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Member postings for mgnbuk

Here is a list of all the postings mgnbuk has made in our forums. Click on a thread name to jump to the thread.

Thread: Neil Hemingway Kits
03/07/2020 20:01:33

or at least it did, until I read this on the Hemingway page:

[quote] The table assembly arrives engraved with 0 -180 divisions. [/quote]

As my machine does not have the markings, Michael, I can't say for certain. But Tony Jeffree has a build log for a later machine with some vey clear pictures here

Photo 20 is a close-up of the table & the graduations look more like punched than engraved to me - the raised areas around each mark can be seen where Tony stoned them off. The ends of the marks are square, where engraved marks would have rounded ends ?

Nigel B.

Thread: Emco FB2 Quirks and Additions
03/07/2020 12:05:03

I intend to add to this post from time to time.

yes

As a Taiwanese FB2 clone user, I look forward to the coming installments. I took the simple solution route to let mine breath by just backing off the filler cap by a turn & letting it breath through the thread clearance - not as subtle a solution as yours, Gray, but it seems to work OK.

Nigel B.

Thread: Neil Hemingway Kits
03/07/2020 11:58:03

A point that puzzles me a bit about the 'Worden' Tool-grinder is why, having gone to the trouble and customer's expense of (probably CNC-) engraving a big, clear degrees arc on the table, they did not have the numbers engraved too.

I doubt that the degree markings will be engraved, they will most likely have been stamped in by the CNC punch that punched the pieces from the parent sheet. So no great expense to add the marks if this is the case.

Be thankful that you got a version with the graduated table - my Worden is an early version & doesn't have these marks at all (just a plain table) so, at a guess, the sheet metal supplier had upgraded to a CNC punch with an indexable punch holder between the inital design (bearing rail near the wheel) & the later one (bearing rail at the rear). If you look closely at the marks, you will probably find the longer lines are made by stamping two short lines end to end, so only one tool required. Adding numbers would have required a lot more tools (0 to 9) & the CNC punches I have seen (which is admittedly not many !) didn't have very large tool carousels. I believe that some more modern machines also have a laser, so then laser engraving of the numbers would then be a viable option.

Nigel B.

Thread: TOOL BOXES
01/07/2020 20:36:20

I have a couple of "Stack On" 3 drawer roll cabinets, a "Stack On" 9 drawer chest & 3 drawer mid unit on top of one & an Aldi 3 drawer chest on the other.

The "Stack On" items came from Halfords & have stood up well to probably 20 years use. Far better quality than what must be very entry level Snap On units we have at work - these have "friction runners" on the drawers rather tha ball bearing slides & most have worn through now. They were very stiff to operate when loaded. The Aldi chest is not as good quality as the "Stack Ons"- the drawers are noticably flimsier, but it was cheaper. The "Stack On" items were also available branded as "American Pro" IIRC.

Also got one of Chronos's wooden toolmaker's chests when they were selling "seconds" at one of the Harrogate shows. Some were quite badly damaged, but I found one that had just sprung a joint in the main outer box. A smear of PVA in the joint & application of weight to hold it together and I can't see the repair. Overall a nicely made box - IIRC the seconds were £60-something, rather than the £120-ish normal price. Just need to make bench space to be able to use it.

A Clarke branded 3 door steel wall cupboard sits above the Super 7 & holds all the accessories for the lathe. All the cupboards have keyhole perforated backplates & it came with a variety of hooks & 3 shelves. This is pretty cheaply made but does the job - though I wouldn't pay the current £114 asking price from Machine Mart. Similar items are available on Ebay for around £70 at the moment & I was thinking about getting another to put near the milling machine & shaper.

Nigel B.

Thread: Tungsten carbide for shapers
01/07/2020 20:08:59

I have mainly used brazed tip carbide tools on my Boxford, as they were the only suitably sized tools I had to hand when I bought the machine. As they have worked well, I have not investigated HSS options until recently, when I bought a length of 1/2" square HSS to play with. Not sure of the provenance of the tools I use, but probably UK made rather than Far Eastern.

