Anyone have a spare mini toolhead they want to sell?

I am looking for a lulzbot mini toolhead or hotend they are interested in selling or trading for the version that came with my mini which is a .4mm setup to print 1.75mm filament. PM me if you have one available :slight_smile:

I’m keeping mine, but I’m curious about why you want to give yours up. Over and over I hear that 1.75mm is better than 3mm for one reason or another – usually that it takes less pressure to push the thinner stuff through the nozzle. What has been your experience with a 1.75mm setup?

[removing link to incorrect hotend – see post below for correct link]
and a nozzle for $8: http://www.reprapdiscount.com/hotends/70-hexagon-nozzle.html

Obviously there’d be a whole disassembly process which would be much harder than swapping toolheads.

The RepRap hotend is not the version for the Mini. 3DMakerWorld has the Mini version: http://www.3dmakerworld.com/store/parts-accessories/hotends/hexagon-ao-hotend (you need to select the options, including 24V). It comes with a 0.4mm nozzle so you will need to purchase a 0.5mm one from RepRap (or MakerFarm if you want one located in the U.S.: http://www.makerfarm.com/index.php/hot-ends/hot-end-parts/5mm-hexagon-nozzle-for-3mm-filament.html).

I was going to go this route so I would have a spare hot end, but decided to go with an assembled toolhead from LulzBot instead (easier to swap out quickly): https://www.lulzbot.com/products/lulzbot-mini-tool-head. This costs more, but includes everything and is ready to go.

I’m not interested in giving up my spare toolhead, but may be interested in buying your 1.75mm/0.4mm toolhead; however, I am also curious as to why you are looking to change.


Chazz

Thank you for the correction – I’ve edited out the erroneous info.

Thanks for the useful information everyone. I was interested in converting it to stock for a couple reasons. The foremost is that, being new to this, the measurements and settings suggested in the various profiles are tooled to that hotend. I am still learning so eliminating custom modifications from the equations makes troubleshooting easier. As an example, with the self leveling bed I think figuring out and adjusting the z axis to account for a slightly differently sized hot end the software is accounted for as well as extrusion settings is problematic sometimes. Also lulzbot recommends HIPS for the machine and there seems to be a wider range of HIPS options available to me via 3mm.

So far my experience has been pretty good but I have hit a few significant hurtles. I went through a bad clog with PLA where despite my thinking I got it cleared it continued to be a problem for a few days. Eventually I got the extruder working right again when I switched over to HIPS but man that one PLA roll I bought caused a ton of problems. I was doing pretty well with HIPS until today when I seem to be getting delamination issues all the sudden despite no outward changes. I built an enclosure out of cardboard but it doesn’t seem to have helped any. I tried with the fan off in the enclosure and that was a mess. I am currently trying increasing the print bed temp from 110 to 120 which should raise the ambient heat in the enclosure. Will see how that turns out.

I have printed some beautiful stuff with the .4mm hotend and the 1.75 filament. No feeding issues really to speak of. Its just when I am troubleshooting I like to remove as many barriers as possible and this modded hot end adds to the complexity. Maybe I am just not giving it a fair shake.

The only de-lamination I ever had with HIPS was on a long part (just fit on the bed diagonally). This was also the only thing I printed that had any lifting. Neither of the defects was significant and didn’t impact the end use so I didn’t try repeating with any changed parameters. I think the de-lamination may have been due to the HIPS cooling off too much so I didn’t get a good bond. The minor lifting was a one end and could have been due to uneven bed heating (corner vs. center). I have since added an enclosure (sides only, top is still open) to avoid any cool spots.

I run HIPS at 240C hotend, 100C bed (110C made it too hard to get parts off the bed, but 105C or 110C should have corrected the lifting on my long part by keeping the entire bed warmer), 2.85mm diameter filament and 95% flow. My startup procedure is to preheat the bed to 80C while heating the hotend to 250C. I then extrude 20mm - 30mm to make certain that everything is OK, pull the strand off the nozzle tip with the tweezers and hit “Print.” While the hotend is cooling to wiping temperature, I use either a brass wire brush or a 3M medium scrubbing pad to manually wipe the tip of the nozzle. While this may be over doing things, I haven’t had any problems for quite a while, even after not using the Mini for a month (with a roll of HIPS “mounted”).

What are you asking for the 175mm tool head?


Chazz

I did a bone head move and forgot to update my filament size from the default when I reloaded the default profile testing the enclosure . Fixing that and using the enclosure I have been printing perfectly again. I have the default 240 on the hotend and I do 120 on the bed. I also have my flow at 88% which was the math my hotend calibrated to. I have no issues with getting the parts off after they cool.

If things stay running this well I guess there’s probably not much need to go stock. I may order some abs too just to try it.