6,5 questions about lubrication, hot ends, software and settings...

so i finally put some time in to upgrade my prusa to a prusa 2 and it's a lot better. first print was great, second print was just perfect.

i spend some time tuning my extruder so my build envelop is as big as possible.
i now get a true 220 x 205 x 138 mm, so more than enough for what i need.
it's a prusa 2 with sangluino 1.3,sprinter, and a mendel parts heated bed and extruder
i'm still going to add some cooling near the nozzle to make bridging easier.

so the questions.
1) do i need some lubrication on the rods for the linear bearings?
2) i printed a joris cup but did not find how to turn of top in skeinforge, so i had to stop the print during the last 3 layers. print is still very nice.
3) i installed cura, so i could use the "joris" settings for the Z-axis. anyone has good settings for a sprinter prusa for cura (0.5 nozzle), setting are a little different than on other slicers (like you need wall thickness instead of number of walls)
4)i like that i can take just the tip of the mendel parts hot end, but it skipped for no reason on one part of my filament. could this be just a bad part of filament
4,5) can someone suggest me a good duct fan stl for the above hot end?
5) anyone used the prusa nozzle yet? is it good?
6) repG doesn't give me a correct prediction of end time (only a million days value), do other people also have this?

thanks.

someone should be able to answer 1 question i guess?

1) From time to time you will need to apply some type of lubrication. White lithium grease seems to work well for me. So does "White Lightning", a wax based lubricant for bicycle chains.
2) ??? Dunno. I use Cura (a simplified package based on Skeinforge) which has a check box that turns off the top layers.
3) In order to properly "Joris" the exterior you would need a single wall. Try .5mm to .75mm for wall thickness.
4) ??? Haven't used the Mendel Parts Hotend so not sure I can help here.
4.5) Depends on your x-carriage and the specific area of the hotend you want to cool. As I said, I'm not terribly familiar with the Mendel Parts hotends. I would have a look through Thingiverse for a Mendel Parts specific fan duct.
5) Haven't tried it yet but it looks pretty slick.
6) Yeah, software hosts can't properly predict print times because all they have to go off of are the print speeds you initially set. Your firmware's acceleration and max speed values can alter this projected print time by A LOT! Have a go with Repetier Host, I found it much easier to use than RepG and has a lot of useful features.

Regarding the bearings... it depends on the bearings used. AFAIK, the LM8uus are pre (and possibly self) lubricated. Generally speaking, though, yes. Grease rather than oil. A good quality bearing grease rather than more common varieties. Packing your bearings rather than lubing the rail on which they ride.

I can't comment on the remaining questions

yes you need lubrication. some 3-1 oil works short term, but someone on this forum mentioned excellent results from motor oil for a car engine.

I like using grease, but have used 3-1 oil in trying moments.

Edited 1 time(s). Last edit at 03/01/2013 03:17AM by jamesdanielv.