PCB etch tank pledge - slight change of plan

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Elliot West

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Mar 16, 2011, 5:35:56 AM3/16/11
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Hi,

The PCB etch tank pledge was almost fully paid up - however there was one pledge commitment that hasn't been paid and I've not been able to contact the individual concerned - hopefully they're ok. Recently there has been renewed interest in the pledge and we had a new pledger last night. Therefore I have removed the pledge amount for the individual who is missing in action in the hope that some new pledgers will be able to help us meet our new target of £239.

We now have £220 pledged. If anyone wants to help out with the etch tank to the tune of £19 then your pledges will be gratefully accepted!


Cheers - Elliot.


Earthshine

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Mar 16, 2011, 5:44:45 AM3/16/11
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I'll pledge the remaining £19

Mike

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Mar 16, 2011, 5:47:39 AM3/16/11
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On Wed, Mar 16, 2011 at 09:35:56AM +0000, Elliot West wrote:
> Hi,
>
> The PCB etch tank pledge was almost fully paid up - however there was one
> pledge commitment that hasn't been paid and I've not been able to contact
> the individual concerned - hopefully they're ok. Recently there has been
> renewed interest in the pledge and we had a new pledger last night.
> Therefore I have removed the pledge amount for the individual who is missing
> in action in the hope that some new pledgers will be able to help us meet
> our new target of ?239.
>
> We now have ?220 pledged. If anyone wants to help out with the etch tank to
> the tune of ?19 then your pledges will be gratefully accepted!

Being a jolley benevolent chap, I've thrown in the remaining £19. I'm
going to the Space after work, so I'll try to transfer the funds after
I return. If I forgot then I'll do it tomorrow. If I still forget
after that, please feel free to send a message to the list reading "Are
you going to f***ing pay?!".

Regards,
Mike.

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Mike

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Mar 16, 2011, 5:49:08 AM3/16/11
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On Wed, Mar 16, 2011 at 02:44:45AM -0700, Earthshine wrote:
> I'll pledge the remaining ?19
>
>

Looks like we can buy £9.50 of developer and £9.50 of etchant now, too.

What sort of UV box do we have?

Mike.

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Adrian Godwin

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Mar 16, 2011, 5:50:44 AM3/16/11
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What's the feeling about the big tank that's coming up for auction tomorrow ? Should these pledges be considered for that, or would pledgers prefer to buy the single new one ?

It's potentially a much better tank and is likely to be cheaper, but is not new.

-adrian


Ciarán Mooney

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Mar 16, 2011, 6:24:25 AM3/16/11
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Hi,

> What's the feeling about the big tank that's coming up for auction tomorrow
> ? Should these pledges be considered for that, or would pledgers prefer to
> buy the single new one ?

Someone on the mailing list suggested various aspects to look for in
an old etching tank. Did you manage to inspect it?

I can see problems arising from the second hand tank involving
installing, repairing and maintaining which won't be worth the cheap
purchase price.

Personally I'd rather buy a new one that takes up less space and is
more suitable to our needs. Whilst PCB etching is becoming popular I
don't think we are near the scale for something as big as that second
hand tank.

We have they money for a nice new one, so why not get it?

Ciarán

Russ Garrett

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Mar 16, 2011, 6:34:43 AM3/16/11
to london-h...@googlegroups.com, Ciarán Mooney
On 16 March 2011 10:24, Ciarán Mooney <general...@googlemail.com> wrote:
> Personally I'd rather buy a new one that takes up less space and is
> more suitable to our needs. Whilst PCB etching is becoming popular I
> don't think we are near the scale for something as big as that second
> hand tank.
>
> We have they money for a nice new one, so why not get it?

The one on the auction isn't just one tank like the one we pledged for
- it's a whole etching station. So you have one tank for developer,
one for etching, and one for spray rinse, plus a sink which doesn't
get corroded by etchant. That makes the whole etching process a lot
more efficient.

So I think it's worth bidding on, as long as it's in a relatively
decent condition.

--
Russ Garrett
ru...@garrett.co.uk

Charles Yarnold

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Mar 16, 2011, 6:35:12 AM3/16/11
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We have had quite a bit of interest when a tank similar to the auction one was offered to us as a donation (sadly it didn't happen). It doesnt seem to be hugely bigger than the white pcb cupboard that we have now...

On 16 March 2011 10:24, Ciarán Mooney <general...@googlemail.com> wrote:

Russ Garrett

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Mar 16, 2011, 6:37:13 AM3/16/11
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On 16 March 2011 10:35, Charles Yarnold <charles...@gmail.com> wrote:
> We have had quite a bit of interest when a tank similar to the auction one
> was offered to us as a donation (sadly it didn't happen). It doesnt seem to
> be hugely bigger than the white pcb cupboard that we have now...

Yes, by eyeball it seems to ideally fit where that cupboard is
currently, and that makes plumbing easy too.

