Status of the Laser Cutter - Still out of order

67 views
Skip to first unread message

asc

unread,
Aug 14, 2011, 5:56:14 PM8/14/11
to London Hackspace
Hello all,

Summary: Laser cutter is still out of order, it might look like it is
working but you will be damaging it. Please don't use it until
further notice.

I came in to day and had a look at the laser cutter with Sol and it
looks like there are the following problems.

1) There was a dirty fingerprint on one of the mirrors. This is
likely to be the cause of many of the problems. The mirror took a
long time to clean given that the persons grime was burnt on, the
mirror is barely functional and will need replacing soon.

2) The water coolent container has magically been opened, unsealed and
it has been contaminated. There is now stuff growing in it and we will
need new 25L deionised purified water to refill it, after giving the
entire system a thorough decontamination.

3) The laser cutter has been used when clearly marked as out of
service (other than the other people attempting to fix it). This will
have been damaging it further. The out of order sign was there for a
reason and it is pretty prominent.. I would have cut ok, but it would
have been damaging things further.


Point (1) is likely to have been causing all the focus problems that
have led to the wires being zapped and poor cuts. We have two spare
mirrors, but I'm keen to see how this cleaned mirror goes for a little
while before replacing.

The air assist, I couldn't see where the problem is, so I think that
is ok.

Cuts are working after the clean, however with the water cooling
system being contaminated waters temps got hot quick. This needs to
be investigated further after the systems been cleaned, new water
purchased and then put in to the laser.

Now some interesting news: The tubes should be lasting 2000 - 3000
hours now.
http://hpclaser.co.uk/index.php?main_page=page&id=13&chapter=2&zenid=e60511d3859fc03b0aba0ce041d32a99

"Our View and now tested over nearly 5 years, we supply arguably the
best glass tubes made we test trial and run the tubes although we
suggest the life as 1200-1500 working hours our tube manufacturers are
now giving an estimated life span of 2-3,000 hours. These claims can
be easily substantiated as we have customers running in excess of
this, one example running a 60w tube running 24hours in production in
excess of 12 months and still going strong."



Lessons learned:
1) Dirty finger prints destroy mirrors and cause much grief for
everyone.
2) Out of Order signs get ignored.
3) Inquisitive people open clear sealed containers :(

-asc

Charles Yarnold

unread,
Aug 14, 2011, 6:08:57 PM8/14/11
to london-h...@googlegroups.com

Just a small correction, 1) has happened *since* the lasercutter was labled out of order as a mirror check was part of my last maintenance.

Sol

tom

unread,
Aug 14, 2011, 6:10:44 PM8/14/11
to London Hackspace
is there a physical part we can remove from it and lock away whilst
its under repair?

On Aug 14, 11:08 pm, Charles Yarnold <charlesyarn...@gmail.com> wrote:
> Just a small correction, 1) has happened *since* the lasercutter was labled
> out of order as a mirror check was part of my last maintenance.
>
> Sol
> http://hpclaser.co.uk/index.php?main_page=page&id=13&chapter=2&zenid=...

Tim Hutt

unread,
Aug 14, 2011, 6:14:50 PM8/14/11
to london-h...@googlegroups.com

The key?

Martin Dittus

unread,
Aug 14, 2011, 6:16:16 PM8/14/11
to london-h...@googlegroups.com
Also, if you (anyone) would like to own up to this -- no need to do it publicly, but would be nice if you could talk to Charles/solexious or Steve/asc and apologise. I'm sure you did it with good intentions, but we'd rather know for certain that the person has understood the problem and won't do it again than remain in a perpetual state of concern that it might happen again. Let's not make a habit of ignoring well-placed signage.

m.

Mark Steward

unread,
Aug 15, 2011, 12:31:24 AM8/15/11
to london-h...@googlegroups.com
FWIW, it appears to have happened at 8am on Friday:

James Mastros

unread,
Aug 15, 2011, 2:41:18 AM8/15/11
to london-h...@googlegroups.com
On 14 August 2011 22:56, asc <asc...@gmail.com> wrote:
> Lessons learned:

> 2) Out of Order signs get ignored.
> 3) Inquisitive people open clear sealed containers :(

I think numbers 2 and 3 are largely down to "when things are broken
for a long time without visible change in status, people get
inquisitive and try to do their own investigation".

This email is a very large step in the right direction. Thank you.

-=- James Mastros / theorbtwo

tom

unread,
Aug 15, 2011, 1:19:27 PM8/15/11
to London Hackspace
no, you can turn the lock drum with a screwdriver

On Aug 14, 11:14 pm, Tim Hutt <tdh...@gmail.com> wrote:
> The key?

Niels

unread,
Aug 15, 2011, 1:46:52 PM8/15/11
to London Hackspace
I think he meant removing a small but significant part of the laser.
So that it doesn't run.

Adrian Godwin

unread,
Aug 15, 2011, 1:56:18 PM8/15/11
to london-h...@googlegroups.com
Wouldn't it be better to find out who is ignoring the notice and ask them not to do that ?

