Primary School 3D printer

[SimpleSi]

I'm reluctant to try printing direct onto the plastic tray but I'll try spraying onto the blue masking tape that comes with it and try again today

[SimpleSi]

tried using hairspray and no raft - made no diff - 1st layer didn't stick and just moved around with printhead

[plexer]

What temp is it printing at?

 

Ben

[SimpleSi]

Its set for 230C

[SimpleSi]

Actually it might be 215C - the main monitor implies that but the profile file seems to say 230C

[plexer]

How To Succeed When Printing In PLA

 

Ben

[SimpleSi]

Well just going backwards

Spraying with hairspray didn't make it possible to print raftless and now even raft models don't stick.

 

The nozzle drips plastic so in 40% of cases I end up with a little ball of plastic in the middle or the model that then hardens and then the nozzle hits it on subsequent passes.

 

My experience has been quite disappointing and I'm close to the stage of sending it back as it doesn't actually work reliably enough

 

Simon

[pcstru]

Proving the point perhaps that there is no such thing as a cheap plug and play extrusion 3d printer - there is just too much to go wrong.

 

230 or even 215 sounds too hot for PLA, normally around 180 is generally recommended (I print first layer @ 200 and then drop to 180/190 depending on teh piece). That said, there is often quite a difference between the temp at the thermistor bead and the actual lower chamber where the PLA melts, so don't pay too much attention to the absolute reading. Dripping/ooze is a sign that temp is too high.

 

If hairspray didn't work just remove the blue tape and reapply a fresh layer. You need to do that every so often anyway - it wears out. I found printing onto tape was OK but only for smaller pieces. Larger ones warp and the corners start to lift.

 

Persevere - you will get there, it's just not simple or easy.

[plexer]

Indeed these things are not plug and play no matter what one you get which is why I'd be loathe to pay big money for the "high end" ones I'd rather pay less and spend just as much time sorting it out.

 

If it's oozing that much temp seems too high trouble is different pla and different colours can need different temps there is no one temperature fits all but if it's too hot then you'll just push the material around the bed and it won't have time to stick, drop the temps and make sure z zero is very close to the bed.

 

Ben

[RTi]

Re the Hairspray.. I'm sure any old hairspray wont work.. it has to contain a certain ingredients... look for Vinyl or Colopymers on the can.. Edited July 21, 2014 by RTi

[plexer]

Cheapest stuff or mega hold is normally best you don't want anything with fragrance, silicone or oils in it.

 

Ben

[plexer]

Nothing Labs (Rich Olson): Filament Roundup! (3D printing in all sorts of stuff)

 

Ben

[SimpleSi]

Well I've found the equivalent of Edugeek in the Makerbot world

https://groups.google.com/forum/#!topic/makerbot/qMGz6LpXciE

 

At the moment, I'm trying techniques of

 

1 Living with raft situation

 

2 Taking sides off and leaving door open

 

2. Adding a small object in the near left corner so that any balls of plastic don't much up main model

[GoPrint3D]

SimpleSi I can see that you are receiving a lot of good advise on the forum which is great. Have you tried slowing down the speed of the first layer? as for the raft issue are you attempting to print the Cube still or another piece. Whilst the machine is a plug and play often here are a number of factor that stop it working effectively as you are discovering. The MakerBot 2 which uses PLA is set at a temp of 20 and we are getting good results out of this using the blue tape and (no hairspray).We have had to slow the speed of the first few layers down on some prints, tends to be ones with circular bases as the Extruder does drag the filament around if it is going too fast. We have also changed the FeedBack Rate. Is the machine extruding ok if you print different models, it may be that you have a faulty Head, we have experienced this. in the past where it sing loaded extruder was leaving blobs and string effect on the pint.

[SimpleSi]

OK - its seems the raft issue is the same worldwide.

 

Rafts stick (in various degrees) to models.

 

Printing raftless on the Makerbot Mini MIGHT be possible but its not a realistic option in the classroom

 

The raft sticking is a major problem for printing flat box type things (such as a Raspberry Pi case ) but not as big an issue on a vertical model (chess piece type) and I think the pupils are going to be designing more of the latter than the former so we should be OK with that

 

The remaining issue is that plastic dribbles from the extruder and Mr Makerbot has not programmed their start sequence well enough to try and make sure that this dribble doesn't turn into a little ball and gets left on the raft causing big trouble when it hardens and the printhead runs back over it !

 

Now I'm not too sure why Mr Makerbot hasn't done this

 

My current workaround is to place another small model in the near left corner, away from the actual mode required, so that any dribble/ball is left there and hope that it doesn't interfere with the main model

 

Hopefully, when I get time, I'll video how it goes wrong and send it off the Makerbot and get them to just automatically do a little dance to shake it off

 

Simon

PS It was very interesting goign to Manchester MakerFaire and talking to both 3D printing Maker types and 3D printer sales/user types

 

The Makers all said that no 3D printer works all the time and the others were all very upbeat on the operation of their own particaular model and its abilities

 

One particular stand were telling me how their printer was wonderfull and once calibrated it was "perfect" - I came back later to find they'd printed something flat and that the raft has stuck to it

Edited July 28, 2014 by SimpleSi