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Electronics => Electronics => Topic started by: BANE on April 02, 2008, 11:04:37 AM

Title: lazer melting plastic
Post by: BANE on April 02, 2008, 11:04:37 AM
Hello, I am working on a robot that can welding two small pieces of plastic with a laser.  I don't know much on lasers or if they can melt the amount of plastic I need.  What I am welding is two plastic wheel like discs together along the circumference.  The diameter is about 2.5" and I have a servo underneath it to rotate it.  The laser Will be in a stationary position directly in front of the welded surface.  As the servo rotates 360 deg. the laser should melt the two completely.

What my question is what type of laser to buy, where to buy it and do lasers melt standard plastic or burn it? ???

I have two computer fans and proper ventilation for it.

Bane
Title: Re: lazer melting plastic
Post by: AndrewM on April 02, 2008, 04:35:03 PM
A 200mW laser is capable of melting very thin plastics (slowly), and that is the most powerful "retail available" laser I have seen.  To effectively melt plastics like you are talking about would require something in the magnatude of 500mW to 1W laser (that is a best guess) which you are not likely to find available to a consumer.  If you do, please let me know where because I could have some major fun with a 1W laser. (*poof* and Andrew goes on the homeland security watch list for that one statement)
Title: Re: lazer melting plastic
Post by: cooldog on April 02, 2008, 05:04:22 PM
try these


http://www.instructables.com/id/Laser-Flashlight-Hack!!/

http://www.instructables.com/id/Laser-wood-burning-pen/
Title: Re: lazer melting plastic
Post by: BANE on April 02, 2008, 06:23:56 PM
hey i found a 600mw one here:
http://www.markettechinc.net/details.aspx?SPID=46&PPID=Products&_kk=dfb%20laser&_kt=436247c9-242b-4d12-ba1a-45e142c8a0ed (http://www.markettechinc.net/details.aspx?SPID=46&PPID=Products&_kk=dfb%20laser&_kt=436247c9-242b-4d12-ba1a-45e142c8a0ed)
If you do, please let me know where because I could have some major fun with a 1W laser. (*poof* and Andrew goes on the homeland security watch list for that one statement)
lol  :D

heres another
http://www.lasermate.com/HighPower808LD.html (http://www.lasermate.com/HighPower808LD.html)

what about focusing muitiple lasers on a single point?

check out pics of my robot(not finished) and the plastic to be melted ;)

Bane
Title: Re: lazer melting plastic
Post by: BANE on April 02, 2008, 06:35:20 PM
Hey andewM, i found you a 1W laser generator thing a bober
http://www.dragonlasers.com/catalog/532nm-1000mW-Green-Laser-p-16215.html (http://www.dragonlasers.com/catalog/532nm-1000mW-Green-Laser-p-16215.html)
pretty cheap if you as me :o

check out this one too
http://www.dragonlasers.com/catalog/Aurora-GW-price0-p-1-c-274.html (http://www.dragonlasers.com/catalog/Aurora-GW-price0-p-1-c-274.html)

Bane
Title: Re: lazer melting plastic
Post by: airman00 on April 02, 2008, 08:26:43 PM
very nice design BANE , very organized

you used CNC right?
Title: Re: lazer melting plastic
Post by: AndrewM on April 02, 2008, 09:51:18 PM
Those lasermate high power diodes look pretty promising, but you would probably need a focusing lens of some sort (basing that statement off the beam divergence spec).  I wonder if they will sell them to the general public...  I'll get a friend to call  ;D

check out this one too
http://www.dragonlasers.com/catalog/Aurora-GW-price0-p-1-c-274.html (http://www.dragonlasers.com/catalog/Aurora-GW-price0-p-1-c-274.html)

You can see from the above video just how long it took to light the match and then cut through the paper with a 150mW laser.  A 200mW (true 200mW, most labelled that measure in around 180mW) with a proper focusing lens might be able the melt those wheels together at a slow rotation.

