Member postings for Marcus Bowman

Baldric,

I have not had any real problems with mine. I do occasionally drip cutting oil onto the cable, but that has not caused any problems. I have sometimes also bumped inot the cable with my hand or my jar of cutting oil, but that's not a problem. What you can't do is move the slide at high speed, as the electronics can't catch up. The display alerts me by flashing, and I reset it. So that is occasionally a nuisance as I tend to lose any reference position.

The big plus, for me, is that the counter/display unit has 9 different Datums, so, if I am using a four-way toolpost, I can set a Datum for each tool, then press a button to call up the Datum for each tool as I use it.

Marcus

John Wilding wrote many serialized clock projects for the Horological Journal, back in the 1970s and 80s, most of which were replicated in his books. My first clock was one of a series of three he created for beginners, and it was his 16th Century Clock (see http://www.clockmaking-brass.co.uk/16th_century_clock.htm). It has only one hand, which simplifies the construction considerably. That is a design I would thoroughly recommend.

That design was later modified to make the frames simpler to construct, and the design was published in Model Engineer, Issues 3775 (18-30 April 1986) to 3799 (every second issue in that sequence, so issues 3777, 3779, 3781, 3783, 3785, 3787, 3789, 3791, 3793, 3795, 3797, 3799), and entitled A Weight Driven Brass Alarm Clock. That design incorporates a bell, and a one-at-the-hour passing strike .

If it was me, I might be inclined to the 16th Century design, but using the simpler frames from the Brass Alarm Clock, just because it is simpler without the alarm. There is also the question of the bell. The original source is long gone, but it would be easy enough to get a substitute from clockmaking-brass.co.uk (with whom I have no connection).

Wildings series in HJ was originally entitled An Introduction to Clockmaking with the Unimat 3, and he worked his way through 3 designs: The 16th Century clock, the Castle Clock, and The Scissors Clock.

http://www.clockmaking-brass.co.uk/castle%20clock.html

http://www.clockmaking-brass.co.uk/scissors.html

I like the Castle Clock which I think is aesthetically very pleasing.

Both the 16th Century and the Castle clocks are weight driven. and both are very suitable for the beginner.

The Scissors Clock is spring driven, elegant and fragile looking, but is not a beginner's clock.

I have made several of the much later Wilding projects, and they are all accompanied by copious easily understood building instructions.

The 16th Century Clock still hangs proudly in the lounge.

If you need more specific information, send me a PM.

Marcus

I have a DRO fitted to my carriage, which can also be used on the cross-slide (although I never use it that way nowadays).

The DRO is based on a wire which unwinds or retracts from a small box with a readout. I have a couple of these, and as I recall I bought them from BW Electronics, who used to advertise in ME. I believe they stopped supplying DROs some years ago, and may well have stopped trading at that time.

That's maybe no help, but I will say that the wire method has a lot going for it, as the wire can be routed through pulleys or pins. On the pillar drill, I run the wire around two pulleys on its way to the end of the quill, while the readout is attached further up the head.

Marcus

J

I'm glad you managed to get the damper sorted.

The spec of the saw blade varies a bit depending on what you are cutting. For steel, and most other metals, I use 10TPI (Eclipse All Hard blade). For plastic, I use 6TPI which can need a bit of care when starting the cut, and is not suitable for small diameter bars. That's a Starret because the technical people there gave me good advice on number of teeth etc. 6TPI is useful for aluminium blocks too, but for both plastic and aluminium the blade must be very sharp. I have used 7TPI too, instead of 6TPI. The big advantage of the 6TPI is that it clears the chips and cuts sufficiently fast that the plastic doesn't melt with the friction and grab the blade. I had that trouble a lot with large diameter bars of plastic, before I changed from 10 to 6TPI.

As for the Whitworth thread, I suspect my saw is much older.

I notice that the cast arm on the main casting which operates the damper had been repaired (quite badly) before I got the saw. Because my damper cylinder has a groove running down the inside, the damper is not effective, and the force of the balde assembly coming down a bit too hard over a long time and lots of cuts has now severed the arm once more, leaving me a tricky repair job <sigh>. Having said that, I wouldn't want to part with the saw, as it does a really good job, if a little slowly at times.

