How good is a sub ?100 3d printer ?

[curious aardvark]

Adding this here just in case you start somewhere in the middle and miss all the stuff that happened before I printed anything -
DO NOT BUY ONE OF THESE AS A FIRST PRINTER !
THEY ARE A FIXER-UPPER !. iF YOU DON'T HAVE THE EXPERIENCE OR KIT TO DO THE FIXING UP - BUY SOMETHING ELSE :-)

Every now and then I look on ebay to see how cheap the cheapest brand new 3d printer in the uk is.
Last week they'd dropped to just under ?80 - which is ridiculous. I mean, this is with courier delivery for a large box weighing about 20lb.
I can't believe that they can go much lower.
I didn't want a used machine - this is all about brand new printers with that just finished factory smell when you open the big box of bits :-)
(also how come the forum no longer reoognises uk pound signs ?)

You can also get a delta kit virtually identical to my he3d k200 for ?125 - my k200 was just under ?200, about 12 months ago.
If I just wanted another workhorse - that's probably the route I'd have gone down, as it could sit on top of the existing one.
I was going to get a monoprice mini-delta - but they're ?160 and I don't want to spend that much at the moment.
It's still on the list - but not at the moment. Hoping they'll drop the price to match what it costs in the states, which is actually less than ?125.
It's a helluva good deal across the pond - not quite so good over here :-(
I will be having a moan about that at the monoprice stand at ctc, at the end of the month !

So this exercise is all about much cheapness and how good a machine you can have for under ?100.

So at this moment in time there are actually three machines on ebay that ship from within the uk, for under ?100 including delivery.

The standard a8:


The 2018 a8 with a more rigid improved frame:


And this weird thing: X23D i3 3D Printer:


There are some dodgy looking plastic deltas that ship from china - but after tax they'll be over ?100 anyway - plus are really really nasty, use printpens for extruders - yeaurggghhh.
Now the thing above, I would not get for a number of reasons. It looks a little like a creality ender 3 - but don't be fooled. It lacks all of the decent features of the ender3.

The single left hand z screw is something I would avoid, coupled with a heavy cross bar and wheeled carriage, just screams uneven print.
Also the bowden extruder on an i3 - why ?
Then there's the single central rail for the heat bed. Really don't like that. Just looks fundamentally unstable.

The basic W5 a8 has a 220x220x200 build volume (well some ads say it does, some say 200x200x180).
That was tempting.

So I've ordered - about 10 minutes ago - the ctc 2018 a8.
why ?

Primarily because it has a more substantial and rigid looking frame.
Also it claims it comes in only 5 pieces/modules and apparently can be put together in about an hour.
I liked the sound of that.
So other things I like: dual z-screws, direct drive mk8 extruder, which i can modify for flexible filament in about 10 minutes.
Dual support rails for the heatbed - looks pretty stable and hopefully won't need calibrating too often (although we'll come to that).

The frame is plywood - okay pros and cons.
Not as rigid as aluminium - but real easy to attach stuff too with wood screws or bolts.
The build volume is larger in the x&y than any of my current machines - so that's something I can really use.

I have also ordered a sheet of 0.5mm pei from china for ?4.84. Considered printbite, but that would have pushed the cost over the ?100 limit, so decided to try it's poorer, and much much cheaper cousin.
I'll stick the pei directly to the hotbed with double sided vinyl tape. If I need something different I can get a sheet of 3mm aluminium and make some clips. The aluminium would not cost me anything as my local aluminium engineering firm, still owes me :-)

From the pictures: It needs a print area cooling fan - I have some turbo fans in stock, they were just over ?1 each i think.
It also needs an on frame filament holder - not a problem.
I also need to get an inline switch and make a power cable with an on off switch. No idea why the chinese don't think on/off switches are necessary - I like them :-)
So that's ?2.86.

Initially I don't see anything else obvious

So currently I'm at about ?88.
A knock off bltouch leveller probe can be had for around ?10.50.
Not sure I'll need it as the printbed has my favourite - knob at each corner - levelling configuration.
But it's in budget should I feel like buggerng about with one at a later date.

The printer should get here tuesday or wednesday.
So watch this space :-)

Oh yeah one thing my beady eye noticed was that the adverts state that the machine uses .x3g files.
Suggesting that ctc had a bunch of their makerbot clone motherboards stacked up in a warehouse and when they stopped making their clones, decided to use the boards in an i3.
As I plan on using simplify3d anyway, this is not an issue for me.
But it potentially gives a motherboard that can do dual extrusion, should I think about playing with a 2-into-1 extruder setup in the future.

I wouldn't go for another dual nozzle setup - while easy to do - it's a real pita lol