New brazing hearth

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Sci

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Aug 15, 2011, 4:42:29 PM8/15/11
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Thanks to Kal, the space has a new brazing hearth now! Kal, Billy and
myself (and mother with van) brought it over to the space today along
with the other bits. (sadly we weren't allowed to take the vacuum
chamber in the end, but if Kal lets us know if the scrap man does take
it, maybe we can go to the scrap man direct for it?)

While driving to the space we came up with the idea of making the hearth
run on bottled gas, which I suspect will be more workable than having
mains gas installed in the space, and the associated issue of having to
plumb it in at one site permanently. I *think* it would also mean
avoiding those working on repairing it having to be CORGI registered.

The hearth appears built to take mains gas, with an optional oxygen
tank. Mains gas is (apparently) between 22-30mbar (peak 75mbar). A tank
of propane is (apparently) 700 to 13600mbar. So it'd need a pressure
regulator.

I've also found an old coin-payment gas meter on ebay. It takes
shillings and sixpence, but could be modified to take pound coins and
50p maybe, or else get an electronic valve and use the coin unit from
the old gambling machine. The idea here would be to ensure there was
always enough money to get the bottle refilled by charging for gas
actually used.

The problem with doing it electronically is finding a flow sensor. I
couldn't see one cheaply, and unless anyone has objections or better
ideas, I'll try and grab the ebay meter which ends in 3 days.

Billy also suggested using the large fans out of the HellBench (laminar
flow bench) to build an extractor for it.
We should keep an eye out for spare bits of metal ducting we can use to
keep it ventilated to outside with.
It'd probably be good to get it on some locking castors too.

It's currently by the bellow-hearth. I think the new one will surpass
the bellows one in all ways once it's working.

I'd be keen to help in getting it running, obviously. :)

--

Also thanks to Kal we have a wide selection of welding-rod sizes (some
may be contaminated/damp), some graphite crucibles and a few other bits,
which I'm sure Kal will go into with any usage advice/constraints. :3

~ Sci

spooq

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Aug 15, 2011, 5:19:36 PM8/15/11
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why could you not get the vacuum chamber?

good job btw

Luke

Sci

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Aug 15, 2011, 6:26:53 PM8/15/11
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If I understand right (collection was a bit of a rush), while some of
the things there were going to be re-used after-all, the administrator
(?) was there to limit how much or what free stuff we could take. I'm
not sure if this was concern over liability regarding the old equipment
being used or if they were going to receive some money for the scrap. In
either case, the chamber was more substantial than the photographs
suggested. Very heavy steel, about 18" dia, about 2ft high and mounted
very securely to a heavy trolley. Probably 1980s retrofit of a 70s
chamber. A loss, but not hard to build a better replica.
The limit seemed rather arbitrary/ad-hoc, but that's just my own
impression and I'm not going to complain about not getting enough free
things!

Kal stuck his neck out for the space here convincing the uni to let us
take what we did and deserves thanks for his effort! :)

The engineer present was lovely and enthusiastic, and seemed eager to
see these things being potentially re-used rather than scrapped. He was
pretty much loading things into our arms. Small things that might not be
noticed by admin, but things. :)
I think Billy may have persuaded him to come visit the space too!

Kal

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Aug 15, 2011, 8:12:02 PM8/15/11
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First of all, thanks to sci and billy for putting up with the ever
changing plans.

The administrator was basically a real pain to deal with but we got
there in the end, and yes he was getting money for the scrap metal
which is why he was less pleased about giving us anything big and made
of metal.

The technicians on the other hand are a great bunch, shame they didn't
run the place.

In addition to what has been mensioned are : a very good quality,
almost new stirring hotplate, that simply had to have the on off
switch replaced in the body (which I have now done). This is in the
wet room at the moment with a sticker on it.
It requires a proprietry kettle lead which I have, so if anyone wants
to use it please email me to ask (my email is on the do not hack
sticker). It's worth a fair bit, being decent scientific lab
equipment, so I want to take Very good care of it.

Some really nice boxes for optical microscope accessories, if noone
finds a good use for then, in terms of for storing nice things in,
then I will happily find a place for them at home.

Other little bits here and there like another face shield etc

Personally I can't wait for the hearth to be up and running, reminds
me of my school days :)

Tim Storey

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Aug 15, 2011, 8:31:10 PM8/15/11
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Well done folks

t

Sci

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Aug 15, 2011, 9:22:43 PM8/15/11
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On 16/08/2011 01:12, Kal wrote:
> First of all, thanks to sci and billy for putting up with the ever
> changing plans.
>
> The administrator was basically a real pain to deal with but we got
> there in the end, and yes he was getting money for the scrap metal
> which is why he was less pleased about giving us anything big and made
> of metal.

I am curious, had he already got a quote on how much they'd give him for
the lot? Steel and iron, traders buy at no more than �200 per tonne. So
about 20p a kilo! Aluminium only 50 to 70p/Kg or so.
There's probably some money in the copper windings of the motors and
coils, but not a lot since they're a pain to recycle easily.
But he did seem pretty stuck on it going, so guessing he wouldn't have
sold them direct.

Don't suppose you know which scrap merchant they're using? Could maybe
still get some of the interesting bits if we're willing to pay? Not all
scrap merchants will sell, but you never know.

Sci

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Aug 17, 2011, 8:44:20 AM8/17/11
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Okay, the pay-meter on ebay is at �12, and that's getting to more than I
want to gamble on it being both usable, convertible AND functional.

We'll just get the hearth working as-is and fit in some sort of
pay-timer later.

Anyone got any castors with brakes on? Can use some of the angle iron
that's about to make a trolley for it with space behind for bottle
storage and extraction gear.

~ Sci

Luke Graham

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Aug 17, 2011, 10:29:27 AM8/17/11
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Actually I do have a set at home, I will see if I can dig them out tonight.

Luke

On 17 Aug 2011, at 13:44, Sci <s...@sci-fi-fox.com> wrote:

> Okay, the pay-meter on ebay is at £12, and that's getting to more than I
> want to gamble on it being both usable, convertible AND functional.
>
> We'll just get the hearth working as-is and fit in some sort of
> pay-timer later.
>
> Anyone got any castors with brakes on? Can use some of the angle iron
> that's about to make a trolley for it with space behind for bottle
> storage and extraction gear.
>
> ~ Sci
>
> On 15/08/2011 21:42, Sci wrote:

Billy

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Aug 17, 2011, 4:02:39 PM8/17/11
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I've got some more salvaged angle-iron i can bring in, now i've got an
easy way to carry it.

There's a bag of castor's and wheels next to the wood-stock/wire rack.
Whether they're appropriate is another question.
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