Can't say I have had any issues with chipping or dulling on the return stroke. I have been mainly roughing out steel parts to finish off on the lathe or mill, taking 1- 1.5mm DOC with a "couple of clicks" feed. Chips come off hot enough to make you take notice if they go down your shirt.

Turning or milling tools with inserted or brazed carbide tooling frequently encounter & deal with interrupted cuts - don't hear much of major problems in those applications.

Nigel B

Thread: Exploding Grinding Wheel
30/06/2020 12:49:12

I just came across this idea of bonding a wheel to a backing plate for face grinding....

The company I did my apprenticeship with had a vertical spindle surface grinder (may have been an Abwood) in the toolroom that had an abrasive ring "wheel" bonded to a steel backplate. The bonding material was heat softened - to change a wheel, the backplate was heated until the old wheel could be removed & the old adhesive removed with a wire brush to clean out the recess in the backplate. New adhesive was a yellowish brown powder that melted to a smelly dark brown thick paste when it was applied to the hot backplate. A new abrasive ring was settled in the hot paste & left to cool before remounting and dressing. There is a swinging head "die punch" grinder with a similar wheel arrangement where I work now - it could do with a new abrasive ring, but I have not investigated changing it as the machine gets negligable use.

The toolrom roof had a hole from a bursting cup wheel on a tool & cutter grinder - small wheel, but a bit of it still managed to get two stories high & have enough energy to punch through what was probably an asbestos sheet roof panel. The hole was duly pointed out to all incoming apprentices as a warning not to mess about with grinding wheels.

Nigel B.

Thread: wonky thrust bearings?
28/06/2020 10:26:36

I've ordered some FAG 51102 and will keep my fingers crossed that the are better than the (cheaper) first pair.

Did you sepcify a precision class for these , or just go with general purpose bearings ?

As with other bearings, ball thrusts come in various precision classes & for a ballscrew support application where minimal axial variability is required I would expect to specify P5 or P6 grade.

I once spent a day with a plie of ball thrust bearings sat at a surface table with micron dial gauge checking to find the best of the lot for a spindle bearing installation on a Jones & Lamson lathe - non of our usual suppliers could source the correct precision class from stock, so BSL sent their entire stock of standard grade bearings for us to find the one with least axial runout.

In the end, one was only a few microns out from precsion spec. The customer didn't complain about the rebuilt machine performance, so I guess it was OK. These were much bigger than you are specifying, so easier to check - I sat an assembled bearing on the surface table, put a weight on the top race & checked the axial runout of the top race while rotating the assembly under the DTI. The variations in runout were suprising, with examples at both ends of the tolerance range from the samples supplied - the one chosen was only just outside precison grade, while others were barely within general purpose grade.

Nigel B

27/06/2020 17:24:50

I've used a pair 51102 thrust bearings

Have you fitted the races the right way round ? The two "washers" in a ball thrust race are not the same - one is a "housing washer" with a precision OD & clearance on the ID, the other is the "shaft washer" with precision ID and undersize OD. Putting the "shaft washer" into the housing causes problems - found this out the hard way on someone else's horizontal borer a long time ago (built wrong at the Russian factory).

Nigel B.

Thread: Halifax 524 Headstock
23/06/2020 07:39:27

That looks to me to have been caused by lifting the machine with a sling around the spindle - a tactic I have seen machinery movers use on several occasions & it always makes me cringe.

Nigel B.

Thread: Pesky Government Announcement!
19/06/2020 16:14:33

Rastrick Grammar. I've a feeling that a forerunner was Rastrick Central School or something similar. If I'm right, then there is a good chance that my mother attended that school leaving with Matriculation Certificates in 1936.

Rastrick Grammar School was independant & very old, tracing it's roots to a school started by the local St. Mathews church in the 1300s & it is unlikely that your mother attended there, as it was a single sex boys school. It "went" in the mid-80s, merged with a local comprehensive school to become Rastrick High School. The local single sex girls equivalent was Brighouse Girls Grammar, my wife being one of the pupils there. That, too, closed in a re-organisation & the premises are now retirement appartments. There was also Rastrick Secondary Modern School, know locally as "Rastrick Common", as that is where it was sited. That is where you went if you didn't pass the 11 Plus.