--
Russ Garrett
ru...@garrett.co.uk

Mike Harrison

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Mar 16, 2011, 6:41:50 AM3/16/11
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I would not be at all surprised to see that tank to go for way less than the new tank price,
especially for a large item in an auction of unrelated other stuff.
It has to be worth putting _some_ bid on it, even if less than the new tank cost.

If the floor space occupied is really an issue you could literally saw the top down, discard the
rest and house it in a simple rectangular box, or cut down the frame - the construction is a box
frame of steel, faces with plastic panels, so an angle grinder and welder could easily reduce it to
any required size. Maybe use any unused spray-wash tanks for the darkroom guys.

However having a well-partitioned area including a sink for PCB work and other messy tasks is a very
good way to keep things outside the immediate area tidy, clean and un-corroded. A PCB tank is always
going to need a permanent dedicated place to live - you really don't want to be moving tankfuls of
corrosive liquids around.

One thing to check is the actual tank size - According to the catalogue it's a PB710 which has
10x12" tanks - not sure if the proposed new one was the same.
http://megauk.com/production_lines.php

I really don't think there is any major risk with something as simple as this - Adrian has offered
to go see it to check for mechanical damage/leaks and can test the heaters, which are the only main
failure points. Anything else would be a cheap & easy fix.
And it's a 4-tank unit and so has 4 heaters, of which you only need one in the etch tank, so you'll
have spares.

Mike Harrison

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Mar 16, 2011, 6:44:18 AM3/16/11
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Overall dimensions are: width 1185mm, depth 580mm, and height 900mm.
Water inlet is via washing-machine couplings on rear, drain can be out either side or rear

Elliot West

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Mar 16, 2011, 6:54:10 AM3/16/11
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So - who is going to bid? I suck at auctions...

Ciarán Mooney

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Mar 16, 2011, 6:54:41 AM3/16/11
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Hi,

Well it seems people are happy to take a punt, I shall conform to the consensus!

If Adrian is checking it then we can probably avoid a lot of the
problems I'm worrying about. When can you report back Adrian?

There was also the issue of who can actually bid on the item. I seem
to remember Adrian saying he had the capability but was unable, and
that Mark had access to the mysterious system.

Is anyone willing to bid on it for us?

Ciarán

Adrian Godwin

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Mar 16, 2011, 7:05:24 AM3/16/11
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On Wed, Mar 16, 2011 at 10:24 AM, Ciarán Mooney <general...@googlemail.com> wrote:
Hi,

> What's the feeling about the big tank that's coming up for auction tomorrow
> ? Should these pledges be considered for that, or would pledgers prefer to
> buy the single new one ?

Someone on the mailing list suggested various aspects to look for in
an old etching tank. Did you manage to inspect it?


Inspection is only possible today. I tried on Monday but got thrown out :-). I will go tonight and be sure to take note of what  Mike suggested.

 
I can see problems arising from the second hand tank involving
installing, repairing and maintaining which won't be worth the cheap
purchase price.


There may be repairs necessary but all equipment needs repairs eventually. It's part of maintaining tools. Given that an item like this doesn't really wear (it just uses up heaters etc.) the main thing would be to ensure there was spare cash to replace parts. As Mike pointed out, it contains quite a few spares already due to overcapacity.

 
Personally I'd rather buy a new one that takes up less space and is
more suitable to our needs. Whilst PCB etching is becoming popular I
don't think we are near the scale for something as big as that second
hand tank.

We have they money for a nice new one, so why not get it?


I don't really understand  'we can affiord it so we should do it'. If there's a possibility of getting better, cheaper, why not do that ? The important thing to check is that it is indeed better and cheaper - ie it doesn't have hidden costs etc.

If you were going for something like a triple tank, I'd agree in some respects : that covers the essentials of developing, washing and bubble etching. It still needs permanent space to set up as you don't really want to carry a tank of chemicals around.

But the single tank will only help the etch process. All the other steps are still present, and a triple tank is a lot more expensive. Not that it's useless, by any means - it would be a fine improvement, and if that's what's available and affordable it's a good choice.

The bench, if it's any good, provides a place to work, both tanks (and some others) and intermediate wash stages. The sink part is resistant to etchant. There is cupboard storage underneath. It could be installed in place of the unit 23 sink and provide a very good facility for no additional space.

 I do agree it's over the top for current use, and I think the usage will only grow in numbers rather than the need for greater capacity. But if it costs less than something that was only an incremental improvement, it seems like a good option. I don't, however, think it's worth spending more than the single tank even allowing for some replacement parts.

Note that I have no axe to grind on my own behalf : I have the triple tank at home and it's plenty for my needs. That's why I haven't pledged for this one. I just hate to see people spend their hard-earned money when there's the option for something better, and I find second-hand equipment offers fantastic value compared with new. Sure, it takes more work - but that's part of hacking. I am willing, though, to help as far as possible with transport, repairs, installation etc. to make sure you don't get a bad bargain.

