Here is a list of all the postings Chris Crew has made in our forums. Click on a thread name to jump to the thread.
|Thread: Trugrip conversion|
If you implement this modification I believe I am correct in thinking that the Trugrip collet has a left-hand thread whilst the 5C collet has a right-hand thread. Therefore, when closing a modified chuck the key will have to be rotated anti-clockwise. Can someone else confirm this is the case?
Edited By Chris Crew on 20/10/2021 23:50:29
|Thread: J & S 1310|
Well, Andmar did get back to me in a very civil and professional manner and they could help me but, although I am sure the price is very competitive for a new back-plate, it is a little out of my budget. So the search goes on for a suitable used part or I will just have to get down to making one.
|Thread: SKY abandoning their satellite customers|
Who needs it? The best entertainment and educational programs are usually to be found in the workshop but for the occasional BBC Iplayer documentary or YouTube instructional video I find that BT copper is more than adequate, although I must admit I am located only a couple of hundred yards from the village exchange and FTTC cabinet, others may not be so fortunate.
|Thread: J & S 1310|
Howard, thank you. I think we can now discount any idea that the taper is INT/ISO as I have just measured the taper major and minor diameters (as far as is practicable) with a digital vernier. The major diameter is almost certainly 1.4375", which corresponds to the dimension given in the e-mail, and the minor diameter appears to be 0.850. over a distance of 2.250". There is approx 0.500" of parallel beyond the end of the taper of 0.750" diameter. This contains a fine thread which I suspect will be 0.625" UNF L/H. Not sure what the included angle will come to without drawing it out and applying some elementary trig.
I did e-mail Andmar as advised by David and attached a photo of the taper I require alongside the one I bought in error but so far I have not received a reply.
Edited By Chris Crew on 08/10/2021 15:50:29
Thanks to you all for your kindly advice. I have e-mailed Andmar with an enquiry and I am just awaiting on their response.
Pete, I have INT30 tapers on some milling machine tooling and it does not fit the grinder work-head. Someone is suggesting INT20 may be the one to try but I have never actually seen this taper before, so it may be quite rare.
John, the 1.4375" dimension is of the large end although I have not measured it myself to confirm. The taper data was supplied by a J&S legacy dealer who also supplied a few other details about my machine which actually surprised me as I had no idea such details would be on record. This was the email he sent me: -
Pete, Yes, it is my listing and, yes, I did buy this one blind but in error. I have tried to get the correct one from several J&S legacy dealers but nobody has been able to help me. It was one of the dealers who supplied the information about the taper but he was unable to supply the correct taper.
I have a J&S 1310 EIU cylindrical grinder the work-head of which has an internal spindle taper of 1.4375" 3.5"/foot. I have never been able to source an additional J&S chuck back-plate with an integral male taper of this size. The only alternative is to manufacture one in the lathe, finishing it on the grinder itself as I have J&S accessories with this taper integral to them to use as a setting gauge. However, if this taper is a recognised standard I may be able to obtain one from a dealer.
So, does anyone recognise this taper as a standard or is it particular to J&S machines?
|Thread: Backlash on Warco GH1230 Carriage|
You don't say whether the machine you have bought is new or used. If it is new a half turn of back-lash seems excessive and even on a used machine a little over the top. Although I have no experience of Warco lathes I can tell you that I consider my Colchester Student to be in excellent condition for its year but the saddle hand-wheel shows up to an eighth of a turn of back-lash when I use the power feed. This is because, I assume, that there is back-lash in the saddle gear-train, back-lash in the rack and pinion and a little slack in the hand-wheel bushes. If your machine is new and Warco provide good service a word in the right direction may help and even if your machine is used they may be able to offer some advice or replacements for worn parts. It seems that you are winding the saddle by hand to eliminate the back-lash and take up any slack so naturally the gearing etc. will not show any slack but you never eliminate it completely under normal operating circumstances because all gearing has a certain amount of back-lash which increase with age.
