Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[carlmt]

Thank you Sylvain 
 
Yes, a CD containing ALL the photographs taken of the prototype construction will be included.
 
Unfortunately, due to copyright issues, I cannot include photographs of the real ship but these are plentiful on the web - after all, that is where I got nearly all mine from!

[ballastanksian]

Sorry if you have answered this before but how do you vent the gases and fumes? Is there a filter in the extraction system in the cutter case or does it vent naturally from louvres? I am interested and assume that to prevent you getting overcome with poisonous gases that you have something to prolong your ferry kit developing life

[jarvo]

How long does the lazer last??? you mentoned that the lens was replaced because of splatter, is this similar to welding???


Regards


Mark

[carlmt]

Sorry if you have answered this before but how do you vent the gases and fumes? Is there a filter in the extraction system in the cutter case or does it vent naturally from louvres? I am interested and assume that to prevent you getting overcome with poisonous gases that you have something to prolong your ferry kit developing life

HA ha - yes, I would like to live long enough to actually enjoy this hobby!!!
 
For extraction, there is a 4" dia flexible trunking that passes via a powerful extractor unit to vent outside.  Ours is vented through a panel in the personnel door of the garage/workshop into a side passageway (ours) alongside the house.  This passage acts as a bit of a venturi and so any breeze blows the fumes away quite quickly.  They do pong somewhat, and I really wouldn't use the machine without an extractor.  With the lid of the machine closed (it wont work with it open anyway), 99.9% of the fumes are contained and extracted to outside.  There is still a residual smell though - and unless there is a powerful room extractor as well, this is almost impossible to eradicate.  As for a filter - no, there is no filter on this unit.  You can get them, and with one the machine can be used in a closed environment without extraction, but they are eye-wateringly expensive and have to be replaced quite often.  Only really of benefit to large  concerns such as educational establishments.

[carlmt]

How long does the lazer last??? you mentoned that the lens was replaced because of splatter, is this similar to welding???


Regards


Mark

Hi Mark - I have been told that the laser can last up to about 2000 hours and our 60W tube costs £350 to replace.  This can vary with use/abuse.  They are cooled by water - de-ionised water - and if this regimen is not observed then the laser life will be short.  Another killer of lasers is the cooling water temperature.  They are best running around 18 deg C.  A decent chiller unit will look after the laser by regulating the temperature, whereas just dumping a pump into a bucket of cold water and expecting it to do the job (it does happen apparently) is asking for trouble!!
 
As for the lens - it wasn't splatter that killed it, it was shattered around the edge.  This must have happened at the factory before delivery as the technician noticed it when he was demonstrating to me the method of removing it fro cleaning.  So long as it wasn't touched, it worked fine as the focusing centre of the lens was OK.  It was only when I HAD to clean it that it finally fell to bits. If you don't try to laser something you are not supposed to , then there should be no splatter or any other detritus to affect the machine - but obviously the fumes contain particles in suspension, and these WILL damage the optics - hence the need to clean.
 
The key to having one of these machines working well is good set-up and a rigorous cleaning regimen.  Keep the optics clean, replace the cooling water every 3 months and lightly oil the sliders etc., ad it will last.  With the investment we have in this machine, that regimen is not difficult   

[Unsinkable 2]

Fantastic job you are doing  . So professional and looks amazing. It's good to see someone realise their dream. Well done, and good luck with the sales. U2

[Brian60]

I've had mine for about 2 weeks  now and I'm still learning my way around it. I'm in the middle of carrying out some upgrades to it. The extractor fan supplied is a real abomination and doesn't have a good seal to the rear of the machine, they supply some foam tape to help here.

But I am making the extraction slot on the rear of mine larger and installing internally a couple of 6 inch computer cooling fans. I'm making up a new coupling to fit the rear of the machine so it can fit flatter up to a wall, run out some 3 inch tubing parallel to that and couple the whole lot up to the original extractor fan out side. So at the end of the day I will have a much neater/quieter unit with extra fans! Also mine does not have the air assist lens head included in the buy price, so I have one of those on order.