-adrian
 

 


Adrian Godwin

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Mar 16, 2011, 7:11:04 AM3/16/11
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I have very limited access to the net at work. I'd have to take the day off, or leave a written bid. I don't entirely trust the auctioneers not to make the best of a written bid, but that might be unfair. It's certinaly a possibility especially if you want to bid for a bargain rather than a surefire win.

It's pretty easy to use the system - you register, which requires a credit card. Then you bid, rather like ebay. The only difference is that the bidding stops when there are no further bids, not on a timed stop, so sniping doesn't work. Mark has used it for a couple of previous auctions so is presumably familiar with it, but anyone could do it. It's just that being lot 5, you won't have much chance to practice !

-adrian

asc

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Mar 16, 2011, 8:43:05 AM3/16/11
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I'll pledge another £10, there's a board I'd like to make.

-asc

Adrian Godwin

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Mar 16, 2011, 3:03:58 PM3/16/11
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On Wed, Mar 16, 2011 at 11:05 AM, Adrian Godwin <artg...@gmail.com> wrote:

Inspection is only possible today. I tried on Monday but got thrown out :-). I will go tonight and be sure to take note of what  Mike suggested.



OK, I've been and had a look.

It's been used a fair bit, but there's no damage, just a lot of brown stains due to the etchant. All the tanks have been used, but most have white rather than brown deposits. The porter told me it came from a school - so though it could have been abused it will have been supervised and used quite lightly. It has all the accessories (tank lids, baskets, hoses) except the syphon (which is just a cheap petrol syphon).

I couldn't inspect underneath the tanks as the key for the cupboard locks was missing. There was no damage or evidence of repairs around the tank fittings visible from the top. The cabinet seemed in good condition - not tatty or falling apart.

All the heaters appear to be intact, both physically and electrically. Not sure about the air pump - it isn't such low resistance as the heaters and is hard to measure separately, but it does seem to behave the same as the one on mine so may well be OK.  I forgot to check the solenoid valves on the wash tanks but they're basically just washing machine inlet valves so very cheap (and unlikely to be broken).

In general - it looks used, stained, but complete and undamaged.

My feeling is that it should go pretty cheap just because there's pretty limited demand. It's too big for a home user, too dirty for a dealer, and very few commercial users make their own PCBs nowadays. So unless there's a small comany with a prototyping need who just happens to be at this provincial auction, it won't go for much money. So I'm expecting it to go for under 50 and be a superb bargain for hackspace use. But you never know !

It would probably be worth spending a fair bit more - hold back £50 on the offchance that it needs fixing, and use the rest of the pledge, perhaps, and then you'd get way more for your money than the single tank but perhaps have to spend a little while fixing it up (which I'd be happy to volunteer for, btw). On the other hand, it's not my money - if you'd rather have a shiny new toy in a box that's entirely up to you !

Anyway, decision time is tomorrow. Some thought and preparation is required to allow bidding. Don't leave it too late!

-adrian



Charles Yarnold

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Mar 16, 2011, 3:13:16 PM3/16/11
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GOGOGO

Mike Harrison

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Mar 16, 2011, 3:13:48 PM3/16/11
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>All the heaters appear to be intact, both physically and electrically. Not
>sure about the air pump - it isn't such low resistance as the heaters and is
>hard to measure separately, but it does seem to behave the same as the one
>on mine so may well be OK.

The pump is just a large aquarium type,so no big deal

Elliot West

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Mar 16, 2011, 3:26:13 PM3/16/11
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So - who's going to bid? I won't be able to... and it sounds as though preparation is required...
Message has been deleted

Elliot West

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Mar 17, 2011, 4:35:40 AM3/17/11
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Who can pick this up if we win? Looks like it would have to be picked up today or tomorrow if we don't want to be charged storage. They close at 5pm.

Adrian Godwin

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Mar 17, 2011, 4:46:34 AM3/17/11
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Thanks. This needs pushing forward and I'm getting tired of the sound my own voice ..

Collecting it is not a problem - I'll do that.

ms7821 is able to bid but would prefer someone else to - at the moment I think he's expecting to do it, so it would be best to tie up with him first. Register anyway - it doesn't cost anything and only gets you about 4 spams a year.
If you can do it that would be great.

As you say, working out the max bid is useful. I don't think you'll go far wrong with that bid as long as the pledgers are happy with it. Bear in mind that there are various extras on top of the bid price that raise the total - 15% to the auctioneer, possibly VAT as well. Sorry, can't remember if VAT is on that lot but it should say on the website.

It's entirely possible there will be no other bids, so wait for the auctioneer to drop his opening price down to the minimum before diving in.

-adrian


On Thu, Mar 17, 2011 at 8:20 AM, Adam Page <adam...@gmail.com> wrote:


On Mar 16, 7:26 pm, Elliot West <tea...@gmail.com> wrote:
> So - who's going to bid? I won't be able to... and it sounds as though
> preparation is required...
On Mar 16, 7:26 pm, Elliot West <tea...@gmail.com> wrote:
> So - who's going to bid? I won't be able to... and it sounds as though
> preparation is required...

