Confirming my construction, did I do this right?

Been working really hard on the machine.

Tomorrow I will upload a vid!

Thanks uGen!

Well, the results are looking pretty decent for all the trouble you had! Did the PID values improve the situation after all?
I am used to see much smaller values from Marlin, but that may just be another style of representation.

I wouldn't be too rash about contacting the seller because of the larger diameter: There is always a little bit of wiggle room in order for the filament to go through smoothly. Here is a link to the Wiki page for the Excalibur Hot End. The internal diameter for the tube is 3.5mm for example. This link may also be interesting to you since the hot end is designed to be DIY-able.
But is that plastic piece really Teflon? Looks more like PEEK to me...is there a translucent white liner somewhere in the plastic part?
What you described (ABS plug forming) actually is an old problem RepRap users have had when hot ends were not as well designed as they usually are nowadays. So the seller did not learn from year old research :/

Interesting, hope you have access to small lathes. They really should come in handy for this. The ones in our workshops are rather large, so turning a tiny nozzle would be a little bit cramped on these beasts.
Making it an all-metal hot end from the start might turn out to be beneficial for new materials like nylon and stuff.

I know I promised 'tomorrow I upload a vid' well, the next day has been nothing but problems.

The hotend didn't get to printing temperature, the hotbed doesn't function as it should etcetera. I keep running into trouble.

I have opened a topic in the electronics forum to see if anyone there has any idea what might be wrong.
It can be found here:
[forums.reprap.org]

Hope the link works.

I am as-we-speak measuring resistance on the heatbed and checking out if the wiring can be done better to be sure that there is no problem there. Also I will try to see if I can make the whole printing bed a bit more user-friendly. I have been searching for heatbed configurations, but I think the MDF underpart just changes shape too much by heat-influence.

If I have the chance, I will make a aluminium plate in the same shape of the MDF plate and use that as a support for mounting the heatbed on. Also I will give it a 90 degree folded edge all-around to try and make the aluminium plate more warp-resistant.


Thought I was having luck yesterday, but then... FILAMENT jammmmm, and it's not a song
See picture!

Edited 1 time(s). Last edit at 04/04/2013 01:18PM by Ohmarinus.

As promised, some video of the printer printing on that one faithful day when everything worked for one day this millenium

See it here:
[youtu.be]

Edited 1 time(s). Last edit at 04/04/2013 04:48PM by Ohmarinus.

Saw the video! This is what I meant with good video making: You conveyed information while showing what the printer does and tied everything up at the end. Also thanks for the shout-out!

About your heatbed warp: In the workshop I am working in, we pretty much established a heat-insulation standard that is now used on about all the printers me made / helped to make with slight variations. The idea was from someone in the community, though, if I remember correctly.
You just have to take some corrugated cardboard, stack some layers (3 +/-1 should be enough) on top of each other and fix them together (I use Kapton tape as it is rated for heatbed temperatures). Optionally, you can add a layer of cotton padding on top. This is then mounted directly under the heated bed PCB. The underside of the insulation should only get a little bit warmer than ambient.
Alternatively, you can replace the cotton padding with aluminium foil or tape and mount the insulator with a little gap between the PCB and the MDF board. Aluminium is one of the best infra-red reflectors while air is a good insulator, so you get double benefits with this method. Just make sure that you don't short out the heated bed. Again, a little bit of Kapton tape does the trick.
My carriage is made out of printed parts and I don't have any problems with warp due to heat. I am using the aluminium tape variant, by the way.

Making direct contact between heated bed and a sheet of aluminium is not a good idea because aluminium is a good heat conductor (in addition to being a good heat reflector), so you would build a heater that heats a heat sink, essentially.

Also, I have read about your heat bed staying at 80°C...our workshop printer doesn't really go higher than 60°C. When we are lucky, it barely reaches 70°C. Still, most objects print fine on Kapton tape. In fact, the lowest temperature I successfully printed on was 45°C. Furthermore, long prints on high temperature have the side effect of discoloring the bottom of the object. White plastic turns beige or light brown as if it got burned. No idea if this effect is visible with other filament colors and if it has a noticeable effect besides aesthetics on plastic quality.