[hackerspaces] Choosing a laser cutter

Sat Aug 29 20:16:25 CEST 2015

cheap laser power meter, n cheerful.

http://www.amazon.com/Engraving--International-Available-Copyright-Laser_Power/dp/B00ICZRZW6/ref=sr_1_fkmr0_1?ie=UTF8&qid=1440871558&sr=8-1-fkmr0&keywords=co2+laser+power+meter+150w

we also had a member buy one at the same as us, neither of them has
anywhere near the issues you guys had, the old friday afternoon build
maybe ? i know a couple of others who've picked them up too, and
they're often imported as different brands.

didn't buy autofocus, since its not really worth it imho
the big squirrel it came with was fine for the length  of tubing it
came with though we did seal off some areas, used our own air source a
basic diaphragm pump is woefully inadequate.

tube is still going after many hours.

we did upgrade the mirrors and lens, that helps tonnes.

i also don't think you don't get what you pay for, i've seen the same
lasers for sale in the usa for 2-4x for the exact same one. but if you
buy from the bottom shelf at low prices you have to accept what can be
done on a budget, having realistic expectations shopping at harbor
freight changes the feedback comments on their stuff a lot i've
noticed.

lasercut is definitely meh, but i found a newer version and hacked it
about to work with our laser, its still iffy but once you know the in
and outs it works, but them i'm also happy with my moshi 40W for $500.
i have not looked for a new version in the last couple of years, but
someone else may have.

maybe the 150w is a different build platform?

the stop was changed out since the key was misplaced recently,
definitely a bargain basement one.

for sure, the frame is cheap and held together with spit

it is no epilog.

On Sat, Aug 29, 2015 at 10:55 AM, Nathaniel Bezanson
<myself at telcodata.us> wrote:
> i3Detroit got a Weike 150W and we've had to repair it about a million times.
> It's a viable option if you have lots of people with both skills *and*
> inclination to continually keep after such a beast, and we never would've
> been able to afford anything approaching the same power from a better name.
> But, seriously, downtime posts may be the single biggest topic on our
> internal mailing list. You truly get what you pay for.
>
> There's a good bit of braindump on our public list, here:
> https://groups.google.com/d/msg/i3detroit-public/V2wlRDYeVKA/AipAKnirkM4J
>
> The autofocus mechanism has gone back and forth between busted and repaired
> several times, we finally gave up and justuse manual focus. The red-dot
> pointer similarly, but I think it's working again now.
>
> The door lift-cylinders failed, and when we replaced them with a
> slightly-stiffer model, the pot-metal door hinges shredded soon after. Lots
> of metal drilling and beefier hardware later, the door is solid again.
>
> The laser-inhibit switch on the door failed and has been replaced. The
> wiring between the laser and the chiller is embarrassingly bad but hasn't
> actually failed yet so it hasn't gone under the knife.
>
> The power supply has failed at least twice. Once was the inrush current
> limiters, which despite the PSU saying it's the 120v model, were clearly
> sized for the lower current associated with 240v operation. The manufacturer
> suggested bypassing them, but we elected to replace them with the right
> parts. Second, the fuseholder itself inside the PSU melted and blew the fuse
> at the same time (still not sure how that works), but that was a fairly easy
> repair. I feel like there was another failure I'm forgetting...
>
> The emergency-stop and key switches have both failed, again being rated for
> 10 or 13A max, but in a 120v country the machine draws 15A continuously for
> long stretches and things tend to melt. As referenced in the above-linked
> post, the power wiring inside the machine is all commensurately undersized,
> and should be overhauled as soon as you're able. Proper new switches are
> expensive, yo.
>
> The first tube failed "within warranty", but we had to pay shipping on the
> replacement tube, which made it all but moot. See if you can find a way to
> write shipping into your purchase agreement. A cheap laser power meter would
> be great to have for diagnostics but everything I see is megabucks. Knowing
> when the machine sucks because the 150W tube is putting out 20W of light,
> versus when it sucks because something's misaligned or dirty, would be
> awesome.
>
> There were lights installed on the underside of the gantry, which illuminate
> the piece being cut. They started going out in places and then failed
> completely. The machine's internals are 24v so we ran two 12v light strips
> and put them in series...
>
> The vent fan that came with the machine would've been barely-adequate if it
> were positioned directly against the wall with a 3-foot duct to the
> outdoors, but as our location is ~60 feet from the outside wall, it was
> woefully undersized. We blew a bunch of money on a Serious Industrial Blower
> and a bunch of smoothwall spiral duct, and it's much better. Building a
> remote-switch rig to allow the blower to be located near the outside but
> controlled from the operating position was really helpful.
>
> The Leetro controller (and LaserCut software) are notoriously rough around
> the edges, crashing on weird files, too braindead to import SVG so you have
> to use DXF or something, and sometimes failing to recognize the cutter until
> you unplug and replug all the USB everythings 4 or 5 times. A high-quality
> active USB extension cable helped but only a little; the USB on the
> controller is suspect.
>
> The air-assist pump hasn't actually failed, but we finally realized it's
> barely adequate to blow the smoke away from the head, and not contributing
> meaningfully to actually removing material from the cut. We plumbed the
> machine into (dry, filtered) shop-air and *it was like doubling the power
> overnight* -- we can do much thicker cuts in fewer passes, and if the
> conditions are precisely right, we've been cutting thin sheets of steel. Set
> aside the included pump as a backup, but put some proper air into the thing,
> it's amazing.
>
> Also, possibly the weirdest thing: We got two identical machines from Weike
> at the same time, one purchased by the space, one purchased by an individual
> member. They were supposed to be identical in all but paint color, but
> inexplicably the pulleys in one are a different size, requiring the machine
> settings (steps per millimeter or something) to change if you're going back
> and forth between the two machines, say because one is down for repair. We
> still haven't figured out the reason for the build difference.
>
> -Nate B-
>
> opit wrote:
>
> Hello all,
> here at Technarium we're considering buying a laser cutter (water jet
> would be even better, but probably is outside of our financial
> abilities). Maybe any of you have a piece of advice of what to look for
> and what to avoid? What do you use at your space and what didn't work
> out? What's your experience with Lasersaur or with generic machines from
> Alibaba?
>
> Last week there a similar request was posted here, but what we're
> looking for is a larger machine that could also be used by freelancers
> at the space and for custom manufacturing orders. We plan to have up to
> 7500 Euros for it.
> Thanks!
> #o
>
> --
> http://technariumas.lt
> http://blog.technariumas.lt
> http://wemakethings.net
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