I purchased a 'customer returns' PP3DP UP! Mini 3D printer from Toploser and it arrived today.
It was only bought on Tuesday evening so the usual superb service from Toploser
It arrived via UPS in its original box and was well packed. This is very important with a fragile item like a 3D printer as transit damage can be costly to repair.
Toploser had already fired the printer up and tested it so I saw no point in messing around testing it and decided I needed to see what was under her bonnet. There appeared to be few pictures of the inside of these units on the NET so I am providing some quick ones here. Nothing special, just a taster.
Before removing any panels I did my usual 'shake test' to detect any loose parts that could be floating around...... yep she rattled
Upon investigation, via the front door, I found part of a plastic clip. It looked important and I soon identified it as one of the plastic clips that retain the X,Y & Z parallel bars. Time to find out which one was broken. Now this is where it gets interesting. None of the fitted plastic clips were damaged. BUT one was a lighter shade of grey than the others. It served the horizontal parallel bars that support the extruder head. Its bad news when that fails ! The unit had been returned to the original retailer as 'not working'. It is my belief that this was true and that the unit had a failed clip causing the issue. I further believe that the clip has been replaced by a service agent. The unit is now working but obviously could not be sold as new, hence it arriving with Toploser and then me
Ok enough of the forensics, on with the show
I opened the units front and top access doors and these give you a good view of the internal parts. There isn't actually that much inside these units, but a quality build is essential for accurate 3D model making. I was pleased to see plenty of metal and some really nice parallel bars with decent linear bearings running on them. This is a cost reduced version of the UP! so I was expecting to see evidence of corners being cut. Not evident in the linear travel department though
I could see the three stepper motors for the X,Y and Z travel and they seemed decent enough, not some cheap $2 unit as found in toys. The extruder head also has its own stepper motor of course and this is similar to those on the axis drives.
The heated build platform runs on nice linear bearings as already stated. Its action is smooth and the platform looks fit for its role. One platform retainer looks a little bent but I will check alignment height before fiddling as this may be deliberate to get the platform level. Compression springs press the heated platform up on to its retainers, and the working sheet is sandwiched between the two. Decent build quality here too. Much like you would find inside a 3.5" floppy disk drive or modern inkjet printer. In fact the whole thing looks to be a scaled up version of such technology with the familiar bent edge pressed steel chassis to provide adequate rigidity at low cost. It works though and keeps both the cost and weight down.
The Extruder assembly is held in place by three strong magnets
I will be honest and say that I was not enamoured with that design idea but hey, if it works, I cannot knock it, right ?
The X,Y and Z travel is driven by toothed pulleys and belts so excellent engagement and zero slip is assured, just like on a cars cam belt
Belt and pulley quality looks fine, with 'in-line' spring tensioners used to maintain correct tension. No obvious quality issues in that department either
It was time to remove the back cover, behind which the motherboard resides.
The rear cover is held in place by many self tapping screws and this assists in maintaining the rigidity of the metal case around the printing mechanism. Good to see. Once removed the rear can be taken away after unplugging the power switch cable from the motherboard. Nice and simple.
When looking at the printer through the rear, it becomes obvious how little there actually is within the case. This technology is mechanically pretty simple BUT good build quality makes the difference between a decent 3D print and a poor one.
Before I go any further I think it worth noting the following. The UP! Mini is sold with a positive PR spin relating to the enclosure keeping the project piece warm, and away from cooling draughts, whilst it is being printed. I understand such air currents can negatively impact upon 3D prints. Looking at the pictures you will see that the motherboard inhabits the same air space as the project piece and associated heated platform. Also note the number of silver heat-sink's that are present on the motherboard. These are likely drivers for the motors etc. It does not take a rocket scientist to realise that placing a sensitive motherboard, that is producing its own heat, inside a cabinet that is being actively warmed, is not a great idea ! I consider this poor design, especially as there is no forced air cooling of the motherboard. Cooling of the motherboard is via passive convection only, with two relatively small ventilation louvre sets in the rear panel aligned with the motherboard. I suspect that the poor motherboard could get quite uncomfortably hot during long prints in warm environments. The lack of a separate compartment for the motherboard and forced air cooling is IMHO a cost cut that potentially has negative implications for the components on said PCB. It is interesting to note that others have thought the same and have designed forced cooling systems for the motherboard. I shall be doing similarly.
The motherboard itself looks like most Chinese medium quality production and is nothing to get very excited about really. Interestingly the 'CPU' is on a daughter board so that it may be removed. No idea why this is. Looking at the PCB, I suspect that this motherboard is also used in the larger UP! printer. No reason to not do so as the needs of both machines will be almost the same.
The cabling loom that connects to the motherboard is not as tidy as I would like to see but is acceptable. Spiral wrap is used to hold some cables in a neater fashion than having them cable tied or hanging loose. Good effort, but could do better
There are unused connector pads and even a 3.5mm multi pole socket that are not used in the UP! Mini. It would be interesting to know what purpose they serve in other printers. The 'UP! Mini' firmware may not support them however.
The Extruder is a compact assembly that comprises the stepper motor driven filament feeder, the heated extruder nozzle, a PT100 sensor and a small fan to provide cooling of the extruded filament when required (PLA). A small PCB on the top of the Extruder assembly acts as a node for various connecting cables and combines them into a single ribbon cable.
Well that is about it. Nothing more to see really.
I will make comment on improvements that I will be making to the printer in a separate post.
Pictures attached....... enjoy
Aurora