Member postings for SillyOldDuffer

As I read the manual, the DNO 10 is only intended to drive a single motor. Section 13 'Expansion Connector' explains how to connect controllers in a master slave relationship: in this configuration one controller tells another, one per motor, what to do. Again as I read the manual, only two motors.

At risk, one could run 4 identical motors off one controller.

The DNO 10 spec says:

• 12V to 36V
• 100A Peak
• 75A for one minute
• 60A continuous

The most important limiting factor is 60A continuous. Whatever is connected to the controller must not normally draw more than 60A. (Starting an electric motor briefly draws more than it's rated power. to accommodate start surges the DNO 10 controller allows 100A peak provided it drops immediately to 75A for no more than one minute.

Assuming it's big enough (see capacity below) a single 12V battery would power a single big 720W motor (12V x 60A) or four smaller 180W 12V motors in parallel: 720W total, 180W per motor, 15A each.

Two 12V batteries of the same size in series, or a single 24V battery, doubles the amount of power available:

1. a single big 1440W motor (24Vx60A) or:
2. four smaller 360W 24V motors in parallel: 1440W total, 360W per motor, 15A each. OR
3. four smaller 360W 12V motors in series-parallel: 1440W total, 360W per motor, 30A each leg.

Various pros and cons. A single motor means a drive train is needed, maybe not a disadvantage if a gear-box is needed. High amperage wires get hot and waste power, so have to be made of thick copper in short runs. 60A is more trouble than 30A and 15A is ordinary. 12V batteries and motors are a bit easier to source than 24V etc.

The risk that two or motors motors could present an unbalanced load to the controller may explain why 4QD's manual doesn't cover more than one motor per controller. A vehicle should put the same power on all the drive wheels, and bad things happen electrically and mechanically if one or more wheels slip or stall. A professionally designed vehicle would allow for this, which my simple multi-motor suggestions above don't. My feeling, and I have no direct experience, is a hobby designer, driver, or club insurer need not get into a flap about balance. 'Our' electric locos are relatively slow and unlikely to get out of balance on a Club track - we're not building full-size locos required to reliably haul huge loads of iron-ore over snow-filled mountain passes!

Battery Capacity is measured in Ampere Hours. 12V Car Batteries range from as low as 30AHr to about 120AHr. In theory, a 60Ahr battery would power a DNO 10 flat out for an hour. In practice rather less, 80% or 48 minutes max. Worse, a car battery used for this purpose will have a short life - not many recharge cycles before it fails to hold charge. The problem is car batteries are heavily optimised to deliver a few hundred amps for a few seconds into a starter motor; once the engine is running, the battery takes about 15 minutes to recharge, after which it has a long rest! This type of battery is rapidly damaged by repeated deep discharge and long recharge cycles, and particularly by doing it once a week on a loco! The battery will work, but expect it to die quickly.

A Leisure Battery is a better bet because they're designed for repeated deep-discharges. But for a long life (more than about 500 cycles) even these are best not discharged below about 50%. There are also lead-acid batteries specifically made for fork-lifts etc, which perform better than caravan batteries, but are expensive. I've no experience of them but Lithium Batteries outperform lead-acid types. Although they last much longer, the purchase cost is high. I guess for hobby use an inexpensive Leisure Battery will give best value for money - reasonable life and performance without costing a fortune!

Again, I feel the designer of a hobby loco, needn't fret too much about about how many battery recharges he'll get, or exactly how many hours his loco will run for on a single charge. All that's needed is that the loco start and stop when required. It doesn't have to meet commercial cost-benefit targets over a wide range of operating conditions.

Anyone with practical experience of building one of these? I've no idea what the total weight might be. Would four small motors need a gear box or belts to improve torque, or can they drive the wheels directly?

Dave

Heftier very unlikely to be the answer, if a pot is too small it gets hot. An oversized pot just runs cooler, buying bigger than necessary wastes money.

