Page 1 of 2 12 LastLast
Results 1 to 15 of 25

Thread: Engraving on mirrored acrylic.

  1. #1
    Join Date
    Jun 2016
    Location
    Darlington, United Kingdom
    Posts
    46

    Engraving on mirrored acrylic.

    Good evening all.

    Im looking for some help if you wouldn't mind. I've got an award to engrave onto and im having some trouble. When I am carving the letters into the piece I'm using the same settings I would it I was using wood... The trouble is the end product looks like melted plastic and not pretty if you know what I mean.

    I have a redsail x700 with a 60w tube installed. Power set to 20 and speed at 200m/s... Is that the right settings for etching onto acrylic??

    thank you

  2. #2
    Join Date
    Mar 2005
    Location
    Gig Harbor, WA
    Posts
    1,118
    Since you have a piece of scrap in your hands, this appears to be a training opportunity. Keep the power the same and increase the speed........ Start building a material profile for your machine. Make sure the beam is in focus..... change DPI setting and develop a feel on what your machine can accomplish at different setting. As materials change so do the setting.... a profile will get you closer to hitting the mark.

    On my machine I would lower the Hz setting and increase the speed. I can hit my image a second time with the same setting or modified to get a deeper cut.

    .
    Mark
    In the Great Northwest!

    Trotec Speedy C25, Newing-Hall 350 (AMC I & HPGL), Wizzard 2000, NH-CG-30 (Carbide Cutter Sharpener)
    Ricoh GXe3300 Gel Ink Printer, 15" Heat Press & Genny (15 oz Sublimation Mug Press),
    CS5, 5/9/x6 CorelDraw

  3. #3
    Join Date
    Mar 2014
    Location
    Iowa USA
    Posts
    3,475
    Vector cutting or carving, or rastering? If your rastering or engraving a image or text into acrylic you will need to lower the power or increase the speed. Get some scrap pieces to practice on before you do the "real" thing.
    Retired Guy- Central Iowa. , LightObject 40w CO2 Laser and Chiller, Fine Line Automation 4x4 CNC Router- Mach4 ESS

  4. #4

    Extruded

    Quote Originally Posted by Bill George View Post
    Vector cutting or carving, or rastering? If your rastering or engraving a image or text into acrylic you will need to lower the power or increase the speed. Get some scrap pieces to practice on before you do the "real" thing.
    Also it's probably extruded acrylic so you won't get a frosted white finish. It will be more clear.
    Redsail x700, 50watt & Shenhui 350, 50 watt

  5. #5
    Join Date
    Oct 2013
    Location
    Seattle, WA
    Posts
    1,664
    Blog Entries
    1
    Callum

    To add to Mark's suggestion. Go a step further and make a pattern of squares in corel so you can engrave or cut parts of the pattern at different settings. You are basically making a grid of speed settings on one axis and power settings on the other. Look up the recommended settings on your machine for a material and make that the middle speed and power setting for the grid and then bracket your settings around that. Doesnt have to be large. Just on some scrap. When you are done you now have a nice record of what each of the settings looks like so you can quickly choose the effect you want later on when you use that material again. If you were engraving maple for example and had already done a power and speed grid like I described you could pull it out and look to see what power and speed setting gave you the result you want. You can do the same thing with vector cutting, and with vector engraving. (using a vector drawing rather than a raster drawing for an engraving)

    A caution with lasers. Dont rely on someone else's settings. Use them as a starting point for a test? Sure. But dont expect them to apply to your machine. These machines are touchy little devils and what works on one machine may not work on an identical machine. Better to test things and be sure, especially if you are committing time and $$ in materials.

    Hope that helps!

    Dave
    900x600 80watt EFR Tube laser from Liaocheng Ray Fine Tech LTD. Also a 900x600 2.5kw spindle CNC from Ray Fine. And my main tool, a well used and loved Jet 1642 Woodlathe with an outboard toolrest that helps me work from 36 inch diameters down to reallllllly tiny stuff.

  6. #6
    Join Date
    Jun 2016
    Location
    Darlington, United Kingdom
    Posts
    46
    Thank you so much guys!! All great ideas!

    Im going to set up a test over the next few days.

    one thing I must ask tho if y'all don't mind... I haven't aligned the laser from getting it out of the crate.. Will this affect the power of the laser. It is having trouble cutting through 3mm plywood that's all and I thought it would make short work of that.. Also I have the laser 15mm from the material I am cutting, is that the right length and do I need to reset the focus length each time i move the bed up and down??

    sorry about all of the questions!!