-adrian

Niels

unread,
Aug 15, 2011, 2:05:51 PM8/15/11
to London Hackspace
Even assuming that it is one person - rather than the occasional
person that can't read/doesn't think - it would probably be easier to
disable the laser cutter than track them down....

Anyone for a key operated e-stop??? :-) :-) :-)

Adrian Godwin

unread,
Aug 15, 2011, 2:13:42 PM8/15/11
to london-h...@googlegroups.com
I agree it would be easier, but it's not a very good solution. A key-operated estop is easy to circumvent if someone's got a mind to do it.

We have a strategy of putting simple locks on any machines that require special care and training in use, so that they're not used by people who simply don't know that's the case. We don't expect the locks to be circumvented or warning notices ignored. If they are, that's a different sort of problem.

-adrian

asc

unread,
Aug 15, 2011, 2:15:33 PM8/15/11
to London Hackspace
Hello all,

I have ordered 30L of deionized water, it should turn up in the next
few days. When it arrives could someone be so kind as to email the
mailing list to confirm delivery.

-asc

http://www.toolbox.co.uk/tuw-deionised-water-5-litres-7546-118412

matthew venn

unread,
Aug 16, 2011, 6:55:14 AM8/16/11
to London Hackspace
I arrived at the space around 11am Friday morning and had a look over
the cutter;

* turned it on
* checked the axis
* Billy and I looked at the tube itself

We didn't turn on the laser tube itself and didn't do anything with
the coolbot, so I don't think what we did could have contributed to
the temperature rise.

I locked the cutter and put the sticker back on the door after
finishing looking.

Also, I don't think it's necessarily someone lifting the lid of the
coolbot that infects it, spores and algae get everywhere, so replacing
or at least filtering the water is probably something that should be
done fairly regularly.

Finally, how about a temperature sensor on the tube itself, rather
than in the liquid? That way we monitor the thing we actually want to
keep cold.

Thanks asc and sol for doing the research/work, I'm sorry I wasn't
around to help.

Matt

Russ Garrett

unread,
Aug 16, 2011, 7:11:14 AM8/16/11
to london-h...@googlegroups.com
On 16 August 2011 11:55, matthew venn <matth...@gmail.com> wrote:
> Finally, how about a temperature sensor on the tube itself, rather
> than in the liquid? That way we monitor the thing we actually want to
> keep cold.

That's problematic because the cooling water isn't in contact with the
outside of the tube. The tube should be at the same temperature as the
cooling water unless the pump is broken, in which case all bets are
off anyway.

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

asc

unread,
Aug 16, 2011, 5:59:58 PM8/16/11
to London Hackspace
I've done another clean of the dirty mirror and it looks much better.
Water temps looked good tonight and the short test cuts looked ok. I
plan to come in Sunday, clean the bed more throughly and replace the
water. Once complete some longer tests will be conducted.

I gave the bed a thorough brush down and a vacumn today, but it needs
a soak in some tougher detergent to make it sparkle. Hydrogen
peroxide should suffice right?

Does anyone have any advice for doing this?

There has been some talk about adding something to the water to
prevent water cooties, any suggestions or recommendations on an
additive or whether this is a wise decision?

>
> We didn't turn on the laser tube itself and didn't do anything with
> the coolbot, so I don't think what we did could have contributed to
> the temperature rise.
>

All good, no problem, tests would have been and needed to diagnose
problems. The whinge was more directed at people doing sneaky full
jobs, not your open testing and investigation.


> > I have ordered 30L of deionized water, it should turn up in the next
> > few days.  When it arrives could someone be so kind as to email the
> > mailing list to confirm delivery.
>

I have just received confirmation the water will be delivered
tomorrow, as usual the courier company is kind enough to give a 12
hour delivery window and expects someone to be anchored in the space :
(. Hopefully it comes when someone is about to sign. If it is
missed could people keep an eye out for missed delivery cards and
email me please.

Jo

unread,
Aug 17, 2011, 9:44:18 AM8/17/11
to London Hackspace
Hi everyone,

I was very sad to discover the unfortunate condition of the laser
cutter when I came in to use it last week. It sounds like you already
have a firm plan for fixing it, but let me know if there's anything I
can do to help. I have no technical skills but would be happy to
research or contribute towards costs of getting it fixed :)

best wishes,

Jo

Neil Mendoza

unread,
Aug 17, 2011, 10:49:56 AM8/17/11
to London Hackspace
> I was very sad to discover the unfortunate condition of the laser
> cutter when I came in to use it last week. It sounds like you already
> have a firm plan for fixing it, but let me know if there's anything I
> can do to help.

Ditto.

I'd also be happy to contribute to getting it running again if
necessary...

Cheers,

Neil.

