Tuesday, October 15, 2013

$22 J-Head Mk V Clone

I saw this $22 J-Head Mk V clone, on E-bay, and decided to order one to see what it looked like.  I figured that since the J-Head Mk V series of hot-ends are well over a year old, and the specifications out for the same amount of time, that the clones should be getting better.

Today, I received it in my mailbox and immediately opened it up to take a look.  This is what I received:

Once I took it apart, I noticed that the PTFE liner is missing.  There isn't even space to install one.

Including the lack of a PTFE liner, I noted the following issues:

  • There is no thread sealant between the nozzle and PEEK.  Most likely, the hot-end will leak.
  • There is no way to adjust out any internal gap between the nozzle and PEEK.  This can result in the nozzle jamming.
  • The PEEK vents are 0.115 inches deep and the specification is that they need to be 0.150 inches deep.  In addition, the PEEK vents do not follow the rounded contour of the filament path.  They are milled flat so that the PEEK gets thicker towards the milled struts.  This will not provide for optimal cooling.
  • The heater block section is considerably larger than the normal specification at 0.725" x 0.625" x 0.378" as opposed to 0.500" x 0.500" x 0.325".  This shouldn't cause much of a problem, however.
  • There was no PTFE liner.  This hot-end will not work with PLA.
On a more positive note, the orifice length was 0.027" or slightly over 1/2mm.

I guess this just re-enforces the adage that you get what you pay for.