Prusa i3 - Increasing Precision And Stability?

Hello fellow reprappers,
Ive been getting to know my trusty Prusa i3 for the last 6 months or so and i have printed some nice pieces on it, however, the quality of the prints can vary, sometimes it comes out perfect, other times the layer stacking will be fractionally out (similar apperance to Z banding), this shows up more on flat vertical surfaces. I want to use this printer as a print farm machine, which means i need to improve the precision of the layer stacking / print quality and increase the overall stability of the printer to ensure more consistent high quality prints.
I have the single sheet version of the i3 (rework) and although its very nice to look at, the lack of support on the main frame seems to me to be abit of a failing, dont get me wrong, the frame isnt flapping around or anything but i can feel it resonating while printing and cant help but wonder if it is contributing to some of my issues.

To address this i have found this,
[www.ebay.co.uk]

I know its MDF and not aluminium but the design itself looks to be much more stable, i am not aware of any direct comparisons of the print quality between the MDF frame and the single sheet frame so i could be way off base with this.

I love the look of the new makerfarm Prusa i3v and would definitely upgrade my printer to run on vslot extrusions but i cant seem to find any instructions on how to do this.

The other thing that i will do to increase the precision of the Z axis is to replace the standard m5 threaded rod with tr8 leadscrews although im unsure whether or not to get the motors with the leadscrew built in to them or to get some leadscrew rods and use flexible couplers.

Im running an E3D-v5 with a 0.4mm nozzle so i could get a smaller nozzle, perhaps 0.25mm although i have read that some people have issues going down that small, im already running gt2 belts so i dont think i can do much with the X and Y axis' except perhaps switching out the lm8uu's and replace them with bronze bushings, im not sure if this would actually help though.

Well thats my situation, please feel free to correct anything ive said that is wrong or if anyone has any other suggestions i would be more that grateful to hear them

Steel lasercut frame.done

I haven't seen a lasercut steel frame anywhere, i bet it would be quite expensive, i'm not sure if it would anymore stability than the MDF version. I still havent found out for definite if having the full frame provides better quality prints over the single plate version, in theory the Lasercut MDF should be better, anyone know if it is or not?

No,mdf or alluminum could never be better. Why? Im 3d printers like in all CNC machines strong rigid heavy frame provudes better stability..

Now you will ask...why everybody uses extrusions,mdf,dibond? Becouse its easy available.

I have now fast on 300,infill on 90 and perimeters on 50 mm/sec with acc on 3000. and prints are same like on standard I3 with much lower speeds. And it goes faster,i just dont need it


Btw my frame waz 2 beers in local metalwork shop.

These frame stabilisers (thingiverse.com) may help solve some issus.

Quote
3dkarma
These frame stabilisers (thingiverse.com) may help solve some issus.

agree, i had one set of thoose when i had classic i3, its huuge improvement

I'm planning on purchasing the I3 kit soon, but I'm as well concerned on the lightweight and lack of support of this machine. I have access to plasma cutting service and I thought to order the frame cut 10mm steel and weld a support structure similar to the frame stabilizers beforementioned onto it. I also planned on mounting the whole machine onto a thick plywood plate (20-30mm) which I would place into sound insulating container.

The vibrations will certainly decrease the print quality, but into what extent it can be decreased by rigidifying the machine is a different question, because the moving parts' assembly will be the weak point. In very high accelerations the belts will certainly stretch a little and the extursion assembly would vibrate.

These issues are of course more of those matters who need to farm with their machines. Someone making some single parts for random times and needs can use such low speeds that the most lightweight frame will suffice, but anyone looking for making more than few parts in decent time will certainly face this issue.

plasma cutter is not precise enough for frame. try laser