Tyr

unread,
Aug 20, 2011, 2:20:00 PM8/20/11
to london-h...@googlegroups.com
Any idea when it's likely to be up and running and able to do jobs
again? I have a lot of low power (10%) cutting to do at some point
when it's back on its feet.

--
Nick Turner
Tyr of the Arcana

matthew venn

unread,
Aug 22, 2011, 4:54:56 AM8/22/11
to London Hackspace
Yo Asc, Sol,

I've never bothered with cleaning the support mesh other than removing
it and vacuuming the bits out.
I checked ?laser from robonaut and there's a message about air assist
causing power drop, is this current?

I was thinking of coming down to London either later this week or
early next week, any time be good for a laser fixing session?

Matt

asc

unread,
Aug 22, 2011, 6:14:41 AM8/22/11
to London Hackspace
Hello Matt and everyone.

Executive Summary: It's nearly fixed, hopefully by Wednesday - time
and life permitting.

> I've never bothered with cleaning the support mesh other than removing
> it and vacuuming the bits out.

It needs it every so often. Every cut leaves gunk on the mesh (once
clean I was suprised it how much) and it appears overtime to effect
the material being cut with the little flare marks - which i suspect
is the gunk being vaporised and marking the material. The test cuts
after the clean have been nicer. Though I wouldn't recommend doing it
often as it is a dirty job and the mesh is a right pig to get flat
again after taking out.

> I checked ?laser from robonaut and there's a message about air assist
> causing power drop, is this current?

Nope, I'll update shortly.

> I was thinking of coming down to London either later this week or
> early next week, any time be good for a laser fixing session?
>
> Matt

I think it is pretty much set, I cannot


Work done yesterday under Sol's careful eye:
1) Emptied the water.
2) Cleaned out all the pipes (the green ones had nice slime in them) -
needed a stick with a rag to give it a good rigorous scrub.
3) Cleaned out as much as possible all the other water related stuff
by rinsing in a mild detergent for ages.
4) Fixed kink in laser tube water cooler input.
5) Refilled system with new deionised water.
6) Conducted test jobs.


Result:
1) Cuts are nice and sharp.
2) Cooling system is clean
3) Temperature looks all good.
4) Cuts are nice across the entire bed.


Things still left to do:
1) Realign one of the axis, it is slipping. (Important)
2) Do a long test so make sure laser cutting is not degrading over
time. (Important)
3) Put some type of restriction device to stop tubes having too much
slack and being kinked. (Somewhat important).
3) Add something to the water to keep cootie free. (Not important)
4) Give the bed a chemical bath. (Not important)


Observations:
1) There was a kink in the input water cooling pipe once the back
cover was closed, this essentially meant not enough nice cool water
was not getting to the laser tube. This would have meant the tube
would have heated up and degraded its life. This looks to have been
caused by curious hands. The cooling system works, but if can't
measure the temperature inside the laser tube, (the kink was just
before entering the tube).
2) One of the axis is slipping a bit, this will be fixed tonight,
tomorrow or Wednesday night. Time permitting.
3) Alignment of optics looks all good at the moment (thanks to Sol).
4) Something needs adding to the water to stop growths - does anyone
have any recommendations?
5) More people need a good training in servicing, too much burden is
being put on too few people to maintain and fix the cutter. We need
to acknowledge that servicing and maintenance takes significant time
and it is unreasonable to assume these responsibilities will be with
someone else... it's a community, step up and help!

Summary:
Most of the things I and Sol have looked at and addressed these last
few visits can be summarised:
Negligence - resolved by a more training. Essentially people not
understanding what the symptoms mean and their severity.
Curiosity - There needs to be a boundary here. Dirty fingers, water
contamination, and opening the back up and introducing a kink that
broke the cooling system...
Maintenance - people need to give it a clean or vacuum every so often,
gunk forms on the mesh and debris. We aren't talking about a massive
scrub down, a simple vacuum will help.


To the person who regularly misunderstands my emails and irc comments,
please refrain from snarky comments this time. If my english leads to
any misunderstanding or confusion please email me off list. Or well
volunteer yourself.

-asc

Billy

unread,
Aug 22, 2011, 7:24:24 AM8/22/11
to London Hackspace

I realise that there's an issue with the amount of time that Sol has
right now.

I'd like to learn how to maintain the laser, but there hasn't been
time for him to teach this recently.

It occurred to me that as well as the basic induction "Here's how you
use it", it would be good to have a "Here's how it's built", and a
"Here's how you clean it" training session.

It would have meant that some of these hassles could have been worked
on earlier, which would have made the trouble-shooting run quicker.

Sam Kelly

unread,
Aug 22, 2011, 7:37:25 AM8/22/11
to london-h...@googlegroups.com
On Mon, Aug 22, 2011 at 11:14 AM, asc <asc...@gmail.com> wrote:
4) Something needs adding to the water to stop growths - does anyone
have any recommendations?

