Is there some way (hack) to print at 270C?

[cookingissues 0]

Thanks. I hope this is the right place to ask. I have an Ultimaker 2. I'd like to print polycarbonate. From what I gather, 255 C is the rock bottom minimum you can print PC at without jamming but 265-270 is much better, and that to achieve reasonable speeds (above 30 mm/s) requires closer to 270. Is there a workaround to the firmware limit of 260C, and if so, will the extra 10 degrees damage the machine? Can the firmware be altered in the UM2 (it has been a while since I've done arduino programming but if someone points me in the right direction I can prolly handle it).

 

[Daid 306]

https://github.com/Ultimaker/Ultimaker2Marlin/blob/master/Marlin/Configuration.h#L162

That's the line you want to edit.

Also take note of this edit you have to do to the Arduino environment:

https://github.com/Ultimaker/Ultimaker2Marlin/blob/master/Marlin/Configuration.h#L407

And finally, you are doing this at your own risk. The teflon piece in the hotend is not designed for these temperatures, so that might deform. (You could turn a replacement from alu if you have a lathe, that might prevent problems with the teflon. But no guarantee on that)

 

[gr5 2,172]

As Daid says the only part that is at risk is the teflon isolator. It's the white part located just above the nozzle. You can see it without taking anything apart. Even at 240C it tends to deform under pressure of the spring over even just 100 hours of printing apparently. At 270C it will deform that much faster. When it deforms you tend to get underextrusion. You can test for underextrusion by printing this at 230C and anything above 6 or 7mm is fine:

http://umforum.ultimaker.com/index.php?/topic/4586-can-your-um2-printer-achieve-10mm3s-test-it-here/

You can usually fix the isolator by drilling it out. But that isn't always enough. It won't actually melt until around 300C.

Make damn sure your 3rd fan (at the rear of the print head) is spinning and blowing air before you attempt this!

Also aluminum is a good conductor of heat which might be a problem here if you make a new isolator out of aluminum - you don't want the bowden to melt. So maybe use stainless steel? I don't know. Not sure what temp the bowden can handle.

https://answers.yahoo.com/question/index?qid=20070512125006AADRFoq

 

[jbeale 0]

If you are going to machine something, the isolator might be a good application for a machinable ceramic like Macor: http://en.wikipedia.org/wiki/Macor

It is stable up to 800 °C and being a glass ceramic it has much lower thermal conductivity than metal: Aluminum: 205 W/(m.K) Macor: 1.46 W/(m.K)

Macor is a somewhat exotic and expensive material, but you only need a small piece.

 

[nallath 1,120]

You should also note that it needs to have a quite low static (and dynamic) friction with PLA.

 

[MartijnvG 16]

It also needs to provide a seal so the material won't flow anywhere else except up or down.

 

[3poro 9]

Is there a workaround to the firmware limit of 260C, and if so, will the extra 10 degrees damage the machine?

 

First of all, thank you for your post - it motivated me to investigate the 2nd Pt100 sensor I have lost. Both sensors I have lost after just weeks of use. I print primarily ABS, typically at 260C. With standard UM2 setup, already the 260C temperature seems to cause problems for the PTFE isolator. After I added airflow on the PTFE isolator, I haven't had such problems.

As there are several Team Ultimaker members reading this thread, could one of you give details on the temperature sensor used in UM2? What are the specifications of the actual Pt100 sensor component? What kind of solder is used between the sensor component and the wires? What kind of insulator materials are used? What is the coating material of the wires?

Here's my earlier post on my issue: http://umforum.ultimaker.com/index.php?/topic/5431-thermocouple-failure/

 

[nallath 1,120]

All that kind of data is in the Github (read; Can' t be arsed to look it up ) .

 

[3poro 9]

All that kind of data is in the Github (read; Can' t be arsed to look it up ) .

Really? I found this: https://github.com/Ultimaker/Ultimaker2/blob/master/1185_PT100_B_sensor_(x1)/B1185-B2P-A.pdf

...but I can't really find answers to my questions. In the document it's written:

"Temperature range: 0° C to 400° C"

...which really prompts the question about the materials being used.

 

[3poro 9]

Daid, nallath, MartijnvG - are you still there? My UM2 had about 3 months of downtime altogether - due to two original Ultimaker Pt100 sensors failing. When I asked about details on the sensor, I got a pointer to GitHub. The 0C...400C indicated there is a very bold range, given the structure of the sensor. I see there solder, some (Teflon based?) insulator tape, PTFE coated wires etc - are they really rated up to 400C? I'm not sure the sensor is good for continuous temperature of 260C (which means the temperature gets regularly a bit over 260C).

 

[nallath 1,120]

First off, apologies for not replying the first time, it slipped through my nodification list. I'm a software engineer, so I really can't help you that well with in-depth hardware issues. That being said; I believe the sensors that we used are speced for 0 to 400 degrees, probably because it's a off the shelf part that we buy. You are correct in the observation that we limit the temperature to 260 in our firmware, due to the teflon parts not being able to withstand temps of above 260.

The PID regulator should try to keep the temperature at 260 if you tell it to do so, but it will fluctuate a bit around that temperature, it's quite possible that it will be a bit above that for some time when the temperature is still settling in.

If you sensor failed, I can offer no further advice then to contact support or use the info on Github.

 

[3poro 9]

I believe the sensors that we used are speced for 0 to 400 degrees, probably because it's a off the shelf part that we buy. You are correct in the observation that we limit the temperature to 260 in our firmware, due to the teflon parts not being able to withstand temps of above 260.

The PID regulator should try to keep the temperature at 260 if you tell it to do so, but it will fluctuate a bit around that temperature, it's quite possible that it will be a bit above that for some time when the temperature is still settling in.

If you sensor failed, I can offer no further advice then to contact support or use the info on Github.

 

My first Pt100 failed quite totally (http://umforum.ultimaker.com/index.php?/topic/5431-thermocouple-failure/), so I couldn't figure out much about it... The 2nd one I opened and it looks like the soldering between the actual sensor and the wires had given up. Most solders melt (fail) at around 250C. Also, I challenge you to give links to Teflon-based insulator tapes and wire coatings which are be rated for temperatures up to 400C What I could find are rated up to 250C or 260C - which is not quite enough for the temperature sensor (when printing at 260C, which is the default for ABS).

Now I have a self-made temperature probe (also Pt100) which has already lasted longer than the 2nd original Ultimaker unit I had