Has anyone been 'at it'? The symptoms suggest someone has fitted a log pot rather than a linear type.

Almost for sure a pot fitted for motor control should marked 'LIN'. If yours is marked 'LOG', changing the pot for the correct LIN type should fix it.

(Linear tracks range evenly, whilst logarithmic tracks change progressively more rapidly. Log pots are very common, because the human ear is logarithmic - volume control - but they're inconvenient on motors.)

Dave

I guess it depends on the orientation of the coil relative to the bob.

Cima (and I) both have side coils. These don't have a mid-coil position, as I understand the question, so the impulse should simply be applied when the bob is at max speed (i.e. at BDC)*

I guess a coil laid under the bob is time sensitive. If fired late, I imagine the magnetic field braking the bob, rather than accelerating it. Therefore the impulse should. be timed to start somewhat before BDC and to end at BDC exactly.

Are you proposing magnet that flies inside a coil like this:

If that's what's proposed, I think a magnet pulled into coil configuration behaves like a flat coil under the bob, in that energising the coil after the permanent magnet has passed coil centre will act as a brake. (In a solenoid maximum magnetic field occurs in the centre of the coil.)

Incidentally, I use an iron-cored coil because it fits into a much smaller space and produces a stronger magnetic field. However, the core slows down development and collapse of the magnetic field, which I imagine to be late with soft edges compared with the sharp on/off field produced by an air-cored electromagnet. Anyone know if that matters! Another mystery...

Dave

* Reading the HJ article linked by John ruined my day. It reminded me I forgot to 3D-reprint my magnet and IR beam holder! Due to a mistake, the current holder isn't long enough to impulse at BDC as designed. Fixed ages ago in CAD, but never in the real world. Aargh!!!!

Page 183 of the manual says:

The video makes uncomfortable viewing for those who disbelieve in Climate Change or think fossil fuels are the only way of meeting energy needs. What they said 19 years ago about renewables is now clearly wrong.

Wrong about climate too. Since Kyoto in 1992, no evidence has emerged suggesting Climate Change isn't happening, or that Fossil fuels are innocent. And in the same period no significantly large new sources of fossil fuels have been identified anywhere in the world. Instead, all the evidence that has emerged - lots of it - is consistent with man-made climate change. Including a build up of temperature readings showing that global heating is proceeding faster than predicted.

Putting it bluntly, the figures strongly suggest the scientific consensus is right and climate deniers are wrong, wrong, wrong.

I'm afraid announcing 'Winston Churchill said "There are liars, damn liars and statisticians"' won't wash. Even if Churchill had said it, and he didn't, then the premise is wrong. Whilst true that false claims supported by massaged numbers are popular with advertisers and politicians, this does not mean that all statistics are false or misleading. Far from it!

Statistics is a branch of mathematics where both working and data can be, and should be, checked. Although rarely done by shoppers or voters, checking is a routine part of the scientific process. When science agrees statistics are valid, they are much more trustworthy than man-in-pub assessments.

The statistics relating to climate change can't be dismissed with a catch-phrase. Not good enough. When statistics are suspected of being wrong, the mistakes in the data, and/or logic have identified. In contrast, opinion, beliefs, conspiracy theories, previous experience and 'common sense' that don't bother with evidence, or make it up, are all valueless. Dismissing statistics as an entire discipline is wrong.

Why do people chose to believe nonsense in the face of evidence? Many reasons, none of 'em good I fear: Ignorance, embarrassment, lack of imagination, vested interest, stubbornness, pride, short-term advantage, wishful thinking, consequences too big or scary to comprehend, or small-c conservatism.

Maybe deniers just haven't twigged that energy policy that made sense in 1970 won't work in 2070. History suggests change is ongoing, whatever grandad thinks: energy in 1970 was very different to energy in 1870, and 1870 was nothing like 1770.

