Member postings for Peter Cook 6

Possibly! On my Vienna's the barrels do not have a second hole, so the only way to record them is to disassemble the movement, disassemble the great wheel from the barrel and then poke the new cord through the small hole, tie a big knot and pull tight then put it all back together again.

If you can get at the inside of the barrel through the 3mm hole, then you may be able to tie the knot and pull it inside. A "leader" of soft thin wire which is easier to manoeuvre and bend to capture through the 3mm hole may help. Measure the length of the original cord and tie a loop at the other end to hang on the hook on the baseplate.

Once reinstalled in the case wind about half the cord onto the barrel while keeping some light tension on it, thread on the pulley, hook the other end in place and add the weight. Then wind up the rest.

If you fully wind the cord onto the barrel before hooking the other end up, it all gets difficult under and behind the dial. Half way gives you room to work.

I would change both (and if you can strip down and service the clock) while you are at it - once one has gone, you will be doing it again soon for the other.

Removing the dial and hands probably won't help unless the front plate has holes in them through which you can reach the barrels. Most Vienna's don't. Just be careful how you lay the movement down to work on it. I use a plastic bowl about the same size as the dial to make sure that it's not resting on the hands.

Typo

Edited By Peter Cook 6 on 06/08/2022 18:44:30

Thanks folks. Mystery solved, the fusible resistor suggestion led to Queen Mao Electronic - Products - Resistor Color Code

That site says "If an additional fifth band is black, the resistor is wire wound resistor. If an additional fifth band is white, the resistor is fusible resistor." I had not seen that before.

So it's probably a 1 (or possibly 2) ohm 5% wire wound 5 watt resistor. I can't see any signs of damage elsewhere on the board. I am thinking that the sort of power it would take to blow that resistor would have left some sort of evidence on the rest of the board which is mainly surface mounted IC's and resistors.

I might venture a repair. The unit has been replaced by the supplier under warranty, so it's an academic exercise

Thanks again.

I have a dead LED batten. Opening it up I found that a wire wound resistor had overheated - and gone open circuit. However I cant figure out what resistance it was supposed to be.

It's a 5W(?) series resistor between the incoming 240v mains and the control circuit.

The colour code seems to be Red-Black-Gold-Gold-Black which beats me. Two gold bands seems to have escaped my code charts. As has a black tolerance band. But Black as the first digit also seems wrong!

Can someone with more electronics experience possibly give me an idea of what It might be.

Thanks

Ah, but I do have plans for that function - if they ever come to fulfilment I will let you know. As part of my clock project ( and the table controller is on the plan to help with gear cutting), I will need to make the chime barrel.

It has five tracks with 16 pins per track. The angular spacing of the pins create the sequence of notes for the tune.

I am thinking of setting up the barre on the rotary table, and creating a spreadsheet of the angular positions based on the tune. Export that as a sequence of angle commands one for each track and use the commands to drill the necessary holes.

PS I made a small change to the code. I have set the default table ratio to 72 to suit my table, and added a default value for  backlashSteps to avoid setting it up every time I switch on.

Edited By Peter Cook 6 on 25/07/2022 19:14:56

Can I just resurrect this thread to say a big thank you to Dave (SOD) for both the Arduino code and the motor mount design - seen in a different thread.

I built the mount for my little table, and after wiring up the electronics it all works fantastically well. I only need to mount the electronic components in a box, and I am in business.

Thanks again for making this available.

Have you thought about an electric system. Something cannibalised from a small hybrid car. Never looked at the details, but there are firms that specialise in retrofitting electric drive to older vehicles. They might have the components.

As a first pass I would use one of the online beam calculators as suggested by Martin.

Calculate the weight of the deck, add the ATV, rider, trailer and sheep, divide by two and treat as a point load in the centre of each I beam - see what sort of deflection it computes.

Then take the heaviest axle load ( ATV+ Rider /2 or Trailer + sheep), and treat as a point load in the centre of one length of the proposed decking. See what sort of stress and deflection you get.

If both deflections are acceptably small, then distributing those weights around the bridge will give you some considerable safety factors.

If anything looks dodgy - then as Bizbuilder says - get a structural engineer to run the calculations for you.

Just out of curiosity I ran the numbers for the I Beam through a couple of online calculators

I Beam Moment of Inertia Calculator (amesweb.info) give the second moment of intertia of an I beam. I got a cross section of 15sq in and a MI of 423.75

Using those numbers and putting a 2 ton point load in the centre of the 9M beam Free Beam Calculator | ClearCalcs gave me a deflection at the centre of the beam of 0.75" 

Sorry misread the length - had to recompute

Edited By Peter Cook 6 on 20/07/2022 17:43:25

They are probably Zinc Air chemistry. The Zinc reacts with Oxygen in the air to generate the voltage. They are probably packaged in a vacuum ( or inert gas) to extend the shelf life. Removing the seal allows oxygen from the air to enter. It may take a couple of minutes to percolate through the zinc.

If you have access to a 3D printer, it is not too difficult to simply print a division plate with the number of holes you need.

