Member postings for John Abson

' John, WTLD is definitely not part of the designation - I should have made clear that the positioning of this stamping on the ring, relative to the stamping of its basic designation. So you don't have your date tables any more, but what about the site of manufacture ? Since the bearing was made in this country there are only two possible sites, Luton and Irvine. One or more of these letters should define that, should it not ? '

Hello Gerry,

Would have been made either in the old 1911 factory at Luton (which closed in the late 70s) or the 'new' post-war factory at Sundon Park (on the north side of Luton and still producing spherical roller bearings); just to keep things nice and complicated both were identified as Luton made products. Irvine only made water pump spindles, one high volume taper roller bearing and small deep groove ball bearings.

I'm still scratching my head on the WLTD bit!

/J

Hello Gerry,
Year of manufacture marking would have been a single letter - on this vintage it would have been stamped on the soft outer ring before HT and grinding . Kicking myself now for not retaining a personal copy of the date tables! There was a workaround for work in progress left over at the end of the year - a single dot was chemically etched at final assembly to the right of the letter on the hardened and ground ring face to indicate 'year plus one'. Current methods of laser marking don't half make such things easier.

WTLD isn't a familiar part of the bearing designation - it may have been a 'special' for a specific customer. Internal clearance (axial in this case) would be denoted by a letter C followed by a number: 2 for one class less than Normal; 3 for one class more,etc.
J.

Interesting to read this thread, albeit a bit late to the party; Skefco was the brand name for products of the British factories of SKF (as well as in India, South Africa and Australia) until the globalisation of the group's production which started in the late 60s, when the brand was progressively dropped - the last few bearings branded Skefco were made in the late 70s for the aftermarket, subsequently replaced by the SKF brand. If your friend wants to stay safely up in the air, country of origin is the least of their worries, noble as it might have seemed at the time. From the mid 70s, SKF in the UK has been called just that - SKF (UK) Limited.

I realise you've already sourced some of your requirements, but I assume the application is in some way safety-related. Specs for bearings are historically surprisingly relaxed, usually stipulating the maker's designation, thus making them a 'black box' design following whatever General Catalogue specs were applicable at the time. More recent applications (e.g. jet engine main shaft bearings) are the complete reverse with the customer's design and specifications being hyper-detailed though (ultimately) often following the bearing supplier's design rules for the internal parameters; these products are tested destructively to the extreme for design validation.

Corrosion - be careful. If there's any sign of external corrosion (under an eye-glass) assume there is some developing on the contact surfaces (balls and raceways), which classes the bearing as 'failed'.

Cages - good point; most SABB (self aligning ball bearings) nowadays have nylon (plain or glass-filled) cages which aren't tested at below zero temperatures and get brittle. Don't use them unless their use is specifically prescribed. Steel or brass cages are what is needed.

If you cant find original parts, try HB Precision in Honley, but tell them the application.

Good luck with your quest,

John


PS as a footnote, I worked for SKF from 1978 to 2020, initially at Luton (becoming company QA manager including being CAA/JAA and MoD release authority) then ultimately becoming Head of Quality for the entire group, based in Gothenburg. A fascinating career with many twists and turns, but never lost my love of getting my hands dirty and always had a workshop of my own.

Edited By John Abson on 29/09/2023 16:24:59

Edited By John Abson on 29/09/2023 16:26:02

Anyone else’s copy with the pages out of order?

Presumably to do with the print layout…

/J

Edited By SillyOldDuffer on 15/05/2023 11:25:29

Rather like democracy, then!

/J

As we seem to be swapping anecdotes rather than opinions (and thus in a much more congenial place), how about metric deep groove ball bearings (ie those with external dimensions in metric units - e.g. 6207 for a 35mm bore)?

Yes, the ball dimensions are all inch sizes (or fractions thereof).

Go figure, as they say....

/J

Nice one!

However there are 24 hours in a day so time is definitely Imperial based (yay!!) John Harrison was, after all an Englishman - oh crikey, are degrees of latitude and longitude metric or imperial??? (think I'll just go and hide!)

I've noticed an increasing move in ME to use metric dimensions. It makes procurement of standard materials and tools easier and in some cases cheaper, in the UK at least. DROs especially on milling machines - 'once you've used one, you'll never go back' seems common - simply switch between metric and inch. Even my digital calipers do the same.

Fits and tolerances really don't come into it, once you've made the mental adjustment (OK, some people will never make that jump, but that's not because of the measuring system base IMO).

I spend a lot of my life restoring and making parts for old pipe organs, all made to inch dimensions. Makes a lot more sense to use inch on those, but metric on more recently built instruments. Errors are less and its easier to measure in the respective measuring system base used on the original. Likewise, when building a model designed in inches, one is better sticking to inches.

I was recently 'given' a Bosch tape measure as a promotional giveaway. Functionally it's the best tape measure I've ever owned (and I've lost dozens and found a few ) but is only marked in metric. After about half a day, I felt liberated from the tyranny of the inch!

/J

Edited By John Abson on 04/03/2023 10:24:39

When I lived in The Netherlands about 30 years ago, my house had a form of PIV installed with heat recovery. Built on reclaimed polders, something was needed to counter humidity levels in the building. It also of course saved on heating bills. If I were building a house today I'd definitely install/specify such a system. Even if confined to the upper storey, where installation in the loft would be relatively easy, it would still have a beneficial effect.