Use a 2% v/v solution of sodium hypochlorite (ie. 1 tablespoon of bleach per litre). It's basically the same stuff used in power station water cooling loops. (I'm assuming that the cooling loop never runs through metal, only plastic & glass - if it does, the increased free oxygen can accelerate corrosion by a very small amount.)
 
5) More people need a good training in servicing, too much burden is
being put on too few people to maintain and fix the cutter.  We need
to acknowledge that servicing and maintenance takes significant time
and it is unreasonable to assume these responsibilities will be with
someone else... it's a community, step up and help!

 I'm actively keen to get training in servicing, when calendars coincide, which won't be for another week and a half or so.

Cheers,
Sam

--
Sam Kelly, http://www.eithin.co.uk/

That's it.  We're not messing around anymore, we're buying a bigger dictionary.  -  Tibor Fischer, The Thought Gang.

Tim Storey

unread,
Aug 22, 2011, 8:47:21 AM8/22/11
to london-h...@googlegroups.com

Thank you for getting on the folks.

I agree with the point about the significant maintenance times etc.
I would very much like to learn how to service the laser cutter, so if
any one wants to schedule some time to actually show some of us that
would be great

t

Charles Yarnold

unread,
Aug 22, 2011, 8:49:06 AM8/22/11
to london-h...@googlegroups.com
On 22 August 2011 12:37, Sam Kelly <s...@eithin.co.uk> wrote:
On Mon, Aug 22, 2011 at 11:14 AM, asc <asc...@gmail.com> wrote:
4) Something needs adding to the water to stop growths - does anyone
have any recommendations?

Use a 2% v/v solution of sodium hypochlorite (ie. 1 tablespoon of bleach per litre). It's basically the same stuff used in power station water cooling loops. (I'm assuming that the cooling loop never runs through metal, only plastic & glass - if it does, the increased free oxygen can accelerate corrosion by a very small amount.)

Sadly it does pass through metal in the active cooling part of the system.

Also just a small note, when the lasercutter was taken out of service the kink wasn't present, so I'm not sure if that will have contributed to the problems seen then...

I have a cleaning rota on the wiki page, will adjust the time intervals to mean more regular maintenance.

Alec Wright

unread,
Aug 22, 2011, 8:48:58 AM8/22/11
to london-h...@googlegroups.com
On Tue, 2011-08-16 at 14:59 -0700, asc wrote:
> There has been some talk about adding something to the water to
> prevent water cooties, any suggestions or recommendations on an
> additive or whether this is a wise decision?
I wonder if water ozonisation would be a possibility? I saw an ozone
generator in a charity shop earlier for £2.50
signature.asc

Ciarán Mooney

unread,
Aug 22, 2011, 11:05:54 AM8/22/11
to london-h...@googlegroups.com
Hi,

> Sadly it does pass through metal in the active cooling part of the system.
> Also just a small note, when the lasercutter was taken out of service the
> kink wasn't present, so I'm not sure if that will have contributed to the
> problems seen then...
> I have a cleaning rota on the wiki page, will adjust the time intervals to
> mean more regular maintenance.

As a first approximation why not just dump a cheap bottle (or two) of
vodka into the reservoir? Of course you could use some ethanol bought
from a chemical supplier too. I'm sure that it'll heat up in the laser
but I don't know if that will cause problems, depends on the heat in
the laser tube that they alcohol mixture is exposed to.

Ciarán

Russ Garrett

unread,
Aug 22, 2011, 11:20:28 AM8/22/11
to london-h...@googlegroups.com
On 22 August 2011 16:05, Ciarán Mooney <general...@googlemail.com> wrote:
> As a first approximation why not just dump a cheap bottle (or two) of
> vodka into the reservoir? Of course you could use some ethanol bought
> from a chemical supplier too. I'm sure that it'll heat up in the laser
> but I don't know if that will cause problems, depends on the heat in
> the laser tube that they alcohol mixture is exposed to.

I'm not sure ethanol in that concentration is particularly harmful to
microbes. Yeast certainly will operate fine up to 18% ABV, and a litre
bottle of vodka in 25l of distilled water is only going to garner you
1% (plus whatever nutrients happen to be in cheap vodka to help the
microbes grow).

I think, as I've already said, that hypochlorite is the best bet,
although I hadn't considered the copper coil in the water cooler. I
wonder if it could be combined with a corrosion inhibitor?

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

Nigel Worsley

unread,
Aug 22, 2011, 11:28:03 AM8/22/11
to london-h...@googlegroups.com
> I think, as I've already said, that hypochlorite is the best bet,
> although I hadn't considered the copper coil in the water cooler. I
> wonder if it could be combined with a corrosion inhibitor?

Beer line cleaner would keep the bugs at bay, not sure about what effect it
may have on copper though.

NIgle

Dirk-Willem van Gulik

unread,
Aug 22, 2011, 11:31:16 AM8/22/11
to london-h...@googlegroups.com

Why not use the normal additives* with plain old distilled water ? Cheap that way.

Dw.

* http://www.accepta.com/water_treatment_chemicals/cooling_water_treatment.asp

Russ Garrett

unread,
Aug 22, 2011, 11:33:17 AM8/22/11
to london-h...@googlegroups.com

I think that tends to be hypochlorite.

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

Stephen Early

unread,
Aug 22, 2011, 12:14:59 PM8/22/11
to london-h...@googlegroups.com
Yes, beer line cleaner is sodium hydroxide and sodium hypochlorite, usually with an indicator chemical that is purple to start with and turns green as the cleaner is used up.

I brought some along when I was setting up the casks for the open day.  I can't actually remember whether I took it away again afterwards or left it under the sink — look for a 5l container labelled "Prosan Plus".

Steve

Alec Wright

unread,
Aug 22, 2011, 12:14:53 PM8/22/11
to london-h...@googlegroups.com
Having never heard of beer line cleaner i'm guessing that purple is
phenolphthalein. Not sure what the green is but probably the same thing
which marks pH7 in universal indicator.
signature.asc

Russ Garrett

unread,
Aug 22, 2011, 12:20:51 PM8/22/11
to london-h...@googlegroups.com
On 22 August 2011 16:31, Dirk-Willem van Gulik <di...@webweaving.org> wrote:
> Why not use the normal additives* with plain old distilled water ? Cheap that way.
>
> Dw.
>
> * http://www.accepta.com/water_treatment_chemicals/cooling_water_treatment.asp

After reading this is does look like the Done Thing is hypochlorite +
corrosion inhibitor. Any clues as to where we can get it in small-ish
quantities?

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

Alec Wright

unread,
Aug 22, 2011, 12:18:57 PM8/22/11
to london-h...@googlegroups.com

I have some calcium hypochlorite. Bleach contains sodium hypochlorite.

signature.asc

Mark Steward

unread,
Aug 22, 2011, 12:25:21 PM8/22/11
to london-h...@googlegroups.com
Swimming pool maintenance companies?  Or I can bring some in with a bit of warning...


Mark

Mark Steward

unread,
Aug 22, 2011, 12:25:41 PM8/22/11
to london-h...@googlegroups.com
(It's called sanitizer in the context of pools.)

Billy

unread,
Aug 22, 2011, 12:33:36 PM8/22/11
to London Hackspace

Granted that we NEED this stuff to stop the cooling system growing
cooties, what will it do to the cooling effects of the system?

Could we test it on one of the old tubes first? Save the functional
tube for when we've got the kinks out?

Do we have another spare tube? Or do we need to start the pledge for
the next one now? :))


>In Aug 22, 5:25 pm, Mark Steward <markstew...@gmail.com> wrote:
> On Mon, Aug 22, 2011 at 5:25 PM, Mark Steward <markstew...@gmail.com> wrote:
> > On Mon, Aug 22, 2011 at 5:20 PM, Russ Garrett <r...@garrett.co.uk> wrote:
>
> >> On 22 August 2011 16:31, Dirk-Willem van Gulik <di...@webweaving.org>
> >> wrote:
> >> > Why not use the normal additives* with plain old distilled water ? Cheap
> >> that way.
>
> >> > Dw.
>
> >> > *
> >>http://www.accepta.com/water_treatment_chemicals/cooling_water_treatm...

Russ Garrett

unread,
Aug 22, 2011, 12:37:19 PM8/22/11
to london-h...@googlegroups.com
On 22 August 2011 17:33, Billy <bi...@billycomputersmith.com> wrote:
> Granted that we NEED this stuff to stop the cooling system growing
> cooties, what will it do to the cooling effects of the system?
>
> Could we test it on one of the old tubes first? Save the functional
> tube for when we've got the kinks out?

The tubes are *glass* - as long as we're cooling the machine with
anything short of concentrated hydrofluoric acid, the tube is the last
thing which will be affected. The main issue is the cooling coil
inside the water cooler, which is copper.

> Do we have another spare tube? Or do we need to start the pledge for
> the next one now? :))

The laser cutter usage charges should cover that, at any rate.

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

M

unread,
Aug 22, 2011, 1:17:29 PM8/22/11
to london-h...@googlegroups.com
Someone just asked me to mail the mailing list to say the cooler is
running, just in case it was an issue.

--
>
++++++++++[>+>+++>++
+++++>++++++++++<<<<
-]>>>+++++++.>++++++
+++++.+++..---------
.++++++++++.<<+++.<.

asc

unread,
Aug 22, 2011, 1:37:48 PM8/22/11
to London Hackspace
On Aug 22, 6:17 pm, M <a.turntabl...@gmail.com> wrote:
> Someone just asked me to mail the mailing list to say the cooler is
> running, just in case it was an issue.
>

That is all good and no problem, it will turn on and off during the
day.

So everyone understands how the cooling system all works. Much kudos
and respect must be given to Charles for making this, it is awesome
and far better than what HPC recommends.

