Nothing wrong with those Marantz Studio monitors, Pete! 
Watched an episode of The Whirlybirds, which I remember watching when I was a young nipper. It was really bad, in every way imaginable. Ah well - Champion The Wonder Horse next, I suppose.
4 Likes
So long as it’s not muffin’ the mule, that’s animal cruelty!
4 Likes
Great heli’s tho…I loved those bubblefront Bell (I think) 'copters.
But not actually illegal, as I understand it… Not that I would know!
True. It was just the plot, the dialogue, the acting and the filming which were awful. It was a bubble cockpit, but not the type that were used in MASH - the whirlybird was a bigger aircraft, but I’m not an expert in such things.
I did have quite good success for quite a while, but for 2 or 3 weeks now I haven’t managed to print anything at all! Very frustrating. The prints keep coming out more like brillo pads than anything, which crumble easily in my hands. Full of gaps and pockets. I’ve tried all sorts of things - dismantled the hot end, cleaned the nozzle, cleaned the extruder, tried drying the PLA - and just now tried some brand new PLA (Geeetech). Same result, even with that little test thing (cube surmounted by a cylinder). I’m expecting a new nozzle to arrive some time in June, but I really don’t understand why every print fails now.
Any suggestions?
Can you post a picture of the failed prints?
Is the first layer OK or is that patchy as well - can you also add a picture of that?
What type of printer are you using? (& is it a Bowden or direct extruder?)
Which slicer are you using?
Is it making any odd noises?
Have you changed the slicer settings / printer profile?
Have you made sure the hotend temperature sensor and heater are properly fixed into position?
Have you taken the hotend apart and cleaned it internally?
First layer varies but often looks OK. The printer is a Tronxy 5XSA Pro, which looks to me like it uses a Creality extruder, and a Bowden tube. Slicer is generally Tronxy’s though I have tried Cura. The test print that I am using is one that comes with the printer, and that I have printed perfectly well before a few times. No odd noises really, a little graunching sometimes from the bit that moves the filament, I think. The slicer settings for this test print haven’t changed. I think that the hotend temperature sensor and heater are properly in position. Not sure how to check that, but the wires go where I would expect them to. I have taken the hotend apart and cleaned it as best I can. It’s a 0.4mm nozzle.
The first photo is about when the problem started. Part way through a print, it went wrong. The bottom half was fine.
The second photo is of the walls of a print, the bottom layer seemed to be pretty much OK, but then it all went wrong.
I haven’t any photos of the cube/cylinder, but can do that if it would help.
Thanks for having a look.
OK, I’m pretty sure you have a blockage in the hot end, the question is where and why.
The ‘bit that moves the filament’ is the extruder graunching here indicates that the filament isn’t feeding correctly and that the drive gear is chewing up the side of the filament rather than pushing it through the hot end; the effect can easily be seen on the side of the filament when you withdraw it. Typically this is because the hot end is partially blocked. This can be due to poor quality filament (inclusions of other stuff that won’t melt), contaminated filament (dust and other stuff getting picked up on the sides of the filament), build up of residue (gradually bits of overheated filament build up just behind the nozzle), or constriction of the heated end of the Bowden tube.
The answer in each case is to take the hot end apart (remove the heater and sensor then heat it up in an oven to take apart the mechanical bits), clean it thoroughly (I recommend replacing the nozzle with a new one), and check the dimensions on the end of the Bowden tube. Ensure that all areas that are touched by the filament are properly cleaned (you many need to use dichloromethane to do this).
Assemble the hot end again and heat it up to running temperature then re-tighten the heater block and nozzle at the maximum temperature you are going to use (this is what seals the hot end). Then ensure that the Bowden tube is seated properly into the hot end, but don’t apply too much force or that can cause the end of the Bowden tube to constrict.
OK, thank you. I will try all that. I’ll have to get some dichloromethane - I have acetone, but I don’t think that does much with PLA does it?
I’ll take it all apart tomorrow and see how that goes.
Cheers
Steve
Dichloromethane is the best solvent for PLL and PET, but for PLL hot tetrahydrofuran does work to some degree (tetrahydrofuran is an indifferent solvent for PLL at low temperatures).
Today, I’m indulging in my very favourite task.
In the kitchen, taken the double oven to pieces, and giving it a proper clean.
Sometimes, the fun just never stops, does it? 
2 Likes
We have a guy called Mr Oven that does ours.
1 Like
Ah, but I’m doin’ that self-isolatin’ thang. 
1 Like
I cut a hole for the hatch in my newly glass fibred deck. Broke my heart!
Too cold for epoxy today.
Bruce
(I also splashed out on some headphones-more later!)
10 Likes
Skilz 
1 Like
Xanthe - many thanks for your advice. Today I received some replacement nozzles (they are so cheap for the standard brass ones) and it is currently printing the test piece, and it is looking good so far. What a relief. I can now tray the main print (which is very large - about 400mm long).
Thanks again - I can start sticking my hair back on for future use.
The largest print I’ve done so far took 11.5 hours even sliced at 0.3mm layer height.