Successful Printing???

Hey all, we recently purchase a TAZ 5 for our classroom. It is our second printer, the other being an old 3d Touch. Recently we have been running a lot of parts and have had VERY few successes with the TAZ.

If I run PLA I get a clogged extruder nozzle. If I run ABS I get such poor bed adhesion and warping that any part over about 1.5" square is guaranteed to fail.

We run 3mm Matter Hackers Filaments and process using CURA
We have tried the following temp settings both with and without cooling fan.
---------Bed Temp------- Extruder
ABS----100-110------- 240-250
PLA----90-100--------- 200-210

I have tried running various speeds and infills, but we typically use 20% infill and stock feed rates (They have given the best results).
Out of 20 ABS parts this week, 6 printed without a complete failure, and only 2 of those 6 were useable and not excessively warped. We have completely given up on PLA.

Where do we begin to make this printer operational?

I cant speak for PLA as I only print in ABS but your bed adhesion issues might be caused by bed leveling/Z height ect. Use 110C for the bed and 240C for the nozzle. Its rarely your temps that cause adhesion issues as these tend remain constant.

  1. Make sure your bed is leveled. I personally got tired of messing with the finicky paper trick (which is actually fairly accurate if done correctly) and just bought a $15 dial indicator from harbour freight to guarantee bed level.

  2. Once you know your bed is level, dial in you initial Z-height. You need to squish that first layer into the PEI bed. Without squish it wont stick. I find the recommended “printer paper barely dragging” to be a little to high. Give your Z end stop a quarter turn clockwise. I personally calibrate Z-height by sight. Keep lowering the Z end stop (and thus lowering the nozzle) and printing a few lines until you start to see tracking (center of the extruded line is thinner than the edges). It will look like a wheel rut. Once you achieve this, slowly raise the Z height until you no longer have tracking. It takes a little time the first few times, but eventually this whole process doesn’t take longer than 5-10 minutes.

  3. Lastly make sure to clean the bed. Rubbing alcohol works… Kinda. After every few prints I sand my PEI with 2000 grit sand paper. Put some elbow grease into it.

We rub the bed with alcohol before almost every print. I tried leveling and lowering the z stop multiple times. I have now just about lowered it to its limit (still not hitting the bed, maybe 3 thousandths left). It made things better, but I still get the head dragging the first 5mm or so of skirt without it adhering and then when the second layer begins the first layer comes loose and the whole part just gets drug around the print bed.
I also sanded the bed.

We have a .35mm nozzle; would a .5 work better by giving a wider surface for adhesion? Our BFB rarely has this problem even without a heated bed.

Turn off the fan and use a 5-10mm brim on the object. That should help mitigate the ABS warping.

Make sure to adjust the initial nozzle height with the hot end at extrusion temps. This will ensure the brass has expanded. Two sheets of paper is the proper gap.

I find the best way to level the bed is through dial gauges attached to the X. This will quantify the Z distance (X-rods to bed) at each corner. I like this dial gauge and this bracket… I actually like using two on either side of the toolhead simultaneously. :slight_smile:

Thought I would follow up on this.

After months of frustration, I sanded the bed with 100 grit paper (yes, only two zeros) and then soaked it with acetone and let it set.
While the acetone set on the bed, I laid the spatula on its side and scraped the bed like I would use a wood scraper in the shop.

This improved things but didn’t fix the problem so we upped our print temperature to 255 and have not had a failed print since doing so.

We also cut the raft out, moved the skirt to 10mm, bed temp 100 with part cooling.

Thanks for all the help.

If you were swapping between PLA and ABS, that’s where your nozzle clogging issues were coming from. You need to completely purge the nozzle of any ABS before putting PLA through it else it will just clog.

For your PLA problem, it’s likely that the small squirrelcage fan that is used to cool the barrel of the hot-end isn’t working properly.
I had that on my TAZ 5 after I’d owned it for a couple of months.
Once I changed that fan out for a 40mm axial fan blowing on to the barrel, PLA was happily squeezed out all day and I haven’t had a clog in months now.

You aren’t using the cooling fan with ABS are you? 255 is unusually high for layer adhesion, and would indicate to me that you are either getting a particularly cold draft from somewhere, or the thermistor is acting up. Any chance this is living directly under an air conditioner duct?

I enclosed my Taz 4 and shut of the fan with ABS. Keep the bed at 100 C for the whole print. My Taz 4 is a work horse

Nozzle clogging with PLA is a common problem called “heat creep”.
There is a thread all about it:

The Taz 6 abandoned the tiny blower and uses a huge 40mm fan to cool the heat sink. This works, but I think this 40mm fan is a bit overkill. … olhead.JPG

I designed a duct that uses a 25mm fan. Haven’t had a jam or a clog of any kind since I did the swap. Here is the link for the duct, 25mm fan, etc.:

A number of folks have made the modification and they all report it solves the PLA heat creep problem.

Bill D.