    Thanks
    Cal

  7. #7
    If your wood was say, 1/2" thick and the acrylic you're working with is 1/8", and you HAVEN'T (re)focused the lens-- that could be the reason for your acrylic issue--
    ========================================
    ELEVEN - rotary cutter tool machines
    FOUR - CO2 lasers
    THREE - fiber lasers
    ONE - vinyl cutter
    CASmate, Corel, Gravostyle


  8. #8
    Join Date
    Oct 2013
    Location
    Seattle, WA
    Posts
    1,664
    Blog Entries
    1
    Callum,

    The laser has a very narrow depth of field to its focus. So yes, you do need to refocus anytime you change the height of the bed or the material. They should have given you a focus gauge to help with that. Basically it usually is a piece of acrylic cut into a rectangle. One side of the acrylic will be the correct distance to set between the underside of the lens tube and the surface of what you are working on. If you change lenses, or you change to a different focal length lens you will want to make a new gauge to go with it. Focus is critical with any laser.

    Did they include directions on how to change the focus? Did they give you a gauge to help focus?
    It is also not a bad idea to check the alignment of your mirrors. Odds are they are OK. But you never know. Doesnt take long to check and it gives you peace of mind.
    Lastly, you may also want to check your table to be sure it is dead level with the XY axis of your laser. Getting your lens in focus is not helpful if the table is cattywumpus to the gantry. Hopefully they gave you directions for all those things?

    If you think of it, you might add your laser (make model, power, size) to your signature in the forum. Then each time you post something that basic info is visible to us so we have a clue what your setup is. It can also be helpful if you add your location to your profile, which will then appear in the top right of each post you make. Then if you ask for a source for materials you wont have Mark and I suggesting you drive down to 1st Ave in Tacoma, WA for your source when you are in the Seychelles or some other far distant land. Unless you want to come to the Pacific Northwest for supplies of course!! Always happy to have visitors!!
    900x600 80watt EFR Tube laser from Liaocheng Ray Fine Tech LTD. Also a 900x600 2.5kw spindle CNC from Ray Fine. And my main tool, a well used and loved Jet 1642 Woodlathe with an outboard toolrest that helps me work from 36 inch diameters down to reallllllly tiny stuff.

  9. #9
    Join Date
    Apr 2013
    Location
    Tennessee
    Posts
    145
    Spend some time aligning the laser. Make sure the mirrors are clean while you're checking the alignment. Make a focus tool and use it every time....once aligned, you can cut a line on a slanted piece of wood to find the correct focus (see below).

    http://www.sawmillcreek.org/attachme...9&d=1415731178
    Hobby Laser - 1800 X 1300 dual tube Shenhui (100 and 80W)

  10. #10
    Join Date
    Jun 2016
    Location
    Darlington, United Kingdom
    Posts
    46
    That's great guys. Thank you so much.

    Ive had a quick look at the mirrors and they look a little dirty so I'm going to give them a clean and align them when I get back later. Also there is a setting in my control panel to reset focus length.. Should I press that after everytime I move the bed up and down?

    finallu in regards to the bed I don't think it is level as if I'm doing a large piece, say around 400mm the depth of the carve on the left looks great but the right looks a little shallow. The only way to adjust the bed is with a knob on then bottom right of the bed. I can't see any fine adjustments?

    pictures to follow

  11. #11
    Join Date
    Apr 2015
    Location
    Austin, TX
    Posts
    590
    This sounds like a focal issue most likely to me. It is very important that you correctly set the focal length from the lens to your workpiece every time. Even a few cm too high or low will result in problems.

    Most lasers have an autofocus button, BUT if you've never calibrated that to begin with, it's likely worthless until done properly.
    60W, Boss Laser 1630
    75W, Epilog Legend 24EX
    Jet Left Tilting table saw and Jet 18" Band saw
    Adobe Creative suite and Laserworks 8

  12. #12
    Join Date
    Jun 2016
    Location
    Darlington, United Kingdom
    Posts
    46
    image.jpgThis is the only settings I can find on focus... Will this be what I need to change each time and is 2mm correct?

  13. #13
    Join Date
    Jun 2016
    Location
    Darlington, United Kingdom
    Posts
    46
    image.jpgAlso this is the bed lifter screw. But for some reason the picture has gone on upside down??

    When end I turn this the other three turn at the same time but the bed isn't perfectly level... Does anyone know how to change this please

  14. #14
    Join Date
    Mar 2014
    Location
    Iowa USA
    Posts
    3,475
    I think you need some time to learn your machine. Did it come with a Users or Owners manual?
    Retired Guy- Central Iowa. , LightObject 40w CO2 Laser and Chiller, Fine Line Automation 4x4 CNC Router- Mach4 ESS

  15. #15
    Join Date
    Jun 2016
    Location
    Darlington, United Kingdom
    Posts
    46
    No Bill. That's why I have turned to this forum for help

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •