Printing and product quality issues


#1

Since 3 weeks I am trying to work with the k8200. Up till now I am unable to get proper results.

As an Industrial design engineering graduate I have been building and working with 3D printers (Ultimaker & many REPRAP variants), but never have my efforts been so frustrating and disappointing as working with the Velleman k8200.

Some of the issues encountered;

  • bed is not flat due to insufficient rigidity of the aluminium base and the way it is fixed by four screws (they cause the bed to bulge when tightened) (bulging also caused by screw holes through heated bed being too small, they needed to be drilled to a larger diameter)
  • bed gets even more dome-shaped when heated (as many others on this forum I too added a glass plate to overcome this problem)
  • bed is unable to reach 60ºC at ambient room temperature (this causes insufficient adhesion and warping when working with ABS)
  • in factory configuration the bed is hard to get level due to the placement (hard to reach, too little space) and length (too short) of screws
  • screws (levelling and limit switches) have a tendency to loosen while the printer is in use, it is necessary to adjust and tighten them before every print
  • wiring is insufficient to supply the power needed to heaters and motors and are a pain to strip and solder (I had to replace them)
  • filament feed is not guaranteed (I replaced the bearing of the feeder assembly, but after many hours of experimentation (spring tension, increased motor amperage) it is still not trustworthy)
  • the metal lip of the limit switches are so loosely fitted (they are able to rattle sideways) that the screw with which the axis limit is determined is able to miss the switch if not carefully positioned (this needs to be checked before every print to avoid scary collisions and the possibility to burn out the motors) especially the z axis is problematic, since the adjustment screw and the limit switch are not properly aligned
  • screws with which the x and y axis limits are determined are very hard to reach for adjustments and tightening
  • the supplied threaded bar that needs to function as a z axis lead screw was significantly bent (I had to replace it with a straight one a layered cake effect due to variations in layer thicknesses)

The design is a direct copy of the open source 3Drag design. (source: http://reprap.org/wiki/3drag) Velleman did not had to invest much in product development.

I was seduced by the sturdy looking aluminium frame and the benefit of not having to source all the components myself, but after three weeks I am having a hard time to justify my 700+ euro investment.

Please respond.


#2

I have to say Im begining to come to the same conclusions. I printed a part off earlier on the works ultimaker and its printed correctly. Same part i had about 6 attempts at at home using the K8200 and one problem or another has caused issues.

Certain items needs to be addressed, and if needbe replaced FOC as out of the box the unit is not fit for purpose regardless of home assembly or not.


#3

I’m an electronics engineer and very good in electronics but a big disaster in mechanics (even nailing 4 planks together is an invincible barrier for me). Nevertheless I managed to put this thing together and I found it relatively easy, although it took about 10 hours work. These are my personal comments on your problems (in green text).

[quote=“wiscon”]Since 3 weeks I am trying to work with the k8200. Up till now I am unable to get proper results.

Some of the issues encountered;

  • bed is not flat due to insufficient rigidity of the aluminium base and the way it is fixed by four screws (they cause the bed to bulge when tightened) (bulging also caused by screw holes through heated bed being too small, they needed to be drilled to a larger diameter)
  • bed gets even more dome-shaped when heated (as many others on this forum I too added a glass plate to overcome this problem)
    [color=#008000]These points above: this is a problem and I also used the trick with the Ikea mirror. Although I heard from a mechanically intelligent person that you can solve it easily by making the mounting holes of the heated pcb a bit bigger in the right direction.[/color]
  • bed is unable to reach 60ºC at ambient room temperature (this causes insufficient adhesion and warping when working with ABS)
    [color=#008000]This is not true! I agree it takes 15 to 20 minutes, which is way too long but it DOES work! I used a schematic found on this forum also to power the heated bed with a 20 Volts supply from an old laptop. This works much better and faster. I even get 70 degrees within a number of minutes.[/color]
  • in factory configuration the bed is hard to get level due to the placement (hard to reach, too little space) and length (too short) of screws
    [color=#008000]True but space is limited. When following the instruction to the letter (what I had to do because of mechanical disaster), no much adjustment is needed.[/color]
  • screws (levelling and limit switches) have a tendency to loosen while the printer is in use, it is necessary to adjust and tighten them before every print
    [color=#008000]This is absolutely not true! Follow the instructions and if they say you have to fasten certain things, then do so. I’m printing 3 months now and I’ve never had to refasten one screw or nut.[/color]
  • wiring is insufficient to supply the power needed to heaters and motors and are a pain to strip and solder (I had to replace them)
    [color=#008000]Not true! Wiring is just about sufficient enough and stripping of the wires was totally no problem. Did you use the correct equipment?[/color]
  • filament feed is not guaranteed (I replaced the bearing of the feeder assembly, but after many hours of experimentation (spring tension, increased motor amperage) it is still not trustworthy)
    [color=#008000]Absolutely not true: NEVER had a problem with that. Even with difficult pieces where the filament is regularly taken back and forth, I’ve never met such a condition.[/color]
  • the metal lip of the limit switches are so loosely fitted (they are able to rattle sideways) that the screw with which the axis limit is determined is able to miss the switch if not carefully positioned (this needs to be checked before every print to avoid scary collisions and the possibility to burn out the motors) especially the z axis is problematic, since the adjustment screw and the limit switch are not properly aligned
    [color=#008000]Again: not true UNLESS you did not follow the advice in the instructions about which screws should be fastened well or not (see the same problem about fastening screws you mentioned earlier: these problems are correlated)[/color]
  • screws with which the x and y axis limits are determined are very hard to reach for adjustments and tightening
    [color=#008000]–> Not very hard to reach, just difficult. Tightening had to be done in an earlier step of the proces when it was easier to do -> did you really follow the manual by the letter about how fastened the screws needed to be?[/color]
  • the supplied threaded bar that needs to function as a z axis lead screw was significantly bent (I had to replaced it with a straight one)
    [color=#008000]Mine was straight but this can happen. I agree.[/color]

The design is a direct copy of the open source 3Drag design. (source: http://reprap.org/wiki/3drag) Velleman did not had to invest much in product development.

I was seduced by the sturdy looking aluminium frame and the benefit of not having to source all the components myself, but after three weeks I am having a hard time to justify my 700+ euro investment.

Please respond.[/quote]


#4

I think your missing the point.

The kit should be assembled as per the instructions and ready to go after calibration.

Not a case of having to modify parts here and there.

Ive re-wired the heater and heated bed wires now and bed is possible to reach 60°C easier. Mechanically bit seems to fall off here and there despite using thread lock. one particular print i left running the bearing holders detached from the bottom plate… Nice mess that was…

If a sheet of glass is the Velleman approved method of ensuring the bed is flat then a sheet of suitable glass should be included in the kit of parts.

Never had extruder feed problems. However am having slicer problems and software inconsistancies.

Vibrations Im hoping to reduce by replacing the belt pulleys with pulley the same as on the stepper motors. watching the belts rotate on the bearing outer diameter my printer steps over each tooth.


#5

Please read my whole story: I assembled according to the instructions and the only real problem I had was the bed that wasn’t flat. The easiest way is to add an Ikea mirror but with a file, it is perfectly possible to do it without mirror. So because I am too lazy to take a file, Velleman can’t be obliged to include Ikea mirrors ;). Velleman did not approve the use of Ikea mirrors, people (owners of the printer) on this forum did.

So there is no real need to modify parts, it are just improvements. My printer did work out of the package but now it works just better.

When you fastened the bearing holders enough (see the manual), they wouldn’t have become loose … I’ve never used glue to keep nuts and bolts in place. Everything is “natural” here.

Software also worked from the first moment. Although, like posted everywhere, for some parts I created another profile for the slicer. This is normal as there is no profile that is 100% suited for every object to print.

I don’t have problems with the bearings the belts run over but I agree this can be another improvement, but as I said: this is mechanics and I’m not specialised in mechanics ;).


#6

Thanks Skudman and Laserguy
Laserguy, I have to agree with Skudman; you are missing the point a little. (Yes, I read your whole message, I am pretty sure Skudman did as well). Of course I do believe that your experience differs from mine, but that is not the point here.

I too assembled according to instructions and I am familiar with building/designing machines (it is my job :slight_smile: I am curious why you are called Laserguy (honestly, I am! Do you work with systems involving lasers?) My day job at the moment is designing mechatronics that uses lasers to determine the temperature of gasses inside an experimental reactor).

The point is that this Velleman product and build experience is simply unsatisfactory to justify a 700 euro investment and hours/days of lost time. It has been quite frustrating and after hours of effort the result still is disappointing. That wasn’t the idea of buying a kit. Like Skudman wrote, I too think that the kit should be assembled, calibrated and then ready to be used. I don’t think many of the k8200 owners were that lucky.

In retrospect, I think I was better of buying a kit that I had experience with (Ultimaker that I had to build at University) and provide me with the results that I expect.

Dear Velleman, this experience makes me a little sad, since I am building your kits from the day I became 11 :), but at the moment I am considering to send the k8200 back to you and ask for a refund.


#7

Ok, your point is:
The kit should be assembled as per the instructions and ready to go after calibration.
Agree?

As per instructions and after calibration: it worked for me. So I don’t see why you are complaining: I just followed the instructions to the letter and it worked. Do the same and it will work for you. :wink:

All the rest is tweaking and improving to your own taste.

Yes I work with show lasers (a few 100 mW to 11 Watt RGB).


#8

Here is someone with a similar experience as mine:
http://www.mustun.ch/michael/works/velleman-k8200-erfahrung/


#9

Yes, there are people who have problems but in relation to the number of devices sold, it is only a very small number.

The Swiss person really mentions things that are simply not true: the wires are not extremely hard to solder and not too thin. It can be your opinion but therefore it is not the truth: these kinds of cables are soldered by millions of people a day without them being rocket scientists (that’s a fact!). Measure the voltage drop over the cables: everything is within very reasonable limits (that again is a fact!).
Rusty elements in one night? Sorry, impossible under normal circumstances. These things are oiled. Ok, afterwards you should oil them further but they really don’t rust in one night …
One thing I can agree with: those 5 meters PLA are a joke indeed ;).

Like a customer in the industrial CNC scene once said to me: if I want the precision of an industrial printer, I’ll pay this price twentyfold or even more.

Problem is that people who have no problems almost don’t post blogs or messages … this gives a wrong impression of the situation. Again: I built this printer myself and most of the issues with bolts and nuts becoming loose are not an error of Velleman’s but of the people that did’nt stick to the letter of the manual while building it.

Things that can go wrong and are product faults are: a bed that is really bent from the beginning (before mounting), a Z rod that sometimes gets bent by transport, a controller board that is not perfectly flashed, belt gears that are not perfectly centered and defective motor. But these things get replaced by Velleman.


#10

Hi,

I read the remarks on said swiss website before I got the printer, decided I’d still try it and have to agree with the previous post. Apart from that weird suggestion to print a board cover needing 7 m PLA with only 5 m included, the instructions did not fail me.

Since this is just another branch of RepRap, it should be clear that this is no industry standard device. It’s not about investing money and loosing time, but investing time and creating “things”, knowledge, etc.

Well, my 2 ct. YMMV.

Cheers,
kuraasu


#11

I have to agree with laserguy, I managed to build it without any problem and I must say that the manual is actually quite good. The printer is working fine, no problems with software etc. It took me some time to adjust the mechanics to make it run smoothly but that was all. The only thing I have to do now is play with the settings to make the prints look and feel nicer. To bad I don’t have the time right now for this. I am not a mechanic guy but some of my collegues are and they think it looks good.


#12

I have built 2 of these and they are working great.
The only problems I had is when I skipped a step.

I also read on this board and the FAQs about the bed.
Now I’m just seeing if I can get it to print better by making some of the things that others have.
Motor mount, fan nozzles thing like that.
I have no problem with things sticking to the bed.
It seems the more I use and clean it the better things stick.

For the price point you will not get a better printer.


#13

haha, ok ok, since you are all so very factual :stuck_out_tongue: I guess I have to admit that I must have been spoiled with previous Ultimaker/Mendel experiences and expected similar results from the Velleman printer. (Yes, Wrong way, that machine (Ultimaker1) is indeed twice as expensive as the k8200)

Still, my opinion remains. I feel it is bad practice what Velleman shows with this product.

I am sure some of you will hasten to “correct” me again and again. Its all due to my lack of skills, right? 8) Well…, I have a working printer and it does print. However, like the title of this thread says, I am not happy with the quality of the printer and not happy with the quality of the printed objects. Many suggestions and solutions are given on this forum to improve the k8200, that is much appreciated and enjoyed. Still, I believe Velleman could have done a better job, even within a retail price of 700 euro.


#14

I think the price is ok for the printer. Even though I was used to in the past better by Velleman. It is an open development and it also no secret was made. Most of the problems likely to be caused by manufacturing tolerances. Even people with other types of printers have similar problems. Note also that it is a kit. Meaning: It is not tested and equalized finished device. And the least likely to actually have experience in assembling such devices. There are actually all just little things but clearly reflected in the printing results. I hope here is a little further developed on the device by Velleman.


#15

Its a bargain basement printer we all knew that when we brought it. I was intending to buy a Thingfarm 1 but at the time they had stoped supplying them. Im not by anymeans incapable of following instructions, in fact ive been responsible for assembly guides for much bigger assemblies than the K8200, And Ive been in the Electronics/Mechanical design industry for the last 20 odd years. Fact is though I followed the instructions to the letter and Ive yet to have had good results. We have had a Ultimaker here at work for over a year now and the results are astounding, yet again though without Instructions issues and poor quality parts. We have rectified most of the issues over the last year. Ive had the K8200 for almost 3 months now and not really progressed from printing crap. If you read the instructions only the 0.84 version of repetier is supported, only on this forum did i discover that there are configurations files for 0.90 and that it is supported. My biggest bug bear has been the wiring and the bed. and its those areas that everyone on here is saying its all ok… but hardly any of you are using as “stock” per instructions. If this is the prefered method even suggested by velleman why arent these suggestions being rolled out by velleman?

At the end of the day i expected to be able to build the printer as per the instructions and have a printed part that was fairly representable of the 3d model on screen give or take layer lines and support material locations.

Yes im happy to pimp my K8200 with a bit of bling… but like the ultimaker should i have had too?

not anywhere is it stated…

The affordable budget printer from velleman that might print ok providing you join the forum and redesign the whole thing as per the forum members have…


#16

Both of the printers are still stock about the only change I have made is I printed the fan nozzle for both
I have made the mount for the Z axis but have not installed it to busy printing other things.
I think I can get better prints out of it but I do not expect print quality from a $20,000 machine.

If you look at some of the post you will see few post from others that are just starting out
They have to build the machine (this gives them a better understanding of it)
Then trouble shoot it (still a better understanding) then use it.
All of this without breaking the bank.

If you look on thingiverse there are a lot of parts being made to improve a lot of the other printers as well.


#17

just wanted to throw my hat in the ring I’ve had my k8200 up and running for two weeks in that time I’ve been very satisfied with what I got for the money. Now some may have expected a high end printer for entry level money. But it was pretty obvious from the start even before I bought your printer it was a work in progress, or a great place to start is the way I look at it. yes I had trouble with warped bed and broke my thermistor trying to flatten, then got out my countersink bit and enlarged holes. no problem. parts curled or detached mid-print so I used 180 grit sand paper and wipe bed off with a bit of acetone on more problems. I find it very satisfying to solve problems and fix bugs. I have learn 10 times more this way than I would a “plug and play high end printer” not that I can afford one. I plan on adding a fan on opposite side of print head, and add a shroud around hot end but this is what makes this my printer. and by the way I’ve been in industrial technologies since ten years old or before my father was a world class geek before geeks were cool.I studied at Oklahoma State University electronics and industrial technology/process controls just for starters. programing is my only weakness. but this build was simple by the book and good instructions is a understatement thank you for the k8200.


#18

Update as of October 2014. My experience is that the K8200 still sucks. It is a deign disaster. Underated power supply. Bad Z-Axis. Crummy print bed. No support. Parts not available. It goes on and on.

Velleman makes a ton of kits, but they should be ashamed to lend their name to the K8200 POS!

I’m getting some 1/2 decent prints after two months of experimentation with parameters, but overall the quality of the prints is vastly inferior to other products. I’m going to be scrapping the K8200 and buying a decent printer. No more throwing good money after bad. For example, why buy a better extruder when the power supply can’t handle it anyway?

Now there is a 2 extruder 1.75mm K8400 that you couldn’t give me for free! I’m going to do everything I can on the Internet to discourage new victims from wasting their money on Velleman printers. If the company really cared about their reputation and about their customers they have had plenty of time to address problems that have gone unsolved for two years.

For those who can’t bring themselves to admit they made a mistake, don’t bore me with your stories of how you fixed up your K8200 by spending a lot more money on it than the original purchase price. It might have been a “bargain” two years ago, but time marches on. It is now overpriced and vastly inferior to other products such as the new Dremel that is a rebranded Asian printer. Here in the USA, I can drive 10 minutes to the nearest Office Depot and buy a printer off the shelf that is supported by Office Depot. I suppose the greatest problem Velleman has is its attitude that no support is necessary for a kit because kit builders are not average consumers.

Shame on you, Velleman. Withdraw the product instead of recruiting new victims.


