The thicker wire, to push in from the top, should be 1.6 mm in diameter. The length is about 110 mm.
The smaller wires for the nozzle are 0.2 mm in diameter, length 25 mm.

Material: stainless steel.

The XYZ support says, that it is a problem of the z-offset, that I have to make sure, the belt tension is correct and that I have to clean the nozzle.

I dismounted the device partly, to find out, what the real problem could be. So I discovered it, solved it and found, that the support persons of the manufacturer do not have any experience and not any know-how about the function of their machines. Nothing.

Because I bought it more than 6 months ago, there is no warranty left, altough I never used it. So by fact, it is a NEW machine.

I did a lot of work on this printer. Unfortunately I do not have any pictures for documentation.

I lowered the pressure on the feeder mechanism by reducing the tension of the spring. It had a force of about 3 kg. This high tension causes the stepper motor to block, if only a small amount of higher force is required, to feed the filament - hearable as a "clack, clack, clack" with an optical vibration of the filament at the same beat.
I lowered the tension to about 300g, by the use of a screw driver to increase the spacing of the springs windings. The feeder is located on the upper left side of the printer. You have to unmount the half of the case, to be able, to reach it.
The force is estimated by the pressure force on the thumb, to move the feeders leverage.

I also lowered the pressure of the springs in the filament detectors, to allow a smoother guiding trough. There are two detectors, one in the filament feeder, one in the extruder head. To do this, I took the springs out, pulled it to the double of the original length, cutted it in the half and sat it back in.

It is a bit tricky, to open the extruder head. Make sure, not to brake the fasteners out.

I had to fix the entry for the filament on the extruder head with a nylon washer, mounted under the fixation, to thighten it. It was loose and caused a misleading of the filament on entering the extruder.

The metallic cone inside the extruder head had some sharp edges, where the filament was jammed mostly. After smoothening it a bit, the filament was sliding trough without any problems.

Now it prints perfectly.

for nozzle cleaning tool, google "0.4mm Drill Bits" in amazon U.K. and looking for something look like this

https://www.amazon.com/Improved-MK8-Ext … Drill+Bits

Afraid I wont be much help in regards to good suppliers in the UK, but there are plenty of others that should be able to help you out

the top right two item of the above image is what you need.