Volcano hot end

Hi,

Have been looking for a reason to try out the Volcano Hotend from E3D.

Very tempting to wait until I’ve tried one out before taking on the really big print jobs.

The claim is that while you print much faster, due to the nozzle size of up to 1.2mm, you actually gain strength.

The other main concern is the loss of resolution, which you definitely lose a bit of in the sub-mm range, but I don’t think that would matter for the MPCNC print jobs. Dimensional accuracy is claimed to be un-affected, which does make sense.

Any thoughts?

J.

Larger diameter of nozzle work great for large parts it save a lot of time in production.
You can try it just to drill your existing hotend. We use 0.6mm - 0.8mm nozzles
in regular J-Heads for some production printers without loosing much quality of prints.

Doing what you suggest and keeping the layer height to < 80% nozzle diameter would get you to 0.6mm, which would be great.

I understand going beyond that is going to push the melt speed to the limits to keep the flow rates up. I believe this is why they incorporated a longer melt zone on the Volcano, allowing the filament to pick up more heat.

0.9mm layer height should be possible! Fairly chunky looking I would think.

I have already ordered the knock off Volcano kit from China. I’ll let you know how it goes.

I switched to a volcano last week. I have only tried the 0.6mm nozzle so far but it has pretty much doubled my print speed. So far nothing I print really needs the detail of a smaller nozzle so I’m happy.

Where would one find the bits to drill out a nozzle?

I’ve seen such bits on Amazon/eBay/Aliexpress. Most people I’ve seen just use them to clean their nozzles. I personally wouldn’t bother using them to drill out a nozzle as the bits are so small I’m sure I would end up snapping them. Nozzles themselves are cheap enough I would just buy the size I want instead.

First tests with the volcano clone. Went straight for the 1.2mm nozzle.

First parts are fugly! Not just because of the fact I am printing at 0.8mm layer height, but also because it’s ooze city and I have some over extrusion, which at this height shows up really bad. Need to calibrate retraction and feed rate.

But…the parts are really strong, and the print speed is amazing. I’m doing a spool mount part at 1/3 of the speed from before with my 0.4mm nozzle at 0.26mm layer height. No apparent loss of dimensional accuracy.

Seems this might be the way to go for me printing MPCNC parts.

I have been printing some parts with a .5mm nozzle and my hole inner dimensions are tight, using simplify. Scared to go any bigger.

What slicer are you using?

I am using Slic3r. I don’t see why internal dimensions should be smaller. I take it you’re ruled out a slight over extrusion.

I have printed a z-lower with my e3d v6 to check for dimensions, and the bearing was a perfect fit, so I’ll be in a position to see about internal dimensions once the volcano is dialled in enough to try it. Pics and settings will be posted following that.

I have a feeling 0.8 will be too far, and expect to find the sweet spot at 1.0mm nozzle and 0.6mm layer height. Nozzle temperature was going down a bit at times with that volume of PLA pouring through.

I found out about Volcano before MPCNC, so when I recalled the claim that parts are stronger, I was keen to try it out.

Initial impressions of the parts is that they are harder to break, but perhaps a tiny bit less rigid. Perhaps a little less brittle, but I don’t know if any lack of rigidity would be an issue.

They should be just as rigid if you’re using the same infill and shell settings as a smaller nozzle. Also all outside dimensions should be the same as a smaller nozzle since the slicer is going to take into account the orifice size. Just like using different sized end mills to cut the same part. As long as the surface details are larger than your nozzle diameter it will work.

There is a section of my print which has no infill which is a bit bendy, which gives me the impression that brittleness increases when layer height decreases. I’ll try to find a way to measure, because I am beginning to think that ‘volcano prints are stronger’ is too simplistic.

I agree there is no reason why big layer heights should have any impact on dimensional accuracy, in particular for MPCNC parts.

Don’t get me wrong, I agree it shouldn’t. That is why I asked about your slicer. All other dimensions are just as accurate as a .4mm nozzle print from the exact same printer, except vertical hole ID. This leads me to believe some weird slicer glitch is going on. I will design a test piece and test it when I catch back up on printed parts orders…

The part I have been testing with is the Large XY piece. Everything is perfect, prints way faster, the two hole that connect with the XYZ part undersized and need to get drilled out, the rest of the dimensions are great. Tried all three part versions, same hole is tight. I will try another slicer but that means a .4mm print then a .5mm print, both at 75% layer height ratio/nozzle diameter.

