Simon2.4's Voron Saga

[Simon2.4]

Heated chamber testing 2

I unplugged the included thermostat as I believed it was hindering thing but I was afraid the thing could overheat so I did incremental testing with power settings and, well, It contradicts some of my earlier conclusions: the actual fan IS enough to dissipate the heat load. I did not measure the fin temperature in the same place as before so the max of 180 mentioned earlier corresponds to the highest measurement below (I assume, though it's probably hotter now logically)

power setting, fin temp, chamber temp, delta

0.40 = 110 c:27 delta = 83
0.50 = 128 c:30 delta = 98
0.60 = 135 c:31 delta = 104
0.70 = 140 c:33 delta = 107
0.80 = 143 c:34 delta = 109
0.90 = 145 c:35 delta = 110
1.00 = 146 c:36 delta = 110

Also, I measured the Current drawn at 100% power and it's 1 Amp +-10% , which puts this heater at about 125W, not the 250W advertised. I'll bet that it was meant for 250W @ 240V not 120V , so It's giving half here in Canadia. I'm preetty sure I'm going to need another heater. I should have known, Chinese specs should be cut in half

I'm going to get this guy instead rated for 750w @ 220v which is probably true for this one; so 3 of the other units stuck together and should give a real 375W @ 120v sigh... back to Fusion360 for me

EDIT bad math!    Power (W) = V^2 / R  so half the voltage gives a quarter the power, not half...

[Simon2.4]

Chamber heater - new chapter

I've been working on the new design of my HV hat and putting alot more thought into it this time.

The chinese PTC heaters have no certification or standardization, etc. This heater is the most dangerous part of my build and I'm cheaping out... not good.
I started looking at real enclosure heaters like the ones used in industry but I could not find anything under 150$ that had at least 250 watts.

Then I settled on this:

For 20$ It's components are approved for sale in Canada/USA and It turns out cheaper than the Chinese garbage heaters.  Also, when it burns out one day, This unit will probably still be sold by Amazon.

It's in the mail now: cant wait to discover that the insides contain the same PTC unit..

[Simon2.4]

Version 2 HV Hat - Housing - Glamour post

Improvements:

-Printability: thick walls with infill instead of 2mm solid walls, No inverted pyramid prone to warp.

-Versatility: Not designed with single purpose. except for the valve, function is added separately. Housing is just a housing.

-Thermal insulation: the infilled walls are insulating.

-Wire management

-Better valve - no servo for now. can be added later.

-Style used a hex instead of of octogone in Voron Tradition. Worked the appearance a bit more.

[Simon2.4]

Milestone: Superbe quality ASA printing !!

With the HV Hat prototype finally working I was able ti get my heated chamber going and tuned.

I started with watermark control but it sucks. the hysterisis is over 3 degrees even when renge is set to 0.5 . With PID, the temperature stays within 1 degree.

I will cover PID tuning in my guide to come.

[Simon2.4]

V2 = no good yet.. more design needed. I still used inverted pyramid shapes though they were steeper, It was not enough and the part warped. Just can't have that shape on large parts: it made PLA fail so I'm not that surprised. I got that first layer squish dialed in and adhesion was excellent with a generous layer of hair spray. I tested different methods for bed adhesion including kapton tape which does work well but I don't want shiny parts, the tape layer is super delicate and very hard to apply without tiny dust getting under. On the textured bed, the finish is really nice and the integrity of the part is amazing. too bad it's no good. When I did the voron cube and benchy, I had the cooling fan on for better results so I left it for this part too. That may be part of the problem.

next revision: No inverted pyramids for real this time and I think I'll try to design it in multiple parts to assemble instead of a large single part; not sure yet but maybe have the wallt seperate from the large flat top.

Back to F360 again... V3 incoming!

[3dKaosMonkey]

I claim to be no expert.. but any reason your not using a brim or mickey mouse ears on the corners?