The laser cuts its line in the material, but depending on the base material it can burn/melt easily. To combat this you can get attachments for the lens head, that direct a jet of air downwards that keep the work cool and help blow out any small flame that might develop. Carl is correct about the water temperature, anything over 20-22c is going to kill the laser tube quite quickly, but this would only apply if the thing is running for hours at a time like a production line. Mine so far manages about 15 minutes of work. The reason is I don't have lots to cut with it! My time is taken up drawing the stuff in Coreldraw. I've spent 19 hours over the last 3 days drawing hull frames in Coreldraw. The laser can cut one of those frames in about 6 minutes if using 5mm plywood, or considerably less if the plywood is 3mm or styrene!

[ballastanksian]

Interesting knowledge chaps. A friend of mine, who does a little work for Vintage model workshop, is considering buying a Laser cutter and I have been feeding him your pearls of wisdom. He has looked at a few machines but I think he needs the time and opportunity to invest.

Reading what you say about regimens shows that in fact, cutters and printers do not seem to be for the faint hearted

[Brian60]

Ian the laser is just a tool, just like a craft knife, simple to use in reality. The clever part is being good with the software to actually draw the parts, its a steep learning curve, but once you have the drawing package, corel draw, rd works laserdraw or whatever is used mastered, everything else is easy. If you can already use coreldraw or similar it is even easier!

Perhaps we need to move the laser stuff to a new sub forum? MARTIN!!!!!!!  I can already see that they are the way forward for all modelling not just boats/ships.

[essex2visuvesi]

Have you guys considered adding some kind of coolant additive?

[Brian60]

You see a lot of talk about coolant additive essex. You have to ask yourself is it needed? Where is your laser located? In an outside unheated workshop? If so anti freeze is a good addition to stop the coolant fracturing the laser tube which is full of cooling water, bit like a car radiator. If the laser is indoors where the temp is always above freezing then its no problem at all.

A bigger threat is the water temperature getting too hot through the laser firing. Heat build up does more damage to the laser tube and shortens its life drastically. I have a sealed 10litre container with de-ionised water (why don't we say distilled anymore?) At the moment mine doesn't run long ebough to raise the temperature. If I ever get around to using it to turn out parts commercially, I will look into installing a chiller unit to keep it at an optimum 18-20c.

[barriew]

I have a sealed 10litre container with de-ionised water (why don't we say distilled anymore?)

Because it isn't   It is treated with a de-ionising resin to remove the impurities.


Barrie

[essex2visuvesi]

If you go for a chiller look at aquarium chillers, they should have the power you need for not too much money


http://www.amazon.co.uk/gp/product/B00YMGL142?keywords=aquarium%20chiller&qid=1449069155&ref_=sr_1_1&sr=8-1

[carlmt]

Well - I guess it had to happen once!!!
 

 
That is a part of our laser tube - there is another piece out of shot.
 
Unfortunately, with the cold weather we have been having, the water in our tube froze at some time and blew the glass of the tube - where the water inlet points are (the narrowest diameters).  The tube was still working fine before this - but is now scrap.  So that is £400+ for a new tube, and a valuable lesson learned.  I got complacent and didn't realise just how cold it got in the workshop when I wasn't in there working.

When I replace the tube I shall be adding a special anti-freeze to the cooling water...........
 
Out of action until the tube is replaced......... "xxxxx"!

[JimG]

Another way of protecting against freezing is to fit a low wattage bulb in the laser compartment. This will provide enough heat when running to keep the temperature above freezing. Fit two if you're not sure.

Jim

[Kim]

Carl,
other things to consider are -
ambient temp
dew point and thermal shock.


i have a burst tube for each of these lessons ...


before fitting light bulbs, trace wires etc consider the above...


