Voron 2.4 : two questions

[YaaJ]

1st question is about chamber thermistor placement. It seems two are popular : the gantry rear extrusion, and the toolhead. For the toolhead, the LDO kit came with a 100k NTC, and a link to a Stealthburner door with a thermistor holder. There's a EBB36, and there will be no door. But had an idea : my toolheads all have 104NT thermistors, and the PT100/1000 amplifier is unused. I will remove the 4pin JST2mm connector, and solder a through hole PT1000 to the PCB, these components are tiny and cheap : 2.1x2.3x0.9mm. Ordered some, they will be there tomorrow. Will go in place of the JST two middle pins. Should do it.

Before I think of modding the EBB36, I routed two cables from the Octopus to the chamber. Where could it be interesting to put them ? Plenty of 104GT/NT, if you have ideas, or would like some experimentation, please tell... For example under the bed or whatever (there's a Nevermore, 4x bed fans under the bed sides, and will add an exhaust). Also could route two more (2 free analog inputs)...

Voron website is not very helpfull : "Place the chamber temperature thermistor in the selected location"

2nd question is about the doors and panels. Many mods. Difficult to say what system is better. What are your prefered system ? The Annex seems very popular, there's also the FilamentLatch by richardjm (satisfying mechanism, pretty sure one coyuld play with all day long !). Not very keen about magnetic ones, but maybe I'm wrong ? Was also thinking of adhesive magnetic tape : I have some, it is thick, and not super strong...

[zogzogzog]

I just ran mine up and poked it out of the cable chain going up to the gantry.  The wiring was long enough to reach all the way to my Octo Pro underneath and it's in the part of the chain that doesn't really move.  Seems to be pretty useful there.

If I go CAN, I might add something near the toolhead but I wonder how much the readings get whacked from the hotend.  I personally wouldn't bother running more wiring through the gantry chains for a temp sensor.

Curious as to how 4 bed fans will work - lot of airflow there.  With 2 bed fans and a 750W bed heater maxed at 60%, I can outrun the bed heater during initial warmup if I run the fans too high (I start at about 20%) and get an error from Klipper.  I start the fans slow and don't crank them up to full until the bed has reached full temp and stabilized.

With the 2 fans and temp sensor where it is, I can reach 58-60C.  I also have a "cover" made from a mylar space-style blanket for heat retention.

I never even run my exhaust fan; I heated all that air up, I want to keep it in there   My grille is something I printed on my old printer using PLA and planned to re-print in ABS - eventually.  2 years later and eventually hasn't gotten here yet- that's why it's got a warp to it.  Someday...

As far as door latches, magnetic has been great for me with tape holding the various hinges and latches to the door.  I'm using a mod of someone's 270 degree hinges which let the doors got all the way flush to the sides which keeps them out of harms way; I highly recommend them  I needed to mod the hinges to clear my side panels which are out a little wider to cover the corner gussets on the printer frame.

The richardjm latches are great!  I'm super happy I changed to them - they make pulling panels for cleaning or maint *super* easy.  When printing PLA, I pull the top panel and never worry about too much heat building up.  And like you said, the mechanism is just really nifty and satisfying to mess with - I've got 0, non, nada complaints with those - they are something I would highly recommend.

Edited January 5 by zogzogzog

[spamttx]

I have 3 bedfans, if I set the fans to 60% before I start the bed heater, kipper is happy. If I start them after the bed heater is on, I have to ease up on the fans making sure the bed temp is always increasing.

[fedgez]

I found the better place is on the rear gantry, you will know what the temp is at the point the toolhead is laying down plastic, above that and at the tool head will be hotter readings in most cases.  Also having some extra bed fans helps.  I can't run mine above 20% at warmup along with a nevermoor running at 100%.  I can bump them to 50%, but there doesn't seem to be a need to go above 20% in my case for even long prints.

[Dirk]

A1- I added my 'chamber-thermistor' later. So I bought a 1m cable length thermistor (5 pieces for 3 euros on aliexpress), and plugged it on one of the thermistor ports on the MCU, lead it to the exit through the Z-chain and fed it up as high as I could, where I thought it would be a representative temperature of the backside of my Voron 350  It is about the same location in the above picture from @zogzogzog But my thermistor I left inside the chain, protected from any possible damages. 

