life. Everything has a finite lifespan and as old British machine tools pass down the years it stands to reason that they do so in a progressively degraded condition. I have never had a DRO because I can achieve all the accuracy I need through knowing the machine and a little experience. Someone will get a machine capable of another 54 years work when it's time to sell-up but it can never be as good as a new machine no matter which country it originates from, IMO.

Tell me, have you been funny long?

I have a Myford ML7R (enhanced to S7 less gearbox spec.) and a Colchester Student. I suspect that you will find, like me, that the Colchester as a lathe will walk all over the Myford, but only as a lathe. The Myford is a complete machining centre in itself with every conceivable accessory designed or manufactured for it over the years. On mine, with the attachments I have made, I can turn, mill, slot, hob, divide, graduate etc. plus a few other jobs over the years. On the Colchester I can only turn and part-off and that's about it but I wouldn't be without either machine.

"Progress is all very well, but it has been going on far too long," Mr Algernon Myford said when queried on the possibility by the press. That is why Myford is today the world's leading supplier of machine tools.

I am taking that comment as being a slightly sarcastic, but amusing, quip. However, it could be equally applied to a whole bunch of erstwhile British manufacturers who had an initially successful product and just kept on producing basically the same thing with very little investment, enhancement or improvement until the market and technology moved on and other and other, mostly foreign, manufacturers overtook them.

I will cite Morgan Cars, for example, which is now an Italian company, I believe. Founded in the 1930's and producing basically the same car until the 21st century. Why did it never move on and become like a British version of Toyota or Nissan? It just puzzles me.

Edited By Chris Crew on 31/05/2023 07:19:15

Edited By Chris Crew on 31/05/2023 07:20:05

Can we all get over this? Undoubtedly car theft happens but you would have slightly less chance of winning Euromillions than someone stealing your keyless car with a loop of wire, just about the same chance as someone happening to be looking over your shoulder just as you are entering your banking app details in a crowd in broad daylight. Most of these panics and scares are just utter nonsense fuelled by a sensationalising press on a slow news day and I would think some of the scare stories are merely urban myths anyway. Obviously, fraud and theft are a reality but most frauds succeed through the gullibility of the victim and most thefts are opportunistic due to the lack of security precautions. That doesn't diminish my sympathy for any victim of crime because I have been robbed on more than one occasion and it's not nice but I don't let the thought of it affect my enjoyment of life.

I believe this type of knurling tool was originally a Marlco product. It's very good up to a point in relieving the pressure put upon the work and lathe spindle by a tool-post mounted knurling tool but there is a flaw in the design. I made the 'standard' size version when it was described some years ago in a model engineering publication and also a double sized one to knurl the large index ring on a Quorn I was making (still yet another unfinished symphony!). This was a little less successful as the knurls tended to wander a little due to the increased flexing in the elongated arm. The problem, in my experience, lies in the eccentric at the rear of the upper arm as when the lever is operated to increase the pressure on the knurls the top arm is moved slightly which tends to destroy any nice pattern generated when the knurls are rolling in 'synchronism'. Other than that, providing you bear this issue in mind, some nice results can be achieved when the knurl pattern emerges and no further adjustment is made.

Edited By Chris Crew on 21/05/2023 22:11:28

As far as I have been concerned with milling in the back-shed it has always been a matter of 'guestimation' in both vertical and horizontal milling. There are treatises available on the subject because all materials have a cutting speed and it is possible to calculate the optimum rate of removal taking into account the number of teeth on the cutter and its diameter etc. but as with lathe speeds these are usually 'industrial' speeds were rate of production is the paramount consideration.

I don't know which milling machine you have, I have a Senior knuckle-head for vertical milling which is far too slow for cutters much less than 3/8" even on its fastest speed. I have a Harrison M1 for horizontal milling which is good for taking big bites out of noggins but its all guesswork for as far cutting speed is concerned. To me, if it sounds right and looks as if it is doing the job then it is right.

So in summary, I would suggest the smaller the cutter the faster the speed and the lighter the cut with progressively lower speeds for larger cutters. The depth of cut and rate of feed will always have to be a matter of judgement for me as clearly I am not going to plough a 3/16" end mill into a lump metal at a slow speed because it is obvious to me it will just break.

I am also interested to learn how others approach the matter.

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It got me puzzled too and I had all the time in the world to examine the real thing in the museum. I am flattering myself that I may have got there eventually if the rail wheel and suspension hadn't been hidden by the locomotive chassis, but the animation on wiki explains everything in less than a minute. A very clever and basically simple mechanism once you see it in operation although I would think that the design engineering is highly involved. 

Edited By Chris Crew on 15/05/2023 13:02:34

Jez,

Thank you for putting me out of my misery, all is now explained!

I must admit that, having never seen this mechanism before, I was completely baffled by its operation but the animation in the wiki article makes everything clear.

