mandag 9. mai 2011

Mendel-parts.com - v6 hot end first impressions

I've been using the v6 hot end from mendel-parts.com for a couple of days now, and although that is not enough time to do a complete review, I would like to share a few things I've learned.

  • It's working beautifully! I always thought the hardware was to blame for my sub-par print quality, but with a proper hot end and skeinforge 41, I was able to spot the hardware problems. A new belt on the x-axis and metal gears on x and y axis did the trick.
  • I (and I'm not alone) needed to glue the PTFE tube/liner to the brass part to avoid it forming a blob which clogged up the whole thing. I did it by roughing up the surface of the PTFE and the inside of the heater barrel, and put on a very small amount of thermal glue. Take care not to clog the barrel! It seems to be working out nicely. Here's a picture after the first failed attempt at attaching it to a wades. The mounting bracket failed, and both the PTFE and PEEK pushed out of the barrel, resulting in all sorts of funky cleanups.

  • I don't like to glue the thermistor in place. Both because it would be impossible to remove, and because the thermistor I have from ultimachine is too big to fit. I could of course use the thermistor supplied with the hot end, but then I would have to change the temperature table which is not readly available. Anyway, I went with my decision of attaching the thermistor to a ring terminal and replace the copper ring with it. It worked out fine, but the temperature was WAY off. Because I use to weak springs on Adrians extruder, I had to increase the temperature to 205 degrees to get proper extrusion. After a while it clogged up and I found this inside the barrel. (Be warned, it's not pretty).
    •  I now extrude at 180-185 and it works beautifully, I think I could go lower still.
    • EDIT: I have a theory the gunk was bits of PLA the extruder grinded off the filament, and not necessarily the temperature.
  • I didn't damage anything apart from breaking off the filament guide off "driven-holder.stl". Here I'm printing a new "idler-holder.stl" to have a spare.
  • To sum it up:
    • The mendel-parts v6 hot end works great!
    • Glue the PTFE tube to the barrel (carefully).
    • Use strong springs on Adrians extruder.
    • Test your temperatures with natural PLA to check for discolouring.
    • Skeinforge 41 with volumetric 5d is incredible! (Don't waste your time slicing with the old repsnapper windows build that's available).
    • When you turn off the machine, leave the plastic inside. I had no problems extruding straight away when heating it up again. If you pull it out it will most likely form a plug.
Update 01.02.2012: I've used the v6 hot end for a long time, and it's decent. Though because the melt chamber is so large it drools a lot, and the filament lingers a long time when changing colours. The Arcol v3 and J-heads (and others?) has no such melt chamber, only a straight path to the nozzle, which I find is a better solution. This is written only for completeness sake, as the v6 is no longer sold. Though the v9 looks similar, I have not seen it in person and don't know how it performs.

Well.. I'm off to figure out why skeinforge 41 sometimes decides to home during a print. It's no problem when it homes towards the endstop, then it just goes back to printing. The problem is when it anti-homes away from the endstop, trying to push the x carriage or the bed off the bars. I could attach endstops there probably, but that's just circumventing the problem.

Edit: Oh, and I made a funny Minecraft Creeper Keychain, check it out.
 -Nudel

3 kommentarer:

  1. I got a V6 Hot end from Botmill & haven't been able to get it to work for more than a few minutes yet. I was wondering if you had any insights into this situation. Initially it will extrude very well - but after about 5 minutes the filament becomes very difficult to push in and eventually jams. After taking it apart several times I noticed what you mentioned above - that plastic would get under the ptfe tube and push it up and out of the peek barrel. I just tried putting a 6mm washer with a 3.6 mm hole in it on top of the peek barrel (with the ptfe tube in side the barrel). This appeared to hold the tube in place but after about 10 minutes of testing it slowed/jammed & clogged up again. Do you perhaps know any other ways to address this? Thanks!

    SvarSlett
    Svar
    1. Hi, sorry I didn't see your comment earlier. I don't use the v6 at the moment, as I don't use the printer it's mounted on, but I remember having some trouble with leaking, yes.

      One thing that I think helped only a little bit, was roughing the ptfe tube with sandpaper and gluing it in place.

      More important was I actually tightened the bolts until it deformed the extruder cold end(!), which was solved by adding a small 4mm aluminium plate under the cold end. Then I could tighten it so hard the peek block started bending. I also added a fan to cool the top of the extruder.

      Since it's a while ago, I'm not entirely sure, but I might also have cut the ptfe tube a bit too long, so it was compressed when mounted, forming a good seal. Perhaps a o-ring could help?

      Your problems could also come from wrong temperature settings or e_steps. Post to the reprap forums for more help.

      Slett
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    SvarSlett