Don't buy this hotend

Post Reply
kbot3d
Posts: 110
Joined: Sat Apr 13, 2013 12:09 am
Location: www.kbot3d.com

Don't buy this hotend

Post by kbot3d » Thu Aug 15, 2013 5:15 pm

After selling a number of extruder setups and a couple dozen full printers of various styles, some have chosen to purchase a hotends.com hotend clone from ebay. At the request of a local who wanted to cut a few corners, I ordered and installed a $36 clone from ebay. They are similiar in build but do NOT perform the same. I have built enough printers to solidly say that the $30 discount is not worth the headaches.

Enough so that I went out of pocket at a loss of $70 and bought the customer a replacement hotend before even delivering his custom printer. To each his own but I thought it only fair to give this notice. The money you save on a cheap hotend will cost you time , aggravation and filament. Please dont purchase a mk4 or mk5 clone on ebay

cvoinescu
Posts: 4442
Joined: Thu Jul 19, 2012 6:50 pm
Location: Camberley, UK
Contact:

Re: Don't buy this hotend

Post by cvoinescu » Thu Aug 15, 2013 7:32 pm

I second that. A fraction of them may be good, but hotends.com and the authorized resellers are the way to go. Generally speaking, if it's a new Mk IV on eBay, or if it comes with a 1.75 mm "conversion kit", it's almost certainly bad. If it's touted as a Mk V, check these tell-tale signs.

The original J-Head Mk V and Mk VB:
  • is made of brass (yellow), not aluminum (white);
  • does not have a nipple at the tip of the nozzle;
  • has a fairly shallow shoulder at the base of the nozzle cone;
  • does not have a grub screw;
  • has five grooves on the PEEK part, not four;
  • has nicely, cleanly machined grooves in the PEEK part.
Also, I'm sure the eBay people don't pay Reifsnyder any royalties.

Here's a sample from an eBay seller, claimed to be a J-Head Mk V, which fails on all six counts.
FakeJHeadMkV.jpg
Fake J-Head Mk V
FakeJHeadMkV.jpg (92 KiB) Viewed 2777 times
I've also seen absurdities such as "All in one GENUINE J-HEAD set Original Improved Design", "UK made all-in-one J-HEAD set ! Original Design!", and "All in one GENUINE J-HEAD set for RepRap Made in theUK" [sic].

On the other hand, this one may well be the real thing, although it's hard to tell.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

kbot3d
Posts: 110
Joined: Sat Apr 13, 2013 12:09 am
Location: www.kbot3d.com

Re: Don't buy this hotend

Post by kbot3d » Thu Aug 15, 2013 8:46 pm

The one in the pic is exactly the clone I have. It is a waste of money. To add to the notes listed. The inner hollow setscrew is an oddly larger size which does not allow for a teflon insert so there is an open cavity for the filament to deform causing jams. If using a bowden line like is needed for a rostock, this also means no chance of retraction to change colors as the filament swells in this cavity and will not draw back into the line.

phr0ze
Posts: 17
Joined: Mon Mar 31, 2014 6:17 pm
Location: Columbia MD

Re: Don't buy this hotend

Post by phr0ze » Tue Apr 15, 2014 6:48 pm

The easiest thing to tell is the number of slots in the peek is 4 then its fake. Apparent in most photos. If the hotend is too wrapped up in tape to count the slots then don't buy a hotend from that moron either even if he has the right parts as he has taped over all venting. (http://www.amazon.com/JMT-Printer-0-35m ... ead+hotend)

I get my hotends from Makerfarm.com or 3dmakerworld. Both arrive very quick in the US (2 days).

Post Reply