I bought a hand pump spray bottle of Camellia oil quite a few years ago from Axminster. They promote it as a rust preventant; it works for me and is easy and not too unpleasant to wipe off. There are plenty of other sources on Amazon, promoting it for cosmetic purposes, but whether it is really the same or not (and I'd be cautious about acidity/alkalinity) I don't know. I also use it to preserve newly machined/cleaned up ferrous parts.

For me, the key to preventing rust is avoiding high humidity/sudden temperature changes through a combination of good insulation including roof and floor (a friend uses insulation panels from insulated truck bodies; I'm a bit more posh and shelled out for rockwool slabs RW4 grade), gentle heating with a small oil-filled radiator on a low setting, and some high level vents to allow air to circulate. The insulation (especially in the roof) also helps to reduce solar gain on hot sunny days.

Interesting to read this thread and the many words of wisdom. If I may add a few comments of mine, even if not very wise :

Insulation: a key to avoiding rust is avoiding condensation, and the key to that is avoiding rapid temperature changes. Insulation slows down the rate of heat transfer and thus temperature changes and avoids condensation on surfaces where there is a temperature difference. It also helps a great deal in the summer, especially with roof insulation which avoids the effects of direct sunlight beating down on it.

Spray foam. Anyone who instals that is signing a pact with the devil. Yes, it insulates, and is easy to apply. After that, it's a nightmare with entrapped moisture, lack of ventilation, outgassing of nasty chemicals and difficulties in building maintenance. Slab foam or rockwool insulation is a much better way to go.

My own workshop is a reasonably substantial timber shed with 50mm of Rockwool RW4 grade** covered with 13mm OSB (Sterling) board panels for the walls and ceiling, which make for easy attachment of storage shelves, small tool racks etc. The floor is timber, laid on concrete slabs bedded on a very light dry sand/cement mix. Machines are mounted on anti-vibration pads through holes in the floor, resting on the concrete slabs underneath. A couple of holes at rafter height allow a through flow of ventilation which helps reduce humidity build-up.Windows are 'economy grade' commercial timber double glazed units.

A number of people have mentioned roofing felt; Onduline corrugated reinforced bitumen panels over battens laid on OSB panels are far more durable and easy to replace when eventually needed. The air space in-between adds to the insulation effectiveness. Sold at Wickes.

Heating is a small and simple oil-filled radiator with a thermostat.

It makes for a most comfortable working environment and even in recent -8C external night time temperatures was a pleasure to work in with the timber floor being easy on the feet and legs.

In your case, I would line out the concrete garage (internal shed approach as suggested) and insulate.

/John

**Rockwool in the more technical grades is available from Rockwool distributors over the counter, often a wider range than the usual DIY 'sheds'. Rockwool have a very helpful technical helpline. Google is your friend here.

Edited By John Abson on 18/12/2022 11:29:36

Just a note of warning from an old SKF guy. Heating the bearing to ease assembly on the shaft is perfectly fine, but don't go over 120C. And needless to say (so why do I? ) press on to the shaft through the inner ring and not the outer ring.

Thanks, Journeyman, what I suspected. Seems about the same (with some differences) to the WM16

Orrell list this machine on eBay which is f.o.b. Blackburn. Complete with long table, power feed but no DRO at £2200. The WM16 is out of stock at the moment so can't price compare.

Does anyone have any knowledge/experience of Cormak mills?

They seem similar to the usual WARCO and other offerings - the company is Polish. Pricing - as far as one can compare - seems similar to competitive. They do some long travel machines. UK agents are Orrell Group (in Blackburn) who seem to mainly offer agricultural machinery.

I bought a pair out of curiosity, safe in the knowledge of the £10 or so I saved that I wouldn't otherwise have spent . When I put them on my wife laughed at me which overcame any 'not another parcel' remarks.

Overall impression is that they are nicely put together and they seem to work well. The white plastic is attractive but perhaps more suited to an optician's clinic than a model engineer's workshop

Comments otherwise:

- LED light strength on the low side of OK

- if you are sitting at a bench the magnified field of vision is rather in the direct line of sight and (using the spectacle arms rather than the elasticated headband) I had to bend my head forward to lower it to suit my workplane (hope that makes sense).

For the reduced price I'd recommend them, even if not 100% perfect. For those of us with vision problems they could well be just the thing. I could see myself using them for detail painting and lining out.

/J

Yes but doesn't he drive a personnel carrier (paragraph 3 section d)?

How do they get type approval, or is it a maintenance issue in which case how do they pass their MOTs? I agree that one sees a lot that aren't well adjusted.

It could be down to an increasing prevalence of automatic gearboxes where a brake application is needed when stationary to prevent creep. The countermeasure is to apply the handbrake, or put the gearbox into park (easily enough done on our Honda where there is a P button).

I agree it distracting, and has become all the more so with high level / high intensity brake lights.

Another of my pet peeves - and one that IMO truly needs addressing as a safety risk - is the habit of emergency services when attending an incident to stop with their emergency lights on full, and often blinking as well. They are quite blinding and make it impossible to see the road clearly when passing them in situations where emergency personnel may be walking out into the road. I'm pretty sure I've seen emergency lights which go onto a 'dim' mode which would surely be more appropriate. Sometimes think there is an element of 'look at us, we're attending an emergency' about this behaviour.

This article in Grist outlines the results of research into arguments denying climate change, in particular how denials are diminishing and criticism of solutions increasing.

Closer to home, has ME thought of using biodegradable mailing bags rather that polythene? My Chartered Quality Institute journal does, so it would appear to be perfectly possible .

Edited By John Abson on 02/12/2021 10:54:04