Rolive

Hi, I'm trying to attach an ER11 chuck to a 775 motor to use as a spindle for my custom CNC machine. The machine is meant to make circuit boards so a 775 motor is good enough for that. Perhaps wood engravings could work too.

The issue is however, the chuck I'm trying to attach has way too much play when putting it on the shaft. The bottom of the ER11 chuck is not flat either so pushing it all the way down to the motor is not working.

The goal for this setup is to mill traces of 0.2mm wide. Perhaps 0.1mm if the V-bit allows for it so it should be on as straight as possible.

I have tried putting the chuck in the freezer overnight in an attempt to make the hole a bit tighter but that was not good enough.

Is there a good method to do this? I could just order a readily made 775 spindle from Ali but that seems a bit wasteful.

This is an idea that entered my mind. As far as I understood lithium ion batteries still need oxygen from the air to burn.

They don't provide their own oxidizer IIRC but they do reignite when left to dry because they rapidly build up heat again. Please correct me if I'm wrong.

Edit: I was wrong: https://www.sciencedirect.com/science/article/pii/S2352152X24008739

The cathode breaks down into oxygen among other things.

Would it make sense to have a lithium ion battery inside an airtight enclosure and fill it up with nitrogen? This way the only source of oxygen is from the decomposing cathode but that should react away quickly. The fire will be much less intense than in regular air. Assuming the enclosure holds.

Is this a silly idea? Is it even worth doing?

Is this feasible at all?

My idea is to have a battery of 112 Li Ion cells in series, ending up with a nominal voltage of about 414V. This is apparently how car batteries are configured as well and it's the easiest for an EGS002 inverter.

Charging however is quite difficult as stepping up to those voltages is not trivial.

The idea is to have a charge pump circuit on every single cell. 2 mosfets for charging, a capacitor, 2 mosfets for discharging. The capacitor would charge from a 4.2V supply and discharge into the battery.

The mosfets on the battery side can be controlled with optocouplers. The gate voltage is provided by cells further up in the chain so the gate always has at least 12V on it.

Is this a bad idea? Things that come to mind are the mosfet losses. Essentially the on resistance counts 4 times per cell but usually the rDS on is in the 20 mOhm range, so 80 mOhm per cell.

Balancing is much easier this way.

Perhaps a compromise that charges several cells in series and watches the balancing could work too if efficiency is the biggest reason against this.

I'm aware of the safety considerations.

What would be the best way to do this? I have made a 16s li-ion battery system and would like to build an inverter myself as well. For that I will be using an EGS002 module and according to the datasheet that requires a 400V DC source which will be converted into a sinus-ish waveform using sPWM.

I also see circuits online from dubious sources such as instructables that claim you can also apply the sPWM signal to 12 or 24V and then run that through a transformer for the same result. This is not in the datasheet, but does it work? This sounds like an easier setup. With my battery it would require a different transformer ratio.

Since I'm using a 16s battery the voltage will be in between 48V at its lowest and 64V at its highest. The feedback should be able to compensate for this.

As for transformers, I have a few 1:9 (European) microwave transformers, it would be nice if those could be used for this project as they're more than capable of big loads.

Ideally I would like to build an inverter that can provide 2000W of power, perhaps more. The whole idea behind the battery/inverter system is being able to power household objects when the power goes out. The ultimate goal is to troll my neighbors in that once in 5 year event.

Of course there is the commercial option, which I might use, but I want to learn how they work as well.

This is a design I'm working on. The idea behind the wave pattern is so that they can be stacked without losing all too much space compared to rectangular cell packs.

I'm putting a 60C thermal fuse in between each cell pair. Should a cell overheat, the fuse will pop and render the pack useless. This is an additional safety feature on top of a BMS and periodic manual checkups with a thermal camera.

The idea behind all cells pointing upwards (positive facing up) is also a safety feature. Should one start to vent or catch fire the flames will go up immediately triggering an extinguisher above the cell pack.

Let me know what you think! I'm not finished with it yet but if you want the design files already let me know I'll send them to you.

Edited with a deshittified version of imgur.

This is a customized version of the Ender 5 Mercury One.1 mod. I had two 10mm rods lying around that would fit the X axis and wanted to use the MGN12 rail for a custom CNC project instead. Please check the Printables link for more information as well as a FreeCAD file.

https://www.printables.com/model/1399143-ender-5-mercury-one1-x-10mm-rod-mod

I also think that having the hotend centered between two rails may allow for a larger reachable print area at some point. Later I want to remake the way the heated bed is mounted so that a larger bed can be used while still having the same Ender 5 footprint.

