New hot end

[AndyP]

I must be one of the lucky few to have actually had a printer delivered and be playing.

I have never been impressed with the print heads performance so in search of higher resolution and less "ooze" I have just fitted a Merlin hot end from here and am suitably impressed. The 0.3mm nozzle gives a much neater print with less blobs than my original and the 0.2 is even better if a little fiddly to get set to the correct height. I have got layer height down to 0.15mm so far.
I had already moved the extruder to new mount directly on top of the hot end to try and reduce the latency inherent in the Bowden set up and it seemed to make a small difference.

That is 30mm fan from Maplin because I couldn't make the supplied 40mm fan fit between the carriage and the print bed. Fan shroud is hidden but designed in 123D Design and printed on the Sumpod so nearly a "rep rap"

Andy

[jason]

Nice

[bdureau]

I am also strugling with my hot end which keeps on being jammed.
I think that I know where the problem is and I am now going to put a PFTE tube inside the nozzle barrel.
I quite like the way you fixed the feeder motor

[AndyP]

I thought the motor mount was a bit of a lash up but it works so that is all that matters. Did it for the original hot end mounted on the mdf carrier.
The Merlin hot end came with a pretty aluminium slotted mount that doesn't quite fit the sumpod but more importantly didn't provide any reall fixing for the hotend so I made a an alloy version with Sumpod fixing centres and at the same time turned up a replacement aluminium bit (slotted bit at the top) for the hotend but with an extension on the top soo that I could hold the hotend firmly in position with an O ring which you can just see in the photo above.

I never had any problems with jamming with the original hotend, this one:-

I seem to remember it was important to get the ptfe Bowden tube all the way down the thing to whithin about 3 or 4mm of the nozzle opening. I have just measured mine and there is 70mm of Bowden tube after the blue plastic locking ring on the top fitting.

Andy

[ratmonkey]

This was my way how to mount the Merlin -> Merlin mount

[AndyP]

Now that is a neat solution. My instinctive reaction to the need for a part is to reach for a lump of metal and show it to the milling machine, obviously haven't had the printer long enough.
Is that a cooling fan duct I see below the mdf carriage? where did you mount the fan?

Cheers
Andy

[ratmonkey]

Yes, this are fanducts to cool the print.
The fans are mounted at the back of the carriage.
I used 30x30x7mm fans. So they fit without loosing build volume.
The ducts look a bit bulky but it works fine for me.