This topic contains 37 replies, has 14 voices, and was last updated by Steve N 2 weeks, 2 days ago.
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Hello,
Iam using Robox since christmas. Green abs works fine. Also black seems to be fine, BUT white abs sucks!. I have done this project ( Assembly of ROBOX Dual Nozzle Head.) now couple times. I think that when you print small objects often, then calibrate and again print and abs dont flow enough it will burn inside the heating chamber. The design of the aluminium block (heating chamber) is bad i think too. Tomorrow i try again now yellow pla. If this shit happens again, i am going to do some modifications to heating module. I am going to try block the cavity to the another nozzle ( 0.8) that it wont get material at all. I use custom setting and use only one nozzle. It might even better if change it to 0.5 mm nozzle. I think too that there is something wrong in new AM. I found also that theres material all over the nozzles and printer head. Too much pressure or something like that…
Sorry for my bad English. I am quite frustrating to this machine.
yellow pla prints great for me - as does cornflower blue
Steve N | Creator of things both virtual and physicalHere are the results from my head rebuild… :/
- I decided to start with a purge. This resulted in the small nozzle getting clogged by some piece of hardened material that I got left inside.
- Removed the nozzle and cleared it.
- New purge. This time it vent smoothly. But material kept oozing out from the nozzles (I knew this was likely to happen, as I used thicker fiber washers).
- Try to re-calibrate nozzle opening. But fail. Thus I will have to get thin washers (or adjust needles, but I do not want to do that).
It was about now that I noticed material starting to come down from inside the head
My first thought was that for sure the silicone gaskets was not up to the task. Though after closer inspection, it was actually coming from the fiber washers by the “input tubes”.I will fix that leak by using some of the red silicone gasket on the fiber washers. I will also get thinner fiber washers for the nozzles. Hopefully there will be a new test later this week.
The Imgur guide will be updated when I get around to fixing the dead again.
Cheers,
@miffmaster I think my previous post was eaten by world press - but I do cheer for you! Definitively keep us posted and update imgur page (or make another one)!
UPDATE: My printer is now in working order again. After fixing the leaky fiber washers. Realizing during calibration that the needles got switched around, and correcting that. My printer is now better than ever before
See the guide for details on the update.
Hopefully, it will continue to do so for a long time…
@miffmaster wonderful! Thanks!
BTW - is it worth you posting some links where to get washers (and link to specific ones you’ve used)?
@click, I would but nothing was bought specifically for this.
- Red “hight temp” silicone gasket - Sold in most hardware stores.
- Silicone paste - Like the stuff for CPU coolers.
- Fiber washers - Any kind. Mine was 1 mm thick, so I sanded them down to size.
Now the silicone material I used to replace the o-rings for the needles is going to be tricky. The stuff i used was actually from a camera lens. It sat on the focus ring to provide better grip. My “plan B” might be more attainable… Get a large O-ring with a cross-section diameter of 3 mm. cut a 1 mm “disc” out of it, and poke a hole through the center of it.
But since I have not tried “plan B”, I can not say if it would actually work. It would be a much “firmer” gasket than the silicone one I use now. Oh, and don’t forget. I have no clue at to what kind of life span this silicone gasket might have. Time will tell.
Anyway, the idea is that both of these options result in a gasket that has a square cross-section (in contrast to the round cross-section of an o-ring). The square shape will give a larger contact surface with the needle, and also, as pressure increase. It would “flatten” thus pressing harder against the needle. Well, at least that is what I believe… Hope I make some kind of sense (it’s late and I am tired).
How much current do heater need?
I was thinking to skip solder iron part and use heater to soften extra plastic, heater is “glued” to its hole anyway with PLA and i got new head coming so i dont have anything to lose
@poju, I have not verified this, but a good guess is that it gets 12V. Given the 5 ohm resistance of the heater, it would mean 6A. That is 72 watt. Which seems about right considering the observed temperature rise when a print is started.
Now, it is a REALLY BAD idea to hook it up to 12V without any kind of temperature control. It would not tale long for the temperature to go beyond 200°C. At temperature above ~250°C both PLA and ABS tend burn (though not as in fire) and become really hard and difficult to remove. This is the most important reason I used the soldering iron. You can set the temperature. Thus not risking to burn the plastic.
Thanks for guess
I tought it would be something like that, ill just start with 6V and up it in little steps. Main reason for using heater is to get it out as you can see it have some burned PLA in there.When i get electrick parts out of way and some plastic thats easy to remove i plan to soak it in ethyl asetate
You could also use chemicals to get rid of the material. Acetone for ABS and ethyl acetate for PLA. IIRC PLA can be dissolved using other stuff like MEK or something, but they have non-trivial safety concerns.
I can confirm that ethyl acetate works somewhat - it won’t dissolve the PLA completely, but causes it to become brittle enough to be easily scraped off using the Robox spatula/chisel.
Please refer to attached drawing as to how I dunked it, total immersion was probably 30 mins? A good soaking for a couple of hours would I assume do a whole lot better…
Ran into an error message today on my printer, removed the head and found this. Yet another problem, in an endless line of problems.
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