Truth is mankind has always had to face challenges and adapt to circumstances. We are no different and the game will be going on long after we are dead, and all our notions dust. In the meantime, the best moves in the game are made after identifying trends, not by fighting change on the assumption that nothing needs fixing.

If anyone wants to disagree with me, please explain what's actually wrong with the data and logic of a specific climate change statistic. No points awarded for claiming all statistics are untrustworthy because statistics are sometime deliberately used to mislead. It's the liars who can't be trusted, not a checkable scientific endeavour supported by checkable mathematics.

I vote for following the evidence, not fact-free opinion.

Dave

Edited By SillyOldDuffer on 23/07/2023 17:06:20

I think this method makes it possible for Michael to achieve higher accuracy with what he has. (DC31k suggests Archimedes too.)

Density is Mass/Volume. By definition the density of water is 1 because 1g of water occupies a volume of u cunic centimetre (at Standard Temperature and Pressure, 0°C and 1Bar.

Knowing the density of pure Platinum (21.45 g/cc), Michael checked his wire by weighing it and measuring its length and diameter to calculate volume. Two fundamental problems: the accuracy of his scales, and the accuracy of the length and diameter measurement. The latter being suspect because Michael's diameter measurements suggest the wire is not the same diameter throughout, and may not perfectly round.

Archimedes removes the need to measure length and diameter, and the shape of the object doesn't matter. It eliminates two of the three main error sources, leaving only the accuracy of the scale to worry about. (This is a simplification! Although Archimedes is as improvement, there are other, smaller, sources of error which might need attention.)

In the Archimedes method, the scale is set up to measure the sample's buoyancy, in this case Michael's Platinum wire.

• On the scale is placed an open topped container of water
• A gantry is placed across the container
• From the gantry a wire ending in a platform is dropped into the middle of the water
• The scale is zeroed
• The sample (Michael's wire) is placed on the immersed platform, so it is completely underwater
• The scale is read. It registers the samples buoyancy, which is the weight of water displaced.

Michael's scale has a resolution of 20mg but we don't know if it's that accurate (see Robert Atkinson's comments). . That means the accuracy of the scale needs to be established, for which see Kiwi Bloke.

Another issue: pure Platinum is 21.45 times heavier than water, so Michael's perfect scale should read 0.018648019g. Oh dear, that's pretty much on the scale's 20mg limit. The density ratio between water and platinum is too high. No problem as I'm spending Michael's money - either he buys 5x more Platinum, or replaces the water with Mercury!

Or does anyone know of a liquid that's denser that water and cheaper than Mercury?

Dave

I think I said the same! My point is VFD powered motors don't lose torque at high RPM. At the middle and higher end of the speed range, they perform as well as anything else. In which case 1500W trumps 750W.

Picking up Jason's question about power and rpm, carbide works best at high-speed and high-power. Taking a deep fast cut with carbide on my WM280 removes metal spectacularly quickly. I rarely run it flat out though because doing so creates an unpleasant spray of glowing chips. Taking it gently is more fun and less likely to set fire to my woolly jumper! The main advantage of the big motor is providing reasonable torque at low VFD speed, partly compensating for not having gears!

Though I'm drunk with power, any motor between 500 and 1500W is adequate on a medium hobby lathe.

Dave

You could try a spark test.

I've not found sparks work particularly well, probably because I haven't learned by sparking known metals or because the system doesn't cover the huge range of alloy steels available.

I came seriously unstuck as a beginner because workshop gremlins ensured my entire collection of scrap-metal was difficult to machine. All of it was horrible! Not surprising, because modern manufacturing selects metal to suit their design goals, and then heat-treats or plates. The result can be scrap that's downright unfriendly.

