Genuine Silicon Coated Wire for Soldering

[Nigel Goodwin]

That's what I use for rebuilding motor resistor banks, like in the second photo.



View attachment 136985

Nice picture

When I was at college, along with a few others, I was moved at the end of ETV3 (Electronics and TeleVision) to T3, a technicians course - ETV was a four year course, so I effectively skipped the last year (I'd also skipped the first year). Other people in T3 had done the older RTV (Radio and Television) course, which was seven years - so it was their 8th year at college.

Rather bizarrely, for one of the afternoon classes, we were in the heavy machines lab - this had huge motors etc, and live three phase mains bare brass terminals on the walls One lesson we were doing phase shift, but the capacitor and the resistor were about three feet high, a foot square, and came on wheels - and had to be wired to the afore mentioned bare brass 440V terminals. Considering I already did this both at school, and earlier in ETV, I wasn't impressed.

Anyway, a couple of weeks later, we were given a magnet, a coil, and a galvanometer, and told to drop the magnet in the coil - and watch the galvanometer go 'whee'.

I was completely bemused by this, I'd done it at school in Physics about 11 years old - and I just sat staring at it.

So the teacher came up and said "what are you doing", to which I replied "I'm not doing this load of sh!t for a start", I did it at school years and years ago, and many people on this course are electronic professionals in their 8th year of college - do you think we need to go back to primary school?.

The teacher was less than impressed, and went off to see the head of the college (presumably to have me removed from his course ) - needless to say it turned out that they had completely cocked up, and we weren't meant to in that lab, or doing the first year work they were assigning us.

Yet no one else had complained?.

So that got sorted out, but the course was a complete waste of time, I was learning nothing, so I dropped out after Christmas

 

[Pommie]

we were in the heavy machines lab

The thing I remember from that lab was breaking the current to a LARGE inductor with a knife switch and seeing the huge sustained arc it produced. They also braked (sp?) a HUGE motor to demonstrate the phasing effect when the lights pulsed!!!! Couldn't do that today.

Mike.

 

[Nigel Goodwin]

The thing I remember from that lab was breaking the current to a LARGE inductor with a knife switch and seeing the huge sustained arc it produced. They also braked (sp?) a HUGE motor to demonstrate the phasing effect when the lights pulsed!!!! Couldn't do that today.

Mike.

There used to be a room with a huge electrical display in it - massive walton/cockcroft multipliers, and a huge Jacob's Ladder (like a Frankenstein set) - but we never got to see it working. Apparently it wiped out TV for the entire town if they turned it on

They also had a computer, in it's own room, which ran on valves - no idea if that ever worked or not? - I seem to recall they got it surplus from somewhere?. We did have a play one day with a Teletype, which connected to the Open University computer.

 

[E63]

These two kits are both definitely silicone rubber insulated; I got them as I needed some extra flexible power wire for a project.
I've just flame tested a reel from each, to confirm they are really silicone and not some other soft plastic; five seconds in a gas flame had no effect on the larger, the smaller caught fire, leaving an odourless white powder ash - silica. Definitely silicone rubber!

https://www.amazon.co.uk/gp/product/B07G712DY4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

https://www.amazon.co.uk/gp/product/B06Y5KZ17V/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

If you want some single strand type that can withstand an occasional touch from a soldering iron, look at Kynar insulated wire-wrap wire. I use that a lot, for both wire wrap construction and general prototyping interconnects, and it can definitely stand brief contact with no visible effect.
It is very fine though, so not suitable for anything but small signal connections.

In fact most of my applications are small, so this Kynar product seems interesting. Thanks for that tip.

 

[E63]

Is anyone aware if the silicon style material can be 3D printed?

 

[rjenkinsgb]

High temperature materials exist; ULTEM and PPSU as examples. They are not flexible and need special high temperature extruders and build plates / enclosures.

PUE is a printable rubber; any machine a direct drive extruder or reasonably short bowden drive should handle that, it prints at about 240'C.

3D printable materials for normal filament-type printers have to be "thermoplastic" - re-meltable, so not inherently heatproof.

Many other plastics are "thermoset" - once formed and allowed to cool or solidify, they cannot be melted without destroying them.

Hypothetically, it should be possible to extrude RTV silicone, but not with a normal unmodified printer.

 

[E63]

High temperature materials exist; ULTEM and PPSU as examples. They are not flexible and need special high temperature extruders and build plates / enclosures.

PUE is a printable rubber; any machine a direct drive extruder or reasonably short bowden drive should handle that, it prints at about 240'C.

3D printable materials for normal filament-type printers have to be "thermoplastic" - re-meltable, so not inherently heatproof.

Many other plastics are "thermoset" - once formed and allowed to cool or solidify, they cannot be melted without destroying them.

Hypothetically, it should be possible to extrude RTV silicone, but not with a normal unmodified printer.

Thank you for all of that useful detail. I own a Qidi 3D printer, but I've not explored in detail what it's capable of beyond what's advertised. I would like to be able to 3d print a bulb enclosure, one that resists temp by also doesn't become a brittle mess over time.

Or perhaps you know a material that already has similar characteristics that doesnt necessarily have to be silicon I can use on a 3d printer?

 

[rjenkinsgb]

Firstly, I got the abbreviations mixed up.. Polyurethane 3D filament is TPU, not PUE, sorry.

That is rated up to around 80'C, so may well be suitable, depending on the lamp type?

I've used the Amazon Basics one, that seems to work well and the cost is not too bad.

https://www.amazon.co.uk/AmazonBasics-Printer-Filament-1-75-Spool/dp/B08895Y2CP/ref=asc_df_B088955JFT/?tag=googshopuk-21&linkCode=df0&hvadid=463057449530&hvpos=&hvnetw=g&hvrand=14750301565740918378&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1007258&hvtargid=pla-1187939471752&th=1

Keep it in a sealed bag with desiccant when not in use.

Like many filaments, it will absorb a trace of moisture that can make it spit and bubble during printing, if left open.

I use a heated drier / dispenser box with that and with PETG etc.

https://www.amazon.co.uk/JAYO-Filament-Dehydrator-Filaments-Compatible/dp/B08P5L45XV/ref=sr_1_4?crid=V2BDJIB4J4U9&keywords=filament%2Bdryer&qid=1652101299&s=industrial&sprefix=filament%2Bdryer%2Cindustrial%2C70&sr=1-4&th=1