I tweaked on my printer a bit

I am not a fan of cooling fans… I am thinking water cooling the hot end is pretty cool…

Watercooling my MakerGear Prusa RepRap
I’ve been fighting with printing 1.75mm PLA. The thicker brass in the hot end causes the heat to creep up more and make the ‘melt zone’ so long and sticky that the printer jams up…

18 Replies to “I tweaked on my printer a bit”

  1. I find it curious that this fix is infinitely more complex than a cheap fan. +Mike Creuzer Are you trying to use 1.75mm filament in a hotend designed for 3mm? That seems like a bad idea to me and possibly the reason you have periodic jams.Both MG and Jhead use a ptfe liner that needs to be sized for the filament you are using, 2mm and 3.5mm I.D. IIRC.

  2. +Brian Evans the makergear hot ends don't have a inner PTFE liner.  They have this PTFE insert near the top of the cold end (which is absolutely worthless btw), but the entire brass barrel is un-lined.  It looks like they actually discontinued that style hot end.

  3. +Anthony Morris Youre right but that upper ptfe insert is a different ID depending on the filament size and so is the brass barrel. My suggestion still stands that if he's using the larger barrel then that could cause the 1.75mm filament to buckle, cool down, and jam. You did give me an interesting idea to lap or polish the brass barrel ala prusa's hotend as that might provide better results. My MG hotends have been flawless both 3mm and 1.75 except when I ran cheap ass chinese filament through one of them. Fast heatup, consistent temps (+- 0.02 deg), and no jams. The ceramic paste is a little delicate though.

  4. I did this 50% because I can, and 50% because I've gone through 3 of those little fans, as many different mounts, and am out of tiny fans.

    That whole definition of insanity thing… I wanted to try something different. I'd bought the materials for an aquarium heater project, and this seemed like a fun expansion on it.

    I have both 1.75 and 3mm hot ends. Ordered both when I got my MG Prusa Kit a year ago.

    I like my MG hot ends. I've had no problems with them that aren't of my own creation except for printing 1.75mm at fine z heights <= 0.1 with slow speeds ~ 30mm/s without that little fan.

  5. +Brian Evans I would love to see someone polish the inside of the makergear hot ends, I'm also sure they would function a ton better.  But seeing as the hot ends look to be discontinued, it's probably a moot point.

    1.75mm ID tubes cannot be polished according to Josef Prusa.  He said he looked at offering a 1.75 version of his nozzle, and they just couldn't get tooling small enough.

  6. +Mike Creuzer Well that makes sense… Ive only done a couple of prints at .1 and just found that I am too impatient. I could see that the Jhead would be better here.

    +Anthony Morris I doubt theyre discontinued… Rick has had a lot of orders for his M2 that he's trying to catch up on them so he periodically pulls stock off his site. I bet theres a way to polish the barrel though… Ill have to sometime ask my colleague at the University who teaches Jewelry and see what she says.

  7. +Mark Kimsal A general problem with hotends is when the filament starts to soften high up in the barrel and then cools down which will cause a filament jam. You want the filament as cool as possible down to the heat chamber. The jhead uses vents milled in the side of the peek holder while the MG hotend is just shorter.
    +Anthony Morris That would suck if thats the case but when I look at their hotends page it just says out of stock. If +Rick Pollack discontinued his hotend that would get interesting for all the makergear owners out there.

  8. I have the long barrel MG hot end, designed for original Mendel.  I put some washers down on top of the hot end insulation, but it looks like the barrel in the photo has some extra insulation above the ceramic heater blob.  Take that off.

  9. I pretty much stopped having trouble when i switched away from the MG hotend to J-Head. Now that I'm used to the J-Head, the MG seems really clunky and kludgy in comparison.  Of course, part of the difference could be that I'm always using a fan on the J-Head, but I want a fan to cool the print anyway – it makes a big difference in print quality to have some air moving on the print.

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