I don't think this should still be called an Ender 5 and this point. Perhaps a Frankender will do.

Right now all it has is a plotter adding but I'm also making a mount for a mill and lasercutter. It's meant mostly for making circuit boards but should be able to handle other projects as well.

It's designed in FreeCAD and some parts were sourced from discarded laboratory devices from my job as well as a broken 3D printer.

Here's a link to the FreeCAD in its current form. I'm not happy about Google but this is to be shared for free so it's okay.

https://drive.google.com/file/d/1TaGmB2l-2IpyjhtpyuxbR6gJtIwyiHvx/view?usp=drivesdk

Right now it's a bit messy but I intend to post it to printables.com later when it's fully done.

The video is sped up 8x. I think it can handle this speed realtime as well.

3D printer toolheads often have large blower fans with big fan ducts ending in small holes and I wonder how necessary that is.

These large part cooling setups are most of the size of the toolhead and significantly reduce print area. Blower fans also do not produce much pressure so those fan ducts greatly reduce their effectiveness.

Does it make sense to, instead of using a blower fan, use a small compressor like for an aquarium and have the airflow delivered Bowden style to a small nozzle? The airflow would be substantially higher than from a fan. Noise isn't really an issue for a tiny compressor.

Has anyone tried this? I might eventually but don't have the time to set it up now.

This is a WIP and at this point don't know if it's going to be successful or not. I'm currently building it. The idea is to use the Mercury One build but modify it so that it uses 10mm rods on the X axis instead of an aluminium extrusion with an MGN12 rail. I have a set of these rods on hand and want to use the MGN12 rail on a DIY CNC instead. These rods seem good enough for a 3D printer and I don't want to waste them.

I have decided to modify the Mercury One so that it has a different X assembly and a completely custom toolhead that houses the stock Ender5 hotend or a MicroSwiss hotend coupled with an Orbiter 1.5 extruder. Later I'll make a different toolhead for a better hotend but for now the MicroSwiss is good enough.

The red parts are original MercuryOne parts, the green ones are the ones I designed. I haven't bothered with rounding or chamfering yet. I have also imported some things from GrabCAD such as the BLtouch, hotend and fans.

This is quite the Frankenstein creation and I wonder, what am I supposed to call it? It barely resembles an Ender5 at this point, only the frame does.

I feel a bit bad for still using Gdrive but here's the FreeCAD file. I only put things in Gdrive that I want to share publicly so idc if they spy on me. https://drive.google.com/file/d/1WFskq_OpdML4qeyOsKfkcaarW1QUJOB5/view?usp=sharing

Hi all. Does anyone have experience with the BMSs from Daly? I'm looking to get a 16s BMS for a DIY li ion battery pack. I have a large box full of li ion 18650 cells and want to make an emergency battery system for home use.

That power outage in Spain motivated me to finish this project.

This is for older car models that do not have built-in navigation or bad navigation. My car is old enough to have a cassette player.

This model is made for a Toyota Yaris from 2001 and the phone inside is an S21 Ultra that would otherwise have been sitting in a drawer.

I have sacrificed the original sunvisor to get the swivel part out and modeled a new sunvisor around it. Since this car is really old it's okay to make these modifications.

So far the driving experience has improved a lot, it is a pretty decent location for a navigation system since you can focus on driving much more easily than having to look down and to the right.

The models and FreeCAD design file may be found here:

https://www.printables.com/model/1256013-toyota-yaris-sun-visor-with-navigation-phone

Hi all

For the past couple of years I have been running a Raspberry Pi4 with PiHole and PiVPN. Both of which I'm very satisfied with. My ISP recently changed the IP address assigned to me, this doesn't happen often but did cause my VPN profiles to no longer work. Simply changing the end IP address in the VPN config does not work so the configs had to be remade entirely. If this happens again and I am not near home, what would be a way to regain access? Can that be done remotely?

I am concerned with the possibility that my IP changes while I'm on a vacation and then lose access to my NAS and other home systems with no way to get it back until after.

I am considering a script that generates a new config file and sends it over email when I send a specific text to a phone, that could work. Is this over engineered? Something like a deadman switch could work too.

Thanks!