Ok so the new makerbot is here which i have already put to work prying the part that the used printed kept messing up. I'm using painters tape now.

Unfortunately I cleaned the heck out of the extruder with wd40 and canned air. I did this till canned air and wd40 sprayed right through in a even stream. Then I tried the print agian and the extruding stopped even quicker this time! Ugh. Furthermore I am wondering what these wierd patterns are on my first layer of large items..

each time I restart it's like it gets clogged up even faster. I checked a couple things , first making sure that there were no snagged area of filament or tangles. I also checked temp of the extruder once I noticed the clog which was probably about 3 min after it happened and it was still hot enough to melt the pla. I read online i could put thermal past under the heatsink to the extruder but I don't know if they even makes sense. Any help here makerbot pros?

I've never seen the wrinkles that bad before that's crazy! The wrinkles typically tell me that the nozzle is to close to the build plate but since they are really bad I suspect there is something else contributing, unfortunately i'm not really sure what that could be but I'll keep thinking about it.

I always recommend people to use rafts for everything. They can be a real pain to remove sometimes and the first layer is never as smooth. However I have found that rafts help with reliability and warping dramatically. When using rafts everything has more room for error, for example build plate levelness, environment fluctuations, warped build plate, weird wrinkles, etc. I have two recommendations to make your life a little easier when using rafts though.

1. The Makerbot bushiness card is to thin to properly level the build plate (my EZ-Robot cards work perfectly). Use a thicker card or just leave more room the best you can.
2. On prints that have a large surface area on the build plate you are going to want to try and separate the part from the raft wile its still stuck to the plate.

The thermistor on the rep 2's are not very durable. If you continue to get air prints I would remove the thermistor and test for faults. It causes more problems them you would think. If its intermittent and the temperature dips for just 5-10 seconds the plastic starts to thicken making the feeder gear work harder which starts a grove in the filament that it then struggles to get out of. That's just one scenario out of an endless list.

After getting many failed prints in a row I always get Jeremie to check the thermistor, most of the time it turns out to be intermittent from a break in the cable. Typically its right at the beginning were its bends to go up and out of the extruder assembly. Be really careful when removing it they are seriously fragile don't take any shortcuts go slow and remove any parts in the way to give you the room you need. We run on a tight schedule so I know how attractive shortcuts are but it will only make your day worse.

Try turning the model just a bit so that the lines are not straight on the X - Y plate and re-slice, then try a print.

As boring as it sounds i watched a test print for 18 min and it appears that the makerbot has trouble holding temperature. It is set for 230 but never makes it up there. It is hovering around 226 to 227. Several have suggested maybe I have a dud thermosistor. I will email makerbot tommorow. I basically had to be sure this was not user error first.

Ah ha! , the dang makerbot filament has kinks in the filament!

I caught the kink before it made its way into the extruder. If there were more kinks like this then I can see why the extruder was stopping up.

Do you have the spool in the correct position? Should look like the picture below.

I'm sure there are guys with more experience than me, but thought I would chirp in as I've had exactly that first layer 'bubbling' in lines issue before on a previous reprap machine when printing PLA. Two things caused the problem .... First was as Corey suggested, the nozzle to bed height was too close .... And secondly there was an occasion where it was a bad batch of filament.... It generally seemed to print like it was greasy (although it obviously wasn't) bed sticking problems etc. I switched to Faberdashery filament, adjusted the nozzle height and had perfect first layers.

Cheers,

Jay

Ps if the nozzle is having trouble hitting the required temp, I would imagine its going to either be a thermistor that is under reading and the psu / hotend is unable reach the now higher actual target temp due to power limitations, or I have seen it where the psu isn't kicking out enough voltage - the control circuit reading accurately but not enough power to hit the target temp.

Hope things get sorted for you quickly

Yup , it's in the correct position. I managed to print a part. I got up tonight to get a drink of water and saw it had completed. So great progress there. I will try another part while I am at work and check on my lunch.