I’m not sure to understand everything (bad english), but normaly, if you don’t do nothing, with Slic3r or Cura or Simplify, with a 0.4 nozzle, you loose around 0.4mm in diameter for a vertical hole. That’s why there’s an option in Slic3r: “XY_compensation” since one year now. If you use an X mm nozzle, you must put ‘-X/2’ in this option, and then you’ve got a perfect size hole. External size will be the same for every nozzle, but not internal size. In general, I’m using Slic3r with XY_compensation for every ‘mechanical parts’, and Curaengine for every ‘artistic part’(faster and less internal crossing).
Try it with your big nozzles Ryan.

I spent a few hours working with different nozzle sizes and different settings, and found that the limit for me seems to be printing at 0.6mm layer height. I got this calibrated fairly well with the 1mm nozzle. From my experiments, some of the issues with going higher are around cooling. Airflow needs to be increased in keeping with the volume extruded on some parts.

I found the XY compensation to be unnecessary. I tried it and had a big gap around the bearing hole. Printing without it, the bearing was snug, just as when printing with the 0.4mm nozzle.

My part has a bit of PLA curl, once I get that fixed I’ll put up the pics

I printed the Z-Lower part in 0:37, compared to 1:45 at 0.26mm (same infill), so it’s promising to save some time. As for strength comparisons, if there are some specific tests I can do, I’m willing to try. I have all kinds of hammers and vices to torture with!

Not much to add about settings. I did try to set layer width to match the nozzle diameter, but it has the same results as letting slic3r decide (default).

The surface print quality is not great looking yet, not sure why. But the part is accurate and strong.

In some places you’ll see bits of the brim left on, and some places it is cut off.

Volcano prints wanted to warp a bit more. I have resorted to sanding the blue tape a bit, cleaning with surgical spirit, the spraying with hairspray (extra hold, with copolymer). I thought, if it works on glass (sometimes it’s hard to get parts off the glass) it would work on tape, and it does. No lifting at all now.

Tried it out on the Bottom_corner part, to see how it went with ooze and overhangs.

In both of these issues it’s proving a challenge, but part came out looking otherwise very nice in 37m.

The problem with overhangs is documented really well here: http://www.akeric.com/blog/?p=3407

As for retraction, I’ve tried bumping up travel rate and retraction length - up to a ridiculous 10mm, which came close to causing a clog, and was no better than 4mm.

I’ve played with retraction speed and print temperature too. Just won’t go away. I’m guessing you’d need a different hot end design to allow the length of retraction really needed to stop ooze at this print volume.

Looks like these issues are ones I might have to live with

There is no problem with overhang after all - I failed to spot that other overhangs were fine. The problem was that Slic3r was collapsing some walls down to 1 path thickness because the layer width wouldn’t fit at least twice.

Lowering the perimeter layer width solves it, but lowers print quality (had to go to perimeter layer width 0.6).

As a hack, I pulled the face of the stl to widen the wall. This made for a good print on the top corner, but more thought is needed if there is to be a solution for the bottom, because there is no room to widen as the conduit runs over it.

The red part is the successful top, the black is the failed bottom corner

Modified stl attached for reference.

EDIT: It wouldn’t let me upload the stl (security reasons)

So I have a perfect part printed at 0.6 layer heights and 0.6 layer width. No STL modification necessary.

The fact is, the flow rate requirement seems to be dramatically different depending on the layer width. I guess this is a firmware issue (Repetier for me) rather than a Slic3r issue.

With 0.6mm LH x 1mm LW, a flow rate of 82% gives perfect results.At 0.6mm LH x 0.6mm LW, the ideal flow rate for me is 110% !!

It is because of this that my attempt to resolve the xy detail issue by printing narrower perimeters could never work.

There is not a flow rate (extruder steps/mm) that works for 0.6mm LW perimeters and 1mm LW for everything else. The only solution is to do a default LW of 0.6mm and up the flow rate.

The upshot of all this is that some prints (top and bottom corners, tool mount so far) need a narrower LW and corresponding increased flow rate. The difference in print time is :

Top_Corner:

0.6mm LW, 0.6mm LH, 110% FR: 34m
1mm LW, 0.6mm LH, 82% FR: 28m

This part is listed as taking 2:06 on the parts page. Strength tests maybe to follow, but the parts seem f*cking strong.

Edit : the given flow rates are in relation to a 100% flow rate (steps per mm) arrived at via calibration and tweaking on my E3D v6 all metal universal hotend.