You would not know the place I used to work, as their premises were purpose built on a new industrial estate started in the mid-80s. It was on farm land, with access shared with an established chemical works nearby (variously Hoechst or Union Carbide - don't know what they made). The land was on the left as you drove from West Vale up the hill towards Holywell Green centre, opposite the golf course. The land had been a steepish sided valley & it was levelled with ash from the former Elland coal fired power station (long demolished & that site now also being an extensive industrial estate, one of the tenants being Mitutoyo) - that stuff had very poor load-bearing properties & made necessary some very heavy-duty foundations for the 20 Tonne gantry crane in the works. The floor was 600 mm thick concrete.

Huddersfield isn't too bad a place, though it is not the place it used to be. Local politicians don't help, with some rather strange priorities to waste money on while ignoring the basics & the town centre is struggling as many are. As with many towns around Leeds, it is viewed now as being dormatory space within the "Leeds City Region". All part of the "Northern Powerhouse" carp that the politicians spout about that is making life a lot less pleasant around here. A move to somewhere quieter to retire has a lot of attractions !

Nigel B.

18/06/2020 19:24:34

Attended Elland Grammar School.

Wasn't familar with that school, so looked it up Found that I did know it after all, but it has been known as Brooksbank Comprehensive for as long as I have been aware of it - my sister went there for the last couple of years of her education & I passed it every day on my commute to my previous employer (when I was in the works) at Holywell Green.

Tuel Lane in Sowerby Bridge was part of the commute to Broadbents in Mytholmroyd from Rastrick for 15 months or so until redundancy stopped play. Boxford's "new" premises are a right turn towards Halifax at the top of Tuel Lane.

Nigel B.

(born in Hudderfield, brought up in Rastrick & ex- Rastrick Grammar School)

Thread: Can summer car tyres be used in winter?
18/06/2020 08:06:18

More important IMHO is to change the engine oil to a winter grade to handle low temps (check your service manual).

Something that has not been required here for decades. Modern multigrade lubricants are very low viscocity anyway - 0W30 or 0W20 is the default for many modern engines & even the older ones were 5W30 or 10W40. Not much scope to go for a lower viscosity there. Unlike Australia, we don't have to worry about very high temperatures - low 30's is about as hot as I gets in the UK, though it was 43 degrees C in Northern Italy when I was there last summer. My 5W30 lubricated diesel motorhome didn't complain at that & also ran fine at -3 degrees C locally over Christmas.

Best car I had for snow traction was a rear engined Skoda Estelle 120L5 - narrow tyres + the engine & gearbox weight over them + a softly tuned engine, it had no problems with West Yorshire hills in snow. It did benefit from a couple of bags of sand in the boot over the front wheels to improve the steering, though.

Nigel B.

17/06/2020 07:55:09

Most car tyres sold in the UK will be "Summer" tyres.

Winter tyres have different tread compounds to remain flexible at lower temperatures + more and wider sipes to better clear snow & water. The combination of low temperature flexibility and larger sipes allows snow to be shed from the tyre, rather than packing into the tread. The disadvantage to Winter tyres in Summer conditions is that the more flexible compound wears faster in warmer, dry conditions, plus they are generaly less fuel efficient and frequently noisier. IIRC the temperature has to be below 7 degrees C for Winter tyres to start to offer an advantage over Summer tyres.

I managed to get a set of steel wheels with nearly new Avon Winter tyres fitted for my last car at a bargain price from Ebay. They were noticably grippier in snow & generally gave better grip in wet conditions than the Summer tyres fitted as standard, but fuel consumption increased (around 2 mpg less) and road noise also increased. After 4 Winters (at around 4000 miles per Winter - tyres rotated each time they were fitted to put the greatest tread depth to the front wheels) they were pretty well worn out, as Winter tyres require a greater minimum tread depth than Summer tyres (4mm IIRC) to function correctly. These wheels may fit my current car (originally bought for a Kia Carens, now got a Hyundai i30 with same diameter wheels & same size tyres but not tried them to see if spigot diameter & bolt pcd are the same) but I din't bother last Winter as it was pretty mild. The tyres only have one more season in them & I'm not sure I would buy another full set (Winter tyres have to be fitted as a full set).

