Stuff your 3D printer has made today...

[Mart63]

Indeed and I had prior to the black print then changed the filament. The subsequent print is also ok. I don't level between every print, do you?

I've done loads of prints recently and all were fine. Started a print yesterday and the brim on one side was stringy, but not on the other side. I needed a small amount of manual adjustment on the stringy side. Auto levelling wouldn't fix this problem.

 

[My Old Landy]

I've done loads of prints recently and all were fine. Started a print yesterday and the brim on one side was stringy, but not on the other side. I needed a small amount of manual adjustment on the stringy side. Auto levelling wouldn't fix this problem.

I'm not arguing, these things are temperamental. I am sure it is the filament in this case though, as without any manual intervention, it is printing fine with other reels.

 

[daedalusminos]

Some on here might have realised I've an interesting in the original LED watches. This is another in my collection, a BENRUS Techni Quartz in original box. It's actually very nice condition but the box is missing its 'collar' (the ring insert that takes the place of the wrist).


The original collar may have been burgundy flock covered to match the rest of the box, no idea and couldn't find any reference so I got a bit creative an pulled the BENRUS logo from the box lid and modelled something in F360. I wanted to try out a clear resin so decided to emboss the logo on the back in a de-bossed field.

The first test piece printed well but as expected it's far from clear due to the surface texture of the layer lines refracting the light, unlike FDM clear prints the actual body of the item is homogenous so I'm hoping should have good transparency. There's a few methods to getting rid of the surface imperfections. Here the left hand side is as printed but the right has been coated in clear lacquer - an improvement but not good enough


The next method is to cure the item before washing thus curing on the resin clinging to the surface, there's a few problems with this - the resin tends to form sags (messing up surface finish and filling in details) and the fact the supports have to be removed after curing results in some surface imperfections.


The third and best method is mechanical polishing and it's come out pretty well after 600, 1000, 2000, T-CUT and finally 4000 paste though I think I could have got it better. I think the logo with its frosted (unpolished) field is a nice feature.

 

[m_c]

A little tip when that happens... stick it in the freezer overnight. Differential contraction will sort it out.

I'm not even sure that would work with the Geeetech glue, as I'm not entirely sure what it is.
Even leaving that bed plate soaking in water overnight, the glue can't be washed off the plate.
It does go white like PVA does when it absorbs water, but it just doesn't budge. It just stays like a thin slime like covering on the bed :/

 

[sako243]

During the development of an op-amp filtering stage on that 10 mm × 10 mm PCB, we needed to test some significant changes and someone I work with managed to hand-solder two 0201 resistors vertically with overlapping (but not touching) wires going from the top pins down onto 0201 size pads on the board. I could barely even see what was going on with a microscope!

Reminds me of a story where I was testing a PCB for someone and when hooked up to an electronic load I smelt warmth but everything was fine. Eventually realised what was happening was that the load in constant power mode was able to ramp up current draw faster than one of our protection FETs turned off. The smell was the FET reflowing itself on the PCB, in the hundred microseconds or so it took to turn off a hundred amps or so flowed through the FET, heating it up and reflowing it. Then it switched off and everything was fine.

The solution a colleague came up with was to piggyback a small cap onto the gate resistor of the FET which gave it a bit of a faster kick to turn off. Was likely never going to be an issue in the real world but a neat solution to prevent us respinning a few hundred PCBs.

 

[ajlelectronics]

I'm not even sure that would work with the Geeetech glue, as I'm not entirely sure what it is.
Even leaving that bed plate soaking in water overnight, the glue can't be washed off the plate.
It does go white like PVA does when it absorbs water, but it just doesn't budge. It just stays like a thin slime like covering on the bed :/

Which is why differential contraction is your friend!

 

[My Old Landy]

Well it is nearly Christmas

 

[ukracer]

Well it is nearly Christmas
View attachment 426687

Those look cool. Where did you get the files?

 

[My Old Landy]

Those look cool. Where did you get the files?

From Thingiverse

 

[fizzy]

Finished off the gears for my mate today. Drummond/Myford. Turned out quite well.
Note the large one. Had to swap filament. Easy on the Elegoo.

 

[daedalusminos]

Finished off the gears for my mate today. Drummond/Myford. Turned out quite well.
Note the large one. Had to swap filament. Easy on the Elegoo.