My test now is to stick a sample in the lathe and try and turn and face it. The difference between Free-cutting mild-steel and a difficult alloy is very obvious. The first cuts to a good finish without fuss. Difficult alloys are extremely hard or soft, with any combination of very tough, gritty, easily torn, grabby, crumbly or smeary. Some are just a bit tricky to find the right cutter geometry rpm, feed-rate and depth of cut. Others refuse to produce a decent finish, or rapidly blunt tools, and a few are impossible. Now I prefer buying known metal. When tempted by scrap, I dump it as soon as it proves difficult - it's not worth the trouble.

Much depends on where a scrapyard gets metal from. One serving an area full of machine shops is much more likely to have machinable metal than those taking scrap from domestic or specialist manufacturing. The latter might even be risky to cut - Magnesium, Beryllium, Cadmium etc

All my local scrapyards are hobby unfriendly. They buy metal, but don't sell to punters. Browsing in the yard is definitely not allowed - razor wire and dogs! Others are luckier. A friendly yard might have a hand-scanner to accurately identify whatever elements are in the alloy, and might be persuaded to use it, especially if the customer is a big spender!

Dave

Are you running an Ad-blocker? If so it may be mistakenly blocking part of a legitimate dialogue. Then the display makes no sense because part of it is missing.

If you have one, temporarily disable the ad-blocker and try again.

As Facebook controversially tracks internet users whether or not they have a Facebook account, it's possible a browser plug-in other than an ad-blocker is whacking the dialogue for privacy reasons. I have DuckDuckGo Privacy Essentials installed, which blocks Facebook connections by default. As other security software packages do the same, a setting may have to be relaxed to open the door.

Dave

Best not in engineering circles to use phrases like 'extremely strong', when numbers are available. Super-glue may be 'extremely strong' compared with spaghetti, but it's not 'extremely strong' compared with most metallic joints.

Approximate tensile strengths:

• Cyanoacrylate - about 4000psi, half that in shear, so avoid using glue to support side forces.
• 60:40 solder is strong for a soft solder, about 7500 psi, roughly twice as strong as super-glue
• Silver Solder / Brazing is between 4x and 9x stronger than 60:40 (up to about 70,000psi)
• Welding is as strong as the parent metal. Mild steel at least 62000psi, up to sooper-dooper Maraging Steel at 380,000psi

There's no doubt super-glue will hold a heavy bob. A 0.25" diameter rod 1" long has a surface area of 0.88sq in. Stuck into a hole in the bob, the joint is in shear, so halve the strength, giving 4000/2 * 0.88, or 1766lbs. Assuming an x3 ish safety factor, a 500lb bob would be OK. My concern is movement, not that the bob will fall off! Bear in mind that clock performance is measured in parts per million, so small pendulum problems show up. (From what I've seen of SK's builds his Arduinome is likely to perform well enough for a tiny fault like unstable glue to show up.)

I don't recall seeing anything anywhere how much pendulum rods whip. In normal operation I guess not much because the bob accelerates and decelerates smoothly. Clocks with string and chain suspended 'rods' have been made, suggesting a stiff rod isn't essential. However, rods can whip when the pendulum is impulsed, therefore it's best to impulse a pendulum when the bob has maximum kinetic energy, which is when it whizzes past bottom dead centre.

Dave

From Warco's website, assuming their numbers are correct!

• GH600 is 160kg, footprint 1260 x 580 x 600mm, with 750W from 40rpm to 2000rpm (with one belt).
• WM280 is 210kg, footprint 1350 x 620 x 508mm, with 1500W from 30rpm to 2500rpm (with two belts providing high and low speed ranges)
• WM290 is 320kg, footprint 1302 x 635 x 1270mm, with 1500W from 30rpm to 2500rpm (with two belts providing high and low speed ranges)

All three were strong candidates when I was looking to buy bigger after deciding my mini-lathe was too small. The WM280 won because it was the right size and the sort of work I do doesn't demand gearbox convenience. Steve's requirement does!