[Simon2.4]

1 hour ago, 3dKaosMonkey said:

any reason your not using a brim or mickey mouse ears on the corners?

Some noobness for sure I don't think a brim would help since it needs mechanical force in this case. Ears would be a good idea, however, the print already fills a good proportion of the plate so not much space for extras. Also, the part is printed upside down and I'm trying to make it pretty. Basically, I'm learning to design for printing and I'm aiming a bit too high I think.

[claudermilk]

Warping of large parts is my current bane. I'm not sure what the problem exactly is. I did salvage one print (purge bucket mount arm for Trident) by taping the sucker down by the brim yesterday. Desperation move that I didn't really expect to work, but the part came out fine to my surprise.

[Simon2.4]

6 hours ago, claudermilk said:

Warping of large parts is my current bane. I'm not sure what the problem exactly is. I did salvage one print (purge bucket mount arm for Trident) by taping the sucker down by the brim yesterday. Desperation move that I didn't really expect to work, but the part came out fine to my surprise.

Yah, I'm curious about carbon fiber filament which is supposed to help alot for warping. But the key is designing with warping in mind. The bigger the part, the harder it will be.

RC plane designers that use vase mode even on the most intricate structures and build the internal structure with 'passages' so the shape has only 1 outline. I'm going to explore that approach for my next housing design.

[Simon2.4]

Heater housing - HV hat V3 - The glass sandwich

With full Voron styling

And it prints nice: (with ears @3dKaosMonkey )

 

So I'm moving forward with this design. It's time I finish this.. This heater is stretching the limits of my ADD
 

[3dKaosMonkey]

Thanks for sharing your iterative design process of the heater.  Can't want to see it all finished.

[Simon2.4]

Current state of things.

[Killajoedotcom]

What an interesting build! Following for a while now and it's good to see the progress. 

Are you seeing that having the heater at the top lessens the heating of the chamber? I just always thought heat went upwards but I guess you're also heating from the bottom with the buildplate. How's it working so far?

[Simon2.4]

50 minutes ago, Killajoedotcom said:

top lessens the heating of the chamber?

The fan is there to mix the air in the chamber and the heater is 'in the way' of that. Up to now it has proven good. 

For sure, relying on convection alone would not have worked with the heater on top. My first version had insufficient flow and poor mixing in the chamber.

[Simon2.4]

I experienced an actual failure caused by heating the chamber for prolonged durations that caused a collision:

Hall effect endstop on the Y axis!  surprise surprise . Either the chips themselves have fading sensitivity or the magnets are getting weaker. It happened once the first time I heated the chamber above 60c and I repositioned the magnet. This time there is no position where the original magnet trigs the chip. I put a much bigger magnet in its place and it works... for now. I may revert to good old microswitches if the issues comes back.

 

[ahough]

19 minutes ago, Simon2.4 said:

I experienced an actual failure caused by heating the chamber for prolonged durations that caused a collision:

Hall effect endstop on the Y axis!  surprise surprise . Either the chips themselves have fading sensitivity or the magnets are getting weaker. It happened once the first time I heated the chamber above 60c and I repositioned the magnet. This time there is no position where the original magnet trigs the chip. I put a much bigger magnet in its place and it works... for now. I may revert to good old microswitches if the issues comes back.
 

I was actually getting ready to switch over to a hall effect board for my x and y. Thanks of the heads up on this, I'll be sticking with the micro switches for now.

[Simon2.4]

ASA warping from cooling

I've been having good success with printing ASA parts without warping using ears and parts less than 20mm high; however during cooling, since the buildplate is at 110c and the enclosure at 65, its inevitable that there will be uneven contraction during cooling. this causes the parts to bow:

It's not a big issue with these parts, because it can be quickly and easily fixed.

TO FIX BOWED ASA PARTS FROM COOLING:

1 place your parts on an oven safe clean and flat surface like a nice piece of glass

2 put grills in center position and lowest possible position, put a baking sheet on lowest grill as a radiant shield and the part on its glass plate on the middle grill.