Three hours to go...

I was really hoping that by now you lot had found a volunteer,
thrashed out how much to offer and maybe even
come up with a plan for collecting it if we win.

I'm working nights at the moment so there is significant chance I will
sleep through the auction or get it wrong somehow due to being
half asleep. You have been warned.

I'm going to bid £170 on it unless anyone else steps in (please do) or
otherwise objects. Lets not have a comedy moment where we
bid against each other...

If I'm not live on IRC shortly before the auction starts you can phone
me (number on wiki page).

Adam

Elliot West

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Mar 17, 2011, 4:58:54 AM3/17/11
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On 17 March 2011 08:46, Adrian Godwin <artg...@gmail.com> wrote:
Collecting it is not a problem - I'll do that.

Cool - one problem solved.
 
As you say, working out the max bid is useful. I don't think you'll go far wrong with that bid as long as the pledgers are happy with it. Bear in mind that there are various extras on top of the bid price that raise the total - 15% to the auctioneer, possibly VAT as well. Sorry, can't remember if VAT is on that lot but it should say on the website.

Charges from the website: 20% +18% + 3% (VAT, Premium, Card surcharge)

We have £250
We want to keep back £50 for spares
That leaves £200 to spend
Approximate max bid if we factor in charges: £128
 
It's entirely possible there will be no other bids, so wait for the auctioneer to drop his opening price down to the minimum before diving in.

Does the website provide notification of this? I have no idea how this works...

Adrian Godwin

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Mar 17, 2011, 5:17:31 AM3/17/11
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On Thu, Mar 17, 2011 at 8:58 AM, Elliot West <tea...@gmail.com> wrote:
On 17 March 2011 08:46, Adrian Godwin <artg...@gmail.com> wrote:
Collecting it is not a problem - I'll do that.

Cool - one problem solved.

Sorry - thought I'd made that clear from the start. The place is about 5 miles from my house, and I only needed to check it would fit the car, which it does, pretty well.

Does the website provide notification of this? I have no idea how this works...


Yes, if working properly it will show an interactive window with the current bid price. You hit the bid button to accept it. The auctioneer should also be on audio (but that was broken on tuesday's auction) and this is worth listening to as it gives you a little warning about what the interface is about to do. This is why I suggested joining one earlier in the week to see how it works - you don't have to bid to get an idea of it. It's possible that there's another one that starts earlier if you want to get a hint, but note you have to register for the specific auction you're bidding in.

I'm pointing this all out because, at lot #5, even though it's pretty straightforward, it'll all be over by the time you've worked it out if you're not ready !

-adrian

Elliot West

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Mar 17, 2011, 5:17:48 AM3/17/11
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ms7821 will be bidding - please don't bid against him :)

Mark Steward

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Mar 17, 2011, 5:18:13 AM3/17/11
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On Thu, Mar 17, 2011 at 8:58 AM, Elliot West <tea...@gmail.com> wrote:
> Does the website provide notification of this? I have no idea how this
> works...
>

It's just like a real auction - you see something like "last bid £50
[click here to place bid of £55]", and there's no cancelling your bid
once you've placed it. You get a varying amount of time before they
move on (again, imagining the real auction that's going on helps
understand what's happening). Small items sometimes only flash "last
offer" once, and if it has a minimum and the auctioneer's getting
nothing from the room, you may not even see that. You also need a
solid connection to ensure you don't miss any updates.


Mark

Elliot West

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Mar 17, 2011, 5:26:18 AM3/17/11
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Cool - thanks for the heads-up Mark/Adrian.

Adrian Godwin

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Mar 17, 2011, 5:34:29 AM3/17/11
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Also, you can watch the auction without bidding or even registering. It's a lot more fun than ebay - do it for the experience, they have lots of stuff potentially useful to the hackspace (like, the blue chairs came from there).

-adrian


Martin Johnston

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Mar 17, 2011, 7:13:23 AM3/17/11
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That was cool! Was ours the winning internet bid?

Mark Steward

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Mar 17, 2011, 7:17:01 AM3/17/11
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On Thu, Mar 17, 2011 at 11:13 AM, Martin Johnston
<martin.d...@gmail.com> wrote:
> That was cool!  Was ours the winning internet bid?
>

Yes, for £95 (about £135 inclusive). Annoying that someone was
bidding against me from the Internet, because it dropped to £30
initially.

Adrian Godwin

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Mar 17, 2011, 7:24:02 AM3/17/11
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Not as cheap as I hoped but still a great bargain. Mail me the invoice when it comes (or I may get away with just your bid number) and I'll go pick it up.I should be able to bring it to london friday night.

I will probably have to break the lock unless anybody can think of a better idea - I'm not proficient enough at picking to do it before I load up and I need to be sure there's no bottles of etchant in the cupboard before I get it in the car. I'll do it as neatly as possible (just force the barrel with a screwdriver).