You know had you found that 1000mW laser a week ago it would have been great.  My girlfriend had lasik eye surgery last Friday, she could have just given me the $3K for the laser and I could have done the surgery, saving her $2K.  Either way, she would have never needed glasses again.  Muahahahaha   ::)
Title: Re: lazer melting plastic
Post by: AndrewM on April 02, 2008, 09:55:54 PM
Just incase you decide to give a high watt laser pen a try, take a look here:

http://www.dealextreme.com/details.dx/sku.11315

They care a green as well, if you are picky on the color.  Just be careful on the shipping if you live in the US, as customs has been known to have a problem with lasers over 50mW.
Title: Re: lazer melting plastic
Post by: TrickyNekro on April 03, 2008, 12:16:18 AM
But you could also have more lasers....
But this is going to be quite painful...

Just think of mixing different wave length lasers (green light laser with red light laser...) with a prism, a nice pure glass prism...
Supposing you have two 200mW lasers of DIFFERENT color, including IR... you can get much mixed power at almost 400mW!!!

Suppose you mix IR color, green color and Red color... every laser at 200mW... you're going to get a 600mW laser....
Consider my option...

BTW, where to get the lasers... just try DVD burners and so on... find at google...

Cheers,
Lefteris
Title: Re: lazer melting plastic
Post by: BANE on April 03, 2008, 04:53:45 AM
You know had you found that 1000mW laser a week ago it would have been great.  My girlfriend had lasik eye surgery last Friday, she could have just given me the $3K for the laser and I could have done the surgery, saving her $2K.  Either way, she would have never needed glasses again.  Muahahahaha   ::)
  Nice, never thought of it that way! :D

Those lasermate high power diodes look pretty promising, but you would probably need a focusing lens of some sort (basing that statement off the beam divergence spec).  I wonder if they will sell them to the general public...  I'll get a friend to call  ;D
  let me know what you find b/c i'm interested too ;)

very nice design BANE , very organized

you used CNC right?
    No, not at all actually, I used a jig saw w/ super fine blade and some mad machining skillzzzz :D  But hey, it took alittle more time but saved alot of $$$$

I'm going to make a totoral on it someday when i get it finished

Bane

Title: Re: lazer melting plastic
Post by: airman00 on April 03, 2008, 07:08:52 AM
    No, not at all actually, I used a jig saw w/ super fine blade and some mad machining skillzzzz :D  But hey, it took alittle more time but saved alot of $$$$

I'm going to make a totoral on it someday when i get it finished

Bane



Wow , I'm impressed

Looking forward to the tutorial !
Title: Re: lazer melting plastic
Post by: BANE on April 03, 2008, 10:54:49 AM
So i guess a 200mA laser could work... does anybody have a laser they know of that is like the one on the Instuctables (too lazy to find address, but i hope you know what i'm talking about ;)) under $50 (perferable not on e-bay) that i can legally get?

Bane
Title: Re: lazer melting plastic
Post by: AndrewM on April 03, 2008, 11:58:15 AM
If I am not mistaken the last page of the instructables article you are referring to had a comment where someone posted a schematic for a proper powersupply for the laser.  $4.50 for the laser housing (the 5mW brass housing referred to in the article), $20 for a DVD burner, and about $10-15 for parts for the power supply and you can "legally" build yourself out a higher watt laser.
Title: Re: lazer melting plastic
Post by: cooldog on April 03, 2008, 02:25:10 PM
If I am not mistaken the last page of the instructables article you are referring to had a comment where someone posted a schematic for a proper powersupply for the laser.  $4.50 for the laser housing (the 5mW brass housing referred to in the article), $20 for a DVD burner, and about $10-15 for parts for the power supply and you can "legally" build yourself out a higher watt laser.

