Hello and Moin! from Germany

[JolietDelta]

Well, I got my Rmax in december. And this cute little thing is printing and printing like there's no tomorrow. :-)

I made some changes in order to use it withdual extruders. One thing that I made can be found here: http://www.thingiverse.com/thing:214536. It is a dual extruder mount with integrated cooling. Some more changes have been made in the repetier FW (still 0.83). Dual extrusion works fine now. Setting it up was quite challenging - at least the mechanical part, the adaption of the FW was rather easy.

Reading this forum helped me a lot when assembling my Rmax. So, if you have questions about how I got rid of all the little flaws when getting dual extrusion up and running - feel free to ask. :-)

My Rmax is built for reproducing 3D Data that we get out of our micro x-ray CT (I'm running a lab for non-destructive material testing over here). Initially we thought about buying a rady-to-run 3D printer. Then again, we build lots of our testing equipment ourselves, and that's why I finally ordered one white Rmax kit.

Things and improvements that are currently in the make:

- A 600W glass-ceramic heated bed with plished surface (no more warping, no boro glass, and heating up to 120C in less than 3min.
- A new version of the extruder mount with integrated PLA cooling fan (maybe with integrated effector plate - we will see).
- Integration of our auto-leveling probe that we normally use with our mechanical test rigs (IR laser-based - no need of flipping out/in a micro-switch). *
- Mechanical end stops out, HAL sensors in (should be done this evenning).

*One secondary use of that probe is that we can detect failed prints (lots of ABS/PLA wool, loose objects, stalling of the effector, etc.). The NCs of our test rigs are based on ATMEL MCs. Therefore the proting of the software should be no problem.

A lot of things to do. :-)

Warm greetings from Stuttgart/Ger,

Jens

Edit. My Rmax:

*wörkwörk* :_)

Checking the termistors...

1st and 2nd print (with awful ABS). All that nitpicking seems to pay off...

First test-run with dual extruders.

...still some trouble with oozing. But ok for the first printings.

[Eaglezsoar]

Warm greetings to you also Jens.
The modifications you have made to your printer sounds great. I am especially interested in the 600 watt heated bed and I wonder if you could identify a source for it.
What you are doing with the printer also sounds interesting and I'm sure that some of our users may take you up on your offer to give assistance on the dual extruders.
Doing all of this on your own is impressive. We are also interested in the infrared autolevel function.
I think you are going to get a lot of questions, I hope you don't mind.
Greetings from the United States!

[Orenfor]

That look like very great job..... if you start like that i can't imagine where can you take that Max to....

[Eaglezsoar]

Very Nice! Cleanest work area I have seen.
Don't forget if you have a source for the 600 watt heater you were talking about, would you share it?

[JolietDelta]

Hello and thank you for the compliments. :-)

In our Lab we always have to be efficient and precise. A clean working area and the adequate patience are important cornerstones in every project. My experience with 3D printers (or with mechanical engineering in general) in brief: Precision in = precision out. In other words: you will never get back all the lifetime you have spent with searching for lost scredrivers. :-)

But back to topic:
We use triangulating distance sensors, either with 630nm wavelength or 660nm (non-visible). Theses sensors are fast, reliable and are produced in industrial quality. For a hobby 3d printer this may be a bit overdone - but it is guaranteed to work flawless. The type of the surface of the heated bed doesn't matter (even when it has refractive aberrations like boro glass). The linearity is superb and the resolution of 0.005 mm is far enough.

I'm planning to implement this specific sensor: http://www.drwehrhahn.de/englisch/sites ... s-ccd.html
The manufacturer has distributing agencies in the US. So maybe it is a good starting point for getting more information.
I have seen these kind of sensors also on *bay. Maybe some china-made stuff. I have no experience with those. But I think that even a Chinese copy can provide a considerably higher precision than the best gold-made mechanical micro switch.
I know that Johann implemented a working solution (http://youtu.be/1eNz1l56H5E) - but sometimes it is plain fun to re-invent the wheel. :-)

My idea for the heated bed is to eliminate every kind of thermal warping plus having a highly rigid and scratch resistant surface plus² heating times < 3min (up to 100C). With this in mind I startet searching the internet up and down. I've found a decent solution, developed by Werner Berry for his BerryBot (http://youtu.be/gXUJQuNSLYw). In my opinion this is the way to go.

First I thought about using one of our known ceramic heatplates. We're using this kind http://www.bachrc.de/english/products/c ... index.html of heating in our CTs when testing integrated circuits or embeddet components under live conditions. But with prices > €7k err - no chance.

My wife, an engineer for industrial applications, had the sparking idea (better: a reasonable worry) that I may rip our ceramic hob out of the kitchen. :-) But there's a better and far more convenient solution: when you can find this kind of heater http://www.carlroth.com/media/_de-de/Gr ... 9186_0.jpg and it hase the original Schott-Keramik (worldwide Trademark "Ceran") heating plate implemented - byu it. I bought one (for €55-something), dismanteled it and punt it on our CNC measuring table. I was highly surprised, that this rather cheap cosumer product had an geometric variance (Z) of < +/- 0.0008 mm over 400 sampling points within an area of 150 cm². Everything you need (solid state relay with 12V trigger for PWM-controll by RAMBo, overtemp. protection, built-in thermistor, etc.) comes additionally for free, as part of the original wiring.

I hope to get these mods done in the next few weeks. But loads of work are already waiting in my office. Maybe I should try to clone myself with the Rmax, but I'm afraid of bad layer adhesion.

-Jens