|Thread: Absolute beginner, just bought a cheap lathe|
Chris, we almost share the same name! If you are in Scunthorpe I am only a few miles from you just outside Market Rasen. If you want to come over to my workshop sometime I would be willing to help you all I can and repair or re-manufacture the parts for your lathe to get you up and running. Drop me a private message and we can set up a meeting if you wanted.
|Thread: Screw cutting|
I had a quick flick through the responses and, although I may have missed it, I don't think anyone has mentioned that you don't need to calculate anything when you use the set-over top-slide method. Simply put the tool in contact with the work and then zero both the cross-slide and top-slide dials. Move the saddle to the right so that the tool point is just past the end of the work. Wind the cross-slide in, and hence the tool point, to the correct depth of thread to be cut and then zero the cross-slide dial again. Wind the tool out using the top-slide until the tool point is just clear of the work. Start the lathe and put the cuts on using the top-slide dial. Use the cross-slide to withdraw the tool at the end of the cut and return it to read zero before you put on the next cut with the top-slide. When the top-slide dial again reads zero the thread will be at the correct depth.
Edited By Chris Crew on 21/09/2021 22:41:20
|Thread: What to drive a J & S with ?|
Pete, please don't be troubled by the idea that my kit is not well maintained and cherished, although a little under-used these days, I must admit. Just as a classic car or bike enthusiast collects and cherishes the products of the past or the stamp and dinky toy collector maintains his collection just for the sheer joy and satisfaction of owning it, so it is with my machines. In fact, collecting them became almost a hobby in itself because to me there is something rather special about an old British machine tool. They are redolent of the time when this country led the world in their production with some of the biggest names like Alfred Herbert, when men in brown overalls cycled to the works every morning from a terraced house and thought nothing of the wonderful amount of skill and craftsmanship they held in their hands.That may be just a nostalgic fantasy, but just as with a classic car or bike, is it the smell, the feel or the period design that makes them so special? I don't know and I can't say, it sort of just is! What I do know is that the time is fast approaching when I will have to dispose of the collection and downsize the house because health and age issues will compel that to happen and it will break my heart to see it dispersed after all these years.
Edited By Chris Crew on 20/09/2021 10:49:30
Pete, I have never once said that I don't worry about standards, or shall we say the standard of my work which is always done to the very best of my ability and scrapped if I am not entirely satisfied. I would like to think that, if not 'exhibition' standard it at least looks pretty good and not at all 'amateurish'. In theory, it is possible to work down to 0.0001" on the J&S 540 or 0.0002" on the J&S 1310 but if I was to work to these limits they would only hold for the time they were produced because I do not work in a temperature controlled environment, so both the work and micrometer would probably measure different dimensions depending on the time the measurement was taken. That is partly why tolerances exist and are quoted on drawings, or were when I was an apprentice but that's well over fifty-years ago now. I have no idea what happens in industry these days with the advent of CAD/CAM because I have never dealt with it. So to me, if it looks right, fits right and works right, then it is right.
The point I was really trying to make, and admittedly this is an assumption, is that we are all practical men and only need our machines to run reliably when we switch them on, we are not in the workshop to redesign them or their power supplies, but we may suggest improvements from time to time. All the clever stuff, the design, the engineering and manufacture has been done by the professionals and is encompassed in the machine when we purchase it. We have paid for the professional engineer's skill and merely use the tools he has produced for our own purposes, including the converters and inverters. Again, I must admit it has never once crossed my mind to fit power factor correction capacitors to the distribution board in my workshop for motors running under no-load or that any phase in-accuracy would effect the finish on my work because for all practical purposes it hardly matters, IMO.
Yes, I am very lucky to have a number of machines that were once found in light industrial or educational establishments but this is because, when Mrs.Thatcher was busy closing down a great deal of traditional British industry and the educational curriculum was changing, they could hardly give the stuff away. Working nights in various parts of the country gave me the opportunity during the day to visit factory liquidation sales. I have seen auctioneers almost crying at the prices they were having to knock down. For example, I once bought a fully equipped Brown & Sharp No.13 universal grinder for fifty quid and it cost me £250 to have it shipped home! I still have the thousands of pounds worth of Burnerd collet chucks and Crawford collets that came with it but sold it on when I acquired the J&S.
