584,865 active members*
4,981 visitors online*
Register for free
Login

Thread: Plexiglass

Page 1 of 2 12
Results 1 to 20 of 35
  1. #1
    Join Date
    Jun 2012
    Posts
    393

    Plexiglass

    Can anyone give any advice on engraving in plexiglass. I am using Bobart and I'm having a problem with the Plexiglas melting I guess. I am engraving had about .003 . What would be good cutting speeds of the spindle or router and feeds for plexiglass. Are there any tutorials on Bob Art and engraving. Plexiglass or in any other materials.

    Thank you
    Don
    The time has come the woodworker said to speak of many things. 0f routers and Wood , chips and paints and stains and CNC and other things.

  2. #2
    Join Date
    Apr 2009
    Posts
    3376
    "I am engraving had about .003"

    I do not quite understand.Is that .003 depth of cut?
    What type of tool?Geometry of tool and material of tool?
    If you are melting plastic you are probably going too fast RPM//Can you mist or use coolant?That will help lots.A tool with the wrong cutting geometry or is dull will also create more friction or heat,,which will result in melting.This is why I like High Speed Steel for plastics as you can get a crisp sharp edge on the tool.

    You can browse Al's site and see what he has

    http://www.youtube.com/user/Depoalo

  3. #3
    Join Date
    Aug 2012
    Posts
    621
    I haven't cut any plexiglass, but for plastics in general, jrmach's advice is good, lower rpm and higher feedrate is the way to avoid melting. For engraving, a V-bit endmill or one of the V-shaped engraving tools will give better results. Avoid ballnose endmills, as they're less efficient the closer you get to the axis, and you end up generating heat at the tip, rather than cutting cleanly.

    Luke
    "All I'm trying to find out is the fellow's name on first base" -- Lou Costello

  4. #4
    Join Date
    Jun 2012
    Posts
    393
    I am cutting depth of .03 is that to deep. I am using this V-bit Milescraft 2214 1/4-Inch V Groove Router Bit for Designs. It is carbide
    I will try slower router speed and faster move. The part that worked I liked the look of. I can see have some fun with Plexi as I get better
    with it. If I can find colors that would be nice.

    Don
    The time has come the woodworker said to speak of many things. 0f routers and Wood , chips and paints and stains and CNC and other things.

  5. #5
    Join Date
    Feb 2006
    Posts
    210
    Use dish washing detergent as a lube-coolant. Water it down a bit. Flood if you can. Otherwise brush on This will make a huge difference
    Dave
    In the words of the Toolman--If you didn't make it yourself, it's not really yours!
    Remember- done beats perfect every time!!

  6. #6
    Join Date
    Feb 2009
    Posts
    2143
    Side light with LEDs and you can do some VERY nice effects!
    CAD, CAM, Scanning, Modelling, Machining and more. http://www.mcpii.com/3dservices.html

  7. #7
    Join Date
    Sep 2012
    Posts
    1195
    Quote Originally Posted by Gallchobhair View Post
    I am cutting depth of .03 is that to deep. I am using this V-bit Milescraft 2214 1/4-Inch V Groove Router Bit for Designs. It is carbide
    I will try slower router speed and faster move. The part that worked I liked the look of. I can see have some fun with Plexi as I get better
    with it. If I can find colors that would be nice.

    Don
    Laird Plastics sells scraps of all sorts of plastics and is located just north of Georgetown. The main thing to remember about plastics is that the chips do not carry the heat out with them, so keeping the bit cool through some form of coolant is key. .030" is not very deep, so should be fine. Try the coolant first before you adjust the feedrate, then adjust once you see where you are at with the coolant. It's possible that you are already there for feed/speed, but with a bit like a V bit, I doubt you'd ever get a good cut without coolant unless it's exceptionally sharp, which brings me to my last thought. When dealing with tricky materials, you really have to have quality bits. Sometimes this is expensive and sometimes it's not so much. Aluminum cuts best with higher helix bits that have anti-galling coatings, but those bits are terribly more expensive than a standard bit that works better in steel. Quality router bits (like Vortex) tend to cost more than about anything, but it really makes a difference in the finish quality of the cut and they have more specialized geometry to the bits that are specific to the task. Engraving bits vary a lot in quality, so it may be that you also need a better bit.

    For wood bits, I prefer Vortex which have to be ordered in. For anything other than wood, I go to Cutting Tool Control in Ballard. If you go there, be sure to bring cash for a small purchase. They are used to very large accounts and don't really like running a credit card for $20, but if you only need a couple of bits will happily take cash. If the order is over $100 or so, they'll run a card. They are great guys and are happy to help.

    Cutting Tool Control, Inc

  8. #8
    Join Date
    May 2008
    Posts
    99
    Good advice posted already. Lower RPM / higher feeds / keep it cool.

