Author Topic: 2-knowledge...  (Read 4108 times)

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Offline cabbage

Re: 2-knowledge...
« Reply #120 on: Oct 30 2019 13:53 »
End of priming. Due to the flash or camera it does look a christmasy colour combination(?) But despite this I will give it all 48 hours at least to "harden off".

Sunday I will probably take the lid off the tin of "Malachite", but it is suprisingly the correct colour, the other one would have been "Endleigh" green.





Regards

Ralph

Offline cabbage

Re: 2-knowledge...
« Reply #121 on: Nov 06 2019 11:55 »
Tests showed -I *didn't* like the Malachite. I found it "painful" to look at. It might be the correct colour but I find it too bright!!! So, I have returned to wiring. This has turned out to be painfully slow as the treatment drops make everything VERY fuzzy but it is only for a few days.

This is as far as I have got:





The colours may seem confusing... The motor uses yellow and orange, the red cable is 12V, the green cable is system earth, and the white cable is the Zero Volt Line and black is negative. These are collected and sheathed is spider wrap and terminated with a 7pin DIN male. The spider wrap is heat shrunk to the DIN plug, (an old trick) - thus the connection is only 1cm long(!)

Regards

Ralph

Offline cabbage

Re: 2-knowledge...
« Reply #122 on: Nov 07 2019 11:51 »
Initial "poked wire" tests show that both the theory and practice  of the "Zero Volt Line" system works! As the axles pass over gap in the rail the circuit breaks and the relay returns to the N/C pole and the LED strip lights up.

The next problem is the pickup from the axle to the ZVL wire. One is simple, a loop of wire around the axle, the second is more difficult as it will have to rest on the coning and be held there by the other side of the flange. This is going to have to be hand filed from a section of brass channel.... There will also have to be some form of loading to keep it in contact with the coning. Firm enough for good contact, but slack enough not to act as a brake(?)

There is also the added problem of the equivalent of "leaves on the line" preventing good electrical contact between the leading and trailing axles with the circuit carrying rail. This would also cause the ZVL system to function.

A common application of a ZVL system is the pillar drill red/green button pair.

More eye drops and fuzziness for an hour!!!

Regards

Ralph

Offline cabbage

Re: 2-knowledge...
« Reply #123 on: Nov 08 2019 14:29 »
The first part of the gap detection sysyem has be fabricated and soldered in. The next parts will get fudged together over the weekend. I have ordered the batteries, the Rx and the ESC. The batteries may be a bit on the big side as I have ordered two 12V 7Ah SLA... The eventual aim is for there to be two 2-NOL sets so there may be one battery for each set(?)

I am now going to take more drops and descend into fuzziness. But only for a few more days!!!

Regards

Ralph

Offline cabbage

Re: 2-knowledge...
« Reply #124 on: Nov 13 2019 11:01 »
Now having recovered from treatment and BOY do my eyes ever feel nicer in their sockets now!  I have inserted the 5A slow blow fuses into the rack. Each battery is thus fused at 5A supplying 10A to the ESC and the motors. The connections to the bogies are via "industrial
control" DIN 7 sockets. Each pin will take 3A. The motors are fused at 1.5A. Stall current is 1.75A -not that it should be forced to stall...





The ESC lacks its coolant fan (eBay) and at the moment it is the boring circuit testing phase that I am having to plough through... But, so far no detected shorts or cross links. Once the electrics pass muster it will be time to connect the batteries and hope nothing blows.

Offline cabbage

Re: 2-knowledge...
« Reply #125 on: Nov 18 2019 10:26 »
I now have radio control! No fuses blew and there wasn't any "magic blue smoke" from any of the PCBs...

The next phase is putting the roof on and carving the front part of the roof out of balsa. I had forgotten how *EVIL* balsa was to work with. My hacksaw with 24tooth blade was used to cut the slabs - but even this tore the ends... I dutifully cross stacked the slabs to build my raw shape. It took an hour of steady sneezing to carve the rough and another of galeforce sneezing to sand it...

The roof is made by the std method of gluing corrugated cardboard, then cornflakes packet and finally "cotton duck". The cotton duck is sealed with pva and then emulsioned a couple of times to get a smooth surface.





Regards

Ralph

Offline cabbage

Re: 2-knowledge...
« Reply #126 on: Nov 18 2019 16:15 »
 The PVA sets over night. The result is more Victoria Beckhem than Saville Row - but it will do!





Regards

Ralph

Offline cabbage

Re: 2-knowledge...
« Reply #127 on: Nov 21 2019 14:47 »
Home stretch! I hàve to wire the bogies to accept Zero Volt Line and then - that's it! I will bring one of the cars to the AGM. People can nudge it over the gaps to see it flash.

Regards

Ralph

Offline cabbage

Re: 2-knowledge...
« Reply #128 on: Nov 22 2019 11:15 »
And this is it! The Zero Volt Line ia connected to both bogies.

The first ahot shows the bogie before being puahed over the gap - which you can see to the left.





The next shot shows the bogie with the gap between the wheels. There is now no electrical contact between the wheels and the LEDs fire.





Mug of tea, a couple of gingernuts, start next model...

Regards

Ralph