View attachment 427465

What material did you print them in? Will be interesting to see how well they last.

 

[fizzy]

What material did you print them in? Will be interesting to see how well they last.

Blue ones in PETG rest in PLA.
Yes I wonder as well. I suspect the majority of damaged teeth on Myford/Drummond gears are caused by locking the gears to remove the chuck.

 

[Agroshield]

Will be interesting to see how well they last.

Someone should come up with a design so that the teeth alone can be replaced if they do shear off.

A bit like replacing the starter ring gear on a flywheel, but it needs the 3DP equivalent of a shrink fit.

I have said it before but at the moment there are no gear design programs around that are aimed specifically at 3D printing. Every gear you can design at the moment is done so as if it will be subtractively-machined. That means the root of the tooth is weak when made out of plastic. With an additively-manufactured gear, you can put a much larger fillet in the tooth root, just small enough so it does not clash with the mating gear.

 

[fizzy]

Someone should come up with a design so that the teeth alone can be replaced if they do shear off.

A bit like replacing the starter ring gear on a flywheel, but it needs the 3DP equivalent of a shrink fit.

I have said it before but at the moment there are no gear design programs around that are aimed specifically at 3D printing. Every gear you can design at the moment is done so as if it will be subtractively-machined. That means the root of the tooth is weak when made out of plastic. With an additively-manufactured gear, you can put a much larger fillet in the tooth root, just small enough so it does not clash with the mating gear.

When I get more time I will have a play. As you say teeth will go first so having them replaceable makes sense.
Treating myself to a laser cutter/engraver for Christmas. Only 20W but will cut plastics up to about 15mm. Be interesting to see gears cut from sheet nylon or Delrin.

 

[Dr.Al]

The 3D printer has been very busy over the last few days (three 12 hour prints)

My new laptop has a bigger screen than the old one and also has two display connections (HDMI and mini display port). That means more screen area, especially if I lift the laptop screen up:

The two monitors are also connected to my work-from-home work computer (taking advantage of the multiple input ports on the monitors). When I'm working, the laptop is off and I just have the two monitors, but when I'm doing home stuff I thought it might occasionally be handy to have all three (e.g. CAD model on one, web browser on one, ssh terminal on the third or whatever).

 

[ajlelectronics]

A few things today...

Titan Vacuum hose to Kirby accessories adapter sleeve:

Backing pad for surface mounting spotlights to a beam that can't be drilled. Cable outlet at 90 degrees. :

Connecting box for the spotlights:

ASA seat knob bezel, ASA heater control knob and TPU wiper shaft bezels.




The completed ASA connector box, with threaded brass bushes fitted. M3 screws to hold the lid on.




The connector box and mounting bases for the spotlights.

 

[m_c]

I have said it before but at the moment there are no gear design programs around that are aimed specifically at 3D printing. Every gear you can design at the moment is done so as if it will be subtractively-machined. That means the root of the tooth is weak when made out of plastic. With an additively-manufactured gear, you can put a much larger fillet in the tooth root, just small enough so it does not clash with the mating gear.

It's probably worth having a play with Gearotic Motion - https://www.gearoticmotion.com/
Art (originally creator of Mach 1/2/3) is the main guy behind it, and I'd be surprised if he hasn't already added such capability as it's capable of producing lots of weird and wonderful gears, although I haven't tried it for a while.

 

[My Old Landy]

The Ender 5 has started to get stringy. I thought it was one reel of filament but it is happening with other reels now.
So today I set up a string test and spent time altering the setup until there was no more stringyness going on.
Great, I set up a 13 hour print of a boat using the new settings and straight away the print has whispy spider webs forming.
I have no idea what is causing it.
PLA 210 deg for first layer, 205 for the rest. Bed 60 deg. Speed 100mm/s retraction 5mm. Prusa Slicer 2.7.1.
Any suggestions most welcome

 

[m_c]

Finished the latest part of this collection today


Various small parts still to go, but I'm waiting for some other parts to get delivered so I can start assembling the bits into something hopefully useful

 

[ajlelectronics]

Is it a metal hot end? Retraction is generally far smaller for those.

Dealing with strings is a simple as pointing a hot air gun at them!