Jr Hotend - All Metal or PTFE lined (Page 1 of 2)

@gravy - I've ordered my 40w heater from China by accident. (One of those listings where it's listed as local but in reality Shenzhen market)
Reordered new block from UK last night so should arrive today/tomorrow.
Probably will swap it at some point this weekend.
I'm curious to see how it'll perform with 40w block.

And to remove the heater block it's quite easy, if you can get your screw loose of course easily, mine was a bit tight.
Only thing be careful not to damage thermistor if you are grabbing your hotend with pliers or so.

But... I have a package from E3D sitting on my desk! Made a decision to retrofit my Jr with E3D hotend instead.
Now I need to find some time to design and refine new mount + find the best way to cable it up properly.
I'll take some time, that's for sure but I'll post my progress somewhere here when there will be some progress.

@gravy - yeah, I found this one and unfortunately wasted my filament on it...
1. When E3D is mounted it's way too high. 200mm higher than original hotend. Around 150mm higher than x gantry metal plate. No chance it will go even close to the build plate. See picture attached.
2. Original hotend tip is only 11mm from the back bracket mount piece and if you'd modify this STL to go down to needed height it would stick extra 15mm forward. That means your printable area would be 150x125x150

Also there's another thing to consider with this design.
Have you thought why current hotend fan is mounted other way round, instead of blowing onto the hotend it sucks heat out?
That's because right behind the carrage you have belts and if you'll blow hot air over them they'll stretch and degrade very quickly.
Wanna know how I know this?!

Anyway, design I'm working on will allow to blow the air but I'll have something like "blast shield" which will guide and redirect hot air th the sides instead.
I'm still struggling with distance from the mount carrage, my current design adds extra 4mm what is enough though hence physical size of the bed is 165x165 what gives me 7.5mm extra space to work with.

PCB I'm planing to mount somewhere on the side, probably next to the extruder so it's easier to wire it up and guide cables along the PTFE tube. I hate that flex cable they've got. So many times I nearly snapped it while cleaning clogs or doing general nozzle clean.

Btw, do you have any idea what is that 2pin connector on PCB?! Is it for that auto calibration sensor Jr WiFi version has?! Been thinking to get one of those probes of eBay and hook it up if that's the case. Only problem I think it needs to be on some specific firmware version which is scary proposition...

Right. As far as designing the mount, I'm afraid that's way beyond my capabilities. As for the 2 pin connector, I have the WiFi version of the print head (although I'm using normal JR). You're correct. The 2pin connector is for the auto calibration. I'm using 2.2.0 f/w so I can hack the filament chip. There is nothing in the settings for that sensor. So I think its a fair assumption you would have to upgrade the f/w. I guess you'd have to be on one of the most recent ones. Personally I'm staying on 2.2.0. I really don't wanna lose the ability to hack that filament chip.

Oooo! I to am very curious how the "calibration" hot end ticks. Please take pics if you do decide to take it apart.

It's a shame the calibration part does not actually work under your current firmware... I was really curious if it actually has an effect on the quality of the prints.

Do you happen to have the instructions included on how to use the calibration feature? Can you scan them? *xyz does not have them online*

Sorry guys. Had a hectic couple of days. Will post photos at 5.00pm ish.

Interesting.

So you push the button down which exposes the switch, initiate the calibration, it does a 9 point calibration, then you push the other button to retract the switch.

It's a fair bit more simplified than I expected, but I guess it works.

Are you sure you're using the same mount as this guy? His setup appears lower than yours.

F. Y. I. This is where I got the stl files from

https://www.lesimprimantes3d.fr/forum/t … -vinci-jr/

You probably need to run a PID tune on the hotend to keep it from bouncing around at those temps. But unless you have upgraded to a different controller you have no way of doing so unless you can talk to your board through repetier then you could send the command to run the PID and store the values.

The issue is your firmware is calibrated for the 24W and not the the 40W so it can't control the heat ramp of the 40W properly.

@reluttr - I don't see the problem there. I know some people will say "oh, it will draw too much and flex cable gonna melt" - yeah, it's just a fan and doesn't draw as much. I fitted 40w heater instead of 25w and cable handles it surprisingly well.
Also I've designed little part fan if you are interested. http://www.thingiverse.com/thing:1699598

@gravy - yep, heater block size wise is exactly the same.

But just to clarify few things so people don't misunderstand that scary 250c.

1. I'm using Cura as my slicer so I do set temperatures manually.
2. If I define 240c then it goes to 240c (+ a bit of a overshoot), if I define 190c then it only goes to 190c, 210c = 210c, and so on.
3. If you are using XYZWare and temperatures depends from NFC chip of choice, they will only go to that temperature.
4. When using 40w heater cartridge instead of the stock 25w one themperatures doesn't overshoot any more that with the stock heater cartridge if you are using common 190c-210c range. It tends to overshoot if you are going above 235c.

Also about the overshoot when printing on 240c. 250c sounds quite a lot but actually it's only 4%.
4% of 190c is 7.6c, you see that often on stock config Jr when printing 190c that sometimes it goes close to 200c.

All and all. If you've been using your stock Jr heater and someone would swap the heater over the night to the 40w one without you knowledge you wouldn't see any difference what so ever!
By swapping the heater there are only 2x benefits: 1st - it reaches initial temperature quicker, 2nd - you can go over 214c if you want or need and ONLY IF you set higher temperature manually.

Sorry if all that sounds patronising but I just don't want people to misunderstand why there is 250c on the Jr display.

Nice!

Have you noticed a improvement in print quality with the fans attached? Also did you have to do the x gantry brace mod to prevent sagging?