LesHall
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Posts posted by LesHall
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Here in this animated GIF image (click for animation) we see the drastic evolution of Ivan the robot arm that occurred yesterday. When I realized that putting the motors in-line with belt/chain drive meant that the planetary gear joints could be reduced to simple bearing joints, this was the result.
Ivan now accurately touches the magenta ball through -60 to 120 degrees at a radius of one to three section lengths, which I find to be quite a capable result for such a small amount of algebra and trig. He's also low in part count (about a dozen parts total) and both quick (relatively) and easy in printability. I hope you like my latest Ivolution!
Les
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That must be what was happening then, I will switch back to the brass nozzle that was included with the printer. The steel one is just for abrasive filaments anyway. Well, that or run it hot and fast!
Les
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Hi gr5,
I see your point. I wonder what it could be then? I only did the test once, I will have to test more when I get home later this week. I have updated the firmware so that's ok. One possibility is that I am running a hardened steel nozzle that I bought here:
hardened steel nozzle for abrasion resistance
The guy who sold it to me said that it would have worse heat transfer capability than the stock brass nozzles. So maybe the heater is heating up the hot end and the thermometer but not as much of the heat is going into the nozzle and the filament is pulling heat away from the nozzle internally? I should have mentioned this before but I only just thought of it.
I am running PETG filament.
Les
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Ivan has evolved so far since that design described above. Key new features include PVC connecting rods, larger gear boxes, all four joints have motors, many smaller details, and a trigonometry-based control system that plays the "touch the ball" game shown if you click on the following image.
In that image a red ball is randomly positioned within a thick spherical shell around the robot. Then the software runs one algebraic and four trigonometric equations to calculate all of the motor angles. This puts the tool almost directly not the ball almost all the time, a nice innovation that circumvents the mathy forward kinematics and the algorithmic inverse kinematics. I'm not sure but the trig i mentioned may be similar to the distilled-down math behind the forward kinematics for this robotic solution. Anyway, it always gets within a tolerance of the ball position.
I've started to work on the electronics and the software, running the motors at 5V to limit their current (they are 12V 2.5A motors so at 5V they should draw under 1A, allowing them to be driven by one motor chip each and controlled by one Arduino equivalent. Later I'll add ESP8266 for WiFi control.
Les
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Yes everything including the book will be open sourced. I have released AVA's Gear Toy 1,2, and 4 on Thingiverse already, and I am working on Ivan and the book. I can share the current Ivan source code with you if you want to have a look at it now, with the understanding that you will keep me informed of developments.
Les
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here we see Ivan doing a much better job of tracking the red ball with the green tool. I can see it doing some type of 3D printing.
Les
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medusa: ty for info, you know your printing very well i see!
Les
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Yes I agree gr5, and I was wondering about that solution. The wattage rating on a resistor tells how much heat it can survive dissipating, not how much heat it will develop for a given voltage. If the resistance of the resistor is the same, then a higher voltage would be needed to take advantage of the higher wattage.
I was holding off saying this because I was unclear as to whether the 50W heater had a lower resistance or not, I guess not, which makes it perfectly understandable.
My solution? Run my UM2+ stock and wait for a later model such as the UM3 to provide greater heating capacity (if it ever does). Either way, my UM2+ will last me a good long while!
Les
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Hi all,
Sorry that this is vaporware, I plan to print it soon. Ivan is my companion robot. He has taken many small and playful steps in his development into a full robot. In this version, Ivan is an industrial robot arm. Here is the GIF animation that I will discuss with you:
In this image Ivan is playing "touch the ball", a game in which a red ball is randomly positioned by the OpenSCAD design file for Ivan, then Ivan's motor angles are calculated according to four simple trig expressions that I developed and a touch of algebra as well. These do a good job of positioning Ivan's toolhead close to the ball as you can see. This method is simpler than forward kinematics and easier than inverse kinematics. I think, though, they are a form of forward kinematics. Anyway, that is ball tag.
