Looking to the future i would like to put a laser on my lr3 i have btt skc pro board my questions are
1 what is my best options for a laser for cutting and engraving i understand this is a very open question say cutting up to 9mm ply
2 will my board be able to control it
3 as a side note does anr one use a foam cutter on there mchines
Thanks
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I have a NEJE A40640 on mine, and have a NEJE E40 that will be going on soon™
The diode lasers are relatively easy to do, and the default V1 firmware can handle it without issues.
I’m pretty sure that there are some dedicated foam cutter machines out there. LowRider-inspired Foam Ripper / How do I make this? Cutting upholstery vinyl
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There have been a variety of laser modules attached to V1 machines. While there is some research to do, what you are willing to spend is going to be a major factor in module selection.
There are a lot of scam-ish ads for laser modules…false advertising, overblown specifications, bait-and switch tactics. With that in mind, I recommend you buy a laser from one of the major brands, and, if possible, buy it directly from the manufacturer.
When you look at the power of the module you want to look at optical power. Ignore any other power figures. The major brands are selling modules with multiple laser diodes, 2, 4, 6, and in one case 8 diodes. You can roughly figure out the optical power of a multiple-diode laser by multiplying the number of diodes by 5W. So, a two-diode laser module will be around 10 watts. Prices climb pretty steeply as the number of diodes increases. There is one 8-diode, 40W laser module, but, given the wiring, I don’t think it is a good fit for a V1 machine. There are a number of 30W, 6 diode laser modules. Some of the modules have head-to-head comparisons and reviews on YouTube. The modules will be on the manufacturer’s machine, but you should get similar performance running the module on a V1 machine.
The two other factors you might want to consider are the dot size of the laser and the working distance (focus distance) of the laser. Dot size will determine the kerf of your cutting. It may also impact the maximum resolution (lines per inch) for engraving images. Finer/smaller dots may also cut better since the wattage is being applied to a smaller area. Working distance is often hard to determine, but will be the same as the focus distance. I do a lot of cutting with imperfect (some warping) plywood. If I had a smaller working distance, the module would catch on the wood, ruining the job.
Personally, I have the NEJE A40640. It is a two-diode laser, so it is in the neighborhood of 10 watts. I cut a lot of 5.4mm plywood. I’m sure it would cut 9mm plywood, but it would be multiple passes, or a very slow federate. For engraving, I get good images up to 300 lines per inch. When I go above 300lpi, I get banding. I’ve done a lot of projects with my NEJE, but lately I’ve been researching upgrading to a more powerful module. Given the working area (XY) of my Primo, cuts can take a long time.
As Dan indicated, the Marlin firmware for the SKR Pro has laser features enabled. It is set up to use PC9 as the laser PWM pin. If you use a separate power supply from your LowRider, you will need to share the ground between your laser module and your SKR Pro. If you use the same power supply, you want to make sure it can supply enough current for both the laser and the LowRider.
As for foam cutting, as Dan indicated, there are a variety of posts on the forum using a needle cutter. I’ve never seen a V1 machine set up as a hot wire cutter.
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Just checked out your lasers what’s the difference between them looks to me the first one is more versatile
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The A40640 and E40 are pretty similar actually. I think the E40 is a somewhat newer design, and has built in features for air assist. Mine is actually still sitting int he box, and I haven’t unpacked it yet.
The E40 is a fixed focus. While a variable focus seems more versatile, it won’t be quite as sharp as a fixed focus lens will be. Kind of like with photography, where your prime lens will take pictures just a little sharper than a telephoto. The telephoto lens is more versatile, so people put up with the slight degradation of image quality (most won’t even notice it.)
I have a printed air assist cone for the A40640, but when I ran the laser without the air pump going, I melted it and had to print another. Presumably the metal air assist fitting on the E40 won’t have that issue.
The actual lasers themselves should be the same, the control circuit boards seem to be the same, and they have very similar specifications.
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I looked at the new xtool price is steep 1400 us but it is very impressive might have to look at liquidating some toys lol
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If you are talking about the 40W model and looking at using it on a LowRider at some point, I’ve seen videos of the upgrade path to this module for their laser engravers. It appears there is a ribbon cable between the module and the control board that supplies power independently to each diode in the module. I’m not sure what wiring and firmware would be needed for this module to work on a LowRider. You would want to get some specifics from XTool if your goal is to be able to move this module to your LR.
