Hexagon V2

The Hexagon hot-end on the Taz 5 is much different than the one that Reprapdiscount sells. The heater block is much taller and has a retaining plate for the thermistor. The cooling fin section is probably a cm shorter. Even though they are both called Hexagon, the new one really should be called V2 or something because they are not the same.

That said, will Reprapdiscount carry the V2 hexagon or is that a Lulzbot only thing? When will Lulzbot sell Hexagon v2 parts?

We typically try to carry spare parts, but for now since we’re still building and assembling we don’t have anything available just yet. We call our version of the Hexagon hot end the LulzBot Hexagon Hot End.

So, is it possible to hot swap different hot ends as long as the internal thermistor and resistors are the same on both hot ends…? I’m assuming that’s the only thing the firmware is tied to with regards to the hot end…

Exactly. The firmware does not have a way to change the thermistor selection through any EEPROM settings, so provided you use the same thermistor on anything you hook up, the firmware’s going to happily move forward with whatever you’re using. The resistor type doesn’t matter so much, but since there are several different PID values, your performance may suffer. It’ll still work, maybe just not as well or as efficiently. If you know the different PID values for your particular hot end (either from Configuration.h, or from what you’ve determined by running PID tuning) you can update that on the fly, through EEPROM commands.

A guide on that can be found here: https://www.lulzbot.com/support/fine-tune-your-marlin-pid-settings

AWESOME!! clear as mud! thanks!

So obviously the next question is, what thermistor does the new hex hot end end use? :slight_smile: I have one coming in the mail, so it looks like I’ll have to match that one if I get another hot end for my flexi build…

You’ll want to use this thermistor selection:
// 5 is 100K thermistor - ATC Semitec 104GT-2 (Used in ParCan & J-Head) (4.7k pullup)

OK! awesome! Thanks. I’m sure a lot of people will be wanting to know this as they adopt this new hex end :wink:

Thanks for the clarification and enlightenment. :slight_smile:. Keep up the good work.

dang, so if I buy a lulzbot hexagon and already have a Budda I will not be able to make a dually cooly with the two of them together? I was thinking of using my buda for the flexi and the Hex for everything else.

Is it possible to put the Semitec thermistor on a Buda. I’m pretty sure one is axial and the other radial, but might still be possible if you use some kapton tape.

That may not solve your dually problem entirely if there is much difference in extruder height it may be really difficult to calibrate.

You’d have to make sure they have the same resistor also…either the stock one for the budda or the newer, better, cartridge style. :wink: That’s all the firmware cares about really :slight_smile:

Thanks for getting this out there.

Does anyone know if the heater blocks and cooling fins are the same thread for both types? Basically I’m wondering if someone has the RepRap hexagon could they swap the LulzBot heater block onto it. Since I’ve upped my print speed I’ve started to notice that longer heater blocks work a lot better.

Read my initial post. Neither are the same. They are quite different. I’ll try to post pics over the weekend.

Read my initial post. Neither are the same. They are quite different.

Oh bummer! I didn’t think they would be completely incompatible, I figured that it was similar to MatterHackers E3D and volcano upgrade (the volcano is basically just a bigger heater block for faster printing).

I’ll try to post pics over the weekend.

Thanks dude

Yep. No problem.

Ebay or Alieexpress for heater cartridges, can get a pack of 10 (12V 30W) for 10-15$. Can’t beat that.

I bought my thermistors here,


can also get them here,


they’re the new kind, 104GT-2, axial, they’re the new versions, the one’s that slip through the heater block. These are the new standard as I understand it.

Slap those into your choice of hotend and you should be good to go.

One thing I’d like to know, why are most heater blocks so short, so the cartridge sticks out about halfway, isn’t that a waste of heating potential. More surface contact means more heat transferred…

I’ve wondered that myself. Particularly on the Taz Hexagon where the cartridge hangs out significantly.

My guess is that if you make it the full width of the cartridge you actually require more energy to heat the area near the melt-zone; Since you have a larger mass of aluminum to heat up. The cartridge sticking out waiting for your fingers to get near isn’t being utilized, but that is more efficient than heating up some aluminum hanging off of it for no purpose.

Anyhow, I’m sure there are much more knowledgeable people than me around to comment about it.

Update: After comparing Lulzbot Hexagon with the original I’m kind of wondering if the 24v heaters aren’t just longer. The original came with a shorter heater, but I think it might be 12v.

I realize these pics aren’t the best, but it’s the best I can do right now.

The new heater is noticeably longer than the one that came with my Reprapdiscount setup. Would be nice if the new heater was the same length, so it didn’t hang out so much.

This shot will give you an idea how much the heater sticks out. Don’t get your fingers in there!

The angle makes it look like the Reprapdiscount version is noticeably longer, but they are about the same length. The big differences are that the there are fewer heating fins on the new version and the heat block is bigger. Also there is a plate that screws on the right side now to hold the cartridge and thermistor in place.

Here is a picture of my custom ‘Fangtooth’ setup. The big differences here are the fan that comes with it that is more similar to the E3D V6 fan/shroud setup, except the shroud is 3d printed. The mini blower fan on the Taz Hexagon is a pretty neat alternative.

If I had to speculate I would think that the new version has a larger heat block to increase the size of the melt zone and decrease extrusion pressure. The shorter cooling area is probably as a result of wanting to increase the size of the heater block, but not wanting to add any additional height to the extruder. I would love to see a blog post wink from Lulzbot talking about the new hot-end and why they made the changes over the original hexagon.

Regardless of the difference, they both have worked well for me and I’m very happy with both of them. Either is a decent upgrade over the Buda to me.

Cool, nice setup. If I can’t source the blower, I’ll probably do exactly what you did and just a small fan…what size is it? how much cfm does it put out?

Also, you wouldn’t happen to have the .stl file for that extruder mount would ya? :wink:

anyone ever accidentally touch the hot end?? I did one day…realized why it’s called a HOT end…you do it once and then you NEVER do it again :wink:

Well said, the side by sides are great!

I’m following you on this long cartridge issue. Thermodynamics is an interesting subject. I’m going to look at this subject through the lense of high volume printing–understanding that high speed does not mean lots of plastic is getting layed down. Im going to venture that heat capacitance comes into play when you are printing at high volume and also in high detail. For example if you wanted to print layers at 0.3mm, outer perimeter at 50mm/s, inner perimeters at 100mm/s, tops and bottoms at 200mm/s, and infill at 240mm/s. Have the acceleration set to 2000mm/s^2. So the problem with doing this with the budaschnozzle is that it can’t keep the heat up when going from printing a perimeter to printing infill or a large bottom or top surface. One way to fix this problem, print hotter. The problem with that is funny points or overhangs will often burn. The other way is to get a bigger block. A bigger block regardless of its dimensions will increase the heat capacitence which (I think) helps keep the nozzle temp stable if you are printing at a wide range of speeds. So making the block wider to take up the length of the heater cartridge should be a benefit. So I don’t know why the block isn’t the whole length of the cartridge, head scratch.

…I bet it doesn’t matter. :laughing:


If I wasn’t on my phone I would give you the link. There’s a newer forum where orais gives out where to get the little squirrel cage fan.