Prusa i3v Rigidity of 8" vs 10" vs 12" and other Nooby questions

Hi, brand new to the world of 3D printing, so please be kind!

I have spent the last week researching printers, and I think I have settled on a Makerfarm Prusa i3v. The design looks good, manufacturer support looks good and there seems to be an active user community.

I definitely like the idea of building the kit rather than just plug and play, I plan on getting the Heaxagon Nozzle for 1.75mm filament, I really couldn't get and feeling for 1.75mm vs 3mm in the research.

One thing I would like to do is colour the wooden frame, what is the best approach, spray paint of wood stain. The end colour will likely be black. Is it possible that the liquid stain could cause warping issues?

On the 12" kit I notice that there is a choice of RAMPS vs RAMBO vs RUMBA electronics, but I am not sure what the different versions offer.

Finally, although I suspect that the 8" model will support my needs, I would be happy to go to either the 10" or the 12" as I am sure that as I progress the extra capability may be useful. The only concern I have is the rigidity of the larger models, should I be concerned?

Thanks for any input

ex-egll

The i3v's are a great way to go. You can put as little or as much effort as you want to into the assembly and subsequent mods.

The approach to coloring the frame is probably more the look you are going for than anything. A few have reported the Y-bed arriving warped or warping shortly after kit assembly, but there's no historical pattern saying one method of coloring is "better" than another for minimizing warping.

The 12-inch originally was only provided with RAMBO electronics. The option to select RAMPS or RUMBA as well must be very new. Most of the users here are familiar with RAMPS since that's all that has been available on the 8-inch and 10-inch printers. If you order a RUMBA variation, you could possibly be the first and would have to work through issues mostly on your own. The major difference is how they are built. RAMPS starts with a very generic Arduino-type MEGA2560 board where the firmware executes. The RAMPS adapter board plugs onto that, providing connections tailored for the 3D printer application. Stepper motors are driven by individual driver boards that in turn plug onto the RAMPS board. RAMBO has all of that functionality integrated onto one board. RUMBA is sort of in-between in that the MEGA2560 and RAMPS board functionality is on one board but you still use the plug-on stepper motor drivers. Is there a clear winner? IDK, but an advantage of RAMPS is that if something fries you only have to replace the part of it that is fried. With especially RAMBO, if you fry part of the board you have to replace the whole board.

Thanks for the detailed response, time for more researching!

Do you have any info on the rigidity of the 8 vs 10 vs 12?

ex-egll

I'ver had a 12" for a few weeks now, i have to say it seems pretty rigid, but i have never used an 8" to compare it to... it doesnt flex when i pick it up or move it.

I think there's only one or two people with more than one size of MakerFarm printers, so it'll be hard to get first hand input on the rigidity question. An advantage of the i3v series is the aluminum v-rail system. Once everything is bolted together, the rails will give the printer a lot of rigidity, regardless of the size. Areas on the larger printers that *might* be a concern are the larger Y-bed and the wider wood pieces at the front & rear of the Y rails. Colin at MakerFarm has replaced the few Y-beds that have warped, and any issues with flex on those front & rear slats can be resolved by reinforcing them.

As the size goes up, the amount of power dissipation involved with the heated bed goes up. Based on info in various threads, the 12-inch printer is pushing the limit on running a 12V heated bed. You're dealing with upwards of 30 amps of current, which requires some hefty wiring. Just pointing out a consideration you didn't know about...

One problem I had with the i3, was the Y axis rods would bend if I put feet on my printer only on the front and back panels. I have not had that problem with the i3v, so in that case it is more rigid.

Thanks for the replies! Must confess the 30 Amp limit hadn't crossed my mind. So far the good old Canadian way of compromise is tempting. I am leaning towards the 10" model!

ex-egll

Well, a couple of e-mails to Colin (what amazing service) and the decision is made.
12" i3v kit, graphical LCD, Rumba Electronics, 3mm Hexagon head
Order should go in in the next few weeks once I get established in the RV down South.

Thanks for all the responses, there WILL be more questions!

ex-egll

Hmmm.. I just got the default electronics and the 3mm Hexagon head. What did the graphical LCD and Rambo give you that the standard didn't?
I don't think I will be needing 3 Extruders on my 12".

Please expound on what you found out that swayed you in that direction! :)

Thanks!

Cameron

i have the 12" and must say it's doing well BUT i had a very SLIGHT Banding in my prints. after bolting it to a piece of 5/8in MDF
i have not had any problems

eta on instructable is 1 week
it will cover org build and 1204 ball screw Z mods
mind you this thing built and bolted down prints on par to any printer you will find as is
i just like ball screws as they tend to live a longer life then threaded rod and speed Z up a lot at the cost of resolution
but the real impact is small (.00125 mm per step or 800steps per 1mm is still very good and much faster then 4000 steps per mm you get from the 5mm-.8 rods)
the use of thread rod is the one and only thing i dislike everything i have looked at and gone over like 100 times and see no problems or reasons to mod

mods done or soon to be done

1. C42's Z End-stop mount. still far better then included one as my printer is soon to be encased and this you can reach this from the front note: this end stop is set about 3mm below the bed and wired in series with Z probe now as a E stop encase Servo Fails. "done"
2. auto bed leveling. my own custom Mini Servo mount as all i have on hand is 34 spare mini servos and did not feel like buying a 9gram "done"
3. End-stop wiring has been switched to active on open with pullups enabled (this way it will stop if a switch fails or a wire comes loose) note this mod needs no new hardware only a small firmware change and where the wire attaches on the switches "done"
4. extra spring for bed not supporting the hotbed with spring on all 4 corners is odd after doing this i raised the hotbed up an extra 3/32 to 1/4in just encase of a hotend crash on the bed (pushes bed down apx 1/8 before hitting 2nd Z endstop) "done"
5. printable M3 thumb wheels for bed leveling (even with auto bed leveling you don't want it over working and destroying your Z axis)
6. C42's dual hexagon setup. (awaiting my NEMA 14's and hardware kit)
7. LED Ring and 3.14watt Laser (working on firmware) "soon"
8. Painted about 80% of it and left some unpainted as i think it looks cool some black and some wood (parts painted are parts most prone to warping) "done"
9. bolted down to 5/8in MDF board cutout to match footprint of the unit "done"
10. put the MDF on 3dprinted mini Earthquake building rollers (allow the printer to move around and prevent skipping steps from jerking) "done"
11. enclosure with full temp and humidity control "almost done built base today"