Rolive

A thermistor is just a resistor that changes resistance based on temperature. All you need to do is hook up a multimeter and wiggle the cable. If the resistance is consistent then it’s fine.

What helped me a lot is to find a model (STEP file) of the printer you have and import that into whatever CAD program you prefer.

I found FreeCAD to be by far the most pleasant program to use. It is not even close. No accounts, no cloud , no subscriptions, no “AI”. None of that modern SAAS bullshit or enshittification. FreeCAD updates make it better instead of worse.

It is definitely not perfect but it is free and open source and the developers have done a really good job with this.

Anyway, once you’ve imported the model into CAD it becomes much much easier to design parts around it. You can find many models on sites like grabcad.com but you will need to make an account to download (urgh). Just fill in some random BS on a throwaway account and you’re fine though.

I have indeed noticed that with the previous iteration. Then I tried to have the idlers on the same screws that would connect the joints to the rails in an attempt to make the build as efficient as possible.

The belts did not make 90 degree paths from the stepper motor towers and also not from the YX joints to the toolhead. This caused uneven tension that was most noticable when the toolhead got close to the YX joint or when the YX joint got close to the stepper tower. The belt angle would change based on the location of either object and that changed the amount of force needed to pull it.

I’ve learned that the belts ideally make 90 degree angles when pulling something. One belt path comes out the left side of the idler and the other comes out of the right side. At the toolhead you insert the belt from either the left side or the right side to make the belt as straight as possible.

A few years ago I used glass beds. Not fancy ones, I got a large cheap mirror from the hardware store and a glass cutter. Both combined were cheaper than a single bed meant for 3D printing and for PLA they lasted multiple months. PEI is just more practical since it won´t randomly break and is flexible making part removal very easy.

I ruined it by trying to print PETG on it without any adhesion layer in between. It took out a nice chunk of glass from the center.

That is…pretty minor compared to some of the catastrophic mistakes here haha.

I thought of that a well. The resin will likely not get everywhere. The idea was saving costs as resin is kinda expensive.

I think it’s cheaper than using resin haha.

I… may have short circuited the hotend fan mosfet and broke it. I just let them run at full speed since then.

I actually have a pretty decent design already, it’s just that I’m looking to upgrade to ballscrews and unlock more potential with the machine. Image

I’ve gotten two decent ballscrews from my job. One fits well on the Y axis but it’s a bit too large for the X axis so it will need some redesign.

It is meant mostly for milling circuit boards and laser engraving. I believe belts are good enough for that since the bit load is so tiny here.

Later though I want to upgrade to ballscrews and will have to redesign the current machine.

You can make one if you have a 3D printer and some linear rails. I have a somewhat steady supply of CNC parts through my job and have designed a CNC machine around that.

Right. I’m sort of a cheapass so I ordered them via Aliexpress. Next time I will get the proper ones.

I did however find out that the metal bearings, despite the play in them, did not cause the resonances. Ever since I rebuilt the printer to a CoreXY machine some speeds were off-limits. Which is fine I guess but mildly annoying and I want to get it solved at some point.

I used to have this but I’ve built a separate CNC machine for lasering and engraving: printables.com/…/1071387-ender-5-x-mgn12-detachab…

Do I recommend building it? Eh, it will work but there are some issues. 3D printer controller software such as Marlin or Klipper also does not play well with applications like LaserGRBL, Lightburn or Rayforge. They are designed with GRBL in mind or other dedicated CNC controllers. The 3D printer approach used the part cooling fan to control the laser power.

Back then I had custom Gcode substitutions in Prusaslicer which would replace Retract commands with enabling the laser and the opposite command with disabling the laser. It worked pretty well back then and I was able to do some engravings of circuit boards. I

There is one big safety issue, the enclosure is not designed for laser engraving and there is nothing preventing the laser from blinding you through a bad reflection. You will need to be extremely careful with this. The CNC machine I built later has a safety feature where the laser only functions if the front door is closed, using a magnetic sensor. It is not worth risking your eyesight over a bad moment where you don’t pay attention. Engraving lasers are dangerous. Also the fumes are nasty, especially when engraving plastics. The soot and tar it produces will also settle on the inside of your enclosure and also electronics that are in there. You need powerful ventilation to run a laser engraver long term.

As for engraving materials, I have two laser heads, a 0.5W 405nm laser and a 10W 450nm laser.

The 405nm laser can be used quite well to activate etch resist spray or foil and can also instantly and precisely cure UV resin. I could make legible text on a PCB using white resin, drawing the text and then washing off the excess with alcohol. This laser however is not powerful and you won´t get nice engravings on wood or metal with it.

The 450nm laser can easily cut wood and make very nice engravings in it as well. I have also used it in the PCB making process to burn away spraypaint so that the copper can be etched off.

Conformal coating with a silk screen never worked well for me. There were always visible creases and uniformity issues.

I also want to have a consistent layer thickness because the intention is to start with a white layer and on top of that a green layer. I will use a laser engraver to remove part of the green layer to expose white again to make the silkscreen layer.

A spincoater ensures the coating is always exactly the same which is good for laser ablation.

I believe there are settings related to minimum layer time. It will change cooling parameters or might slow the print down to achieve the minimum time.

That might make your smaller prints look bad.

Nice work! I’m considering a similar project and this looks like a good way to do it.

You have to be careful with this. The humidity reported by the local weather station may not be the same as the humidity in your storage room.

I have just gotten an airtight box and a few packs of silica gel and store all my filament in there.

This is exactly why I did it. Also the RGB led strip costs 4 euros here at the Action. Imagine if AliExpress had a physical store, that’s that.

Oh that’s right. The direction pins can also control the light settings!

Actually it’s pretty decent. I do need to install part cooling fans but haven’t done that.

I was trying to use an aquarium pump with blunt needles as part cooling but I find it’s too much hassle.

That is also a factor, I almost always print PLA and ABS/PETG only when the part needs to withstand high temperatures (inside a car for example).