GabrielK's Rostock Max

[gabrielk]

I have already assembled my machine, but I think it will be always work in progress.
Thanks to Geneb manual and videos on YT and all you guys here it was fairly simply task for me although it is my first 3d printer.
Here is my machine I will name it stage 1:

here you can see the my very first prints I use setting from manual:

after printing a lot of calibration cubes and stuff i want to do something else, owl an bear. ( not calibrated extruder at all)

when I was bored of black color I changed filament to green, and all things goes a lot smoother (big difference i nozzle temp between them too I think at the same time i changed firmware to repetier):

After that I try to calibrate extruder to get better infill (change e steps from 292 to 305), and I spotted problems with detached infill, so after Mhackney's tips i redo the u-joints. i take piece of metal 8mm thick ( the same as u jonts) and try to slide it in the arms. They are right now very smooth.
At that time I also make some mods which i describe in mods/iupgrades subforum.
1. extruder - smoother moves, no rubbing,
http://forum.seemecnc.com/viewtopic.php?f=35&t=1168
2.end stops - more consistent Z, more accurate tuning
http://forum.seemecnc.com/viewtopic.php?f=35&t=1170
3.belt tensioner - more control over tension, centering belt, smoother moves.
http://forum.seemecnc.com/viewtopic.php?f=35&t=1169

Lately i have some problems with nozzle so i dismantled it (I didn't check it since first assembly) and i find out something like this:

Tight now i have next to me 1m of 2x4 ptfe tubing and 1m of 4x6 ptfe tubing so I will replace them.

and now questions:
1. Is that normal that wider tube is cutted alk the way?
2.I have old nozzle, so what dimensions should have both tubes (length) and how shoul i cut them, maybe use pencil sharpener to make bevel on the end for better fit?

Please help, and sorry for my english

[mhackney]

Nice post!

Yes, the outer tube is slit up the side so the smaller tube can slide in easier.

I don't know about the length since I do not have the earlier nozzle. Hopefully someone else will chime in.

How hot are you printing? You might be going to high to get burning like that on the teflon tube.

cheers,
Michael

[gabrielk]

There is no burnings, that is burned filament i assume, i think i don't have good seal between nozzle and bigger tube. From the bear print you can see separated layers, this means I'm printing to low? Is that correct?

I remember that when i started machine for first time and i started heating nozzle about 130C I saw a smoke coming out from the nozzle area, and it smoking like that for I don't know 15 minutes. Is that normal?

Since I dismantled nozzle I'm doing something like this right now. Post effects later.

[gabrielk]

here are the results, not perfect but good start, my jar was not tall enough for this print, click attachment for bigger res.

Not the safest thing to do in bedroom

[cambo3d]

that's great i saw that earlier, yesterday; acetone vapor polishing technique on another forum.

[gabrielk]

Thanks guys for replies.

As I write earlier I have to dismantle the nozzle. And NOW I understand how it works.

I coloured photo for better explanation, Please correct me if I'm wrong

1. Green zone - here sits wider tube
2. Blue zone - here sits thinner tube.
3. Red zone - that is melting zone, is that correct? thinner tube is to wide to go there, is that right?

Now other end
Second thing I spotted. I assume it's VERY IMPORTANT how much you screw in your bowden tube M5 adapter, since thinner tube liner sits on it (like in the picture below), So if adapter is not screwed in properly the thinner tube can go up and down for example when you have a lot of retracts. This can unseal the linner on the bottom.

Now I can cut some tubing, In orginal delivered to me the inside tube was about 1mm longer ( for better seal I assume because nozzle is a cone inside).

What do you think about beveling inside tube for better seal for example with pencil sharpener? Good idea?

[gabrielk]

I printed fan duct from thingiverse. And I will try to use it with 5v fan. What should I do to use it, since i read that rambo outputs is 12v (can i do something with PWM). Repetier firmware

[Eaglezsoar]

You can use two resistors of the same value and create a simple voltage divider and get 6 volts out which would be fine for your 5 volt fan.
See http://www.raltron.com/cust/tools/voltage_divider.asp
I would use resistor values of 100 ohm and that should provide enough current to drive the fan with negligible load on the 12 volt supply.

[gabrielk]

instead of resistors can i dial down the maximum PWM
so for 12v full speed it will be 255
and for 5v full speed it will be 106

and then put it in configuration.h:

/** PWM speed for the cooler fan. 0=off 255=full speed */
#define EXT0_EXTRUDER_COOLER_SPEED 255

(I know it's not real 5v)

[Eaglezsoar]

The way I understand PWM, the speed is controlled by sending pulses of 12v to the fan, varying the width of the pulses and how many are applied per second.
The key is that the pulses are still 12v and I'm not sure that would be good for a 5 volt fan. It would probably work until the fan's coils overheated because it was
not designed to have 12v applied irregardless of duration and time.

[aerouta]

May I ask what you are doing with the glass jar?

[cassetti]

May I ask what you are doing with the glass jar?

It's an acetone vapor bath. Basically he's elevating the piece over a bit of acetone, and using his hotbed to heat up the acetone to release vapors which smooth the part.

There are several documents and youtube videos on this. I have tried acetone "Baths" in the past, but that can be tricky - too long of a 'dip' sucks up acetone into the print and melts it from the inside out. Acetone vapor baths are relatively new (and dangerous!) - only a few months since the first articles were posted about it.

Printer is looking good - happy to see your progress with print quality - looking really sharp!

[MorbidSlowBurn]

As cassetti stated the acetone vapor polishing is dangerous. Also don't forget that the video show this being done on the build plate. With that in mind be careful as some components of the printer could be damaged by the vapors.