-adrian



Mike Harrison

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Mar 17, 2011, 7:35:57 AM3/17/11
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If you can tilt it up a tthe sink end & rest on something to get access underneath, there is a large
rectangular tray that sits in a cutout in the bottom panel under the sink - you can probably push
this out and into the cupboard from the bottom to reveal a hole big enough to get access to the back
of the lock (feel for presence of liquid in the tray first!) - I think the latch part screws into
the barrel from the rear so you may be able to just unscrew it.
I think you may also be able to access the hinge screws from the outside.

There will probably be some (dirty) water in the drainage system and a lot of messy gunk in the huge
trap under the sink drain - if you're transporting it on its side you will need to empty this out
first.

rubber gloves, some plastic sheeting and a roll of kitchen towel would be a good addition to the
toolkit...

Mark Steward

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Mar 17, 2011, 7:38:01 AM3/17/11
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Depending on when you plan to go, it's only St Neots, so I'm happy to
pop up and help you get it in the car. I can bring my picks.

Mark

Elliot West

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Mar 17, 2011, 7:55:10 AM3/17/11
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Well done to all concerned - thank you for making this happen.

Adrian Godwin

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Mar 17, 2011, 8:16:56 AM3/17/11
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On Thu, Mar 17, 2011 at 11:35 AM, Mike Harrison <mi...@whitewing.co.uk> wrote:
If you can tilt it up a tthe sink end & rest on something to get access underneath, there is a large
rectangular tray that sits in a cutout in the bottom panel under the sink - you can probably push
this out and into the cupboard from the bottom to reveal a hole big enough to get access to the back
of the lock (feel for presence of liquid in the tray first!) - I think the latch part screws into
the barrel from the rear so you may be able to just unscrew it.
I think you may also be able to access the hinge screws from the outside.


Cheers - that tray may give me enough visibility to check for anything nasty in any case. No need to open the door if there's nothing inside. And the hinge screws could be the easy way :-)

 
There will probably be some (dirty) water in the drainage system and a lot of messy gunk in the huge
trap under the sink drain - if you're transporting it on its side you will need to empty this out
first.

rubber gloves, some plastic sheeting and a roll of kitchen towel would be a good addition to the
toolkit...


Noted !


Mark - thanks, that's great but it's a fair trip for a short job. I should be able to manage but I'll try tonight and if picking the lock seems the best option I'll ask for help on friday night.


-adrian

Adrian Godwin

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Mar 18, 2011, 6:02:46 PM3/18/11
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The tank is at the hackspace and placed next to the hangar 23 sink. It looks pretty good - I don't think it requires any replacement parts and it even came with some chemicals. I've cleaned it up a bit but it could do with more, especially the sink. There is some ferric chloride stain remover in the cupboard which would be worth trying.

See http://wiki.hackspace.org.uk/wiki/Equipment/PCB_etch_station for more details.

Neither waste or water is plumbed in yet, and the tanks contain washing water. If someone feels like it, they can change the water, flush the tanks out and probably fill them. We have all the chemicals except, possibly, etchant.

-adrian

Mike Harrison

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Mar 18, 2011, 6:35:21 PM3/18/11
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Before filling with etchant, fill the etch tank with clean water and check how even the bubbling is
- the bubble bar tends to clog up and it's much easier to remove & clean/redrill before it gets
filled with etchant.
While you're at it with water in there, check what temperature it gets up to 50-60 deg.C is a good
compromise between etch speed and fumes. The thermostat is adjustable.

You don't really neeed to heat the developer, although if it gets really cold in the space maybe set
the thermostat to 20-25 deg.C

If it ever gets cold enough for there to be a risk of freezing, an anti-frost heater in the cupboard
might be wise.

Also make sure all the tank draining hose taps work and the hoses & backup clips aren't on the
point of cracking. Tap and clips are available cheaply from RS.

Once in use, any unused tanks should either be left at least half full of water in or have the
heaters disconnected, as accidentally turning on a heater in an empty tank is bad, m'kay.
It will definitely blow the heater's internal not-easily-replaceable thermal fuse and may melt the
tank

Probably wise to give it its own RCD, 10mA if possible.

Yes, The FeCl cleaner is oxalic acid, and you can get big tubs of it from ebay, however its
effectiveness is rather limited - it takes a lot of it and a lot of very messy scrubbing work to
only partially remove major stains, and probably not worth the hassle as it's only going to get
stained again...

You also want a splashback. Unless they've changed the type of tap they use since I got mine, it is
very effective at spraying water over a surprisingly wide area.

Adrian Godwin

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Mar 18, 2011, 6:42:13 PM3/18/11
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On Fri, Mar 18, 2011 at 10:35 PM, Mike Harrison <mi...@whitewing.co.uk> wrote:
Before filling with etchant, fill the etch tank with clean water and check how even the bubbling is
- the bubble bar tends to clog up and it's much easier to remove & clean/redrill before it gets
filled with etchant.