Ivan's big discs contain planetary gear sets, and Ivan's connecting rods are PVC pipe. Ivan looks unstable but he has screw holes from underneath and a large enough wooden platform to keep him in position. The planetary gear sets are key to Ivan's identity. They function as plastic bearings rather than use metal bearings because, you see, Ivan is nearly all plastic. Except for motors, fasteners, and control electronics (and wooden base), Ivan is entirely plastic. The plastic consists of all 3D printed parts except the section joiners which are PVC tubing for strength and reduction of print time. Ivan will be printed in Nylon, which is ideal for gears.
Also related to the planetary gear sets is Ivan's history of Gear Toys in open source hardware. Ivan is somewhat popular, mostly I deduce from parents printing Gear Toys for their kids. So the Gear Toys have become a learning sequence from toddler to teen and above into adulthood and I thought a robot arm would be nice.
Anyway, that is Ivan.
Les
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Hi gr5,
The situation is that running a 0.8mm nozzle at 0.4mm layer heights and printing PETG, not sure the temp as I am away from the machine for a while, the plastic forms poorly above 20mm/s travel speed. I want to go 40mm/s but I cannot go above 20mm/s and still maintain print quality. So I am limited by the energy put out by the heater core.
Les
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/me awaits additional tips!
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Here is the 50W heater cartridge at an American reseller of 3dSolex:
http://thegr5store.com/store/index.php/ultimaker2-hot-end-heater-50w.html
Les
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I found this:
https://ultimaker.com/en/resources/252-disassembly
for a tutorial on heater cartridge removal and replacement.
Les
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Sander, can you suggest a tutorial that will be close (though likely not exact) to that area of the print head so I can see what will need to be done?
Les
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This is vapor ware - just getting that clear right off the start. I have only designed the concept model in 1,000 lines of OpenSCAD CAD language file. Here is an illustration of the robot operating (click for animation):
This robot, who's name is Ivan, has many fine features :)which I will attempt to describe here. First of all it is entirely 3D printed plastic except for the motors, fasteners, and electronics - and the fasteners are few and few in type. The motors are NEMA 17's, the venerable 3D printing motors used in almost every enthusiast 3D printer including the Ultimaker. The control electronics are simple - arduino or arduino via computer link. The entire robot is designed to be printable on an Ultimaker with a 200 mm build volume (or smaller in a scaled down version).
Ivan is configurable with optional components including an optional rotating base, a necessary first stage, an optional second stage and an optional third stage. The third stage, naturally, is only useful if the second stage is installed. This illustration shows Ivan with the third stage installed (click for animation):
Ivan has planetary gear mechanisms at each joint with a selectable gear reduction. These planetary gear joints also function as bearings, so no metal bearings are required. They are one of Ivan's key Identifying features and are derived from AVA's Gear Toy 2, a popular children's gear toy of my own design. Here is the Thingiverse page on the design (my apologies to the YouMagine fans among us, I simply MUST post the design to YouMagine soon!):
Kids who grew up as toddlers with AVA's Gear Toy 1, youngsters with AVA's Gear Toy 2, and pre-teens with AVA's Gear Toy 4 will fallen love with AVA's Gear Toy 8, which is Ivan's code name in the series of AVA toys. After all, each joint in Ivan is an AVA's Gear Toy 2 or similar.
Besides being an educational and fun kid's toy, Ivan is serious business. There are many applications for Ivan, despite his limitation of having only two degrees of freedom. With three stages Ivan's third stage spins freely so it always points down. This is useful for picking up items with an electromagnet or other actuator that is aligned by gravity. With two or one stages Ivan can paint or deposit concrete, mud, or other material onto a shaped form to create dome homes for human living spaces, from kid's tree houses made of plaster-of-paris to mud huts in India for the poor, to concrete living spaces for the homeless in America or Europe. Of course being a 3D printing robot, Ivan can steer his direction to shape windows and doors as well as thicker wall features, and can build the walls in thin layers for drying purposes. There are many applications that I have envisioned for Ivan to perform.