I generally buy tyres for the cars online from Tyreshopper, who use National Tyres outlets to fit them (at a lot less than National Tyres charge to supply & fit).

Nigel B.

Thread: Brexit No Deal - WTO duty on EU machines/tooling?
16/06/2020 19:22:38

Forget promises and spin, it's time for the politicians to deliver solid results. Let's hope they do!

There is a first time for everything !

Nigel B.

Thread: Mag scales and steel screws?
13/06/2020 14:22:38

Possibly there will be local deviations around the screws.

I replaced the capacitive readouts on a tool pre-setter ( a bit like this one for layout ) with magnetic scales & a budget two axis readout from M-Dro. The Swiss manufacturer of the pre-setter wanted over £3k + Vat for two replacement capacitive read heads, so approx £400 (at the time) for the M-Dro kit was a much cheaper alternative.

After fitting, I checked the positioning accuracy with slip blocks & found that neither axis was accurate & that the two axes were different in their inaccuracy. The horizontal arm was solid stainless steel & the vertical column was an aluminium extrusion with inset stainless rods for bearing surfaces - the magnetic tapes were directly applied to two different backing materials. This inaccuracy was not a problem, as the readout had parameters for linear error compensation. It didn't take long to calculate the correction values and, after a couple of refining modifications to the values, both readouts were showing accurate results against the calibrated slip block set.

The issue with local deviations due to mounting screws (if they did happen) would be that you would want a non-linear compensation, not linear - what is frequently called "pitch error compensation" on CNC machines, where the deviations are entered at a number of points along the axis using the scale reference point as a datum. While some "high end" DROs probably have this feature, it is unlikely that the budget end units would, so even if you were able to determine that such local deviations did exist, your readout unit would not allow you to compensate for them. At my last employment I had a Renishaw ML10 laser inteferometer to check and set non-linear compensation tables on CNC machines - at over £40K for the kit around 20 years ago not something readily available for the average home workshop user !

In reality I doubt that you would notice such errors if they did exist. I would suggest that you check the basic accuracy of the installation using some form of calibrated artifact(s) - say 1-2-3 blocks or slips - and, if your readout has the facility, spend a bit of time setting the linear compensations as best as you can. Then just enjoy the better overall accuracy & repeatabilty that even a slightly flawed system will give you over using the handwheel graduated dials.

Nigel B.

Thread: Compressor inspection
10/06/2020 08:11:00

Likely far cheaper to buy another receiver than pay out for a specialist company.

Probably, though the annual inspection cost isn't as much as you might expect. IIRC less than £500 for the site visit (a couple of hours ) + the certification.

They (the chinese) don’t make long-lived pumps at the cheaper end of the market.

The Clarke small "hobby" type compressors I have used were Italian made. In my experience they are well made & last almost indefinately if the oil is changed occasionally & the inlet air filter is present. The "oil free" type are pretty useless, though - very low duty cycle & short life if this is exceeded.

Nigel B

09/06/2020 09:43:07

Our compressed air installations at work have to be inspected annually - including a 50 litre Clarke portable compressor. There is a calculation - system volume x working pressure in Bar IIRC - and inspection is mandatory in a working environment if the calculation result exceeds a certain number. The 50 litre receiver 8 Bar Clarke compressor exceeded the number & had to be inspected.

The receiver inspections are basically an endosope internal inspection through an end cap / inspection port + an ultrasonic shell wall thickness test + safety valve test & overall visual inspection. The main workshop receiver at work is very large (3 metres tall) and lives outside un-protected - I have been working here for 14 years, this receiver was second hand when it was purchased at around the time I started and it has not had any advisories on any of the inspections in that time. It is more heavily built than a DIY portable type, but is used 8 hours a day 6 days a week for 50 weeks a year.

We use an external specialist company Mandate Systems for our inspections. You could do most of their inspection regime yourself - USB endoscope cameras are really cheap now for a look through one of the receiver end plugs. It would be the ultrasonic shell thickness test that would require equipment not usually in a home workshop. I doubt, though, that you would find much amiss.