computer repair stores just through out broken dvd burners so -20
Title: Re: lazer melting plastic
Post by: BANE on April 03, 2008, 04:59:16 PM
If I am not mistaken the last page of the instructables article you are referring to had a comment where someone posted a schematic for a proper powersupply for the laser.  $4.50 for the laser housing (the 5mW brass housing referred to in the article), $20 for a DVD burner, and about $10-15 for parts for the power supply and you can "legally" build yourself out a higher watt laser.

computer repair stores just through out broken dvd burners so -20

So a DVD burner laser is powerful enough for what I need?  If true = yes! getting a junk computer w/ dvd burner would be great!
I've got some homework to do but i'll check out the instructables article

bane
Title: Re: lazer melting plastic
Post by: airman00 on April 03, 2008, 05:33:19 PM
I'm not sure if the DVD burner laser can melt plastic

I believe it can only pop balloons and light a match
Title: Re: lazer melting plastic
Post by: AndrewM on April 03, 2008, 06:11:34 PM
The DVD burner diodes usually sit between 200mW and 250mW power.  They can melt thin plastics.  I still think something in the range of 500mW or up would be needed for melting the plastic wheels.

I haven't been able to get ahold of my friend to call about the diodes from lasermate.  I'll let you know what I find out though
Title: Re: lazer melting plastic
Post by: AndrewM on April 03, 2008, 08:57:34 PM
Ok, curiosity has gotten the better of me now, and I am wondering why you want to melt the wheels together with a laser instead of some other method like a hot air iron or even chemical welding?  Given the difficulty of finding a high enough power laser and the price associated, not to mention the actual danger to your poor eyeballs; it would seem there would be better choices out there.
Title: Re: lazer melting plastic
Post by: BANE on April 04, 2008, 05:22:52 AM
I'm making this robot for my college portfolio and i just thought that using a laser would be a cool yet difficult project to make.  I mean how many kids make robot's that use a laser to make something?  The melting of two pieces on plastic has no purpose other than being able to do it.  And don't get me wrong on this but if someone gots a better way to make something cool, i'm all ears :D.

Bane
Title: Re: lazer melting plastic
Post by: airman00 on April 04, 2008, 07:30:35 AM
I'm making this robot for my college portfolio and i just thought that using a laser would be a cool yet difficult project to make.  I mean how many kids make robot's that use a laser to make something?  The melting of two pieces on plastic has no purpose other than being able to do it.  And don't get me wrong on this but if someone gots a better way to make something cool, i'm all ears :D.

Bane

a torch would be just as cool and safer
Title: Re: lazer melting plastic
Post by: Anoroc on April 04, 2008, 08:00:58 AM
Make sure your plastic wheels aren't made out of polyvinyl chloride. That stuff is Bad bad bad for you (if burnt). We cant put that stuff in our lasers because, not only can it be lethal, it's also caustic.
Title: Re: lazer melting plastic
Post by: BANE on April 04, 2008, 10:53:16 AM
Make sure your plastic wheels aren't made out of polyvinyl chloride. That stuff is Bad bad bad for you (if burnt). We cant put that stuff in our lasers because, not only can it be lethal, it's also caustic.
  Anyway to tell?  All I know is thats is used to keep paper rolls from crushing (= cheap) and its black.

bane
Title: Re: lazer melting plastic
Post by: Anoroc on April 04, 2008, 11:30:53 AM
ahh, your talking about core chucks :D I know what your talking about. I don't believe those are made out of PVC (not 100% though). Its usually recycled garbage platic. Sometimes those core chucks will have a marbled color effect to them.
Title: Re: lazer melting plastic
Post by: BANE on April 05, 2008, 05:23:19 AM
Hey now >:(, i get these things for free and i'm just going to melt the crap out of them anyway :D

So can i melt the core chucks safely?

Bane
Title: Re: lazer melting plastic
Post by: BANE on April 05, 2008, 05:28:18 AM
I'm making this robot for my college portfolio and i just thought that using a laser would be a cool yet difficult project to make.  I mean how many kids make robot's that use a laser to make something?  The melting of two pieces on plastic has no purpose other than being able to do it.  And don't get me wrong on this but if someone gots a better way to make something cool, i'm all ears :D.

