I crimp things with pliers that's fine. There are ways of building a hotend without kapton tape, if you are happy to have non insulated wires dangling about. There are other high temperature insulation materials, but kapton tape is easy to use since its just like sellotape that works at very high temperatures. However: DO NOT USE NORMAL ELECTRICAL TAPE ON THE HOTEND OR ON ANY WIRES NEAR THE HOTEby konwiddak - Reprappers
Have you considered that your hotend may be cooling down when you start to print? Marlin will refuse to do a print move if the head is below a certain temperature, but will to any other kind of move. Maybe your "min temperature" in firmware is quite high and the movement is cooling your hotend down below this temperature.by konwiddak - Reprappers
Are the new couplings solid plastic or do you have to put a bit of rubber on the end of your motor? A rubberised coupling is far superior to a solid one! Changing to M6 z-axis screws is another good change. I changed to M6 threaded rod and 4.8mm ID fuel hose as couplings and the results are very good! Are any of your z screws slightly bent (roll them on a piece of glass or other flat surface toby konwiddak - Reprappers
Bending stiffness is proportional to the 4th order of the radius - hence why 10mm rods are much stiffer than 8mm. Within stars you can get some silly size power approximations of exponents. The helium flash in a star has a reaction rate proportional to the 40th power of temperature! (according to xkcd) Not relevant but quite interesting!by konwiddak - General
I used to have my printer in the garage, it was probably sub 5C in there. My hot-end took an age to get to temperature but it did print. The parts came out a little weak, but this could have been due to other causes. Comparing 190C Pla to 20C in my room and 5C in the garage, it's not a massively increased temperature difference. I think it would need to be really cold to be completely unable toby konwiddak - General
Just looking at your print though, that has got to be something mechanical, the spacing of the lines is too perfect to be temperature methinks.by konwiddak - Reprappers
I've had the same issue, lovely prints slightly ruined by banding. Two main causes come to mind. 1) z-wobble 2) Temperature Variation To test which it is, turn off any minimum layer times (important to ensure the next step actually takes twice as long) and print at a suitable slow rate a hollow cylinder. (or other similar non-plastic wasting object!) Then with the same settings print two cyby konwiddak - Reprappers
That looks like a very nice print! Now you have installed a fan you probably don't need to limit minimum layer time as much as I originally said. You will need to experiment, 15 seconds is slower than needed without a fan in my experience, but it's a good starting point that should work. It's still useful to have a layer time limit even with a fan since it really helps parts that finish at a pby konwiddak - Reprappers
Have you got the "cool" function enabled in slic3r. Try setting it to 10-15 second minimum layer time and perhaps 3mm/s minimum speed. If this works gradually speed it up until small features are ok.by konwiddak - Reprappers