    Just one additional thought - reading between the lines, I'm guessing you might be running a router, vs a mill. While beone's right on with the dishwashing detergent in water, if you've got an MDF spoilboard setup.... you're probably not looking to get things wet. Ideally, look into something like an ExAir cooling nozzle.... they direct a super-cooled stream of air right on the cut. Short of that.... the entry-level version is simply get some compressed air going right on the cut to clear chips and keep it cool. It's night and day the cut quality you can get out vs. uncooled.

    We make museum exhibits, and use all kinds of materials, including acrylic, on a regular basis. For critical-finish applications, we'll just blast it with air as it's cutting. Works like a charm.

    Good luck

  9. #9
    Join Date
    Jun 2012
    Posts
    393
    It is a router. The machine is a cncrouterparts CRP2448. The router is a Porter Cable 892. I did the lower router rpm and the liquid soap. It worked. I am getting better each time I try something. I make adjustments. here is a link to the 2 items I have tried so far Wood http://imageshack.us/a/img23/9586/k1tx.jpg and Plexi http://imageshack.us/a/img11/5337/zxup.jpg

    Thank You for all the help so far. I am sure I will have more questions.
    Don
    The time has come the woodworker said to speak of many things. 0f routers and Wood , chips and paints and stains and CNC and other things.

  10. #10
    Join Date
    Jun 2012
    Posts
    393
    Quote Originally Posted by mmoe View Post
    Laird Plastics sells scraps of all sorts of plastics and is located just north of Georgetown. The main thing to remember about plastics is that the chips do not carry the heat out with them, so keeping the bit cool through some form of coolant is key. .030" is not very deep, so should be fine. Try the coolant first before you adjust the feedrate, then adjust once you see where you are at with the coolant. It's possible that you are already there for feed/speed, but with a bit like a V bit, I doubt you'd ever get a good cut without coolant unless it's exceptionally sharp, which brings me to my last thought. When dealing with tricky materials, you really have to have quality bits. Sometimes this is expensive and sometimes it's not so much. Aluminum cuts best with higher helix bits that have anti-galling coatings, but those bits are terribly more expensive than a standard bit that works better in steel. Quality router bits (like Vortex) tend to cost more than about anything, but it really makes a difference in the finish quality of the cut and they have more specialized geometry to the bits that are specific to the task. Engraving bits vary a lot in quality, so it may be that you also need a better bit.

    For wood bits, I prefer Vortex which have to be ordered in. For anything other than wood, I go to Cutting Tool Control in Ballard. If you go there, be sure to bring cash for a small purchase. They are used to very large accounts and don't really like running a credit card for $20, but if you only need a couple of bits will happily take cash. If the order is over $100 or so, they'll run a card. They are great guys and are happy to help.

    Cutting Tool Control, Inc
    I will look into both of these places. Thank you for the heads up

    Don
    The time has come the woodworker said to speak of many things. 0f routers and Wood , chips and paints and stains and CNC and other things.

  11. #11

    LED Edge Lit Signs machined on Plexiglas

    Hi Don,

    I don't know what type of machine you have or its capabilities.

    I have cut quite a few LED Edge Lit signs on my retrofitted Shopbot router equipped with a Super PID Spindle RPM Controller. Note: Allows you to slow down the speed of your typical router motor (i.e. 22,000 RPM to a minimum of 5000 RPM).

    Here is some information for what it is worth. Your mileage may vary.

    Plexiglas is not an entirely flat material and the thickness can vary especially in larger sheets. I typically use a Depth of Cut of .020, but if I have issues with varied thickness I may go as deep as .030. I have also VCARVED some of the fonts in a couple of LED Edge Lit Signs that turned out pretty well. It did those in multiple passes i.e. Depth of Cut. Remember, even the slightest scratch on the Plexiglas and the LED Lights will show it when lit.

    Machining: I flip the lettering and graphics and engrave on the backside of the mirrored Plexiglas.

    Material Selection: I have cut some clear Plexiglas signs similar to the ones posted. If you decide to add a clock to it the clock tends to show through. I eliminated that by utilizing Mirror Plexiglas. It is advertised as 1/4" thick but actually about .205 thick Plexiglas. I have a friend in California that has a thin width LEDs that are encapsulated in a nice edging material that has a large lip on the front side and tends to hide the LED Lights from view. Lumenedge - Illuminated Edge Lighting Effect Strip - Edging

    Sign Size: I tend to make most of mine about 11 X 13 which can easily be shipped in the USPS fixed rate box. I cut these utilizing a vacuum fixture and it works perfect for those size signs. When I do larger signs such as a 2 foot X 3 foot I use two sided tape. I have also programmed a couple of holes near the bottom of the sign that accept the 3" long 1/2" O.D. pins that support the sign like a picture frame.

