Hello,
I just stumbled onto the K8200 and have the following questions:
Thanks!
–Donn Morse
Hello;
I am by no means a pro with the k8200 or rapidprototyping,
yet, I look forward to some answers to these excellent questions -
I recommend taking some benchmark data or evaluating the k8200 and similar repstrap printer, at a local print club or 3D club at a tafe/uni… besides being a fun way to meet fellow enthusiast etc… it give a great tactile ‘try before you buy’.
The manual says one thing, though it will be great to hear the experienced users experiences hehehe.
the following is tentative, based on my own journal and experience; temps are a combination from the onboard thermistor, and from 3rd party lazer temperature monitoring (similar to as used in bakeries etc). Calibration check is performed at the start of each print job, at the mid point, and after the print job concludes. (some on youtube, have used a thermal camera even, to get a better average etc…)
in the stock scenario, an out of the box k8200,
average safe operating extruder temp is 200-240degree Celsius,
max possible temp, 345degrees (though, this will evaporate most filament)
the machine would melt down at 280degrees onwards…
with the stock heated bed,
max safe operating temp ~75degrees
max possible temp -125degrees celsius.
(considerably less, if you use some glass or mirrored surface instead, such as nesquick/milo tin superpolished and coat with some sealant)
50degrees is enough to ensure cohesion in most cases, or a thin patina of a glue of your choice = )
I can vouch for the k8200 being able to handle ABS - I recommend using a respirator, as ABS prolonged exposure can cause asbestosis-like symptom (similar to sawdust etc), and a well ventilated area - also, check with a landlord if you are renting etc… as some landlords dislike the smell. PLA and to a lesser extent, PETG, smell much nicer, and are less/non-toxic.
(Do not leave an operating 3D printer unattended, or operated by untrained persons or minors, unattended. = )
In theory, provided you use the correct flowrate, hot end and test… yes, it may be possible to use PETG of various diameter.
I recommend using the procedure described in the velleman k8200 manual - mark to find the extrusion rate and flowrate, and test the plastic, then do some test print (a conic segment, a sphere, some 0.1mm holes with various layer height and wall thickness). if that works, and is not so brittle, you have a viable plastic.
This said, from some horror stories at the local print club;
some people were sold ‘filament’ along with another 3D replicator machine from another website, ali-somethingorother bazaar…, which was actually non-thermoplastic whippersnippy cord - attempting to extrude that material didn’t work, and led more to ‘burning’ and inconsistent results hehehe.
I have also heard of creative individuals, attempting to use plastic fishing line, and claiming it works - this depends on the brand - it must be thermoplastic, etc… (usually of the appropriate number and type, as indicated by the little number inside the triangle, and the PDS for the plastic).
It may also produce noticeable layerlines, if you attempt to print spherical or conicsegments, as compared with a scintilated resin printer, such as Form+1… or industrial rapidprototypers like Shapeways. each type has its own advantages
Good luck, and i look forward to seeing what you can achieve, no matter what printer you opt with.
I appreciate the prompt response. Thank you! (This definitely helps.)
I’d purchased a rep-rap clone during the fall of 2013. However, the company I purchased from no longer manufacturers this model and I anticipate the day when I can no longer find parts to keep it running. As a result, I’m looking at my options.
Your info regarding the extruder and bed temps definitely helps.
In terms of ABS, when I was printing with the media I’d noticed the issue with fumes. To address this, I’d created a plexiglass housing and ventilation system to vent the fumes out of my office. Here’s a brief summary https://www.youtube.com/watch?v=kuB_Fyn_eX8.
Again: Appreciate your help here!
–Donn Morse
@Donnmo
Not a problem at all - that’s what we’re here for. = )
Depending on cost - your other repstrap/reprap device can be an experiment bed? Especially, if you try some of the lazer cutter heads/attachment, newer extruder or newer ceramic polymer or different kinds of filament (self-printing PCBs and lazer-etched are almost in home… soon, six axis and sand-vacuum mold in home 3D resin printers will help solve curved printing problems) .
It will be still useful, and most parts are universal enough - the power supply, the motor… it is somewhat the software which is the problem, and the drivers.
(the lab has gone through a couple of allrounder machines - mostly cannibalized earlier gen1)
An ingenious solution to the fume-problem; thank you for sharing a handy link - and, as some sketches are there, there’s some options others can try also.
Having a few friends, some with emphysema, some with asbestosis (from actual asbestos, or from working 20 years in woodwork shop),
it is a horrible way to go, as it not only shorten the lifespan by ~5years, it also take ~15years of quality of life too.
If they had have known, they would have worn all the gear, sure, it can be annoying, but they’d rather have had that extra time of good health.
As for the temps,
I paraphrase somewhat from the official manual here on the k8200 manual thread (i recommend to make some backup copy of the documentation hehe). The tolerance ranges and avg data are somewhat overstated; they’re a theoretical uppermost limit, but, otherwise, the manual and instructions are AWESOME (in many language also).
the range I convey was based on the 3month average, and some others use a daily 365 chart, from the thermal camera etc.
apparently, too warm a main drive belt, and it can throw things out of alignment; too cold, and it might shake (as well the european users know).
Ideally, there would be a slight cavity under the machine, and the machine would be permanently affixed to the printing bay above the cavity, simply to reduce as much as possible any wobble in the frame.
If extending the printing areas, I’d strongly recommend the extra positioning motors, and telescoping assembly (as opposed to drawer runners or curtainrod holder) - some have made magnetic aftermarket trays etc…
I wouldn’t extend much beyond 2m total area, and multiple extruder or Z arms might be more the way to go.
If the connections are made with the quickchange pins, it can easily be swapped out for the CNC attachment, or later, some aftermarket lazer cutter/etcher or engraver.
I’m looking forward to seeing what you can make, with whichever 3D printer you make -
particularly the dastardly “Conic segment with holes” or “127cell” - those are the hard highwater mark for inhome extruder, I find.