UM2 Top Surface <-> Firmware Poll

[Nicolinux 288]

Hi,

In order to structure data on a possible cause for top surface problems on prints with the UM2, I have started this poll. For more informations please see:

 

• http://umforum.ultimaker.com/index.php?/topic/5375-top-layers-not-touching-um2/
  

 

[varsanyy 0]

Hi

I have the same problem.

I used 14.03 when the last correct print was made. so i tried all of them since 14.03. but nothing was changed. Then i reinstalled .

now i do print at lower and lower speed but it is not the solution

András

 

[gixxer 1]

I've had this problem from time to time. I've only noticed it with PLA and some filaments are more problematic than others.

There's a light blue from colourfabb that was particularly bad. I've found that I've always been able to overcome this issue by going hotter and increasing the material flow from 5 to 35%.

I find that I have to print at 230°C minimum and as high as 250°C. Print speed is never slower than 50mm/s.

Nicolinux I did see in a previous thread that you'd increasing temp and flow with little improvement. It might be worth oiling the pla as it enters the feeder. Sounds mad but I found that after running some ninjaflex with had to be oiled, when I switched back to pla there was dramatic improvement in flow.

If I need to speed up a print for some reason I add some fellows performance shredder oil and crank up the temp.

[Nicolinux 288]

Thanks for the info. You know, we do all sorts of tricks to improve quality but really, the hardware should handle it. There is no justification to print PLA up to 250°. It should print fine as low as 200° or even 210° - regardless of the filament. What we are doing here is trying to overcome some problems that shouldn't be there in the first place.

 

[gixxer 1]

I've only had my um2 for a month or so now and as used for work I've the luxury of ordering many different types of filament to experiment with. The one thing I've noticed is that there are vast differences between brands and especially colour within the same brand.

So I don't think it's especially hardware related but more the feed-stock you use. That's not to say there isn't improvements that can be made but, let's remember that we are not dealing with company's here that have millions to throw at R&D (which would then undoubtedly be closed source).

I'm sure if you where to purchase a £20,000 commercial printer using there proprietary filament the number of variables when printing would be vastly reduced. I'd like to add at this point that from the research I've done the Ultimaker2 seems to be one of the most reliable printers out there at this price range.

Let's also acknowledged that the flow rate (layer height, nozzle size and speed) we print at dictates the temp we use. Having said that I've never had good results printing as low 210 as some people on here seem to. Perhaps if I where to go as slow as 20mm/s but I don't have quality issues at 50 so why go slower

In an ideal world some clever person needs to develop some sort of flow matrix that would adjust the temp and feed rate dependent upon the chosen speed. However with variability between the different filaments and even the individual printers this would be very difficult.