Chris c.

I recently visited the French railway museum Cité du Train in Mulhouse, Alsace which is very highly recommended if you happen to be in east France or well worth a special trip over.

One exhibit, the drive on an SNCF electric locomotive, really puzzled me. I spent a considerable amount of time examining the display but failed to explain to myself how the direct drive from the traction motor to the rail wheel worked or why it was so arranged. Unfortunately there was no information, either in French or English, accompanying the display and I doubt that my elementary language skills could have elicited much from a member of the museum staff, so I moved on to other exhibits remaining baffled.

The drive seemed be direct from a gear on the traction motor shaft to a larger gear that appeared to be coupled to the rail wheel by two opposing levers with short meshed arcs. I couldn't discern any suspension from the wheels to the locomotive chassis, not to say it didn't exist somewhere, but just that I couldn't see any flexibility. The arrangement was quadruplicated and appeared on each end of the four traction motors' shafts so power was transmitted to eight wheels in total.

I am posing this question from a position of complete ignorance, so if I have missed something obvious I apologise, but could someone explain this arrangement or point me in the direction where some further information may be available. Absentmindedly, I failed to make a note of the type or manufacturer of the locomotive, sadly.

Edited By Chris Crew on 15/05/2023 00:12:40

Edited By Chris Crew on 15/05/2023 00:14:06

My workshop is a pre-cast concrete garage with the door aperture replaced by a 'site office' front. It obviously stands on a concrete plinth. I was just going to paint it with garage floor paint but an old hand told me that there is nothing worse than standing on a concrete floor for any length of time. I had no experience of this because my previous workshop had been a pent shed with a concrete plinth set in the floor where the Myford stood. Because of this advice I put a polythene membrane down and boarded it over with plywood. This lasted for about twenty years but water had seeped in and rotted the wood under one of the machines. As a lock-down project I stripped everything out, put another membrane down and replaced the plywood sheets, this time coated in two layers if thick bitumastic paint. I put a further membrane on top and laid a cheap laminate floor over everything. The Myford stand is again anchored into the concrete plinth through the floor with the holes sealed with silicone sealant. It seems fine but I don't think I will be around long enough to see if will have stood the test of time.

You can get TruGrip collets easily enough, they are not made Unobtainium any more but are now made of Expensivium! Just ask Home and Workshop in Sidcup or look on a well known auction site.

I have a special ruler that I think once must have belonged to Paul Daniels as the numbers on the graduations re arrange themselves occasionally. It's a good trick but I should be wise to it by now.

"You recommend a Chinese lathe despite not having one, basing your opinion on the fact that our homes are filled with other completely unrelated Chinese stuff and disregard a service engineers opinion based on assumptions he may be old and bitter? "

With respect, I did not recommend any lathe, I stated that I do not believe Chinese products are 'crap' based on my experience of owning quite a few because there is mostly no other choice, whatever the brand may read. In fact you will have entered your comments on Chinese manufactured electronic equipment which you will have found works perfectly satisfactorily and will continue to do so.

I also stated that I would buy a Chinese lathe myself and that would have to be my only choice because I would not be able to afford a new 600-Group machine or Myford. The former, I believe, was actually using Far-East components in its machines and the latter is selling Chinese made accessories for use on its products. Also, I have not disregarded a service engineer's opinion, whatever age, experience or qualifications he may have as he is entitled to his view. I merely reserved the right to disagree with it which everyone's prerogative including yours in disagreeing with me. What I stated was that I suspected, that if he were of the older generation, his opinion may be coloured by a resentment that most products are now manufactured in China because this is a prejudice I have encountered in many of my contemporaries. They seem to recall almost subconsciously, with not a little nostalgia, the days when this country's economy was founded on manufacturing and this appears to motivate them to dismiss Chinese products as 'crap' when clearly they are not. This view appears to be supported by several other commentators in this thread who actually do own Chinese machine tools, found them to be very satisfactory and probably produce work of a very high standard upon them.

Edited By JasonB on 07/05/2023 06:51:54

You know it really niggles me when people talk of Chinese products bring 'crap'. Of course they aren't, our households would not function without Chinese products which do exactly what they say on the tin. How old is your service engineer? I would bet he is getting on in years and eaten away with resentment that the British machine tool industry now barely exists, and what is left merely assembles Chinese parts and hopes that by condemning the products damage will be done to the importers who he will subconsciously believe have brought about this situation. I don't have a Warco or Axminster machine but if I were to be starting again it would be an absolute no brainer as to what I would purchase, not only because there would be no British machine available within my price range but because even if there was Myford is a very dated design and leaves a great deal to be desired and is not suitable for educational purposes, IMO. BTW, I have a Myford 7R and if it were possible I would take it with me with the rest of my grave goods just like the other old warriors, but I would never buy another.