    The slower you can turn the spindle the better success you will have. The Super PID will allow you to slow your router spindle speed to a minimum of 5000 RPM. The comments you already received about cooling are good ones. I haven't tried the dish washing soap yet but I will. Always ready to learn something. What I currently do is spray some WD 40 on the material prior to machining and rub it over the entire surface to be engraved. I may squirt a little on the surface from time to time if it is a long cut job. The cooling vanes in the router tend to put out some HOT air and it will dry the WD40 or other liquid coolant. I typically run the router RPM between 5000 and 7500 RPM with a DOC of .020 and federate of 30 Inches Per Minute. I have a way of adjusting the spindle RPM and federate on the fly while the material is being engraved so I can tweak it if necessary.

    I currently use a carbide Half Round 1/4 diameter 60 degree bit with a .020 flatten tip and at times it can load up some. I believe what others have said about the sharpness of HSS bits and their performance in plastics. Just haven't got around to ordering one to try out. I got my bit at Bits and Bits Co. 1-800-972-7081 The carbide bit that I have been using is 430-HF60. They have a website with a lot of choices and some knowledgeable people there to help you with bit selection.

    If you would like to discuss some more just drop me a PM and a phone number or your e-mail address.

    Hope this was of some help.

    John
    Attached Thumbnails Attached Thumbnails dan 90th Birthday Ver 2.JPG  
    2007 HAAS TM-1P OneCNC XR5 Mill Pro. Shopbot PRT running Mach3 2010 Screen Set, Super PID and PMDX Electronics.Check out my Gallery on: http://[email protected]

  12. #12
    Join Date
    Dec 2008
    Posts
    4548
    Quote Originally Posted by HelicopterJohn View Post
    I have cut quite a few LED Edge Lit signs
    Those are pretty cool. Care to describe where the leds are located in those and the general setup of the sign itself?

    Thanks.

  13. #13

    LED Edge Lit Signs machined on Plexiglas

    Hi Burrman,

    Don't know what you mean by general setup of the sign. Hope this is of some help.

    Here are a few pictures of how the support pins are attached. I use socket head button SS screws. The black ones tend to rust. The pins are made from .500 Diameter 6061T6 Aluminum and are 3 inches long and drilled and tapped for 8/32 on one end then bead blasted for an nice finish. The other picture gives you an idea where the holes are drilled in the sign face for the support pins. The undercut on the bottom is where the special edging that houses the LED lights fits. The LEDs lay in the bottom of the edging and the wiring exits on the back side of the edging near one end. If you notice in the picture of the edging the taller side goes toward the front of the sign and hides the LED lights. As you can see from the artwork the lettering and associated artwork are flipped and the engraving is done on the back side of the mirrored or clear sign material. You can also use a propane torch to polish the edges of the sign to give it a better look and better light transmission from the LED's.

    One other tip is while these signs make for excellent night lights you can also reverse the lettering and associated artwork and hang the sign from the ceiling with a couple of chains. The LED stripes that I purchase are ordered with a 6 foot wire with a special female plug that mates with the A/C adapter that generates the 12 DC for the LEDs. The A/C adapter also has a 6 foot cord which gives you 12 foot. You can special order any length of cord for you particular needs. The guys at Lumenedge were very helpful to me in picking out the special edging material and what I wanted in making my signs. They also have a big variety of other options, i.e. controllers for allowing the lights to blink and all kinds of crazy stuff.

    If you have a vinyl cutter you can also cut out designs and lightly bead blast for other outstanding results. The Brandon Signs sample picture gives you and idea of what that looks like. One of my buddies does signs for car shows and cuts outlines of cars and trucks and bead blasts them. The possibilities are endless. Just use your imagination. A little artwork and some imagination and you are on your way. Ha Ha

    A lot of tips here that I have found here on this sight and some I found out on my own.

    If you require any further information just send me a PM.

    John
    2007 HAAS TM-1P OneCNC XR5 Mill Pro. Shopbot PRT running Mach3 2010 Screen Set, Super PID and PMDX Electronics.Check out my Gallery on: http://[email protected]

  14. #14
    Join Date
    Jun 2012
    Posts
    393
    Thank you all for the hints and advice on Plexiglass. My second attempt turned out much better. I used WD-40 and a straw . I just kept shooting at the cutter. It worked very well.I slowed down the router to its lowest speed 10,000 rpms and a fast feed rate.I would like to be able to etch the Plexi it some spots. I do not have a vinyl cutter or a sand blaster. Would there be an alternative way to do this. Is there something liquid that would be safe and do the etching. Thank you HelicopterJohn for your input. I also want to thank everyone else as I have learned something from all of you.There is always other ways to get it done. I like the Pid idea but that will have to wait for more money. Right now I am still learning and buying bits as I can. https://imageshack.us/scaled/medium/196/f0yd.jpg

    Any hints on cutting foam. I have some of the pink stuff left over from a project I could use for practice.