As for coolant, don't go for the educational non toxic version ... use the toxic version and you won't get the same algae growth ... i have a bust tube from that experience too... (but be careful ... obviously)


Regards,
Kim

[Kim]

oh and another one for free ...
Don't use chlorine in the system when using some chillers ...chlorine is corrosive ...
a new chiller is the cost of that lessons..


see someone has always got it worse .



Regards,
Kim

[Brian60]

Far easier just to keep the ambient room temp just above freezing. Or just drain the system down when not being used.

[carlmt]

Carl,
other things to consider are -
ambient temp
dew point and thermal shock.

i have a burst tube for each of these lessons ...

before fitting light bulbs, trace wires etc consider the above...

As for coolant, don't go for the educational non toxic version ... use the toxic version and you won't get the same algae growth ... i have a bust tube from that experience too... (but be careful ... obviously)

Regards,
Kim

Cheers Kim!
It was my own fault really as the workshop is my attached garage and there is no heating in there - unless I am working in there when I switch on a heater.  I was checking the water in the chiller unit and, while very cold to the touch, it wasn't frozen.  However, I did not check the tube itself or especially the very narrow water inlet points on the tube itself.  Basic physics would have told me that the water would freeze at these points first, expand and break the glass! 

Of course - it wont happen again!!!!

The anti-freeze is supplied by the machine suppliers so is formulated for the task.

And, as for algae growth, I don't have this problem as I renew the water every three months.  So far - no problems.
And no chlorine is used - just pure de-ionised water (and now with anti-freeze added!).

C

[carlmt]

Far easier just to keep the ambient room temp just above freezing. Or just drain the system down when not being used.

I will go with the former Brian - it is a real pain to keep draining the system down (it gets 90% done every three months anyway) as there is the need to eradicate ALL air bubbles in the tube and, unless the tube is removed, you can never remove 100% of the water.

[ballastanksian]

I read in Model Boats some time back in 2017 that De Ionised water was a problem over time as it reacquired its ions by corroding the boiler metal! I do not know if your coolant system has any metal parts that may be susceptible to corrosion, and the manufacturer may well recommend De-Ionised water as the solvent, but it popped in my mind as I read your message and just wondered enough to mention it.


I would hate for it to become one of those cases of having sorted the antifreeze issue out, the system then fails a few years hence due to the microscopic action of greedy water 

[Kim]

If it helps
We now use the toxic coolant and have not changed the water in a year, even changing the water every week did not stop the algae jamming the flow sensor...
Obviously changing the water more often would be sensible ( good practice) but as a business you have to dispose of the stuff in a way that costs money ...


Just be grateful your not doing your own grp work in this weather ... lol a whole lot of other headaches in that discussion lol
Regards,
Kim

[Kim]

Cheers Kim!


Of course - it wont happen again!!!!

The anti-freeze is supplied by the machine suppliers so is formulated for the task.

And, as for algae growth, I don't have this problem as I renew the water every three months.  So far - no problems.
And no chlorine is used - just pure de-ionised water (and now with anti-freeze added!).

C

If you mean the anti freeze supplied by your laser supplier? .... then think again, it is non toxic so the algae loves the wee dark spaces with warm water flowing past... (flow sensor)
How do i Know ...
Lol
Regards,
Kim

[StarLocAdhesives/FiveStar]

I have been laser cutting since 2005, still on my first tube in the 1st laser cutter i got ( from hpc lasers ) I have made thousands of kits with it, for cooling i use pink halfords antifreeze, had it in it for years and years, before i had water in it from the tap and it got the green slime...i added isopropyl alcohol and it cured the bubbles and killed bacteria so no more slime in the water but would still freeze


Since i changed to the pink halfords antifreeze on all my machines years ago i have no problems with any of them and it gets to-25C here in the winter in unheated buildings and i still use the machines, no ice in the coolant , no broken tubes and no green slime.