Prusa keeps jamming

Greetings,

I have successfully built my prusa I2. recently after I was plagued by the constant printer jams. At first I realized the PLA I purchased wasn't the best quality( I also left it exposed to the elements for a bit by accident). I began storing my PLA filament in ziplocs with silica gels, I then purchased new Filament and a new J-head hot end. I also cleaned and oiled the PLA filament before use. Ideas to what else can cause the jams, and how to proceed with a solution?

Thanks!

Edited 1 time(s). Last edit at 08/01/2015 02:52PM by hevyarms.

My I3 uses a Wades extruder so I'm not sure exactly how your setup works but until I added a fan that blew on the filament where it entered the extruder housing I kept getting heat creep up the filament softening it to the point that it bunched up right below the Hob Gear . Now I have a hotend with cooling fins and a fan and it keeps the heat at the block where it belongs. I could be wrong but oiling your filament sounds bad. Oil burns and probably will leave a residue in your nozzle. I don't do anything with my filament storage and have no problems. Grated I live in Wyoming where humidity does not exist. I think filament storage is wildly overblown but I have only been at this a year or so. I'm sure someone with more knowledge will chime in soon.

I use the wade Extruder, I also have a fan on the side keeping the temp above the hot end steady, but it still finds ways to jam. I haven't tried to keep the fan always on though, I'm thinking I should probrably start trying.

Edited 1 time(s). Last edit at 08/02/2015 10:11AM by hevyarms.

Yes, I run mine anytime the heat is on. If you have this type of setup you may also want to make sure the tension arm is not resting against the hob gear. I added a bigger bearing to give clearance along with an aluminum tube to keep the filament straight.

If you're getting heat creep up the filament, I might challenge that something is wrong with your hot end.

oh, well this is about pla and I don't print with pla at all...because it jams haha.

Anyway, but I still think something is not right about the hot end. Make sure there is a 3-4mm gap between the round heat sink and the square heat block. And have a fan on the heat sink... Pla gives me too many headaches and not enough return on investment. better filament out there.

Edited 1 time(s). Last edit at 08/03/2015 02:34PM by thetazzbot.

I should clarify. My original hotend was one of those black plastic looking types with no cooling fins. I eliminated the upper fan when I got the finned hotend with a fan included. Same deal though, without the fin/fan running the fins get hot fast. With the fan on it stays cool to the touch. The aluminum tube above the hob gear keeps the filament from flexing side to side as the print head moves left and right. Once in a while the filament would get pushed out to the left and start curling up. Just that little movement going off centerline with the entrance hole was enough to cause a jam. The bigger bearing really made a difference. The poor design kept the smaller bearing from putting max pressure on the filament because the white tension arm was making contact with the hob gear. Now filament is straight and true between the hob gear and the entrance hole. No jams since.



Notice the flex of the filament. Before the tube the arc in the filament would extend down to the gear. As you can see it is straight below the bearing. Hope this helps some of my "Cheezy Acrylic Printer" brothers out there.