Bane

a torch would be just as cool and safer


what about the tip of a soldering iron.  I could get a cheap one, tear it apart, (so no handle) and have a motor push it into the surface of the core chunk will another motor spins

Bane
Title: Re: lazer melting plastic
Post by: airman00 on April 05, 2008, 09:11:46 PM
soldering iron idea sounds good

all you need is for the soldering iron to move vertically and horizontally -- all that can be accomplished with gears
Title: Re: lazer melting plastic
Post by: BANE on April 06, 2008, 05:48:16 AM
OK, the old soldering iron looks like my best option.  I want my robot to be all battery operated though, if i used a 9.6 vdc 1.3ah drill battery to just power the iron, do you think  it will work?  I have never tried running a AC appliance with DC ???.

Bane
Title: Re: lazer melting plastic
Post by: airman00 on April 06, 2008, 05:54:40 AM
OK, the old soldering iron looks like my best option.  I want my robot to be all battery operated though, if i used a 9.6 vdc 1.3ah drill battery to just power the iron, do you think  it will work?  I have never tried running a AC appliance with DC ???.

Bane

Just get a different heating element for your set, because thats all a soldering iron is


or just use a small torch flame instead of the soldering iron
Title: Re: lazer melting plastic
Post by: BANE on April 06, 2008, 06:00:25 AM
here is some pictures of what I've built last night on the device to spin around the cores

check out the plastic cover i made from pieces of my old printer, i melted it together with a soldering iron and smoothed it over with rotatory sander

Bane
Title: Re: lazer melting plastic
Post by: Admin on April 06, 2008, 05:07:43 PM
Quote
Hello, I am working on a robot that can welding two small pieces of plastic with a laser.
Strange, you mention weld plastic together, and everyone gets into *cut* plastic mode . . .

Quote
me now, and I am wondering why you want to melt the wheels together with a laser instead of some other method like a hot air iron or even chemical welding?  Given the difficulty of finding a high enough power laser and the price associated, not to mention the actual danger to your poor eyeballs; it would seem there would be better choices out there.
I second this. Chemicals are great for welding plastics together - basically look up the chemical that would dissolve the plastic you are using. The plastics will basically 'melt' together. Superglue can dissolve several plastics, for example.

Also, consider brazing:
http://www.societyofrobots.com/mechanics_brazing.shtml

And contrary to popular belief, lasers do not cut smooth edges. I used to get quarter inch steal laser cut (yes, you read that right) for a project I was working on, and the edges were really rough!
Title: Re: lazer melting plastic
Post by: airman00 on April 06, 2008, 06:09:34 PM
@Bane

why not just use a hot glue gun and use a servo to pull the trigger?
Title: Re: lazer melting plastic
Post by: BANE on April 06, 2008, 06:47:38 PM
Thanks for all the input.  I think i'm leaning towards the hot iron to spot melt the pieaces of plastic together.  Besides i already have a spare iron and all i need is a servo to move it into the sides of the plastics. 
What i need to figure out now is powering a 110 VAC iron with 9.6vdc.  Does anybody think it will work powering it straght or should i get a different heating element?

ps (i just built a sheild door for the entire top of it and made a movie of just the device working w/o any welding, is there any way to post a video with out using utube or another site? (a way just like to would post a picture)

Bane
Title: Re: lazer melting plastic
Post by: cooldog on April 06, 2008, 06:55:14 PM
ps (i just built a sheild door for the entire top of it and made a movie of just the device working w/o any welding, is there any way to post a video with out using utube or another site? (a way just like to would post a picture)
Bane

no
Title: Re: lazer melting plastic
Post by: BANE on April 06, 2008, 07:17:28 PM
Man, that sux >:( (i don't want to have a account with utube (dont trust it))