Gears versus VFD speed control are more subtle. The WM280 delivers full power to the spindle at cruise and high RPMs and at 2000rpm a WM280 really is twice as powerful than a GH600. Not all roses though! Although the 280 has two speed ranges it's done by changing belts, which is a pain, and of course running the motor at low RPM with a VFD results in significantly lower torque. In practice, low speed, low torque doesn't inconvenience me because I don't cut many large diameter coarse threads. Whilst the 280 can do them, there's no doubt a gear head lathe is better for that sort of work. Nonetheless, I've never stopped a job and wished the lathe had back-gear.

Their different speed/rpm/torque characteristics suggest to me that a GH600 will be happier with HSS whilst the 280 gets more out of carbide.  If that matters!

I wonder how noisy a GH600 is compared with a WM280? Gears make a fair old racket. Not that my WM280 can be described as quiet though: even with the banjo moved out of gear, the lathe's two loud continuous electric cooling fans overwhelm my workshop radio.

Dave

Re Steve's moving question, an engine crane is fine. Just remember their splay legs mean a largish turning circle that can be awkward in a tight space.

Edited By SillyOldDuffer on 21/07/2023 14:41:24

I'm looking forward to this one too. Anything described as an 'Arduinome' must be good!

And the post instantly generates a new horizon. I toyed with the idea of super-gluing my chops, and did super-glue the brass flange fitted to the end of my carbon-fibre rods. Super-glue is plenty strong enough, but what about its long-term stability? I had in mind the pioneer clockmakers noticing after a few years that Invar is unstable, a problem not entirely fixed today by tweaking the alloy and careful heat-treatment. Although Invar's instability is molecular, causing tiny movements, they're big enough to eventually show up in a high precision clock.

My first clock's pendulum was noisy, and because a super-glue and carbon-fibre joint moving was a suspect, shades of the Titan submersible, I replaced the joint with a threaded steel rod. The current version is less noisy, but that doesn't prove super-glue was guilty, because I made other major improvements at the same time.

Whatever we do with pendulums, there's always something else. Decades of fun ahead!

Dave

Just checked my WM280 on the off-chance that it's simple 3-speed gear box accommodated those ratios. No such luck, it only does x2 related pitches like 0.5, 1.0 and 2 or 0.75, 1.5 and 3.0.

0.75, 1.0, and 1.25 require 3 different change-gear settings on the banjo - far from ideal even if the workflow can be arranged to cut pitches in batches.

Lots to be said in favour of the GH600, but its noticeably smaller than a WM280 (750W motor vs 1500W, and 160kg vs 210kg), and a WM290 is bigger again (1500W, 320kg). In general big lathes are 'better' than small ones because they're less limited in what they can physically turn. They tend to be more rigid, and have larger spindle holes too, all good apart from size, weight and cost!

One day I'm expecting a hobby lathe to appear with an Electronic Lead Screw, which be told to do any pitch by pressing buttons or turning a knob. Various DIY implementations are available, but I don't know of an affordable off the shelf machine. In the meantime the GH600 is a good option, if quick thread changing is the priority.

The reason I don't own a GH600 is the WM280 is the biggest machine that fits in my workshop and I lathe cut threads relatively rarely: most of my threading is in tap and die sizes. It's a compromise: when big diameter threads are needed having to mess about with change gears is a right pain, especially when a workflow requires more than the occasional swap. Then I pine for a gearbox...

Dave

Quite difficult, or at least time consuming, to make a one-off item like this with ordinary workshop tools. All change if enough of them are needed to justify making special tools, which could then knock them out at a gallop.

I agree with Andrew that the Victorian original would have started as a casting. Castings save time and metal, and these could been moulded a hundred at a time, or more.

I guess the cast blanks were squared off on a big grinding wheel and then sent to be hand-finished by drilling the fixing holes and cleaning up the edges by filing. The template's end profile requires a special file, which could be made from scratch or by grinding a standard half-round file in half. Perhaps a 'quarter round' file is a real thing?

