obious Posted January 4, 2023 Posted January 4, 2023 Hi All, Let me preface this by saying that I have a ‘cheap’ Chinese K40 laser that I’ve had pretty good success with when making cockpit panels (specifically for the F-18). However, laser cutting does have its limitations; the size of the unit makes bigger panels/projects difficult and gets really expensive in a hurry, they’re dangerous and can only either cut or engrave (ie there’s no ability to create depth). The question I have is, has anyone had any success with using a CNC router for their cockpit projects rather than laser cutting/engraving? If so, what are the benefits? Thanks Intel 12900k @ 5.2Ghz, RTX 4090, Samsung 1TB NVME, Thrustmaster Warthog & F-18 stick, Pendular Rudder Pedals - Quest Pro AV8B N/A UFC Build Log AV8B N/A PCBs for sale
No1sonuk Posted January 4, 2023 Posted January 4, 2023 Have a look here for what can be done if you combine CNC router, added laser engraver, 3D printer and manual lathe:
lesthegrngo Posted January 4, 2023 Posted January 4, 2023 I use both - MDF cut with a CNC router / 'mill' for the backplates with a laser cut and engraved fascia. The MDF is cheaper and easier to get than the acrylic, and is available in numerous thicknesses so lends itself to the mounting for the switches and instruments, plus can be pocketed at the front to accommodate a PCB with 805 SMD LED's for back lighting. The downside of MDF is it doesn't hold thin wall sections easily and you can break off thin lips or features, at least with the MDF qualities I can get. Acrylic is not nice to cut with a rotary cutter in a router due to the fact that it can melt rather than cut, which then balls up on the cutter ruining the part and/or the cutter. Whenever I do use the CNC router for it I use a small cutter and use my airbrush to blow cold air continually and directly at the point of the cut to chill the plastic being cut away. It's necessary when you have to machine reliefs or pockets but I do keep it to a minimum. I used to use a mix of water and washing up liquid but it was awfully messy. One material that I used to be able to get but is no longer available that would step in for MDF and be a lot stronger while still being easy to machine is Tufnol, an early composite that was used quite extensively in the past Plywood has the disadvantage in my experience of being a bit less able to hold very accurate and clean cuts (unless you go for expensive grades, not available to me) plus the extra finishing time they require As for not being able to create depth with Laser cutters, that's not entirely true; I have successfully made parts with multi levels and pockets but the limitation is poor depth control and a rough surface finish Hope this helps Les
No1sonuk Posted January 4, 2023 Posted January 4, 2023 Regarding cutting plastic with the cnc router: I use a "bit fan" which blows air down as it spins. This cools the cut and blows the chips away.
parkerfly51505 Posted January 4, 2023 Posted January 4, 2023 (edited) I only have a CNC. It's great for cutting acrylic... cast acrylic only. The extruded acrylic (Rock Hard Plastics) is what heats up fast and melts. Cast acrylic (SimbaLux) chips away and is MUCH easier to use. Engraving is a whole different story and wish I had a laser for that part. I can engrave well enough but its just not very consistent. Granted, my CNC is not super precise. It's built for woodworking. This is one of my better panels but is still not the most consistent from top to bottom. Edited January 4, 2023 by parkerfly51505 2
obious Posted January 5, 2023 Author Posted January 5, 2023 Thanks to the replies everyone, given me a lot of food for thought. Anyone know if Perspex is cast or extruded? Intel 12900k @ 5.2Ghz, RTX 4090, Samsung 1TB NVME, Thrustmaster Warthog & F-18 stick, Pendular Rudder Pedals - Quest Pro AV8B N/A UFC Build Log AV8B N/A PCBs for sale
parkerfly51505 Posted January 5, 2023 Posted January 5, 2023 (edited) 5 hours ago, obious said: Thanks to the replies everyone, given me a lot of food for thought. Anyone know if Perspex is cast or extruded? That's a good question. I couldn't find anything referencing cast or extruded on Perspex's web site. Might have to ask Perspex directly or at least order the smallest pack you can and test. It's fairly obvious once you start cutting. Either your bit starts collecting melted plastic or there are chips flying everywhere! *UPDATE* I was looking at perspexsheet.uk not the actual company perspex.co.uk. Perspex makes both and shows them on their main page. You'll just have to make sure that the reseller knows which type they're selling. ** Edited January 5, 2023 by parkerfly51505 Updated info... 1
No1sonuk Posted January 5, 2023 Posted January 5, 2023 Make a bit fan. Worry less about overheating the cut. 1
parkerfly51505 Posted January 5, 2023 Posted January 5, 2023 Now that's thinking outside the box. Speaking of boxes, I'd have to build a complete enclosure to keep the chips from flying even further!