Hey Admin, being able to upload vidoes would be a cool feature to this site ;) ;)(i dont know much of web pages, but if it was easy to do you probable have already done it :D)
Bane
Title: Re: lazer melting plastic
Post by: ed1380 on April 06, 2008, 07:19:58 PM
you can upload videos to photobucket.
or upload to radidshare. no registration required
Title: Re: lazer melting plastic
Post by: airman00 on April 06, 2008, 07:25:21 PM
I dont think you'll have a good experience using soldering iron to melt plastics together , it is good for melt-cutting the plastic though...

hotglue seems a good bet , or just a plane old torch
Title: Re: lazer melting plastic
Post by: BANE on April 06, 2008, 07:42:32 PM
I dont think you'll have a good experience using soldering iron to melt plastics together

I'm not looking for a really nice weld around the pieces (i know that i wont be able to do that) but rather just ruff and dirty stick hot iron in between pieces, rotate 90o stick in again until 360o, and hope that my robot doesn't melt down altogether :D.

hotglue seems a good bet , or just a plane old torch
A glue gun would be to stringing for my design and i would probably end up burning up robot and plastic altogather with a torch :D)
(dont know if you don't see the pics i posted before, so here they are again :D)
Bane
Title: Re: lazer melting plastic
Post by: airman00 on April 06, 2008, 08:36:32 PM
I see

but try attaching two pieces of plastic together with a soldering iron

right now , just try it

It doesnt work very well
Title: Re: lazer melting plastic
Post by: AndrewM on April 07, 2008, 06:40:47 AM
I'll reiterate my hot air solder iron idea.  Tip doesn't touch the plastic so it might allow the two wheels that are already touching to weld into one.

Another option would be using a syringe with a metal tip filled with a liquid plastic welding compound in it, such as the Tamiya Extra Thin Cement, that can be applied to the seam between the two wheels.
Title: Re: lazer melting plastic
Post by: airman00 on April 07, 2008, 06:56:50 AM
I'll reiterate my hot air solder iron idea.  Tip doesn't touch the plastic so it might allow the two wheels that are already touching to weld into one.

Another option would be using a syringe with a metal tip filled with a liquid plastic welding compound in it, such as the Tamiya Extra Thin Cement, that can be applied to the seam between the two wheels.

hot air soldering iron sounds good

the syringe is also possible
Title: Re: lazer melting plastic
Post by: Anoroc on April 07, 2008, 09:59:04 AM
I recall some kids toy that acutally used melted plastic to simulate soldering. Maybe that toy would do the trick for you! Damn, I wish I knew the name of the toy...
Title: Re: lazer melting plastic
Post by: BANE on April 07, 2008, 10:48:14 AM
I've never used a hot air device before, but is it simular to a heat shrink gun?

Bane
Title: Re: lazer melting plastic
Post by: airman00 on April 07, 2008, 05:27:40 PM
I've never used a hot air device before, but is it simular to a heat shrink gun?

Bane
basically but much hotter
Title: Re: lazer melting plastic
Post by: AndrewM on April 07, 2008, 11:02:47 PM
I've never used a hot air device before, but is it simular to a heat shrink gun?

Bane
basically but much hotter

And a much more focused air flow.  If you have seen a desoldering station (with an electric air pump), then you have basically seen a hot air soldering iron, only the air flows out of the iron (hot air soldering iron) instead of into the iron (desoldering station).
Title: Re: lazer melting plastic
Post by: BANE on April 08, 2008, 01:34:14 AM
I've never used a hot air device before, is it like a shrink tube heater thing? ;D(would try to look it up but i'm doing this and my math homework :o)

Bane
Title: Re: lazer melting plastic
Post by: riquel2me on October 15, 2008, 09:10:06 AM
I bought 200mw green laser pointer from http://www.laserto.com/green-laser-pointer-125mw-150mw-200mw-250mw-300mw.html (http://www.laserto.com/green-laser-pointer-125mw-150mw-200mw-250mw-300mw.html) ,it could burn balloons ,cool!