Schlomo's Robo Beast Inspired Printer!

First things first, credit where credit is due. Thank you to dbefore for posting up his instructions for this build as well as STL's. No way I would have thought to do this without first seeing his printer. Check his out here: http://community.robo3d.com/index.php?threads/the-makings-of-a-beast.6141/

Before anyone asks, my sole reason for doing this mod is because i can. I don't normally print things very tall, but in the off chance that I wanted to make something larger, i wanted to be able to do so with no issues.

This is not a build log, but more of a list of issues I ran into after doing this mod. Mainly with my bowden setup and getting terrible quality prints.



Thats my beast. It is not nearly as clean or well done as dbefore, but it still prints just fine. I had a chamber on my printer before this mod, and that was one of the main stipulations I had for doing this, was to keep the chamber so that I could continue to effectively print ABS. I personally do not print many "show" type models, so ABS, PC, Flex, and other special filaments are mainly what go through this beast.

The modifications were really pretty straight forward once all of the items were procured.

Skip ahead a few weeks the printer was finished! I was so excited so i decided to test the height of the printer and went ahead and printed this.



To be honest, im surprised it even printed. I had accidently set my layer width to 0.4mm, with a 0.8mm nozzle! Doh! Quickly fixed that and printed this tower.



Went down to pop it off the bed and noticed how bad it was.



Lots of bumps and what looked like over extrusion at the start of each layer. Figured, time to start printing calibration cubes!

All of these cubes were printed in order from Left to Right. I slowly changed settings and tried to get the printer dialed in with my 0.8mm nozzle.

All printed in eSUN ABS.

Once i got to this point I really didnt know what to do, so i changed to a higher quality filament from PrototypeSupply.



I had similar issues here which you can see in these close up images.





That was as far as i could get. It didnt matter what i modified at this point, if i changed something one way or another it would just get worse. I tried retractions from 1mm all the way to 10mm while i was using the volcano, and bad results across the board. Over time the cubes kept piling up and i started to make a pyramid.

I started to get frustrated and decided to go back to my V6 and remove the volcano. Upon doing so, i sheared off both the nozzle and the heatbreak....... Yeah, i wasn't a happy camper.

Had to order a new heat break, and figured i'd pick up a 0.6mm nozzle for the v6 and just use that. Got that installed and went on to more calibration changes.

I figured, might as well print something different now, so i switched to Benchy's. Anyone need a fleet of Benchys?



Tried some different settings with each, changing 1 thing at a time, but ultimately having blobs at the start of every layer.




Starting to give up, i decided to change a few things on the pritner. First, i added a parts fan.

I know, " Dont use a parts fan on ABS!" Well, with a heated enclosure, i found this is a necessity for larger or even small prints. I decided i wasnt going to lose anything by not putting it on, so why not. First print with the parts fan was no better than the last. A little better bridging, but that was about it.

Finally, decided to try and shorten my bowden tube. It was 17" long before, as it ran from my Bondtech at the top left side of my printer all the way down to the bottom of the beast, which has a build volume of about 16-17" high. That was the ticket! First print showed some really great signs of improvement, most of the large blobs were gone!



How i mounted the Bondtech was modeled of how a lot of delta style printers mount their extruders. I found that they generally split the distance between the upper and lower limit of the printer, and can reduce the length of the bowden tube by doing this.




This change allowed me to maintain the full build height, and shorten the bowden tube by a good 5-6" (I never measured).

Finally, decided to do a retraction test and bridging test, and i sure was impressed.





While it is not perfect, it has definatly come a long way from above. I am encourage for sure, and the 0.6mm nozzle i ended up with sure makes short work of these prints.

Lots of ups and downs of this mod, but its working great now. Let me know what you think!

-Schlomo

 

That bridging's fantastic! I just got my E3D V6 upgrade finished today. Do you mind if i ask you what you did for your parts fan to get such good bridging? If you have a fan duct or mount that you think works well? Thanks and again, great job!! This whole build is super impressive.

 

All I have is a single fan with no shroud. Works pretty well. In S3D i up the cooling for bridging from 50% to 100%, but other than than just the 1 fan is all I use.

I use Mike Kelly's carriage which has the fans mounted at an angle towards the print for indirect overall cooling, see his thingiverse post for a visual representation.

http://www.thingiverse.com/thing:1252888

 

Thats awesome.

and I use a parts fan on ABS on my enclosed printer, or it just stays too dang hot..