It is bubbling, but would probably still be best cleaned while it's easy. How is it removed ?

 
While you're at it with water in there,  check what temperature it gets up to  50-60 deg.C is a good
compromise between etch speed and fumes. The thermostat is adjustable.

You don't really neeed to heat the developer, although if it gets really cold in the space maybe set
the thermostat to 20-25 deg.C


The developer thermostat does seem to be set about 28. The etchant is about 50, and I think the other two are as well.


There's some of Mega's developer in a bottle. I've found this develops in about 15 seconds, but the instructions that someone's put in the cabinet say a lot longer and I think longer times are usual with whatever we normally use. Is it worth making this up below strength, or is everyone happy with fast development times ?


-adrian

Mike Harrison

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Mar 18, 2011, 7:09:45 PM3/18/11
to london-h...@googlegroups.com
On Fri, 18 Mar 2011 22:42:13 +0000, you wrote:

>On Fri, Mar 18, 2011 at 10:35 PM, Mike Harrison <mi...@whitewing.co.uk>wrote:
>
>> Before filling with etchant, fill the etch tank with clean water and check
>> how even the bubbling is
>> - the bubble bar tends to clog up and it's much easier to remove &
>> clean/redrill before it gets
>> filled with etchant.
>>
>
>It is bubbling, but would probably still be best cleaned while it's easy.

It will pretty much always bubble - what you need to check is that there's a reasonably even
distribution of bubbles along the length of the tank, otherwise it etches unevenly.

>How is it removed ?

Undo the screw that goes into the bottom of the tank at the centre. You can then lift the tank out -
all the wiring unplugs at some stage on its way out - there's a multiway inline plug/socket (may
have plastic locking pins), maybe also a couple of bullet crimps. Depending where the plug sits you
may be able to unplug before lifting.
Once out, remove the heater by removing its gland nut. May need to disconnect to get enough spare
lead. Check the condition of the heatshrink on the end of the heater and replace if necessary
Pull the air supply tube off the end of the bubble bar (may be full of gunky etchant/water), and
undo the gland nut - you can then get the tube out via the tank.

The thing to be most careful of is not to overtighten the gland nuts when reassembling as if you
strip the theads you're very screwed. Hard to say how tight they need to be - probably slightly more
than hand tight, and check for leaks with water before refilling.


>There's some of Mega's developer in a bottle. I've found this develops in
>about 15 seconds, but the instructions that someone's put in the cabinet say
>a lot longer and I think longer times are usual with whatever we normally
>use. Is it worth making this up below strength, or is everyone happy with
>fast development times ?

15 secs is a little on the quick side. I think they suggest 9:1 water:dev which is usually too weak
- something like 4 to 5:1 is more like it. You can top up as it weakens with use.

You will find significant variation in dev times with different board types - I think this is a lot
to do with coating thickness. If it's too weak it just takes longer - if excessively strong it can
over-develop too quickly to recover, especially if artwork isn't very black.

If the 15 secs is with a 'slow' laminate it may be a bit too strong for faster stuff.
Start with around 5:1 water:dev and add developer to taste.
Do some test pieces to check.
As regards laminates I highly reccommend Mega's microtrak stuff, especially for finer pitch boards.

This developer generally has a HUGEmargin between 'develop' and 'strip' unless it's made insanely
strong, so it isn't too critical as long as the artwork contrast is good. The only time it's
critical is with a not-really-black enough artwork. It's generally better to over expose than under
as the former is easier to fix afterwards.

Assuming a well-exposed board, you want to see the exposed bits _start_ turning violet/blue within
about 5-10 secs. A wipe with _dry_ kitchen towel is good for removing remaining resist and gives
cleaner edges than just dunking & washing - dry towel is just abrasive enough to only take exposed
resist off. After it looks done, give it another dunk for a few secs just to be sure.

If in doubt whether it's fully developed , drip a little FeCl (e.g. from the corner of the basket)
- if the copper doesn't turn matt pink instantly, it isn't developed enough, rinse and develop some
more.

or more info see my page www.electricstuff.co.uk/pcbs.html

Russ Garrett

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Mar 20, 2011, 5:36:37 PM3/20/11
to london-h...@googlegroups.com, Mike Harrison
On 18 March 2011 22:35, Mike Harrison <mi...@whitewing.co.uk> wrote:
> Before filling with etchant, fill the etch tank with clean water and check how even the bubbling is
> - the bubble bar tends to clog up and it's much easier to remove & clean/redrill before it gets
> filled with etchant.

I have done this - I cleaned the bubble bar up with a pin and an air
compressor and it seems to bubble fairly well now. I was unable to
replace the screw at the bottom (it was a bugger to remove and it's
basically stripped now), but that's not a huge problem

I also ran it for about an hour with a strong (and hot) solution of
the stain remover. The results were not great, but it did seem to
soften some of the more significant deposits. Decent results may be
had with a washing up brush (or a scourer on a stick) and a bit of
elbow grease.

