How to change Maxtemp ceilings in stock TAZ5?

Hello All! First post!

I bought a Taz 5 new from the MicroCenter in Northern VA and overall, I am very happy with it (though it came out of the box with an idler broken in three pieces and a bed that bubbled when heated - but hey, I am easy :laughing: pic attached).

I print predominantly with polycarbonate (PC). However, as many of you know, objects printed in polycarbonate have the tendency to warp and bow, resulting in failed prints. (Thankfully my broken idler lasted long enough for me to print out a new one in polycarbonate - though the bowing is clearly visible).

The Taz 5’s LCD defaults are 290C for the nozzle and 130C for the bed. In Cura I can go past that to 294C for the nozzle, but if set to 295C and above, Marlin hits the Maxtemp ceiling and goes into shutdown as the temp grazes 299*C.

It is almost impossible to print in polycarbonate (except for very small objects) using my stock Taz 5. Temps just a bit higher than the defaults are badly needed to print in PC.

How can I change the Maxtemp ceilings in my stock Taz 5? Can anyone offer a step-by-step guide or links?

I am hoping to be able to set the Maxtemp ceilings to accomodate working temps of at least 305C for the nozzle and 145C for the bed.

Hopefully I don’t have to resort to purchasing an E3D nozzle. I know that the stock Taz 5 has more to offer than the presets.

Thanks in advance!

(P.S. Polymaker PC-Plus a.k.a Makrolon is prone to breaking, unlike real high-temp polycarbonate which bends without breaking. As such I don’t consider Makrolon a ‘real’ polycarbonate filament for my purposes - even if it is very well behaved and prints with less warping.)

Raising those temperatures is not quite as simple as it seems at first. They are set where they are for a couple of reasons. To change the values themselves you would find a copy of the stock taz 5 firmware (devel.lulzbot.com should have it) open it up with the arduino development console, find the maxtemp values and change them, then find the thermistor value table and make sure it goes up that high for the values you changed. If not, supply approximate values.

The tricky parts come with the physical components. You should be able to get away with 305c on the thermistor, but if you go any higher than that, you would need to switch to a Thermocouple (more information: http://3dprinting.stackexchange.com/questions/204/how-to-get-consistent-and-accurate-readings-from-thermocouples )
The bed is rated for a maximum operating temperature of 120c. Any higher than that and you risk burning it. And your printer. So you would need to find or make (toaster nichrome wire) a higher temperature 300mm x 300mm heated bed. Assuming you do make or find something, you then need to upgrade the wireing, and potentially look at introducing a secondary power supply and a relay of some sort to trigger bed heating. Trying to run it via the stock rambo board and PSU is going to melt something sooner or later. You could probably push the stock bed to 125 or so if you wanted to live dangerously.

Hello PierceT - Thank you for the valuable information! Since Cura can allow the bed to be heated beyond 120C (I was able to go beyond 120C, but I chickened out - I’ve been around these things long enough to know something is going to give - and in the worst way), so the information you provided is extremely valuable to the community.

Seems I will have to upgrade to an E3D v6 or a DyzeEnd-X. E3D’s new miniaturized extruder may also help increase the quality of the prints.

That said, I really believe that Aleph should offer a competing hotend that can withstand way more than 300*C. Just like Apple with it’s iPhone it wouldn’t be nice to see my favorite open source 3D printing company slowly getting left behind the capabilities of other brands (i.e. Samsung, er, I mean E3D, Airwolf3d, etc).

I am certain I am not the only Aleph customer willing to pay a premium for competitive upgrades to our existing Taz investments. Obsolesence isn’t a good strategy.

You can use a thermocouple with a hexagon too. From a physics standpoint either will theoretically withstand 400c aside from the thermistor. You are going to start getting localized cold end warping above 375c unless you add shielding or cooling.

I will attempt using a thermocouple as you suggested. The biggest problem I am facing with Polycarbonate on the Taz 5 is lack of sufficient nozzle heat resulting in layer delamination - the nozzle is not hot enough to melt and fuse each layer together. In any other direction the strength of PC is amazing.

Likewise, with regard to the heated bed when printing polycarbonate, a preheat temperature being recommended is 135c with the working temp during prints set at 140c to 145c - with an enclosure and special adhesive pre-applied to the bed. (I am sure you know all this, but am including it for those who don’t know - there aren’t too many good guides on how to successfully work with PC on the web.)

IMHO and my tip to Aleph is that the most lucrative market is the section of current customers who use the Taz for functional objects, since they would be willing to pay the premium. Sadly the aforementioned temperature ranges are beyond the capacity of stock Taz nozzle and bed. As such, Aleph is limiting itself to sharing that small slice of the pie with the majority of lowest cost 3d printing companies out there.

Maybe in the interest of time and simplicity, I would likely just bite the bullet and purchase a competitor’s 3d printer for $5k-6k.

Then again, when I found my Taz 5’s idler broken, I was able to print out a replacement in polycarbonate just in time and got going again. Proprietary systems won’t allow that. Open source is fantastic, which is why Aleph/Lulzbot is my first choice.

Thank you again for your expert advice!