Marcus

Quartz clock crystals slowly change their frequency of oscillation over time, as they age. Good ones change very slowly indeed, while I imagine cheap ones in cheap movements age more rapidly. The ultra-cheap quartz movements sold on various well known sites provide the kind of quality commensurate with their price. The much more expensive ones you will find in the few remaining clock parts suppliers to the trade (and ordinary punters) tend to follow the usual YGWYPF rule.

It is possible to correct the rate of oscillation, but not worth while in a cheap clock.

Like others, I use a radio controlled clock, when I am not looking at the computer clock which is set to sync with a time server over the internet.

When I was at work, we had a number of radio studios, and each had a radio controlled clock. before I retired, we moved to a fabulously expensive new purpose-built building which had 8 new radio studios. The plan was to run a GPS receiver which fed a time signal to a clock in each studio, so that they were all synchronised. Sadly, the builders sealed the only access channel up to the roof (GPS aerials need to see the satellites), so we had to revert to individual radio controlled clocks. Unfortunately, the studios were on the ground floor, and had thick walls with no external windows, and no way for the weak-as-water radio signal from the German time station, so the nice R/C clocks had a really hard time (but perhaps not so hard as the Presenters and Newsreaders).

Marcus

By co-incidence, I took my damper apart a few days ago, so here are two photos of the internal parts.

The flat bar pivots in a casting on the underside of the hinged casting on the saw.

The slice of a sphere screws onto the end of the bar. A threaded needle rod, tapered at the tip, screws into a tapped hole in the sphere. There is a bolt (shorter than the one you see in the photos) which screws into the threaded hole in the centre of the underside of the spherical slice and that compresses a spring which traps a circle of aluminium against the underside. The needle is adjusted to provide a tilt on the disc, and the oil flows through the holes in the spherical slice. The rate of descent is controlled by the adjustment of the needle. The main threads are 1/4 Whitworth.

Marcus

EN8 (080M40) machines nicely and can be hardened quite easily.

Silver steel machines reasonably well, and can also be hardened. Between the two, my choice would be EN8 because it machines to a better finish. I believe EN8 is stronger than silver steel, but could be wrong about that. If screwcutting, I would use EN8.

EN24T also machines easily to a good finish, and has a greater strength than EN8. The T indicates the material is supplied in a hardened and tempered state, but it still machines nicely.

I have bought both EN8 and EN24T from M-Machine Metals, with whom I have no connection other than being a satisfied customer. Other suppliers are available, etc...

Marcus

Perhaps:

https://www.analog.com/media/en/technical-documentation/data-sheets/ds3231.pdf

I believe boards containing this chip are available for the Arduino, although it doesn't really require much interfacing so could go on a generic breadboard-style shield or a bit of perf board.

Marcus

Here's a variation on this theme:

If someone orders an electronic device which contains a lithium battery, it can be posted quite legally via Royal Mail or any courier service provided the battery is inside the device. But if you order a battery on its own, it cannot legally be sent by post or couriered.

This means buying a replacement battery for, say, a phone must be done in a shop.

Not realising this, I ordered a replacement battery via Amazon. It came via courier, in the usual Amazon way, and it carried a large warning label. It turns out Amazon have a special contract with the couriers.

Unfortunately, Amazon sent me the wrong battery. So I contacted them and they told me to send it back and they would sent the correct battery. They sent a Returns email which allowed me to print a large warning label for the return. I now know it is impossible to send a battery by post, and none of the courier services will touch it either. After exhaustive enquiries, I phoned Amazon. They knew of the problem and simply said 'Just dispose of it'. Fine; but when I tried to order another battery of the correct type they declined the sale.

You can buy them from eBay, via France, where they are advertised openly. How they can send it to you, I do not know, as I decided there are far too many fakes out there which don't have any significant capacity, so left it alone. I'm not fussed about a mobile phone most of the time, so I went back to my ancient £9 Nokia, whose battery still has life after umpty tumpty years. It' so old that the man in the local FONE shop just laughed when I asked for a replacement battery. How he gets his batteries is a mystery.

