Rep 2 doesn't extrude on printing sequence but loads filament ok?

[Franc Falco]

Hi All,

Filament loads fine, but just clicks and nothing extruded when printing? Just started happening, has been fine for ages, but this has just started after recent heavy use of printer

It is strange that the filament will 'load' ok, but to my untrained eye it seems that on the printing sequence the filament doesn't get hot enough to be feed through nozzle and subsequently binds in the tube before it even gets to the nozzle? The filament will then 'unload' showing blobs and a 'stretching' binding as i pull it out (often i am not able to remove the filament and have to dismantle the block to extract the nub of filament poking from the tube) previous 'unloads' always released the filament with a short melted length and no binding

I have the spring loaded lever arm upgrade - up until this point that upgrade had solved any previous extruding issues i had and the printer was working great.

Extruder heating ok - preheat sequence works

Did have extruder blocks in the past but lever arm upgrade solved all those

Same problem is present with different filament - all filaments that are failing to extrude now have extruded ok recently

Tried printing a makerware example and same failed extruder issue.

Cant show you how a print looks - an actual printing sequence doesn't even lay down the first filament 'string'. The extrude blocks immediately, starts clicking and only a slight very broken fine 'hair' of filament is all that is extruded, but nothing that sticks and nothing to create any sort of form.

Levelled the build bed, upgraded firmware and makerware to latest versions..

Tube/nozzle has been cleaned with all recommended techniques.

My confusion is that if i was experiencing difficulty loading the filament i would suspect a blocked tube/nozzle, but loading is ok and the extruded filament is clean, straight and constant - its only on an actual print run it clicks and doesn't extrude?

Any suggestions or thoughts much appreciated

Franc

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David (MakerBot Industries Support)
Aug 30 16:31 (EDT)

Hey Franc,

Thanks for contacting us at MakerBot Support. Sorry that you're running into extrusion issues.

Can you give me a little more information so I know best how to help?

1.) Which printer do you have?

2.) If you have a Replicator 2, which drive block do you have installed? The plunger or the spring loaded lever arm?

3.) Is your extruder heating properly? You can test this by starting the pre-heat sequence.

4.) Have you had any major clogs or jams in the past that may have left PLA residue in the extruder?

5.) Do you have the same problem with different filament?

6.) Do you have this same problem if you try to print one of our example files?

It would be helpful for me to see any pictures of failed prints. It would be most helpful to see them while they're still on the build plate.

Thanks,


David Kim
Support Agent

Franc Falco
Aug 30 14:47 (EDT)

Hi Support,

Just started having the above problem following a very busy use of the printer.

Printer has been working fine recently since upgrading the filament extruding mechanism.

However, it is now showing an issue – initially, the filament can be loaded without problem – pulls into nozzle and extrude in a clean flow.

However, when printing, the extruder will start to click immediately on commencement of print and no filament extrudes.

I will cancel print and check and perform an 'unload filament' - but after the failed print it is difficult to remove filament from nozzle.

Filament, does remove, but it seems to be slightly jammed in the nozzle/tube and comes out very lumpy and stringy.

But once removed, it will reload correctly as before, but subsequently will not extrude on print commence (clicking and no extrusion)

Have performed all the recommended nozzle clearing operations but still no improvement.

Any thoughts or suggestions welcome

regards

Franc Falco

[Jay]

Franc,

Went through this about the same time I upgraded my carriage and arms. I was pulling my hair out and thought I had royally broken something. I had had months of printing with no problems at 220* and was going to ask what you were running. What finally solved (most) of the problem was I found out I had to run the temp up...I print at 230* now. Opaques print fine but you still have to mother the translucent stuff. I had the exact same symptoms as you. 

What have you been using for temp setting? Have you tried going up or down?

Jay

[Franc Falco]

Interesting you mention temp, i. Did try a test at 235 (i normally use the makerware default settings of 230). And testing the 20mm block example at 235 gave a complete print! With a small amount of 'clicking' at the very start of print but after that all fine. so i thought problem solved and tried another print at the new temp - but that failed as before? But i will test at higher still temps via makerware.
So is it that loading the filament sequence is fine (temp wise) but the printing temp setting may be off and showing on the read out hotter than actually is?
What are the optimum increments i should test: jumps of 5 degrees or less?

I've got service tickets with MakerBot and my v helpful UK supplier - so lets see??

Regards

[Franc Falco]

So discovered what the problem was!

My colleague had been using the printer and took the heatsink/fan off to clear out a blockage - the unit came apart and in his confusion put the heat sink back on wrong way around!

Just put it the right way and extruding problem solved...

Until the next issue... all fine for the moment!

[Sarah Davis]

I can post the link when I get home, but I think getting a new extruder is a good idea. Ideally thinking of the mk7, but know they're out of stock in the makerbot shop, but I've managed to find a few that look like mk7's on eBay, for about the right money from china (average of about £50).

I don't want to end up with possibly the wrong extruder again, so if anyone can point me in the right direction it'll be greatly appreciated.