I don't pretend to be anything more than a back-shed amateur, but I have every respect for the professional engineer's knowledge and technical education and I am very envious of it because we didn't even get the chance to go to university in my day, although I hardly think that a lot of it is relevant to the practical 'common-sense' issues we deal with in our home workshops and hobby projects.
Well, we will have to leave it to others to decide who is talking 'egregious nonsense' in the context of operating in a back-shed atelier, won't we, Andrew?
Andrew, again with respect, who gives a 'monkey's' about the power factor in a back shed workshop? I certainly don't and I suspect not many other amateurs do either. If you are working in industry and power correction is necessary to achieve maximum efficiency it is obviously very important. When you have finished a job in the shed the machine is almost always stopped immediately so whatever the poor power factor characteristics of an induction motor are under no load become irrelevant anyway.
I know there are some highly trained and knowledgeable engineers on this site, you may be one of them, but applying professional industrial expertise, standards and theory to back-shed workshops is both impracticable and pointless, IMO.
Gerry, with the greatest of respect, don't you think that you are massively over-thinking all of this? For heavens sake, over 20 years ago I plugged a J&S 540 into a Transwave 5HP static converter with no thought other than getting it to run and it has performed superbly well ever since. For the purposes of a back-shed workshop, which I am assuming you have like most of us, the surface finish on my work has been very good and the machine or power supply have never 'wobbled'. I accept static converters, or even maybe also rotary converters, are now yesterday's technology but all the same they provided the power we needed at an acceptable price and convenience when nothing else was available.
I apologise for these comments if you are NPL trained and want to achieve near-perfection but for all practical back-shed amateur purposes you really don't need to go this deeply into things, just plug the machine into to a suitable power supply and see what happens. I can almost guarantee you won't be disappointed if your J&S is in a reasonable condition. You can make all the adjustments and refinements you may think, or find, are necessary later and most will be in the type of wheel that is fitted to the machine. You may have to change it for a different grit and bond but the chances are your machine will have been fitted with a good general purpose wheel which will cover the majority of your requirements and expectations of finish.
Edited By Chris Crew on 19/09/2021 13:37:45
|Thread: Myford ML7 accuracy|
I cannot add much of value to the comments already made, they are all relevant IMO. But for my twopennorth, if you go for a myford forget all about an ML7 and go for either a pre-cherished ML7R or Super 7. Be prepared to pay several thousand pounds from a reputable dealer or even the new myford itself and get as many accessories included in the package as you can because if you buy a basic machine you will end up paying as much again to make it anywhere near useable. Myford accessories are rising in price almost daily.
|Thread: What to drive a J & S with ?|
Mike, I agree with your comments.
Edited By Chris Crew on 10/09/2021 10:37:09
I have a J&S 540 with three motors, four really but only three are in use at any one time. These are for the wheel-head, the table hydraulics and the selected extractor or coolant pump. I have been running this machine for the last 25 years on a 5HP rated Transwave static converter with absolutely no problems whatsoever.
I always start the motors in a particular order, i.e. wheel-head first, then the hydraulics followed by the extractor/coolant and stop them in the reverse order. The Transwave handles all this without a 'murmer' so, although the technology is probably obsolescent or even obsolete these days, it is obviously a well-designed and reliable piece of British made kit.
Personally, I am not enamoured of fitting single-phase motors to 3-phase machines, I use several Transwave static converters in the workshop and an old shop-made rotary converter, which was built by a special-effects engineer for the defunct Ealing Studios, to power a J&S 1310 cylindrical grinder. I also run smaller 3-phase machines, i.e. a Boxford shaper and a Clarkson T & C grinder with homemade start and run circuitry cribbed from the Electric Motors book in the Workshop Practice series, a small improvement to which was published in Model Engineer in the 1990's under my own name.
Edited By Chris Crew on 10/09/2021 08:17:56
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