Prusa Mk 4

That has sexual connotations, though!  although that is/was the Latin for the metal - symbol Pb - atomic number 82, as our long-lost founder Phil would have insisted.

These are the Extruder parts
 
No PTFE tubing here, that filament tube is very long
The drive system is some kind of epicyclic gear box.
Some kind of lever
 
Rollers
 
From the grooves in the bearings I would guess a pinch system for the filament
 

 

No the Extruder drive
 
The round object below the grease tube is the guide for the sun and planet gears, I tried to assemble the gear box without it, you can't.
 
And the finished article, it happened so quickly and you daren't let go until the screws are in so the camera didn't get a look in.

The 3 plugs are the Extruder motor, Fan and the load cell.
 
This is the Nozzle plus the heater and thermistor 

And there it's all together, the nozzle is cleverly held in with 2 thumb screws, a fact that escaped me for a while, it kept dropping out!
The fan on the left is kept closed by magnets, you flip it open to access the thumb screws.

And a close up of the action
 
Open
 
and closed, you can see the filament catch is currently open.
 

Next is the screen assembly, the software uses the now standard method of turn until the required menu item appears, then press to select.
 
On to the heated bed and Y axis, it's a Prusa proprietary item (so probably expensive to replace) The top surface is magnetic.
 
Only 3 bearings and simply attached with a rubber mat between the bearing and the carriage.
 
Note the rubber feet in the X extrusion.
and the top side 
 

Next is the clever bit, it's quite a large casting and the bed is held down with 9 mountings
 
Only the centre screw is solid, the other 8 mountings are expansion joints!
 
all done
 
 

Final covers on
 
A nice touch, space for 2 spools on top each with its own filament feeder.
 

Something not covered in the assembly pdf was the importance of having the X carriage parallel to the bed. I used a wood block between the bed and the X rails. Winding the Z lead screws by hand I carefully lowered the Z carriage down until the rails just touched the block on each side. I did this several times to be absolutely sure.
Finally I downloaded the latest Firmware file to a stick (supplied) and plugged it into the USB socket of the control panel.
Always a moment of trepidation when you switch something on for the first time
.
.
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What an anticlimax, the screen said loading and then wanted to do a first time test. What could I say?

Since it didn't do anything with the Firmware file the on board firmware was already up to date.
The printer then proceeded to drive the axes (axises) up down, left right, in out. There are no end stop switches, it's all done by current on the motor drivers.
Even the fans get checked
You get asked to put some filament in, then take it out again and finally tap the nozzle
Once the check was done I decided to try a test print, there was a file on the thumb drive for a key chain label, I just pressed the button and off it went, bed leveling all done for you at 9 points on the bed. When the bed had cooled I tried to get the label off the PEI plate, phew, talk about baby poo and blankets, I really battled, eventually I had to remove the PEI plate and bend it to release the part.
First print video is here

 


 

Flexing the bed is what I've seen done as well, on a totally different hobby print. The work 'lets go' with a heart-rending SNAP!

Reference post #3, yesterday I received a quality of service request, oh boy, they really shouldn't have done that, I had a field day! Still no communication from BotShop, but the spec sheet on their website has been changed to the correct one. This morning I received a request from a Courier asking me to re-package the item and it will be picked up from the delivery address. Well that's only going to be Friday when I take Mary to the Chiropractor.

Subsequently having the incorrect item back they asked me for my bank details, I'm still waiting for the money.

It wasn't somewhere in Northern South Africa, was it, where that lawyer with the millions of dollars to give away is supposed to live?