3 turn on oven at 250F or 120c and let it preheat with the part in it, wait about 15 minutes. (if your oven uses the top element for preheat, don't put your part right away. radiant heat from elements is bad)

4 part should 'hardly' bend and feel somewhere in between the resistance of wet wood and solid lead. The idea it bringing the parts temperature up slowly and evenly to reach the glass point (100c for asa) without melting it.

5 leave the glass in the oven, bend your part back in shape and put it back in the oven on the piece of glass. I did this with my hands and it was ok

6 turn off the oven and wait 30 minutes. plastic should be relaxed and straight. It worked 3 times for me now.

When I think of it, it very akin to heat treating metal.  nice

[Simon2.4]

 

[Simon2.4]

I'm starting my job so I'll be less present but I'm still working on my printer:

HV hat V3 progress

I decided to go ahead with the pressure controlled exhaust. It uses the following differential pressure sensor that has a range of -20 to 125 Pascal   or 0.125 %  Atmosphere. very sensitive:

https://www.digikey.ca/en/products/detail/sensirion-ag/SDP816-125PA/6605490

The idea is to have the smallest possible volume of air exhausted to conserve chamber heat. So just enough to have a measurable pressure difference but no more!

The PID loop is driven by an arduino compatible controller and there is a potentiometer on the front panel to act as an all-in-one interface. Haven't figured out what I'll do with it yet but the idea is to at least be able to set the desired pressure and possibly have 'some' overrides on the extremities of the pot's range. Lastly, ther will be limit switches on the doors to accout for that in the programing.

As of now, the PID loop works on the test bench but I'll need to install and use it to properly complete the program.

I'm waiting on the tempered glass panel to finish this heater.

 

Klipperscreen

 

I've added a touchscreen for Klipperscreen and chose the Official Rpi 7inch touchscreen module. I made a custon housing to hold it up at eye level

I've detailed it here:

https://www.teamfdm.com/files/file/483-dro-style-side-mounting-housing-for-official-raspberry-pi-7-inch-touchscreen/

 

Octoprint -   I'm done with it.  When I wire in the heater and screen I will also wipe the Pi and start over with Mainsail

[3dKaosMonkey]

Looks like you have been very busy --   

Question for you on the touch screen -  is the pi mounted to it or do you have it connected via cable.. appears to be a cable but is it like an HDMI or some other type of cable?   I've never worked with them so I am not sure how they connect especially if they do not plug into the gpio pins

[Simon2.4]

8 minutes ago, 3dKaosMonkey said:

Looks like you have been very busy --   

Question for you on the touch screen -  is the pi mounted to it or do you have it connected via cable.. appears to be a cable but is it like an HDMI or some other type of cable?   I've never worked with them so I am not sure how they connect especially if they do not plug into the gpio pins

The Pi mounts on the screen as such:

And I only need 2 USB connections running back down into the base, 1 for the octopus board, and 1 for the webcam. This will give easy access to the Pi too 

 

[Simon2.4]

Last element to the touchscreen: cable management

 

 

[Simon2.4]

On 3/29/2022 at 8:45 PM, 3dKaosMonkey said:

or some other type of cable? 

I realise I didn't answer your question. It uses the Rpi's DSI port for signal and the gpio for power. l think DSI ribbon cables are not long enough as sold to make this mod while leaving the pi in the base. That would require hdmi as you said, so another screen

[3dKaosMonkey]

I ended up with a Waveshare 4.3 and I got a 2ft cable and it runs perfectly. 

https://www.amazon.com/gp/product/B07J9HFSJJ

[Simon2.4]

Just now, 3dKaosMonkey said:

I ended up with a Waveshare 4.3 and I got a 2ft cable and it runs perfectly. 

https://www.amazon.com/gp/product/B07J9HFSJJ

Oh so you got the 7inch screen too? how are you going to mount it?