A Prusa's SCRAPPED Screen?? - PrintFixFriday 154

[@Sembazuru]

I had an issue on my MK3 where the drive gears looked like they were rotating smoothly, but the filament coming out of the nozzle was surging. It was enough that when purging into the air the extruded filament looked like a string of sausages. The hobbed gears were clean, but I think that some nozzle cloggs that I had when printing carbon filled PLA allowed the hobbed gears to grind away a little bit. Replacing the gears resolved the problem. When doing the swap-out I did compare the old gears to the new ones and it looked like the minimum diameter of the old gears was a little smaller than the replacements. Unfortunately I didn't measure or take pictures, so I don't have any confirmation documentation.

[@TheTsunamijuan]

for grub screws. Put some blue or purple loctite on it. or even the wicking green for electronics. (which allows the screw to already be set and in position and should wick into the threads). These are compounds designed for later disassembly. Without the need for a torque or a destructive practice.

[@davidconner-shover51]

Looking for a grub screw for one of my SV04s, the hex head got stripped

[@cubing4eternity774]

And here I thought my PLA prints failing during 48°C heatwaves was due to me not saying 'please' enough times to my printer.

[@soundspark]

@cubing4eternity774 If your ambient temperature is 48°C then you are already close to the softening point of the plastic, which means heat creep is a major risk. Same can go for printing PLA in an enclosed printer without the doors left open for maximum ventilation.

[@MattWilson801]

Force depends on the acceleration of the stop. Energy is probably a better calculation to make to determine the damage on the screen.

[@DD-sw1dd]

This

[@3DMusketeers]

its been MANY years since I took a physics class, so I will assume you are right. Could it be calculated though and what would you need for the energy calc??

[@MattWilson801]

@@3DMusketeers yup! Let me review :)

[@MattWilson801]

assuming the roll has a mass of 3kg and the height of the fall is the height of an XL printer (~0.5m) the roll has ~14.7 Joules of energy. that's not a very satisfying answer. So let's make another assumption: let's make the time of the collision 0.1 seconds. Let's also assume that the roll doesn't bounce and comes to a complete stop. That would give us required force of ~95 Newtons of force during the collision. We can play around a bit and make another assumption: the roll bounced back up at 1/2 its velocity that it struck the screen with. That would increase the force to nearly 150N. That should be enough for us to get a rough idea of the forces on the screen.

[@DuckyWhy]

so about 6:30, to get the velocity of the falling spool of filament when it reaches the screen with (V=2gΔx) in which 19.62m/s=2(9.81m/s^2)(1m), Air resistance is negligible so it is omitted. this is the velocity of the spool when it reaches the bottom of the printer. now to calculate the force is a bit complicated since we are missing a lot of information about the impact that was made with the spool to the screen but assuming about 60% of the force was directed at the screen and an impact time of about 5 milliseconds we can represent the average force as ((mv)/t)*(0.6)=(Average force of impact) which comes out to 7063.20N=(((3kg)(17.854m/s))/0.005)*(0.6). So a good guestimate with a lot of assumptions the average impact force made on the screen would be about 7kN of force or about 1573.66lbf.

[@DD-sw1dd]

Good job calculating the impact velocity from one of the kinematic formulas. I used the potential energy formula. Just mass*gravity*height above the touchscreen. Roughly came out to 29 newton meters or 22 foot-lbs of impact energy. Force is just mass*acceleration (or simply the actual weight in newtons) so it didn’t make much sense in this use case.

[@5jvm0u4]

Sometimes in my bedroom, it's almost hot enough to print small ABS parts in open air if I don't turn on air conditioner, it went 39 degrees last summer when my air conditioner broke

[@shanepearce1629]

you could also use PCB Soldering Aid Tool Kit to remove filament from extruder

[@DiomedesDominguez]

14:01 not destroy it, but I need it to completed disassemble it, just two days ago The filament broke at the beginning of the hot end (HF Obxidian 0.6 for one of my P1S), also a bit of still soft filament broke inside the extruder causing that that part of the filament stuck under the drive gear. I needed to completed remove everything and pushed it with a hot hex key.

[@st0mper121]

I had a filament tangle on my CR-10S Pro. somehow it got kicked sideways yanked off the spool holder and landed on my build plate. I use a Sovol drybox SH02 nothing is falling out of it now.

[@andreask.2675]

Those grooved (or rounded?) extruder gears on the Bambu Lab might seem like a good idea (gear profile is rounded+filament is round=good fit) but they actually are not. The gears have a varying diameter (increasing from the center to the edges) and with every rotation they will will travel different length accross the filament inevitably grinding on the filament. While this may not account for the filament of the user's gears in the images, it will lead to gunked up gears to some degree regardless of the usecase. Continuing watching the video... the same may apply to that giant Big Rep printer: Grooved gears as it looks...

[@Buildonsound]

Grant's Nozzles after this episode *wiggle wiggle*

[@TheTsunamijuan]

A window mounted ac unit, is a good option if you have the power availability imo. Just make sure to treat each printer as a person when doing your thermal calculations. So you get the right size unit. Normally where I live AC has not been a requirement. But the last few years my summers have been significantly hotter than the norm (lived here for 37 years). So I ended up adding two window units to my office, to keep the print farm happy during the warm days. Since summer seems to be my busiest time printing. (during the winter i usually take the air from that room and disperse it through the upstairs to save on heating. Cause it works out about perfect)

[@Sembazuru]

A quick look at Lowe's and the average price for window airconditioners is around the $250 ballpark. So for the cost of an average Ender all your other printers will stop heat creaping on you. ("you" in this case being the generic "you", not specifically the OP.)