When I start heating the printer at 110, I do a home, QGL, home  and then position the printhead at around Z= 110 (4 times +25) .

This way I get a good impression of how the 'chamber' thermistor in the back of the chamber relates to the extruder thermistor (my extruder is off).

See images at start and half an hour later.

 

A2- I use also the 270 degree hinges, the self-locking latches. I considered magnetic but decided against it after watching this. I am planning to replace my 3M tape handles with 'screw' ones because even thought I have the genuine 3M double sided tape, they just let loose once the case is heated up.

I will look up the links of the parts I used.

[YaaJ]

12 hours ago, zogzogzog said:

I can outrun the bed heater during initial warmup if I run the fans too high (I start at about 20%) and get an error from Klipper

Good to know !

Watching your printer, had an idea (because of the thermometer). I will simply make a small breakout board at the rear, so some thermistors can be installed anywhere, or removed. I suspect the temperatures are much lower close to the panels : on another printer (enclosed slinger), I put a thermistor in the Z cable chain, on one side, and compared with a thermocouple floating in the air, over the bed, at 150mm or so : the thermocouple was showing 10° more after heat soaking. It has a active heating, with a food dehydrator under the bed, recycling air... (and when in a hurry, I add a 600W table top ceramic heater !)

I've been thinking of remixing the Stealthburner and adding a PT1000 in front of the hotend fan rather than at the back, measuring  the intake air... Could be a fun project... On the other hand, the EBB36 is mounted reverted, and the PT1000 could be mounted on the back, 100% free air. Best thing to do probably is to do nothing for now, and measure around the toolhead !

12 hours ago, zogzogzog said:

270 degree hinges

Was told to install such hinges in my first thread after subscribing. At this point, didn't google much for these accessories.

12 hours ago, zogzogzog said:

The richardjm latches are great

I love the design ! Much more than the Annex. And they look more reliable.

Your double isolated panels definitely are something I'll experiment with, at first on the zero. Takes too much time for heat soaking. And some mylar by hand, just enough for this small printer.

@Dirk : of course ! The extruder thermistor ; didn't think of using it as a movable temperature probe !

DesignSlicePrint is the video that made me love these latches design ; a couple years back, someone published a video about such designs, and how to tune them, it looks simple, it definitely is not.

Drilling the panels... Hate double sided adhesive, and drilling acrylic isn't easy. I'm even considering going to a local shop and order new doors...

For now, I'm a bit stuck... Again on the drawing table because of the rear cable management with all the drag chains and the deck that still doesn't fit...

[claudermilk]

I also have the 270 deg hinges and the richardjm latches. Excellent, simple mods to add. For my chamber thermistor, I stuck it about midway on the rear leadscrew extrusion for my Trident, which puts it about where @zogzogzog shows on their V2.4. I specifically didn't want to put it on/near my toolhead since that's generating all kinds of heat so I expect readings there to be high. I'd rather they be a bit low so I am sure my chamber is up to temp before printing.

[PFarm]

I use these latches for the panels easy printing and simple to install and remove panels.

[YaaJ]

Interesting... These ?
https://www.printables.com/en/model/292306-voron-24-panel-locks-easier-print-6mm/comments

Print in place, and easy to downsize for a 0.2
Simple and smart design. Will give it a try.

[DieHarder]

I originally wired up a chamber thermistor on the rear gantry extrusion in fear of getting incorrect readings from my Mellow SB2040V2 CAN on the toolhead. However, I also installed a 3007 cooling fan for the CAN and I think that is the ticket. The readings are usually < 1 °C different between the chamber thermistor and the CAN board reading. Without the cooling fan, you might actually get higher readings but I cannot confirm. I'll be removing the chamber thermistor next time I mess with the cable chain because there's just no point.

[YaaJ]

Just installed one in the Z drag chain, and received the PT1000's ; even tinier that expected ! Still thinking of installing it in the intake hotend airflow, after modding the SB main body (not easy to integrate while keeping the nice aesthetics).

The extrusions temperature probably is more representative of the heat soaking, after everything settle. There will be a thermistor touching the gantry ! Thanks for the suggestion.