Sarah

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[sa...@sldmodels.co.uk]

This is the extruder I was talking about.

http://www.ebay.co.uk/itm/221271838223?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

On 04/09/2013 21:08, Sarah Davis wrote:

I can post the link when I get home, but I think getting a new extruder is a good idea. Ideally thinking of the mk7, but know they're out of stock in the makerbot shop, but I've managed to find a few that look like mk7's on eBay, for about the right money from china (average of about �50).

[Jetguy]

DO NOT BUY CLONE EXTRUDERS.

If you think you have problems now, buy that and try printing PLA.

If we've learned nothing, buy genuine MakerBot parts, but if you want to switch, use Replicator 1 parts but to buy them, you MUST contact MakerBot support.

 

I cannot stress this enough. I just went through the battle with 4 each QU-BD extruders. Basically I knew up front I was going to throw away the filament drive section and the stock brass gear. Not worth messing with when printed extruder filament drives are fine if printed in ABS. I've got nearly a full year on the ones in my Replicator 1 dual which I consider bulletproof.

To be fair, the QU-BD is still a good value for the money, even if you throw half of it away.

The parts I retain and use are:

Heater block

Heater cartridge

Nozzle

Mounting block

heatsink (actually these are better than the MakerBot ones)

Fans

screws

 

Technically, you can modify the thermal barrier tubes and make them work too, but it is an extra step and requires and exact size of drill bit (#42).

The drill bit alone could cost more than buying the $11 Makerbot thermal barrier tube for the MK7/Replicator 1/2

I have been using Trinity labs hobbed pinch wheels with good success but they have had some problems lately and the business was a little shaky.

 

Again, I have seen those clones and say stay away.

QU-BD is about the only place I trust and even then, I don't use half of what they make.

[sa...@sldmodels.co.uk]

I've emailed Robosavvy about one, they're in the uk, so even if they have to get it from the USA, any problems and I can send it back to them a lot easier :)

Sarah

[sa...@sldmodels.co.uk]

ok, I'll steer clear of the clones.  Ideally would like to buy from the UK (so I get it quicker obviously with less risk of damage in transit), but even the makerbot store is currently out of stock. 

Sarah

the one good thing about that extruder I mentioned though (possibly) was a smaller option nozzles.

On 04/09/2013 22:20, Jetguy wrote:

[Dan Newman]

> h

>
> the one good thing about that extruder I mentioned though (possibly) was a smaller option nozzles.

There's a reason why most people do not go below a diameter of 0.40 to 0.35 mm: the amount of material
you can extrude, all other things equal, goes up with the square of the radius. So reducing the diameter
by, say, half doesn't double the print time: it quadruples it. So, unless you really need the thinness of
lines you can get with, say, a 0.20 mm nozzle, you're best off not using one.

Dan

[sa...@sldmodels.co.uk]

I'm wanting to make things for model trains, n gauge in this case, like
chimneys, which are small in o / ho scale, and even smaller in n

Sarah

[Dan Newman]

On 4 Sep 2013 , at 3:25 PM, sa...@sldmodels.co.uk wrote:

> I'm wanting to make things for model trains, n gauge in this case, like chimneys, which are small in o / ho scale, and even smaller in n

If you use PLA, a nozzle of width w will allow almost but not quite detail of width w.
If you use ABS, a nozzle of the same width causes detail even wider than w owing to the die swell (extrudate swelling)
which occurs with ABS. (It swells as you extrude it: a 0.4 mm nozzle generally gives a noodle of width 0.5 mm
and possibly even more if you're printing quite fast.)

The reason you cannot get the same width detail as the nozzle orifice diameter is that you have to
squash the extruded noodle a bit so as to get it to adhere to the layer below.

Dan

[Jetguy]

You need to do more research as smaller nozzles are NOT exactly successful.

There is a finite limit to FDM on given the current extruder design. The pinch wheel system has a finite amount of force and obviously plastic has a fixed viscosity. You cannot force plastic through a nozzle at speeds higher than the fixed limit of pressure the filament feed system can make. It's a losing battle because then you need to make more passes for a given layer and that takes time. You cannot speed up federate because flowrate is fixed, and in fact, actually less volume and thus a slower rate with a given smaller nozzle.

Plastic also doesn't flow and bond and ultimately smaller does not equal better.

 

FDM has a limit. When you try to exceed that, you end up in massive failure. The larger 3D community has been testing nozzles far longer than you might imagine, these ideas have been proven over and over.

[Carl]

I am currently running a 0.25 nozzle printing at 0.1mm layer heights using 618 Nylon... I installed it just to see if it would be any good and never expected anything positive... so far, after close on 50 hours of intense printing, I must say I have been getting stunningly good results... 

I have not tried it with PLA and I do not believe that it will work well with PLA... just thought I'd give the feedback I am currently seeing in Nylon!:-)

[Nathan Porter]

I'd love to see some pictures of some of your nylon prints.

[Steve Johnstone]

+1 with the pictures

[Carl]

Interesting... sounds more like a dare than a request! :-)

I'll post some a little later... nothing too exciting though... I'm primarily printing loads of shims for AluCarriage orders at the moment!