    Thank You
    Don
    The time has come the woodworker said to speak of many things. 0f routers and Wood , chips and paints and stains and CNC and other things.

  15. #15
    Join Date
    Jun 2012
    Posts
    393
    I would like to add I went from Lithoplanes to lithophanes without passing out from the lack of oxygen. LoL. inside joke ???

    Thank You
    Don
    The time has come the woodworker said to speak of many things. 0f routers and Wood , chips and paints and stains and CNC and other things.

  16. #16
    Join Date
    Apr 2009
    Posts
    3376
    Quote Originally Posted by Gallchobhair View Post
    I would like to add I went from Lithoplanes to lithophanes without passing out from the lack of oxygen. LoL. inside joke ???

    Thank You
    Don

    I was a little concerned the other month.Glad to see all is good.

  17. #17
    Join Date
    Dec 2008
    Posts
    4548
    Thanks helicopter. It was more about the led placement and direction and how it shines/points at the plexiglass edge.

  18. #18
    Hi BurrMan,

    The LED's actually just lay down in the edging material and contact the edge of the Plexiglas. Flaming/polishing the edge of the Plexiglas that the LED's contact will improve the light transmission. If you have square corners they offer edging that can seal off the edges and do away with any edge transmission of light. Also, I have seen Edge Lit Signs mounted in a picture frame with different colors on each side of frame for a colorful effect. It is amazing how far the LED's will transmit light i.e. 3 feet is not a problem. Of course, the light will also travel around curves which can also be an interesting design. They also offer different controls for the LED's to make them flash and do other neat stuff.

    John
    2007 HAAS TM-1P OneCNC XR5 Mill Pro. Shopbot PRT running Mach3 2010 Screen Set, Super PID and PMDX Electronics.Check out my Gallery on: http://[email protected]

  19. #19
    Join Date
    Dec 2008
    Posts
    4548
    That was it. Thanks Heli!

  20. #20
    Join Date
    May 2008
    Posts
    99
    To build on HelicopterJohn's comments -

    A lot of folks might not be familiar with fiberoptic principles, but standard acrylic behaves pretty much like a fiberoptic cable : the goal is to get as much light into the end/edge as possible, and then as long as it doesn't run into an obstruction, the light essentially bounces (reflects) internally on down the cable/sheet. When we mill something into the face of the sheet, we're providing an obstruction, and the light doesn't reflect cleanly. As HeliJohn says.... when you polish the edges, you allow more light in cleanly, and the light available to illuminate the milled portion is greater. i.e. brighter image. The edges can be polished either by flame (oxy-hydrogen is best, MAPP is more readily available to the average joe, and propane's better than nothing), or mechanically (sandpaper through 1500grit, then polishing compound).

    I say 'standard' acrylic because there is another kind of acrylic commonly used in the sign industry which is specifically designed to behave differently. It's know as Acrylite LED (or aka EndLighten) and it's got a special polarization designed to emit light out of the face when edgelit. Much more expensive, and much more specialized, but very cool.

    Also one note on acrylic thickness.... someone mentioned that thickness can vary quite a bit. This is true for all acrylic sheet, but cast acrylic has much more thickness variation (~15%) than extruded (<5%) acrylic. Cast tends to have better optical properties. As with many things in life.... it's a tradeoff.

    Re: LED strips... there are basically rigid ones and flexible ones, mono color and RGB (color controllable), and within RGB there are digital and analog flavors. The analog ones behave like one big long lamp (all the same color) and the digital ones are individually addressable (i.e. you can change the color along the way, think like rainbow effect). For edge-lit signs, the digital ones are not so useful. Colors can be adjusted either manually, or electronically. Most narrow strips are ~1/4" wide, so anything above 1/4" acrylic will work. As HeliJohn says.... the strip just sits down in the channel, and get the acrylic as polished and as close as you can to the LED for maximum transmission. For curved shapes.... the flexible strips are the hot ticket.

Page 1 of 2 12

Similar Threads

  1. Something better than plexiglass?
    By REVCAM_Bob in forum Community Club House
    Replies: 6
    Last Post: 01-25-2010, 02:48 PM
  2. HELP!! Project with plexiglass!!
    By eduardoreynosa in forum Employment Opportunity
    Replies: 4
    Last Post: 01-19-2010, 02:45 AM
  3. HELP WITH PLEXIGLASS plsss!!!!
    By eduardoreynosa in forum Want To Buy...Need help!
    Replies: 0
    Last Post: 01-18-2010, 07:14 PM
  4. Plexiglass instead of MDF
    By slickrick in forum DIY CNC Router Table Machines
    Replies: 6
    Last Post: 03-30-2008, 03:11 PM

Posting Permissions

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