No1sonuk Posted January 5, 2023 Posted January 5, 2023 (edited) 21 minutes ago, parkerfly51505 said: Now that's thinking outside the box. Speaking of boxes, I'd have to build a complete enclosure to keep the chips from flying even further! Yeah. I have chips EVERYWHERE!! BTW, this is my 3040 CNC router with a 2.5W blue/violet diode laser fitted. Edited January 5, 2023 by No1sonuk 1
parkerfly51505 Posted January 5, 2023 Posted January 5, 2023 57 minutes ago, No1sonuk said: Yeah. I have chips EVERYWHERE!! BTW, this is my 3040 CNC router with a 2.5W blue/violet diode laser fitted. Now that is way cool!!! I never thought you could retrofit like that. I have a million questions but hate to completely hijack this thread. Mind if I PM you about it?
Scott-S6 Posted January 5, 2023 Posted January 5, 2023 (edited) 12 hours ago, obious said: Thanks to the replies everyone, given me a lot of food for thought. Anyone know if Perspex is cast or extruded? Transparent perspex is generally extruded although cast is available. The colours are generally cast. When you have it in hand the difference is obvious, extruded is more flexible. Check what you're buying and check it's actual Perspex. There are good alternate brands but the colours are different - some suppliers will send you whichever brand they have on hand and sometimes it's not even close to the same colour. Do also be aware that cast perspex has significant thickness variation, from piece to piece and even across a single piece. That can make engraving with a standard conical engraving cutter tricky (because very small variations in cut depth change the thickness of the engraving) and you should be very careful if you're making anything interlocking with it. If you're going to go laser then you really want to blow air into the cut and you need good extraction. The laser produces very fine dust (not good for the lungs) and it smells pretty nasty (for cast, really nasty for extruded). Edited January 5, 2023 by Scott-S6
No1sonuk Posted January 5, 2023 Posted January 5, 2023 (edited) 1 hour ago, parkerfly51505 said: Now that is way cool!!! I never thought you could retrofit like that. I have a million questions but hate to completely hijack this thread. Mind if I PM you about it? Yup. That's OK. 24 minutes ago, Scott-S6 said: If you're going to go laser then you really want to blow air into the cut and you need good extraction. The laser produces very fine dust (not good for the lungs) and it smells pretty nasty (for cast, really nasty for extruded). Too much? Edited January 5, 2023 by No1sonuk
Scott-S6 Posted January 6, 2023 Posted January 6, 2023 8 hours ago, No1sonuk said: Yup. That's OK. Too much? If you don't have your laser cutter in an enclosure with a fan and duct pulling the dust out of the window then no I hope you wipe everything down really well before you take the mask off. Dust that fine in your lungs is seriously bad for you.
No1sonuk Posted January 6, 2023 Posted January 6, 2023 The dust isn't as much of a problem as the toxic fumes produced by burning plastics.
No1sonuk Posted June 27, 2024 Posted June 27, 2024 This guy laser engraves self-painted painted panels: https://thewarthogproject.com/the-panel-design This one uses mechanical router engraving, but with pre-made coated plastic: You could use the painting scheme of the first link with the engraving of the second. And most people use acrylic. IIRC, "Opal" acrylic works well to give good light transmission, but also reasonable "whiteness" when no light is on.
lesthegrngo Posted July 3, 2024 Posted July 3, 2024 On 6/28/2024 at 2:15 AM, No1sonuk said: And most people use acrylic. IIRC, "Opal" acrylic works well to give good light transmission, but also reasonable "whiteness" when no light is on Yes, that's exactly what I used As for machining it with an engraver, there is no reason why not, as it will essentially do the same. The advantage with the laser is that it doesn't care if the acrylic is not perfectly flat, whereas for physical machining any distortion will show up as either engraving too deep or not actually touching the surface. As for the laser not burning away the paint, to be honest I have never seen this. I have done panels where I have set the laser to low power and done two passes when the text is very small or detailed, as this does improve the sharpness, and reduces the depth of the engraving, but after the engraving I use dish soap and a soft toothbrush to clean out the engraving and get rid of any residual soot or byproducts Hope this helps Les 2
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