An overview of how the coolbot controls the cooling system for the
Laser Cutter.
* Chiller is always chilling water.
* Once the coolbot detects that the reservoir water is too warm, it
will turn the black power strip on, thus the red light power plug and
the small (noisier) pump turns on. This pumps water from the chiller
reservoir in to the main 25L reservoir and drops temperature to water
being fed in to the laser cutter tube.
* Once main reservoir temp reaches 19 degrees it stops pumping in the
chilled water.

When the laser cutter has the key in and turned on, the big water pump
turns on (it is connected to a power socket on the back of the laser
cutter).

When actually cutting the air assist and extraction fan turn on.

Added to coolbot wiki for reference.

Adrian Godwin

unread,
Aug 22, 2011, 2:57:58 PM8/22/11
to london-h...@googlegroups.com
Is this Milton, aka Boots baby bottle steriliser or similar ?
I think the hardware shop on Shoreditch high street has corrosion inhibitor for central heating systems.

It occurs to me that heating systems don't usually get slimy. Corrosion inhibitor on its own is probably reasonably poisonous to mould.

-adrian

Jo

unread,
Aug 22, 2011, 7:20:14 PM8/22/11
to London Hackspace
Hi everyone,

back to an earlier post, i would be very interested in having some
training in cleaning and maintenance of the laser cutter and was
thinking perhaps some sort of maintenance rota would be a good idea so
that the responsibility doesn't all fall on one or two people...

If you agree then let me know if I can help setting this up. As a new
member I don't really know how you usually go about arranging this
kind of thing, hence the waiting for delegation.

Anyway great news that it's nearly working again, thanks everyone, I
have missed it!

Jo


Jim Hayes

unread,
Aug 22, 2011, 8:58:03 PM8/22/11
to london-h...@googlegroups.com
I was just thinking standard car antifreeze. ?
Pretty tried and tested with copper/aluminium/iron and combinations
thereof in terms of corrosion inhibition, and probably fairly toxic to
whatever grows the water googlies even at low concentrations (or is it
just that they don't like 105 degrees c very much?)
I could be talking complete crap, of course!

Alec Wright

unread,
Aug 22, 2011, 9:08:56 PM8/22/11
to london-h...@googlegroups.com
On Tue, 2011-08-23 at 01:58 +0100, Jim Hayes wrote:
> I was just thinking standard car antifreeze. ?
> Pretty tried and tested with copper/aluminium/iron and combinations
> thereof in terms of corrosion inhibition, and probably fairly toxic to
> whatever grows the water googlies even at low concentrations (or is it
> just that they don't like 105 degrees c very much?)
> I could be talking complete crap, of course!

Alcohols arent toxic until about 30% in water.

signature.asc

Russ Garrett

unread,
Aug 22, 2011, 9:21:31 PM8/22/11
to london-h...@googlegroups.com
On 23 August 2011 01:58, Jim Hayes <haye...@gmail.com> wrote:
> I was just thinking standard car antifreeze. ?
> Pretty tried and tested with copper/aluminium/iron and combinations
> thereof in terms of corrosion inhibition, and probably fairly toxic to
> whatever grows the water googlies even at low concentrations (or is it
> just that they don't like 105 degrees c very much?)
> I could be talking complete crap, of course!

Antifreeze is generally designed - as the name suggests - to stop
freezing. It's not antimicrobial at all.

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

Dave Ingram

unread,
Aug 23, 2011, 9:08:47 AM8/23/11
to london-h...@googlegroups.com
On 22/08/11 11:14, asc wrote:
> Hello Matt and everyone.
>
> Executive Summary: It's nearly fixed, hopefully by Wednesday - time
> and life permitting.
Just to be clear -- do you mean you hope to fix it before Wednesday or
sometime on Wednesday? I have a large number of cuts/engraves that I
need to do before Thursday next week, and I'd prefer to do it at LHS if
at all possible (because I can't really afford to have it done
elsewhere). If I can use it during the day tomorrow, that would be ideal.

Apologies if I sound insistent -- I don't mean to! I really appreciate
the hard work you guys have put into this, and I'd love to help out with
the maintenance in future.


D

Charles Yarnold

unread,
Aug 23, 2011, 9:19:06 AM8/23/11
to london-h...@googlegroups.com
Hi Dave,

How large is large? Even if it is back in order then, it would be best
to ease it back into use than shock it with lots of usage....

Sol

Dave Ingram

unread,
Aug 23, 2011, 9:24:23 AM8/23/11
to london-h...@googlegroups.com
On 23/08/11 14:19, Charles Yarnold wrote:
> Hi Dave,
>
> How large is large? Even if it is back in order then, it would be best
> to ease it back into use than shock it with lots of usage....
It's basically etching place-settings for my wedding (which is happening
in a couple of weeks' time). I can spread those out over the course of a
day, maybe two, if that would help? More details off-list.