My cheap & cheerful (72:1) rotary table had a similar problem in that I couldn't do 25, 50, 75 or 100 with the dividing plates available. I drew a 25 hole plate, and printed it in PLA. It worked fine for a one off.

Typo

Edited By Peter Cook 6 on 19/07/2022 11:43:38

Close. As Peter G says, the router assigns an internal IP address to each device (e.g. 192.168.0.XXX). When that device asks the router for an external connection the router translates (called NAT) the address into [your.external.ip.address] plus, as you surmise, a different port number for each communication. The external world responds to [your.external.ip.address: portNo] which the router re-addresses to the appropriate internal device.

If the router gets an inbound message which does not have a portNo that corresponds to an external connection it recognises, most routers throw the inbound traffic away. It acts as a first line defence for your network.

If you want to allow unsolicited inbound traffic to reach an server inside your network, the usual method is to put that server in what is known as a DMZ (demilitarized zone!), and tell the router to pass all unsolicited traffic (usually with port 80 for http or 443 for https traffic) to the IP address of the server.

But the security on that server needs to be good. You would not want to run the server on your existing computer!

PS this all assumes IPV4 - IPV6 is a whole new can of worms.

Damn emojis

Edited By Peter Cook 6 on 19/07/2022 10:34:12

Edited By Peter Cook 6 on 19/07/2022 10:35:44

Peter - you are not alone, and it's getting quicker. This is a quote from Lee Hutchinson writing in arstechnica (in 2014 bemoaning the passing of the Hayes modems).

"You've almost certainly never seen the place where I grew up, and you never will because it's long gone, buried by progress and made unreachable by technological erosion and the fine grind of time. What I did and learned there shaped me, but that knowledge is archaic and useless. I am a wizard whose time has passed — a brilliant steam engine mechanic standing agape in the engine room of the starship Enterprise."

I spent my working life in the IT industry - and I relate exactly to his sentiments.

It's the confluence of two well known bits of economics, coming up against politics.

Economies of Scale tends to drive the creation of ever larger units - simply because they can do things more efficiently (cheaply) than small suppliers and consequently can offer lower prices while still making a profit. Birmingham Gas -> British Gas. They offer lower prices based on lower costs until they become market dominant when Monopolistic ( profit maximisation by increasing prices) behaviour starts to arise.

Profit gouging monopolies are unpopular with consumers ( read voters), consequently governments try to limit their behaviour - either by regulating them (Ofgem), nationalising them, or by trying to create competition. All of which increases cost which is ultimately paid for by the consumer or taxpayer.

The ideal model is a benign monopoly which minimises its costs through economies of scale, and passes those benefits on to its customers out of the goodness of its heart. Trouble is benign monopolies tend to inhabit the same universe as unicorns, hens teeth and unobtanium!

PS I was once told  that the difference between the rich and the poor  was simple - rich people spend money to save time, while poor people spend time to save money. Not strictly true in the world of hobbies, but  then hobbyists tend to have enough money to have spare time.

Edited By Peter Cook 6 on 17/07/2022 12:20:37

If you really want something to think about - and a long read, try The Age of Surveillance Capitalism by Shoshana Zuboff. The subtitle is "The fight for a human future at the new frontier of power". It was published in 2019 and things have got worse since!

One of my favourite quotes about money - from George Best

"I spent a lot of money on booze, birds and fast cars. The rest I just squandered."

I use (and have used for almost 20 years) a small outfit in Scotland - Calico (www.cali.co.uk). £30/year +VAT for the domain +1Gb mail + 50Mb web space. The mail system uses catchall so [email protected] gets delivered to me and my mail client sorts the different addresses so I can have all the mail addresses I want.

They do more sophisticated packages as well.

I can remember only a couple f outages in the 20 years and they were quickly fixed.

A google search for "MAX-T engineering supplies" got me a hit at Max-T engineering Supplies - MachineTools.com

This gives an address in Stroud which looks like a private house.

Edited By Peter Cook 6 on 14/07/2022 12:02:36

Push the hall sensor closer to the centre. If the magnets are not quite on a perfect pitch circle it may be seeing 3 but

 missing the fourth.

Edited By Peter Cook 6 on 13/07/2022 21:31:12

The 240v one is a "figure of eight" otherwise known as an IEC C7.

Diodes pass current one way, but not the other. In the forward direction they exhibit a voltage drop. For a BAT 41 the drops 0.45v @ 1ma and 1v @ 450ma. So the measured "resistance" depends on your measurement system.

However I suspect you have a bad diode.

One other comment, the continuous current rating for a BAT 41 is only 100ma. At dawn, with the battery drained, your circuit seems to have nothing to limit the current through the BAT 41s. I think you need some beefier diodes, and some sort of current limiting resistance in the circuits.

I have my subscriber number (for MEW), and can access the digital versions back to 1990 - but I seem to have a gap in the archive between 2010 and 2020.

Is this simply a question of waiting until these editions are transferred, or is there some other reason.

For me a s a fairly new beginner, the older editions contain some of the more Interesting (basic) material.