Marcus

The last woodturning chisel I bought was made of HSS and cryogenically hardened. That's a long way away from carbon steel. The sharpening instructions specify slow grinding using lots of coolant. As I understand it, the slow speed is to ensure less aggressive removal of metal. However, I'm not convinced that achieves anything like an optimum cutting speed (wheel-to-work). I use a 'normal speed' grinder when I need to sharpen woodworking tools, but I can see the advantages of using a slow speed when trying to grind something like a fingernail gouge (the Drozda finial gouge being a great test of skill on a 'standard speed' grinder). You probably get more thinking time, which seems like a good thing.

Marcus

I have a cheap (70p?) pair of eBay tweezers which are as flexible as wet seaweed and utterly useless for fine work, but great for just about every rough job. I have several pairs of DUMONT 'DUMOSTAR' non-magnetic non-corrosive finest Swiss tweezers which cost a staggering amount. Each pair has a slightly different shape. As I recall, they were sold as being suitable for work associated with handling samples for electron microscopy. I use them as horological tools. They have very fine points and are suitably strong and springy. In fact they excel at digging fine slivers from under the skin.

They are a joy to use and are thoroughly recommended.

Marcus

I suspect it is the same in many of the 'traditional' hobbies which boomed in the 1960s and 70s, began changing in the 80s and 90s, and have now changed quite radically, in much the same way as in the club you mention.

I used to deal quite often with Reeves, prior to their demise. I have never really dealt with Reeves 2000 so can't comment on their offerings.

Marcus

Some current foreign manufacturers seem to use non-standard metric hex sizes for nuts. A very widely sold 3D filament printer I bought a few years ago had M8 nuts on the holder for the reel. The printer was supplied with a skinny sheet metal spanner, which tightened the nuts OK, but I found that my usual13mm spanner wouldn't fit. Measurement revealed these nuts had a 14mm hex. This was a very lightly loaded pair of nuts, so I can't see a reason for the extra meat. In the end, the inconvenience resulted in those nuts being consigned to the bin, to be replaced by standard 13mm hex M8 nuts. I'm still puzzled, though.

Marcus

Well said, Jon.

I may be in the minority here, but like Howard, I actually like making tools. It's a bonus if they are to fulfil a particular need to do a specific job, but in the end I am not fussed. Tools are just nice things to make; lovely things to have; and a pleasure to look at - as well as a marvel that the thing actually gets completed (most of the time...).

I like seeing tools others have made, and I like reading about tools too. I subscribe to MEW. ME and EIM and I read the articles on making locos and the like, but I find the tools and manufacturing methods of most interest.

Each to his own, I guess.

Marcus

My biggest machine weighs in around 750kg, but it is easily moved using a pallet truck. I guess, for me, the psychologically comfortable limit would be what I could move with the pallet truck, and I think that has an SWL of around 2 tonnes. Lathe and mill are 300 - 500kg and are never moved, Smaller machines are on wheeled cabinets or platforms and can move with a push. Not that there's any space left to move them into...

Marcus

www.hemingwaykits.com sell the castings and materials for a range of rear toolposts, including the GHT version.

Marcus

+1 for Cerobend, but stainless tube is quite stiff, and it will work harden so it will need considerable force and a bit of an over-bend. I had a friend who bent car exhausts commercially using the hard resin, but it was very labour intensive (and smelly).

Marcus

I'm sorry to hear this news. I did not know Chris personally, but I do clearly recall attending an exhibition in Leicester (at the Granby Halls?) around 1977 or '78 where he had a stall and fliers announcing the forthcoming EIM. We chatted for a little while, and I signed up for a subscription, half expecting the venture might not come to fruition. But sure enough, the first issue appeared in April 1979. I have been a subscriber ever since.

I had several articles published in EIM in the 1980s, and always felt Chris and his team made a good job of presenting the content of the magazine.

I enjoyed attending several of the early EIM exhibitions, as they were more accessible to me than the London exhibition, at that time.

It's a pity Chris was not able to enjoy more time in retirement. He made an important contribution to the development of model engineering in the UK.

Marcus

Just downloaded; and much appreciated.

Marcus

John,

That would certainly be of interest.

Marcus