Does anyone make their own files? From Silver Steel rod, shape and harden a sharp pointed chisel to raise a tooth. Then grind a length of Gauge Plate to the required profile, and raise teeth in it by dinging it with the chisel. Ding it many times, many many times... Then harden and temper.

The modern process would probably grind the template with a few profiled wheels. As grinding wheels are made from abrasive particles in a matrix, they can be moulded to any reasonable shape, so well suited to this kind of job.

Knifes such as these steak knives, often have often have complex profiles - these have curvy sharp teeth cut into a curved blade, and look bad on the table unless the set all match.

Knives used to be hand-made by master-craftsmen, and specials still are. Today, most knifes are ground in an automatic machine containing a high-speed profiled grinding wheel. When the profile wears below specification, a sharp diamond wheel engages and automatically re-profiles it. Items like Steve's sash window template could easily be produced by a grinding machine, but only if mass sales justifiy the high set-up cost.

Maybe a metal 3D-print service like this example. An additive process would have no trouble producing a sash template. Probably not cheap compared with DIY though - by definition our time is free! I'd mill from a brass block to approximate shape and file the profile. I think it's worth grinding a half-round file down to get into that corner with a safe-edge.

Dave

I gave up searching for the lost end-cap and made a new one. Luckily there was a suitable lump of cast-iron in my junk box left over from making a chuck backplate.

Armed with a length of PVC drainpipe, two end-caps, nozzle, and a vacuum gauge I was able to test my vacuum pump.

Result: -490mB below atmospheric.

Mild disappointment: I was hoping for -600mB, (+12mB here at the moment.)

Not given up yet. When the end-caps are only held on by air-pressure, the pump only manages to get down to -200mB, even though it's not obvious there's leakage. However, wrapping the Aluminium end with electrical tape almost immediately doubled the vacuum to about -400mB, and then taping the cast-iron end got me down to -490mB.

At this point I noticed a silly mistake! The brass nozzle, which is a push fit through the cast-iron cap, is made the wrong way round. The sealing flange is on the inside and it has to be on the outside. With luck fixing this will improve the vacuum. Then I can try sealants.

Worry beads time: it appears that even a miniscule leak quickly destroys a deep vacuum. My next problem is to hold a vacuum for years without further pumping, and I doubt my PVC soil pipe design is up to it. However, if all else fails, I've proved I can get below the lowest ever natural air-pressure recorded, which was -130mB inside a super-typhoon near Guam. If I run the pendulum inside its tube at -200mB, it should be immune to natural barometric changes.

Dave

Edited By SillyOldDuffer on 20/07/2023 14:45:27

Graces Guide say Mercer closed in 1984. Seems they were primarily a high-end mechanical clock and chronometer maker, so making DTI's would have been easy for them. I guess they were put out of business by the arrival of cheap quartz timepieces.

Don't assume the instrument is still accurate today! It's performance depends on condition, not who made it, and it may be badly worn or damaged. At best it's been knocking around for 40 years, accidents happen, and old oil gums up. Can't be trusted for precision work without testing the calibration across the full range with gauge blocks. Don't fall for what its says on the dial, test it.

That said, it's an indicator, rather than a micrometer, and most of us don't do precision work. As indicators are mostly used as comparators, the calibration may not matter. A typical use is centring work in a 4-jaw. With the DTI in contact, the chuck is rotated and adjusted until the needle barely moves. In this common application a DTI doesn't have to be calibrated. Important though that the movement isn't sticky, remember condition matters!

A possible disadvantage is that a 0.0001" dial is rather sensitive for most work. On a poor surface, the needle will bounce dramatically over minor imperfections, whilst the DTI's ability to centre to within a tenth may not be matched by your chuck! For ordinary purposes a thou or 0.01mm instrument is 'good enough' and less fussy.

Dave

My home is a poor radio location in a valley, and because most of the local power supply is delivered to houses on poles, not buried, it's electrically noisy here. Power cables and telephone wires transfer radio interference throughout the village.