Nigel B.

Thread: The Workshop Progress Thread 2020
07/06/2020 17:48:24

A frustrating weekend in the garage / workshop for me.

I volunteered to make a chuck adapter for one of my wife's work colleagues, who dabbles in wood turning. His lathe has an M24x3 spindle nose with 24mm register & he wants to fit a chuck with an M33 x 3.5 thread & 33 mm register. There are M33 to various nose thread reducers available but not to M24 x 3, which doesn't appear to be a popular size.

First trip-up was yesterday afternoon, when the lathe inverter refused to start up again after a coffee break - Fault Led illuminated. This is an ancient Toshiba inverter that was used and obsolete when I was given it, probably around 20 years ago so I can't really complain. A quick check with a basic multimeter showed balanced motor phase winding resistances & no obvious shorts to earth, though I need to bring my insulation tester home to be sure. I have a number of suitable NOS inverters in storage, but was uncertain whether or not to reform the capacitors before use (they have been is storage for several years) - a bit of researching suggested it might be wise to do so.

Tried the lathe again today & it worked ! Got the part to the stage of cutting the M24x3 internal thread & trip-up number 2 came along - the 34 tooth gear I bought to use with the Myford QC gearbox couldn't be fitted, as the gear quadrant would not rotate far enough (hit the end of the slot). A quick check found that I have all the gears required to cut a 3mm pitch thread with the "official" metric conversion set for the the Myford QC gearbox - but not the spacer to clamp up the gear on the gearbox input shaft. Got one on order from Myfords now. I tried to run the lathe to check how the gear train sounded under power (seemed OK by hand), but the inverter faulted out again.

So I lashed up a 240v to 55v-0-55v transformer & put 55v into the NOS Trend inverter for an hour, followed by 110v for an hour and a half (the drive came to life on this reduced supply), then 240v for an hour. No problems so far, just need to fit it after checking the motor out. I'll put switches on this one to control the spindle direction - the Toshiba was just linked up to sit at a constant 50hz forwards on power-up.

Nigel B.

Thread: New or old style 3 phase motors?
06/06/2020 15:54:31

Do you know where they are manufactured now?

Not sure. They are owned by a Far Eastern company now & as far as I know the Huddersfield site is just a warehouse. Some of the manufacturing equipment was shipped out to Poland & there was also an Indian manufacturing plant.

A late friend of mine worked there from leaving school to being made redundant after (IIRC) 43 years when the die casting facility was moved to Poland. He had held various positions (including a long stint as an instructor in the in-house apprentice training school), but the last was as a manager in the die casting shop. His son & daughter both worked there as well, his son being a toolmaker who worked on producing the die casting tools for the Indian operation. This was supposedly to supply motors solely to the Far Eastern markets & not for import to the UK, but I don't think that stance lasted long.

The Brook companies had been owned by Hawker Siddeley for many years, but IIRC they were subject to a hostile takeover & it all went downhill from there - in the end the companies were sold to the Far Eastern owner (another motor manufacturer) for some nominal figure plus debts. IIRC the Huddersfield plant once employed around 700 people, but by the time my friend's daughter left there were only around 25.

Nigel B

06/06/2020 11:54:25

Modern motors have a much reduced clearance between the rotor & stator compared to older designs.

My previous employer built a number of special purpose CNC lathes for Brook Motors Honley plant (which produced the small motors), the specific aim of which was to machine the end plate locating spigots on the stator casing to be more accurately located with respect to the bore through the stator laminations to allow the reduction of the rotor clearance. The reduced clearance was apparently required to improve effieciency and give better operation with inverters. This was probably about 20 years ago so not really new, but newer than the OPs boxed old stock.

Incidently, according the published Brook information, motors that have been stored for more than (IIRC) a couple of years should have their bearings replaced before being put into operation - vibrations from the environment apparently cause the bearings to Brinell where the static balls have been sat & give noisey running and premature failure if not replaced before being put into service.

All of the Brook Motors manufacturing plants (the main plant was in Huddersfield, with smaller plants in Honley & Barnsley) closed over 10 years ago,

Nigel B.

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