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.
> 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
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
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
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.
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
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
Hi,
Someone on the mailing list suggested various aspects to look for in
> 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 ?
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?
I'll pledge another £10, there's a board I'd like to make.
-asc
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.
The pump is just a large aquarium type,so no big deal
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
Collecting it is not a problem - I'll do that.
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.
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.
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
Yes, for £95 (about £135 inclusive). Annoying that someone was
bidding against me from the Internet, because it dropped to £30
initially.
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...
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
If you can tilt it up a tthe sink end & rest on something to get access underneath, there is a largerectangular 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...
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.
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
>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
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
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
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
If you're printing on a laser, I'd reccommend tracing paper (at least 90gsm), which is generally a
lot cheaper than film.
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).
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
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...
>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.
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...
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.
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
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.