D

Jim Hayes

unread,
Aug 23, 2011, 9:56:27 AM8/23/11
to london-h...@googlegroups.com
>Alcohols arent toxic until about 30% in water.
It's normally Ethylene glycol these days (though you used to be able
to get alcohol based antifreeze and maybe still can).
It's pretty toxic to animals, though I don't know the specifics as to
how or at what concentrations.

Alec Wright

unread,
Aug 23, 2011, 10:10:02 AM8/23/11
to london-h...@googlegroups.com
Tesco antifreeze is pure IPA
signature.asc

Matte

unread,
Aug 23, 2011, 10:19:23 AM8/23/11
to london-h...@googlegroups.com
India Pale Ale?

I'm off to get me some Tesco Antifreeze to drink...

Simon Howes

unread,
Aug 23, 2011, 10:44:23 AM8/23/11
to london-h...@googlegroups.com

You'll get blind-drunk

tom

unread,
Aug 23, 2011, 12:11:54 PM8/23/11
to London Hackspace
what about Watercooled PC coolant? The stuff I have uses an antifungal
to stop my radiators clogging up with crap

Monty

unread,
Aug 23, 2011, 12:22:12 PM8/23/11
to London Hackspace
Used this post to update the Log Book http://wiki.hackspace.org.uk/wiki/Equipment/LaserCutter/LogBook

On Aug 22, 11:14 am, asc <ascd...@gmail.com> wrote:
> Hello Matt and everyone.
>
> Executive Summary: It's nearly fixed, hopefully by Wednesday - time
> and life permitting.
>
> > I've never bothered with cleaning the support mesh other than removing
> > it and vacuuming the bits out.
>
> It needs it every so often.  Every cut leaves gunk on the mesh (once
> clean I was suprised it how much) and it appears overtime to effect
> the material being cut with the little flare marks - which i suspect
> is the gunk being vaporised and marking the material.  The test cuts
> after the clean have been nicer.  Though I wouldn't recommend doing it
> often as it is a dirty job and the mesh is a right pig to get flat
> again after taking out.
>
> > I checked ?laser from robonaut and there's a message about air assist
> > causing power drop, is this current?
>
> Nope, I'll update shortly.
>
> > I was thinking of coming down to London either later this week or
> > early next week, any time be good for a laser fixing session?
>
> > Matt
>
> I think it is pretty much set, I cannot
>
> Work done yesterday under Sol's careful eye:
> 1) Emptied the water.
> 2) Cleaned out all the pipes (the green ones had nice slime in them) -
> needed a stick with a rag to give it a good rigorous scrub.
> 3) Cleaned out as much as possible all the other water related stuff
> by rinsing in a mild detergent for ages.
> 4) Fixed kink in laser tube water cooler input.
> 5) Refilled system with new deionised water.
> 6) Conducted test jobs.
>
> Result:
> 1) Cuts are nice and sharp.
> 2) Cooling system is clean
> 3) Temperature looks all good.
> 4) Cuts are nice across the entire bed.
>
> Things still left to do:
> 1) Realign one of the axis, it is slipping. (Important)
> 2) Do a long test so make sure laser cutting is not degrading over
> time. (Important)
> 3) Put some type of restriction device to stop tubes having too much
> slack and being kinked. (Somewhat important).
> 3) Add something to the water to keep cootie free. (Not important)
> 4) Give the bed a chemical bath. (Not important)
>
> Observations:
> 1) There was a kink in the input water cooling pipe once the back
> cover was closed, this essentially meant not enough nice cool water
> was not getting to the laser tube.  This would have meant the tube
> would have heated up and degraded its life.  This looks to have been
> caused by curious hands.  The cooling system works, but if can't
> measure the temperature inside the laser tube, (the kink was just
> before entering the tube).
> 2) One of the axis is slipping a bit, this will be fixed tonight,
> tomorrow or Wednesday night.  Time permitting.
> 3) Alignment of optics looks all good at the moment (thanks to Sol).
> 4) Something needs adding to the water to stop growths - does anyone
> have any recommendations?
> 5) More people need a good training in servicing, too much burden is
> being put on too few people to maintain and fix the cutter.  We need
> to acknowledge that servicing and maintenance takes significant time
> and it is unreasonable to assume these responsibilities will be with
> someone else... it's a community, step up and help!
>
> Summary:
> Most of the things I and Sol have looked at and addressed these last
> few visits can be summarised:
> Negligence - resolved by a more training.  Essentially people not
> understanding what the symptoms mean and their severity.
> Curiosity - There needs to be a boundary here.  Dirty fingers, water
> contamination, and opening the back up and introducing a kink that
> broke the cooling system...
> Maintenance - people need to give it a clean or vacuum every so often,
> gunk forms on the mesh and debris. We aren't talking about a massive
> scrub down, a simple vacuum will help.
>
> To the person who regularly misunderstands my emails and irc comments,
> please refrain from snarky comments this time.  If my english leads to
> any misunderstanding or confusion please email me off list.  Or well
> volunteer yourself.
>
> -asc

Robert Leverington

unread,
Aug 23, 2011, 12:46:18 PM8/23/11
to london-h...@googlegroups.com
On 2011-08-23, tom wrote:
> what about Watercooled PC coolant? The stuff I have uses an antifungal
> to stop my radiators clogging up with crap

25 litres could be expensive, does yours have an ingredients list?

