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Re: Building my first Morgan - 10 years ago

Quentin's way of using twisted tubes as a frame is ingenius, because this gives a very good stability to the frame with only a few inexpensive parts.I can lift up my Morgan with one hand by just grabbing one of the PVC-tubes. The construction principle may not be the source of problems, but the way I've realized it in my build.

Re: Building my first Morgan - 10 years ago

I don't have photos of straight wall prints at hand right now. I can tell you so far, that the layer-to-layer precision is excellent (no visible fault). But I'm a bit worried about horizontal "waves" at specific parts of the print that come from certain instabilities of the frame (maybe I wasn't accurate enough in building it) and in my latest prints I had problems with the internal bearing of t

Re: Building my first Morgan - 10 years ago

Re: DIY budget heated bed - 10 years ago

The calculation is correct. Seems my measurements were bad though (Wer misst, misst Mist).

Re: DIY budget heated bed - 10 years ago

Quotedc42... Where do you get the figure of 0.3 ohms from? I make the resistance between opposite edges of that sheet about 10 microohms. Maybe I wasn't exact enough: The "sheet" is 220mm x 220mm x 3mm. I don't know the alloy at the moment...

Re: DIY budget heated bed - 10 years ago

Oh, and I forgot to mention that even if this works, I would still use the rescue blanket as a heat-shield on the bottom side of my heated bed. The rescue blanket is working so great, I don't want to ever miss it again.

Re: DIY budget heated bed - 10 years ago

Quotedc42There is no way that the mosfet will switch 150A, despite its theoretical 150A rating. Assuming it is driven by a 5V signal (i.e. from 5V RepRap electronics, not the new 3.3V Duet electronics), then the maximum that you should ask the the mosfet to pass is 32A (the value at which Rds(on) is specified for Vgs=4.5V). At that current, it will dissipate about 4W and need a modest heat-sink.

Re: Project: Teacup Firmware - 10 years ago

QuoteKevinOConnor What I've been thinking of trying out in an experimental firmware is replacing the standard G1 gcode commands with timed stepping sequences. That is, instead of sending the micro-controller a command to move the head a number of millimeters at a specific velocity, commands would be sent to pulse a given stepper pin starting at a specific time (measured in clock ticks) and for a

Re: DIY budget heated bed - 10 years ago

By the way: What is the maximum current I can drive with SevenSwitch at 12V? I'd like to make a test with 30A, but don't want to burn my board. I want to try what happens using a heater with only 0.4 Ohms electrical resistance. The Wiki-entry says, SevenSwitch is good for only 15A. I'm using it at 18A for several weeks now with now problems. The wires get warm (app. 45°C), but they are only 1.5

Re: DIY budget heated bed - 10 years ago

Update: Actual test have shown, that my heated bed doesn't need Kapton on its printing-side. Just a temperature of above 110°C and hairspray does the job very good. So you only need Kapton to fix the heating-wire to the aluminum.

Re: Project: Teacup Firmware - 10 years ago

Quotetheothermike ... Perhaps it is useful for someone...? (hopefully there´s no mistake in it!?) The parallel-arm-SCARA kinetic seems to be easier than the single-arm with respect to calculation effort. In case of the parallel-arm-SCARA, the math for the second (right) arm is identical with the one for the first (left) arm for d=0. Unfortunately, I do not have any programming experience.... Cou

Re: Project: Teacup Firmware - 10 years ago

QuoteTraumflug QuoteRobertKuhlmannI'd like to hear Traumflug's opinion if this would make a seperate branch Yes, a new branch, please. Like one branch per topic. You can base a branch on top of another to have both topics. Uh, and I see I have to speed up my branch integration work. All this stuff has to settle in experimental/master one day. Right at the moment I'm working on getting rid of th

Re: Z-Probe - new idea - 10 years ago

A frame-mounted cam with only 5MP (giving app. 1.25MP in effective resolution) looking at the printbed sounds like a very difficult equipment for good z-axis-measurements. The optic of the cam (assuming it is able to be focused for any point of the whole printbed) is not very accurate. You'd have to measure and correct (in the software) the failures of the lens. Then you only have a very few pixe

Re: Z-Probe - new idea - 10 years ago

Quotereprapraps Weight aint a problem, laserpointers are light as in light: How about the pi-cam (> 20€, 9g)? I think the laser-pointer alone won't do it (not to mention we need a Raspberry-Pi for that). Or do you mean a solution with the cam mounted to the printer-frame? Maybe I didn't get your idea right. Please let me know.