All the temperature set points are now correct, and developer
(potentially slightly weak), resist strip and tin tanks are filled
with the correct solution. I ordered 5kg of Ferric Chloride to arrive
on Tuesday, which will complete the set.

--
Russ Garrett
ru...@garrett.co.uk

Russ Garrett

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Mar 20, 2011, 8:03:32 PM3/20/11
to london-h...@googlegroups.com
On 20 March 2011 21:36, Russ Garrett <ru...@garrett.co.uk> wrote:
> All the temperature set points are now correct, and developer
> (potentially slightly weak), resist strip and tin tanks are filled
> with the correct solution. I ordered 5kg of Ferric Chloride to arrive
> on Tuesday, which will complete the set.

Incidentally, I am interested in this magical air-regenerated copper
chloride process but I wonder if it will have problems with the
residual gunk in the etching tank. I am having some difficulty
fathoming the chemistry of this.

At any rate, using copper chloride isn't going to mitigate any
disposal issues (such that there are, as I can't find any rules for
what can or can't be disposed through the sewer).

--
Russ Garrett
ru...@garrett.co.uk

Ciarán Mooney

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Mar 22, 2011, 7:22:34 AM3/22/11
to London Hackspace
Hi,

I'm glad to be proven wrong, we got ourselves a bargain.

Not sure if anyone else has noticed but the total cost was much less
than has been raised by the pledge. Is there any plans for purchases
with the excess funds?

Ciarán

Elliot West

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Mar 22, 2011, 7:24:08 AM3/22/11
to london-h...@googlegroups.com
From the wiki:

'Excess funds from the pledge are going to be used for consumables and replacement parts to fix it up.'

Russ Garrett

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Mar 22, 2011, 7:38:36 AM3/22/11
to london-h...@googlegroups.com, Ciarán Mooney
On 22 March 2011 11:22, Ciarán Mooney <general...@googlemail.com> wrote:
> Not sure if anyone else has noticed but the total cost was much less
> than has been raised by the pledge. Is there any plans for purchases
> with the excess funds?

I've already ordered ~£50 worth of chemicals, and some drill bits.
Also on my list is more board and some transparency film.

--
Russ Garrett
ru...@garrett.co.uk

Mike Harrison

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Mar 22, 2011, 7:41:34 AM3/22/11
to london-h...@googlegroups.com

If you're printing on a laser, I'd reccommend tracing paper (at least 90gsm), which is generally a
lot cheaper than film.

Earthshine

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Mar 22, 2011, 8:18:04 AM3/22/11
to London Hackspace
Are we going to have a payment system for using it and consumables
like the laser? I can see this being abused.

Adrian Godwin

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Mar 22, 2011, 1:40:09 PM3/22/11
to london-h...@googlegroups.com
On Mon, Mar 21, 2011 at 12:03 AM, Russ Garrett <ru...@garrett.co.uk> wrote:

Incidentally, I am interested in this magical air-regenerated copper
chloride process but I wonder if it will have problems with the
residual gunk in the etching tank. I am having some difficulty
fathoming the chemistry of this.


I'm not sure about that either, and my feeling is that having ferrous ions in the mix is probably not helpful. It seems reasonable to run it for a while with ferric chloride since that will probably soften the dried-on stuff a bit and people are used to it. If we try to clean it fairly thoroughly each time it's changed, it may get to the point where we can try something else.

We can also set up some cupric chloride in a separate container. Maybe run it in a spare tank (I doubt we'll use the tinning tank for long) with a simple bubble bar.

 
At any rate, using copper chloride isn't going to mitigate any
disposal issues (such that there are, as I can't find any rules for
what can or can't be disposed through the sewer).

It does - that's one of the main advantages. So long as it's well-maintained and not polluted, the waste product of cupric chloride + HCl + copper is cupric chloride. Use it enough and you get a spare tank of perfectly usable etchant! I guess this is only a disposal problem if you're making loads, or if you have to ditch a batch because it wasn't keeping well.

-adrian

Russ Garrett

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Mar 22, 2011, 2:38:45 PM3/22/11
to london-h...@googlegroups.com, Adrian Godwin
On 22 March 2011 17:40, Adrian Godwin <artg...@gmail.com> wrote:
> It does - that's one of the main advantages. So long as it's well-maintained
> and not polluted, the waste product of cupric chloride + HCl + copper is
> cupric chloride. Use it enough and you get a spare tank of perfectly usable
> etchant! I guess this is only a disposal problem if you're making loads, or
> if you have to ditch a batch because it wasn't keeping well.

Yeah, the problem I think is that you're still making approximately as
much "waste" as you would be if you were using Ferric Chloride, so we
probably will end up having to dispose of it.

--
Russ Garrett
ru...@garrett.co.uk

Charles Yarnold

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Mar 22, 2011, 9:54:11 PM3/22/11
to london-h...@googlegroups.com
Tried out the tanks today, after mixing the new etchant.