#19

Sorry that the K8200 dissatifies you. That is not an enjoyable feeling. I understand.

Power supply was a weak point indeed. It is not very underrated but the quality the manufacturer of the power supply delivered, is indeed below the normal levels of Velleman. This is not something Velleman could knew before: they just tested with some examples and ordered then a few 1000 for production. This can always happen. How many Chryslers, BMW’s, Toyota’s need to be recalled because some component faults?
For the “bad” axis, there are plenty of solutions you can print yourself. See thingiverse. Like hightechredneck also says: this is also the case for other printers.
Print bed is good but prone to warping. People solved it with Ikea mirrors, Velleman saw this, checked it and Velleman created a glas bed that fits perfectly (better than the Ikea mirror). Problem solved, thanks to the community and Velleman’s concern.
If you type in the search function of the Velleman site “K8200”, you will find more than 17 parts available. When you bought this printer at a good dealer, he will almost be able to get any part for you. Parts not available is simply not true! You can be dissatisfied but that is no reason to tell plain lies.
Quality of the prints here is good in comparison with other printers in the $300 - $1500 range, the very sturdy quality aluminium frame is partly responsible for this good quality. This is also confirmed to me by professional CNC users. The new ultimaker of $2200 prints better. I agree. But the price difference is 70% at the moment.

So all the minor problems are fixable with a bit of time and a few dollars (certainly less than $30!). So that is not a lot more money than the original purchase price.

Velleman tried to make it easier on the parameters by taking a Repetier partnership. You could download that version for free. This helps a lot. And you can see that as a service/support from Velleman because they were not obliged to do that: they could simpy give a list to input yourself in Repetier.

For every problem I or my customers had with the K8200, we always found a good and satisfying solution. So no support is a total lie again. See also this forum where staff of Velleman (even after their working hours!!) always tried to give the best support possible. I can tell you from my experience that there are much bigger and more popular ánd more expensive brands that give a very bad support! At Velleman you get support within 24 to 48 hours. The other one I have experience with waits several days or more than 1 week before answering a support mail!

Please try a printer from Office Depot and tell me how fast they react when you send them a support question by mail? Ask them how many spare parts they can deliver and how long it will take? Do they also have a community that enthousiastically tries to help you all around the world, 24/7?

I know you are dissatisfied and I’m sure you have your reasons for that but please don’t let yourself blind you by anger. This only costs YOU energy and what benefits you have from that wasted energy? There is beautifull quote that says: “Holding onto anger is like drinking poison and expecting the other person to die”.

Velleman always told me that this printer was NOT a plug and play device. It was not meant for people that wanted it to work like “a normal plug and play HP printer”. Some tuning would always be necessary. I always told my customers that to be very honest with them about what they should expect and what not. I think you are given a wrong advice by a seller that did not know what he was selling or that mislead you in some way. Both of them are a shame and it is unfair that you are a victim of that. However: the community is still here, Velleman staff is still here. If you are open to a constructive dialog and open communication, I think you and us can work together to get the best out of your printer. But therefore you should, as a human being, be able to be bigger than your anger.


#20

Laserguy, let’s zero in on a single issue - parts. I live in the USA and there is a Vellerman USA office in Dallas, Texas. I found a distributor who has a friend at Vellerman Dallas who says they cannot get certain parts. I ordered and paid for a controller board which I cannot get. My distributor cannot get it because Vellerman in Dallas cannot get it. Every USA distributor I can locate on the Internet says the controller boards are not available at this time. I only found one distributor who claims he can get the board, but not for another 1.5 months. The latest revised promise date is sometime around the end of November. This is for a vanilla Arduino board!

I want spare parts for my extruder. Velleman Support gave me a part number EXT8200FG for the nylon extruder throat. They claim it is available without buying the entire extruder. My distributor (the guy with the friend in Dallas) never heard of it. I cannot order it or buy it without buying the complete extruder.

I want a replacement gear (the large one) for the extruder. It is not sold separately - you must buy the kit of all plastic parts which is expensive. There were spares of the small gear in the kit, but even then you must tap and supply your own set screw to use them.

There are certain parts that are going to fail. Having spares for those parts is part of the cost of ownership IF you can get the spare parts. I don’t know how many customers are in the USA, but I’d hate to be an owner living in a less populated country unless it was close mailing distance to Belgium.

I don’t know what part availability was like in the past, but at the present time certain parts are impossible to get at any price.