Diamond Hotend not reaching full temperature

I've been struggling with this problem for a while now and would appreciate some advice.

I purchased a Chinese clone of the Diamond hotend which didn't come with the insulation sheet. When I tried heating the hotend without the insulating sheet the temperature couldn't get past 107C due to the cooling fan blowing directly on the hotend. I went to the local woodstove store and got some insulating cloth that is about 1/8" thick and put two layers together to form an insulating shield. After this modification I was able to get to 170C but no higher. I then tried wrapping the lower portion of the hotend with the same insulating cloth. I am now able to get to 186C but no higher. I have tried switching from PID to bang-bang but it doesn't seem to make any difference. I have also tried connecting the hotend to an external power supply bypassing the rumba controller but that didn't work either. Also swapped heater cartridge with a new one, still no luck. I thought the issue might be the ambient air temperature in my basement (62 F) so I turned on the heat bed to 60C and draped a blanket over the whole assembly. No dice.

Has anybody else out there had a similar issue and found a solution?

Use a real diamond hotend and not a Chinese clone?

It sounds like the heater cartridge is either 24V running on 12V or not enough watts to get higher temperatures.

Yeah, I about the possibility of the clone using inferior components but I'm sure the heating cartridge is 12v / 40w because I replaced the one that came with the hotend. I came up with a possible solution?? I saw a post on a 3D printer website where they recommended upping the voltage to 13.5-14v. I tried this with my hotend and with 13.8v I was able to get up to 230C. Question is: will this burn out my heating cartridge or are they designed with some wiggle room for slightly higher voltages?

Thanks for the help on this.

I'm a long time user of the Diamond hot ends (genuine) on a couple of printers. I usually print PLA @ 195 deg C but was playing around with some t glass at 240 degC a few days ago with no problems getting up to temperature. As an aside, I did some testing on thermal compounds a while back, with a diamond sitting on some insulation (not mounted on a printer) and got up to 400 degC and probably could have gone higher. Admittedly that was in free air with no cooling fan but if you have the right fan shroud and insulation around the heat sinks, you shouldn't get much cooling air reaching the nozzle. I use a 40W cartridge heater (24V in my case) but 40W is 40W (as long as you don't try putting 24V through a 12V cartridge).

TBH although my Diamonds are all genuine, I doubt that your problems are because yours is a clone, unless the heater cartridge is sub standard. Cartridges don't cost much so it's easy to try a replacement. The heat sinks probably won't be genuine E3D so you'll likely get some clogging issues but I wouldn't have thought that it would stop you getting up to temperature. Apart from that, it's essentially just a big lump of brass - genuine or clone there won't be much difference (apart from the fact that the nozzle probably isn't the size you think it is, but that won't affect how it heats up).

Are you running a print cooling fan? If so, try turning it off, or slow it down, or direct the air flow away from the nozzle. The Diamond is quite sensitive to having cold air blown over it, due I suspect to it's relatively large surface area. I don't use a part cooling fan at all unless I'm printing something really small with short layer times. Even then, I tend to slow down the printer to get the layer time up to around 15 secs, rather than print fast and use a cooling fan.

Other things to check are that the thermistor is seated well and is reading true. Also, of course, is the cartridge fully inserted? You'll have discovered that the hole in the Diamond is only 15mm deep and most cartridges are 20mm long. I run a standard 20mm one with 5mm poking out the top which doesn't seem to cause any problems.

Finally, I don't know what electronics you are using but do you have the ability to tune the PID settings? You'll find that the Diamond has very different characteristics to a "normal" hot end so you may need to tweak the PID parameters for the heater.

HTH

Ian

I have a similar problem with a chinese diamond assembly bought from "Big Tree Company"
Even with increased voltage it topped out at 157°C.
In my case the isolation material was there, but the heater cartridge sticks out too far (6mm), even touching the fins of the coolers.
The heater is a proper 12V/40W of 21mm length, which by itself is 1mm longer than original 20mm.
The hole in the diamond nozzle however is drilled at 18mm depth at the center only.
The drawing for the original noozle shows that it should be a flat milled bottom at 18mm depth.
It seems that some chinese sellers have 6x15mm 40W heater cartridges for mixing nozzles.
So either the hole needs to be fixed for a 20mm heater or the heater needs to be 15mm.
I've decided to order 15mm heaters, but don't have them yet.

I also ordered the 15mm heaters a while back. They fit very nicely in the Diamond assembly and end up flush with the top. I haven't had time to test how they work but would be interested to hear how they work for you.

I've just ordered some 15mm heaters directly from China, so no testing for the next 4-6 weeks :-(

Hi all, I have the same problem with my homemade diamond hotend I can confirm it is made to the drawing sizes and specs and from solid brass, I have a 12 volt 40 Watt chinese heater and have checked its values with ohms law i.e 12 volt 40 watt calculates to 3.6 ohms resistance which it measures, I reversed the cooling air flow direction of the fan sucking air upwards from the hotend and flowing outward from the cooling fins which has helped, I have made a conical thick felt insulation skirt for the hot end but I cannot raise the heat above 210 deg C when manually setting nozzle temperatures to 240 deg C.
I note from deckingman earlier posts My pid settings may be my main problem currently set at Kp 73.47 Ki 10.34 Kd 128.14 derived from an earlier pid tuning for 200 deg C but I cannot get the pid tuning to complete with the following instruction M303 S240 C5 each time I try the temperature raises quickly to about 105 Deg C and after a long period of time the temperature slowly climbs to around 200 - 205 then hangs and the routine fails with a timeout error without any pid settings I have changed the ATX power supply from a 400 watt ATX to a 600 watt model so I think power is not be the problem as the outcome is the same since changing, can someone please advise with some basic diamond pid settings which may be the thing that allows the tuning routine to complete. I have tried pid tuning from pronterface command line entry and from the smart controller option both ways fail

I look forward to superior knowledge.

cheers for now .

Edited 1 time(s). Last edit at 04/25/2017 02:13PM by papakel.

I've just tested with a new 15mm heater.
The heater fits perfectly and matches the 40W.
However it still had troubles to reach temperature.
Unfortunately I had to stop the test because the cooling fan broke, so I can not say if the top temperature would have been higher.
What I will try next is to test with different cooling ribs.
The heatsinks supplied do not have a separate heat break tube and are machined in one aluminium piece without any narrowed gap.
I suspect that they are thermally way too conductive.
In theory they should have been designed to reduce heat transport as best as they could.
Fortunately I have better machines heatsinks to test.

Hi gents, I have fixed my problem I designed and made an aluminium cone with a 10mm brass nozzle set in the bottom then I drilled the filament tubes to intersect at the base in the brass nozzle as does the diamond and then drilled two 6mm x 21mm deep heater holes vertically between the filament holes to accept 2 Chinese 40 watt heaters and now pid tuning work like a dream and temperatures in excess of 270 deg are possible in a normal space of heating times

Works for me as well after swapping not just the heater with a shorter 15mm one, but also heatsinks with some, which have a proper heatbreak tube.
The original heatsinks are just rubish.
This is not just about heat going away - they also lack a proper transition zone.