The developer was a tad too strong, stripping all the photo resist. I have weakened the solution to the point of developing taking 60 seconds (the time given on the tanks instructions). I had a few thin tracks, but I think this was due to the system being turned off for a while during etching, causing a unknown etching time.

But all in all, once these bits are smoothed out and it is plumbed into water and waste it will rock!

Sol

Adrian Godwin

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Mar 23, 2011, 6:28:23 AM3/23/11
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Yes, I found that developer (assuming you're using the Mega stuff rather than the castic soda) worked very fast.

What strength did you end up with ?

-adrian

Adrian Godwin

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Mar 23, 2011, 6:29:49 AM3/23/11
to london-h...@googlegroups.com

Also, are you heating it ? Probably not necessary according to Mike and others.

-adrian


Charles Yarnold

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Mar 23, 2011, 6:34:25 AM3/23/11
to london-h...@googlegroups.com

I used the recommended mix on the bottle, then weekend it to about 2/3 that. The tank is on, but the heater never engaged. it also seems to separate after a few hours do will be worth adding a please stir before use sign.

Sol

Sent from my Android, please excuse typos and spelling errors.

On Mar 23, 2011 10:29 AM, "Adrian Godwin" <artg...@gmail.com> wrote:



On Wed, Mar 23, 2011 at 10:28 AM, Adrian Godwin <artg...@gmail.com> wrote: > > On Wed, Mar 23, 201...

Mike Harrison

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Mar 23, 2011, 6:46:24 AM3/23/11
to london-h...@googlegroups.com
On Wed, 23 Mar 2011 10:34:25 +0000, you wrote:

>I used the recommended mix on the bottle, then weekend it to about 2/3 that.
>The tank is on, but the heater never engaged. it also seems to separate
>after a few hours do will be worth adding a please stir before use sign.

Room temp is fine - doesn't need heating unless it's cold enough to need a coat on.

Seperation sounds odd - is it the Mega liquid stuff in a tall rectangular bottle
http://www.rapidonline.com/Tools-Fasteners-Production-Equipment/PCB-Equipment/Etching/PCB-Developer/29449/kw/developer
which is a clear liquid - can't see how this could seperate

If not, then the Mega liquiid concentrate is stuff you should be using.

Charles Yarnold

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Mar 23, 2011, 6:59:47 AM3/23/11
to london-h...@googlegroups.com

That's the stuff we have, maybe it just wasn't mixed well..

Sent from my Android, please excuse typos and spelling errors.

On Mar 23, 2011 10:46 AM, "Mike Harrison" <mi...@whitewing.co.uk> wrote:

On Wed, 23 Mar 2011 10:34:25 +0000, you wrote: >I used the recommended mix on the bottle, then week...

Room temp is fine - doesn't need heating unless it's cold enough to need a coat on.

Seperation sounds odd - is it the Mega liquid stuff in a tall rectangular bottle
http://www.rapidonline.com/Tools-Fasteners-Production-Equipment/PCB-Equipment/Etching/PCB-Developer/29449/kw/developer
which is a clear liquid - can't see how this could seperate

If not, then the Mega liquiid concentrate is stuff you should be using.

>Sol > >Sent from my Android, please excuse typos and spelling errors. > >On Mar 23, 2011 10:29 A...

Adrian Godwin

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Mar 23, 2011, 7:04:19 AM3/23/11
to london-h...@googlegroups.com
On Wed, Mar 23, 2011 at 10:46 AM, Mike Harrison <mi...@whitewing.co.uk> wrote:

Seperation sounds odd - is it the Mega liquid stuff in a tall rectangular bottle
http://www.rapidonline.com/Tools-Fasteners-Production-Equipment/PCB-Equipment/Etching/PCB-Developer/29449/kw/developer
which is a clear liquid - can't see how this could seperate

If not, then the Mega liquiid concentrate is stuff you should be using.


That's what was with the tank and I think is what Sol's using. However, it's of unknown age - I know it's supposed to last a long while in the bottle but we really have no idea how old it is so maybe that's a problem. I'm also surprised you can see it's separated as it's supposed to be clear . .if it's not that might indicate what the problem is  !

I've got a newer bottle so if it turns out to be a nuisance I'll bring it in and we'll refill it.

-adrian

Russ Garrett

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Mar 23, 2011, 7:31:36 AM3/23/11
to london-h...@googlegroups.com, Adrian Godwin
On 23 March 2011 10:29, Adrian Godwin <artg...@gmail.com> wrote:
> Also, are you heating it ? Probably not necessary according to Mike and
> others.

The set point on that tank is 20 degrees, so the heater will only kick
in if it gets chilly.

--
Russ Garrett
ru...@garrett.co.uk

Mike Harrison

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Mar 23, 2011, 7:43:09 AM3/23/11
to london-h...@googlegroups.com

I don't think this stuff has any serious shelf-life issues - I don't do many PCBs these days so the
stuff I have is maybe 5-6 years old & still fine. You do sometimes get a bit of a white powdery
crust on the bottle neck.

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