Re: Z-Probe - new idea - 10 years ago

Quotereprapraps Why not use a laserpointer (1-5€ in price) and a pi-cam for calibration? Then u have a server too, and its touchless. depending on where u mount the laser you could as well have a 3d scanner with it. Simple: Think about mounting a laserpointer onto the toolhead of a RepRap Morgan. Guess how accurate the measurement of the distance between nozzle and bed would be? It's too big and

Re: Project: Teacup Firmware - 10 years ago

QuoteEvil Monkey That probe sounds great! The Morgans arms utilize the same axis of rotation for both the X and Y stepper motors. I was referring to the variable in the Marlin version called Scara_axis_spacing. This takes into account the horizontal separation of the geared stepper motor that move the arms. This current build has the geared stepper motors separated by 85 mm. Is it possible to

Z-Probe - new idea - 10 years ago

(copied/moved from a discussion in the "Teacup"-thread) I've got a new idea for a z-probe Task: We need to measure the distance between the nozzle and the bed-surface for several points (the more the better) and store the measurements in an array that will be used to auto-level the bed to keep a constant distance between nozzle and bed on every x/y-coordinate during print. Problem: The nozzl

Re: Project: Teacup Firmware - 10 years ago

BTW: Just found out that I have tomodifiy "update_current_position" too (in dda.c). QuoteEvil Monkey Thank you RobertKuhlmann, that would be extremely helpful. I was thinking that a probe could rotate down in a similar manner to how other auto bed leveling systems work. The arm would then probe in three or four locations and make the necessary adjustments. QuentinHarley's implementation of "arm

Re: Project: Teacup Firmware - 10 years ago

Just describe the concrete requirements you would like to see regarding auto-bed-levelling. I'll open th issue for you. An issue in Github is a point of interest, a task that needs to be resolved by someone. If you go to the homepage of the Github-Teacup-project you'll see a little exclamation mark in a circle on the right side, titled "Issues". You should read them to get an overview what topic

Re: Project: Teacup Firmware - 10 years ago

Auto-bed-levelling is easy to implement, as you can see in Quentin Harley's Marlin-armlevel-branch. But even the Marlin-version Quentin's work is based upon is outdated. I've tried to merge it with the up-to-date original Marlin-branch, but could not get it to work in acceptable time. That also was the time when I began to read about Teacup and to take a deeper look into the Teacup-sources. Teac

Re: Project: Teacup Firmware - 10 years ago

Quotetheothermike Ah, OK....Morgan style.... @Robert: Wouldn´t it be useful to directly implement the kinematics for the (3.) Parallel-arm SCARA where the motors are spatially separated ? When setting the motor displacement to "zero" the coaxial geometry (4.) would be resumed....and one software could serve two different SCARA types. Let's see. In general the mathematics for all four variants sh

Re: DIY budget heated bed - 10 years ago

My approach is very simple, cheap, easy to do and tested: RepReap-Wiki:Robert's heated bed. I'm working with an 18A-variant of this bed (that's 216Watt at 12V; 200mm x 200mm) at 130°C. Due to other projects I didn't find the time to test this bed without Kapton, just polished aluminum and e.g. hairspray. Maybe this would work too at high bed-temps. Key to this cheap solution is Traumflug's Seve

Re: Project: Teacup Firmware - 10 years ago

QuoteTraumflug... Has been discussed quite a number of times and as you see, host <=> controller communications is still in plain, human-readable ASCII and controllers still fill their movement queue them selfs. :-) Reasons: - Binary communications isn't that much faster than ASCII. "X35.678" is 7 bytes, sending the same in binary would be 5 bytes ("X" and four bytes for an integer). Don'

Re: Project: Teacup Firmware - 10 years ago

One general question regarding Scara-printers and printer-firmware: The actual processing interprets GCode-entries e.g. to fill up a buffer with fundamental microcontroller tasks. If the buffer is full, interpretation stops until enough entries in the buffer were processed and deleted. So for simple GCode-Commands the interpretation is ahead of the execution, but for complex commands it can happ

Re: Project: Teacup Firmware - 10 years ago

I've started to implement extensions for scara-printers into the Teacup-Firmware. Thanks to Traumflug for his hints on where to start and to look at. I'm not very familiar to Github, so I'm not sure if I can start a branch without write-access to the project. So I've published my first results in a seperate Github-project so far: https://github.com/RobertKuhlmann/Teacup_Firmware_Scara The actual

Re: Cheap, simple and powerful heated bed - 10 years ago

Quotezelogik This kind of heated bed have already be done with cork and wire long time ago. But it's a really good ideato make custum size heated bed. The knurled nut idea is not bad but it's don't protect the nozzle again crash on the table. Thanks for your thoughts on this. What was the cork for then? Guessing it was a heat isolation then the rescue blanket is lighter, cheaper, easier attached

Re: Building my first Morgan - 10 years ago

I almost forgot to post that my Morgan is finished and working meanwhile. You can see it working over here: My Morgan on youtube

Cheap, simple and powerful heated bed - 10 years ago

I've developed a simple heated bed, based on an aluminum plate with copper heating-wire and a rescue blanket for isolation. You can find it in the Wiki already: Robert's Heated Bed I'm using the 13A variant (12V DC) at 120°C, driven by Traumflug's SevenSwitch. Heat-up time from 21°C to 110°C is app. 6 minutes (didn't stop the time for 120°C yet, but you'll have to add a few minutes). What do yo

Re: Project: Teacup Firmware - 10 years ago

Hello guys (no girls, I think?), Traumflug told me of this project and it sounds very promising to me. I will read me in and contribute, if I can. I'm a german software developer, I'm 48 years old and not very happy with Marlin (need it for my RepRap Morgan though). I like what I've read so far.

Re: Your thoughts about the new PICO hotend - 10 years ago

After "remembering" the guys at B3 innovations of my order, they shipped it yesterday and apologized. Now I'm waiting for my Pico to arrive...