There are a variety of 30W, 6-diode laser modules (including one sold by XTool) on the market that appear to have wiring that easily translates to a V1 build. If I was going to spend in the $1000 range, I would be tempted to buy this laser engraver. The cost for this laser engraver is only a couple hundred more than just a 30W modules sold by other manufacturers. The specs for feedrates and the dot size of 0.1mm compare favorably to other top-tier machines. I would then take the machine and make the laser module swappable to my Primo, so I would use it to cut bigger works.
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Speaking of advice on buying choices, which would you choose, personally, if you did not have a budget for 30W, but could choose between an XTool 20W for $363 (with tax) and a NEJE E80 “24W” for $445 (with shipping)?
I’m working to accomplish (and document) setting up for adding a diode laser module to LowRider.
The laser module has three wires: +12v, -12v, and PWM. Nothing is identified as Ground. Can you advise me on that? I am anything but an expert on electrical.
If you’re expecting it to be a 12V supply then it’s likely that -12V is the ‘ground’. It’s pretty common for things to avoid using the term ‘ground’ in some cases, like if they’re not actually connected to the metal case etc. Return, 0V or 12V Return would be ‘better’ ways of signalling that, though.
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After a second glance, the labelling was actually a bit more nuanced than I first realized.
My first impression was that it looks like “+” and “-” with “12v” in the middle between them, applied to both of them. However, maybe it was instead intended as “+12v” and a simple “-” and then the “PWM.”
Here’s a photo:
I’d say it could read as if the 12V were a label ‘above’ the +/-
So that’d be, +12V, GND, PWM if reading left to right.
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Most of what I know about electronics I’ve acquired through osmosis. My understanding is that voltage is relative. Assuming my understanding is correct, and assuming your connections are labeled correctly, an alternate labeling of the wires is 24V and 0V (ground). Is your module 24V? For both voltage presentations, the potential difference is 24V. If you wait a bit before connecting anything, I’m sure that someone on this forum with more electronics experience will chime in.
It is not 24 V. Based on the power supply it is 12 V. And the diode itself is only a 5.5 W. So we’re talking about just 12 V.
Given my understanding of voltage labeling, it is mislabeled. The -12V is almost certainly ground.
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Okay folks, The three wires are commonly found in the various modules. They are +12, -12 (or ground in other terminology), and the PWM signal.
The +12 and -12 need to be connected to the power source for the laser. Most of our controller boards do not provide the additional current that these modules use. A unit rated for 40W input will be drawing over 3 Amps of current. You do not want to pull that current through controller board unless it has MOSFETs or other power controls.
The -12 needs to be connected to the Controller board as well, along with the PWM signal, to control the power output of the module.
So, a +12 and -12 to the power supply and the SAME -12 and the PWM connected to the controller board. The two devices, DC power supply, and Controller board must share the same -12 (or ground) to avoid the “Floating ground” where the two devices may have sightly different voltage across their plus and minus connections.
I think that’s a close explanation. I’m sure there are others that can improve/correct my errors.
Mike
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Thanks @robertbu, @mbamberg, and @jono035.
Regarding this wiring of the board and the device sharing a common ground… is there a wiring schematic available showing this? Or could one be thrown together? I’m seeking to document things.
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I’m not aware of any wiring diagrams. If you share the power supply between the laser and the control board, you don’t need to a separate ground wire. In this configuration, it is recommended to take the power directly from where the power wires attach to the control board to avoid pulling too much current through the control board. Also, your power supply must provide enough current for both the CNC and the laser. Allow 6A for the CNC and add to that whatever the laser needs to get the total rating necessary for the power supply.
If you are using a separate power supply for the laser, you need to share the ground between the laser and the control board. If all you have is a “raw” laser with three connections, this means adding a ‘Y’ to the ground wire from the power supply so that the power supply ground can go to both the laser and the control board. This ground is only for the PWM signal, and only a tiny amount of current is used for this function. That means the ground wire can be small (26 AWG for example), and it can attach to any ground pin on the control board.
Many lasers come with a companion board. From discussions on the forum and personal experience with one board, their only function is to simplify the wiring. They have a barrel jack for the power supply, a three or four wire connector for the laser, and a two-wire connector for PWM (signal and ground). When using this kind of board, the ground connection for the PWM is provided by the connection to the companion board, so no separate ground Y’ is required.
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Thanks for another great post!!