Ultimately though, Ivan exists to be a robot toy for kids of all ages including us adults parading as children. The wise never grow up. Take a trip back to childhood with Ivan the robot - you won't regret it.
Les
p.s. shall I post the design to YouMagine even though it is vaporware?
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Come to think of it, since I'm getting slow performance out of a 0.8mm nozzle, why not use a 0.6mm nozzle, get full performance for the nozzle size, and higher resolution? Will probably do that.
Les
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from the website:
Individually tested heater cable. We know how horrible it is to change it.1 Year guarantee. Not for use on clone blocks.
http://3dsolex.com/product/50w-heater-um2/
"we know how horrible it is to change it" is not promising... and I'm not overly mechanically inclined. I'll stick with slow for now.
Les
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How about this Volcano add-on kit?
Is that going to fit in my UM2 even though it is twice as long as an E3D? Will the electronics take the load?
Les
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What heater do you use in your um? Maybe you can replace it to a higher wattage
I use the one that came installed in it. I have a UM2+. I did not know an upgrade was possible?
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What heater do you use in your um? Maybe you can replace it to a higher wattage
I use the one that came installed in it. I have a UM2+. I did not know an upgrade was possible?
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When I run my 0.8mm nozzle at a layer height of 0.4mm, I have to slow the speed down to about 20mm/s because the healer just can't keep up with that volume of filament. This is a major limitation in the performance of the Ultimaker.
On the other hand, the Taz 6 now has the MOAR tool head with it's 1.2mm nozzle and upgraded heating and cooling components. It lays down filament like nobody's business.
So my question is: Can the next model of the Ultimaker have an increased heating capacity?
Les
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Now here I am with a band to play
Some sounds unheard coming out your way
You see, I rhyme by myself in time
To call attention to this joke sublime
It'll be about something dear to me
My Ul-ti-maker that so dutifully
Crafts my thought into phys-i-cal
-ity, my joy my idolatry
Now if the rhyme is not found in time
Too bad, I'm new at this sort of thang
I'm here to tell you about one small thing
a way to improve Cura and the thing
I mean to say is the following
Booger Syndrome is the forking thing
You see, I'm keen to 3D printing
Yet my prin-ter is somehow lack-ack-ing
The wis-dom of init-i-al-iazing
Cause the booger at the start of things
Gets dragged into the print so disgustingly
Now if the nozzle was lowered better
a bit sooner like other printers,
then the booger at the beginning
would not be part of my print job thing.
So now you know the scheme of this rhyme
Is to tell you the story of the booger whine!
I'll stop now that you have got the point
Let's fix this fine tune detail of all things!
Buh-bye and all that jazz you know
I'll leave and let you all a smile aglow!
Les
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I'm in too. I'm printing parabolic lenses. Here is how one looks in the LED test fixture that I made for this purpose (prior to polishing):
BTW this stuff does not want to sand. I have grits from 100 down to 3000 in lots of steps and the 100 just will not cut into the defective layers (0.2mm layers).
I am now attempting to print a differently proportioned but identically mathematical lens (thicker at bottom inside) at 0.1mm on a 7 hour print in the hope that it will be easier to sand (finer defects).
It is quite "clear" to me (ugh the pun) that these clear lenses are frosted on the outside prior to polishing. I am wondering iff all that effort (it's very tiring after 3 days of doing it) could be spared with a surface treatment. If not a solvent then how about something additive?
Les
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Just had this silly notion of a Star Wars droid whose purpose in life was to be a 3D printer. Kinda R2D2 with an Ultimaker on top maybe? Perhaps an image exists of that or should be created? It's got me tickled ATM!
Les
Post your latest print!
in What have you made
Posted
Nice flower, I have seen that design on Thingiverse many times and wished I could print it.
Also I love the tug boat, anything electro-mechanical is exciting!
Les