I own a Very Low Frequency receiver, and can measure MSF (60kHz Cumbria, England) and DCF77 (77kHz Frankfurt, Germany) relative to what else is going on in the band. MSF is weak here, barely strong enough to work a clock, and local interference is often strong enough to drown it. This is listening on a deaf indoor ferrite rod antenna borrowed from an MSF clock.

A DCF77 clock might work here, the signal is several times stronger than MSF, perhaps because valley is more open to the east.

The very simple receivers and antennas used in ordinary radio clocks being weedy and vulnerable to interference probably explains why they work intermittently. On a good day, the signal from Cumbria is strong when the clock tries to synchronise, and the band quiet. Success! On a bad day, propagation is poor and the band full of noise, natural or man-made. Perhaps the chap next door is playing with his VFD powered 5kW lathe...

Dave

Back to the original question, yes the oil should be changed. Even if the oil itself is in perfect condition, and the additives that control viscosity with temperature and what happens in the cylinder haven't deteriorated, there's another reason. Problem is low-mileage cars tend to collect water inside the engine due to condensation. Getting the engine hot for long enough is the best way of getting rid of water, otherwise draining the system is the only way it can leave, if then!

Left alone water and oil are whipped into an emulsion that can block oil passages, cause corrosion and rapidly wear bearings.

Might be interesting for anyone who has a car full of ancient oil to drop the sump and have a look inside. I'd expect them to find a layer of goo stuck to the bottom.

Questions like 'Do you need an oil change with less than 10,000 miles in 10 years?' don't have black and white answers. Too much depends on the circumstances. A car kept in controlled storage might be fine, whilst the same model kept in a single skin concrete garage might be trashed. The type of oil makes a difference. The sort of journeys taken are a major factor: ten 100 mile trips per year will be much better for the engine than two hundred 5 mile trips per year.

Personally, I wouldn't take the risk. It's usually safer to follow the manufacturers guidelines than to take advice off an internet forum. Not even a mechanically minded one like this!

Dave

Thank god then that oil is never going to run out and there's no such thing as Climate Change! It means humanity can drive IC cars until the end of time.

Or is it a dangerous fantasy to believe that fossil fuels are unlimited and can be burned forever with no ill-effects?

I hope Bo'sun and Ady1 have evidence that supports their opinions, and aren't just sharing fact-free beliefs.

What happens to our children and descendents if Bos'un, Ady1 and their many friends turn out to be ill-informed optimists? Nothing to do with 'tree-hugging'. As our entire way of life depends on oil, the problem is far more serious than the 'millions unable to charge at home'. Unless we act to avoid the crash...

Dave

You've probably done similar already, but I found it helped to position the receiver with its back to the sun, protected with a blob of plasticine.

The big improvement, I won't claim bomb proof, was putting sender and receiver in sealed Brass tubes with slotted ends acting as a sort of collimator:

The dark side Brass tube above contains the sender, not shielded at the back.

However, the receiver Brass tube, with its back to the sun, is shrouded with a length of Aluminium tube blocked with black plasticine. The only way IR can get in, I hope, is through the collimator slot, which is aligned with the sender.

In my build the collimator is important because IR bounces off all the internal metal work, including the moving bob. I had multiple problems with unshielded IR sender and receiver. Sun shining on the receiver alters its apparent sensitivity, whilst IR from the sender or sun reflecting off the bob and structure causes false triggering. Even though my pendulum should be immune when it's working in a light-proof container, I will retain the shield and collimator, and will probably blacken the shiny metal internals.

At this stage of the game, IR management is more important to me than fitting the fastest possible receiver. The very basic circuit and devices I'm using are good enough to detect that my pendulum period varies distinctly beat by beat (microseconds). Plenty of other problems to fix before I need to improve the IR system.

Dave

Edited By SillyOldDuffer on 19/07/2023 11:57:32