Robert

Yiannis Costopoulos

unread,
Aug 23, 2011, 1:12:45 PM8/23/11
to london-h...@googlegroups.com
On 22 August 2011 16:28, Nigel Worsley <nig...@googlemail.com> wrote:
I think, as I've already said, that hypochlorite is the best bet,
although I hadn't considered the copper coil in the water cooler. I
wonder if it could be combined with a corrosion inhibitor?

Beer line cleaner would keep the bugs at bay, not sure about what effect it may have on copper though.

NIgle



If beer line cleaner is what is needed, I know somebody who's in that line of business, so I might be able to get some, if you are sure that this is what is needed.

Let me know.

Yiannis

asc

unread,
Aug 24, 2011, 8:58:44 AM8/24/11
to London Hackspace
Hello all,

I have failed, I struggled last night to get it aligned. At times it
would align nicely, but after a couple minutes it would get out of
alignment.

I am needing some help here. The problem I have is that for the next
couple weeks I can't really make it in to the space (an hour or two
here and there tops), after that I am then away until November.

Things left needing to do:
1) Alignment of X axis (and Y but that isn't too bad).
2) After alignment a good long cut (30-45 minutes) needs to be made to
make sure power isn't degrading over time.
3) Cleaner added to water (not urgent).
4) Russ also spotted that one of the fans by the controller needs
replacing.

Can someone with more knowledge on this help out? My time from now on
cannot be relied upon, so we are needing a volunteer to get their
hands dirty with this alignment fixing.

So far:
The X axis (from front to back of cutting bed) is a slightly off,
enough to ruin cuts, I have tinkered and adjusted the tensioning on
that belt to make it loose enough not to stress things, but not too
tight to cause the stepper to slip. This tweaking was where I was
getting temporary success in X axis alignment, but it just doesn't
stay. Jasper and I inspected that belt to discern if there was some
gunk or missing teeth but nothing was visible. Personally, I think
the X axis belt is a bit tight - with judgement of tension being
relative to the Y axis belts.

The Y axis needs tweaking too but it isn't too bad. Russ created a
nice template engraving (saved to desktop, as a .mol - so File->Open
rather than File->Import), that works well on the A3 card in the stock
pile. This was showing two problems, one being alignment and the
other being accelleration and decelleration burn power issues (can be
tweaked in software). This accelleration and decelleration issue is
visible when you look at the end of the lines and see that it is
cutting deeper, this is caused by the motors taking time to speed up
and slow down and maintaining the same cutting power as when moving at
full speed. Russ also made another template (unfortunately not saved)
that nicely tests the Y axis accuracy. Essentially creating a box
setting it to engrave, enabling bilateral cutting, and setting the
step as 0.5mm. This engraves a box with many lines 0.5mm apart so any
errors in X and Y axis are pronounced. It was doing "pairs" of cuts
and at one instance doubled up - this indicates a minor Y axis
alignment issue. The problem with adjusting the Y axis and checking
the belts is that you need to dismantle the bed and mess around with
the two Y axis belts. Last night I knew I did not have enough time to
do it and reassemble it all, before knowing I am going to be
essentially away until November. The Y axis belts were not inspected.

Acceleration and Decelleration burning power needs tweaking too, but
this can be done in software and addressed later.



The previous problem of the cutter going off the bed and problem is
explained as follows, though I would be cautious about adjusting
tension willy nilly, it's a pain to get right.
The tensioning of the X axis belt would have been either too tight or
too loose. This causes slipping (the brrbrrbrrbrrbrr sound) and the
controller to lose position of the laser cutter. So next time it cuts
it tries to move the head off the bed. If this occurs turn off laser
cutter, adjust X axis tensioning, then the arm and laser to be gently
moved to the center of the bed. Power back on and the system will
pull the arm back to the origin. You must power it off before gently
moving the arm, this disengages the power to the steppers which then
allows you to easily and gently move the arm.




Tim Storey

unread,
Aug 24, 2011, 9:15:30 AM8/24/11
to london-h...@googlegroups.com
I was going to swing by this evening so I will have a gentle bash at this...
Is there likely to be anyone else around? I should be on-site at around 8.45

t

amx109

unread,
Aug 24, 2011, 9:22:49 AM8/24/11
to london-h...@googlegroups.com
ill be around. i can help out for a couple of hours

Amran

Monty

unread,
Aug 24, 2011, 9:23:28 AM8/24/11
to London Hackspace
Used this information to update the Log Book again.
http://wiki.hackspace.org.uk/wiki/Equipment/LaserCutter/LogBook

Charles Yarnold

unread,
Aug 24, 2011, 9:25:15 AM8/24/11