[@quentinroa2573]

With how expensive the BigRep is, maybe some Tungsten Carbide gears would help as well as clog detection, which should be as simple as adding it to a 1.75mm printer.

[@3DMusketeers]

right?!?

[@soundspark]

Load cells are part of that Stratasys patent dispute.

[@madmaxh3]

I was thinking about the blue Locktite just before you said it lol

[@RedSlashAce]

Thank you for including my print fail! Also thank you so much for the shout-out on my projects 😃 The tech based hotend would be interesting 🤔 Will be interesting to see how you keep the tech from saturating. That screen fail is making me think I should put a cage around my screen now 😅

[@3DMusketeers]

not a bad move I dont think..

[@Speedgaming802]

im glad i still use v6 style hot end

[@DD-sw1dd]

Aside from maybe using Rockset or red loctite (you’ll never change ur nozzle again) no matter what you do those grub screws will need to be checked. The slight vibrations from plane rides into Afghanistan were enough to loosen screws holding optics. Those extruders shake and move much more violently for hours on end. Vibrations are weird with fasteners.

[@madmaxh3]

As always, Awesome video Grant !

[@soundspark]

At least those living in the desert don't have to deal with wet filament.

[@3DMusketeers]

fair!

[@rustyv6274]

I’m in Texas and I have 10 machines. This summer I gave up on all of them and took some of them inside till winter. It’s to hot

[@fanofentropy2280]

m (mass) = 3kg s (distance) = 1m a (acceleration) = 9.8m/s/s u (starting velocity) = 0 v (final velocity) = √(u^2 + 2as) = √(0 + 19.6) = 4.43m/s KE = (1/2)m(v^2) = 0.5 * 3 * 19.6 = 29.4 joules

[@madmaxh3]

Say Beetlejuice two more times, and he would appear, lol.

[@DD-sw1dd]

Energy is more accurate given its a potential energy problem (mass x gravity x height) 3kg (9.81 m/s^2) (1 meter) = 29.5 Newton meters of potential energy (22 foot lbs of impact energy.)

[@sunderoo]

Force = mass x acceleration So it's a simple linear multiplication, since the A (gravity, 9.8 m^2) is the same. 3 times the weight, 3 times the force. I'd be more worried about being higher with the XL vs, say, a MK4. Or your hangars. I mean... Not designed for ANYTHING falling on it. :D

[@3DMusketeers]

Spherical chicken, in a vacuum, on a frictionless plane, right??

[@soundspark]

Don't UltiMaker printers use 2.85mm filament even on small machines?

[@awilliams1701]

so yeah my nextruder nozzle with the obxidean coating got unfixable heat creep (I finally gave up) because I had 1 tight screw and 1 loose screw. The loose screw permitted massive heat creep.

[@awilliams1701]

ohhhh I thought the XL had 2 screws like the mk4 does.

[@3DMusketeers]

really?? that is interesting!

[@awilliams1701]

@@3DMusketeers yup. The wham bam fix it kit is 1.7mm not 1.75. Even it oculdn't fix it. lol

[@3DMusketeers]

that slight bit off was not helping? Have you tried a cold pull with something like nylon, hips, etc? You could look to dissolve the plastic too in a solvent if needed

[@awilliams1701]

@@3DMusketeers yeah I've thought about dipping it in acetone. The trick is the only thing I know of that get's the area above the heat break hot enough is the stove. And I don't know what temps I need. A cold pull in the printer won't work because it's not supposed to get hot up that high. I guess I could cut off a strand of nylon. I do have some.

[@awilliams1701]

oh that's easy to fix. just open up a quantum tunnel to the arctic. That below freezing temperature should help. lol

[@3DMusketeers]

why didn't I think of that?!?!

[@michaelplaczek9385]

Isn’t the XL known to take up to 2kg filament rolls?

[@RoseKindred]

"4 (pause) plus attempts" Oh come on, you know you wanted to add another "F", we heard the start.

[@3DMusketeers]

lololol

[@ThisisDD]

Dude with PrusaXL in The photo, what is going on with the hands???

[@kudkoc]

6:06 what's wrong with white?

[@justinchamberlin4195]

"Oops, our filament diameter is off by +/-15%, too bad for the customers I guess." - Someone at BigRep, possibly a former GST3D/Fremover employee. For a printer this expensive, buying and fitting a smart plug shouldn't necessary (and may not be possible, if the machine is intended to draw industrial-type voltages like 380 or 460). Being able to remotely access the machine, view what's going on, and stop the print if something is obviously wrong seems like an extremely basic feature to me, at that price point...a feature that's available on printers costing hundreds *to* thousands of dollars should be included on printers costing hundreds *of* thousands of dollars. A thermoelectrically-cooled hot end is a really fascinating idea, particularly in an enclosed printer where chamber heating is only nominally provided by the bed. I don't know how much extra heat you'd realistically get from the cold end of the print head, but hey...every little bit helps.

[@awilliams1701]

seriously. I would refuse to have anything to do with any environment over 90 degrees. That's a big nope.

[@3DMusketeers]

but you live in the south??

[@soundspark]

Never work for FedEx then. They'll boil you alive.

[@awilliams1701]

@@3DMusketeers not by choice! Also this building is not 90 degrees. Anything over 80 and I work from home. I actually had to for that very reason once. Something was wrong with the AC.

[@awilliams1701]

no if you look at that screen it looks about 25% of it is completely inoperable. Maybe more. Lets say 1/3. Honestly the touch screen is more likely to survive than a screen. They can be cracked like crazy, but the screen can't.

[@3DMusketeers]

good think the knob is there though!

[@awilliams1701]

@@3DMusketeers yeah, but you can't see what half of it is indicating.

[@3DMusketeers]

need a good memory, or the app I guess