We’ve seen them before, but only now has the Deltaprinter, a very simple and affordable delta printer finally hit Kickstarter.
We saw the Deltaprintr at the World Maker Faire last September where the team showed off their fancy new printer and the very nice prints it can produce. The printer itself is unique in that it eschews printed parts and is instead made of lasercut parts. Instead of belts, each arm of the delta bot is lifted with spectra line, and the entire mechanism is billed as not requiring calibration probably due to the accurate laser cut parts.
On a completely different note, we did notice the rewards for the Deltaprintr Kickstarter are limited. Unlike the gobs of 3D printers on Kickstarter, the Deltaprintr team actually wants to stay on schedule for their shipping dates. That’s an admirable dedication to getting their printer out to backers in a reasonable amount of time.
It says “automatic calibration,” not no calibration.
Very nice! I wish them luck!!
Which, for anyone wondering, is actually better than no calibration. Having spent the better part of 8 years working in laboratory calibration/metrology, I can tell you that it really sucks when you find out that someone in your organization decided to buy equipment that is no calibration because it means you can’t calibrate the equipment even if you want to. Basically, if you go to calibrate it (because you either think it looks like it’s out of calibration or because you have a policy of calibrating all equipment on a regular basis) and find that it actually is out of calibration, your only option if to then throw out the equipment and all test data that might have been effected by it since the last calibration (though, from a technical standpoint, any “calibration” that doesn’t involve the ability to adjust the device is really called a validation and not a true calibration).
This matters to hobbyists with 3d printers because it effects the ability of printed parts to fit together correctly and because NO piece of equipment can ever truly stay in calibration forever. While you can get away This is especially true for mechanical devices (with electrical meters, like DMMs, you may be able to go for many years without it going significantly out of calibration assuming you purchased a decent brand)..
Why couldnt you just modify the output of the equipment yourself if it doesnt support calibration? For things like scales, wouldnt any calibration do nothing more than add or subtract a offset from the value measured? For other items such as reference voltages couldnt you just know to offset the set value by a certain amount?
For hobbies and personal use you can get away with splicing in an MCU to add or subtract but for a company anything without a chain of custody and/or standardized method is unacceptable.
The calibration is there to test the instrument throughout it’s entire useful range, determining the offset is only one part of the calibration procedure. There are also times when calibration is not possible and is an indicator of failing equipment or components. With ‘no calibration’ instruments it is impractical to determine the difference.
To add to what Leithoa said, in a corporate situation (or even a publicly available 3d printer at a hackerspace type situation) you can’t assume that everyone will know to apply the external offset value correctly. By relying on it, you’re adding an additional source of potential human error.
Additionally, your concept of a simple offset assumes a common drift across the entire range of measurement. Sometimes that’s just not the case. For instance, what if there happens to be a specific part of the z-axis threaded rod that deviates worse than the parts above and below it (I’m not saying that present 3d printer calibration techniques already handle such a situation, as I don’t know if they do, but I’m just trying to make a 3d printer based example of what I’m talking about)?
One thing not mentioned is that in a any situation where a measurement must be certified, adjustments such as you suggested are not acceptable. The measuring device must be certified, if the device cannot be calibrated to operate within the specifications needed, the device will not be certified. If the device fails the certification process, it cannot be used for anything requiring the certification.
Certainly, this is not as big a problem in a hobby situation where one is doing limited amounts of prototyping. However, if one is attempting to produce a product that can be marketed, then one needs to insure that the tools and instruments being used to produce the prototype are calibrated properly. Adjustments after the fact just cause more trouble than they are worth.
Ironically, even when we assume a hobby situation, the caliber of quality must meet or exceed professional grade in order to insure that the measurements of the prototype are accurate. Using adjustments as you suggest, just makes it that much harder to insure you have accurate specs.
Calibration is done by measuring connecting rod length, hot end offset and carriage offset. Bed leveling can be done with a simple endstop switch and with tweaking in the software can be bed leveled (calibrated) before every run. Motor steps per milimeter are fixed physically, so there is nothing to really complain about. Bed leveling won’t even be neccesarry if the frame is measured up properly, and asuming it hasn’t changed in dimension. Calibration can be done in the software.
Checkout auto bed leveling on the kossel mini: http://www.youtube.com/watch?v=1eNz1l56H5E
Good point. Additionally, I feel the “automatic calibration” statement is a bit of a stretch.
The current implementations of any “auto-calibration” using an effector probe have shown only limited success (I state this from both personal experience and waaay too much time on forums discussing this exact issue). I installed a probe on my Rostock and have experimented by mis-configuring the firmware, as to emulate a first-time commissioning. With a well tuned machine, Marlin’s “calibration” code (G29) does a good job of compensating for a non-flat build surface, but can’t really correct for bad geometry or incorrect firmware configuration. I think that using the term “calibration” for what the Marlin code does could be better described by “bed-mapping,” as it simply probes the surface and builds a linearly interpolated map that is applied to every z-coordinate the firmware calculates. To me, calibrating is what you have to do to get the effector movement to be flat, and it can require a lot of patience to finely tune a delta machine.
That said, maybe their “minor modifications” to the Marlin code include a working auto-radius calibration. As the delta radius is *the* defining parameter, not to mention the most difficult to determine, for getting true motion with a delta machine, if the process of determining it has been automated, I can’t wait to see their code!
Congrats Shai
Thank you draeath!
“The printer itself is unique in that it eschews printed parts and is instead made of lasercut parts.”, no it’s not. Printrbot has been shipping laser cut printers for a long time now.
I’m curious to see what Printrbot is going to do. Deltaprintr uses the printr mongier, something PB is known for. They might be looking to get acquired…
I’m honestly not a fan of this design. It looks wobbly, unstable, and CHEAP. The SeeMeCNC Rostock Max kit is $500 more and much larger. This is a kit for kiddies.
Wow, a machine that costs twice as much might be a better machine? Groundbreaking.
Thank you Dr. Frist for your expert opinion based on your comprehensive evaluation.
I like the fishing line/wire based approach to linear motion (I’m assuming the cord goes around the corner and up the supports), I’ve wondered about something like that (but on a larger scale) but always worried about drive slip.
Also, on the restricted pledge limits, I wonder why more don’t do such things in order to avoid the problems of “being overwhelmed”, a good idea indeed.
Super Awesome Sylvia’s WaterColorBot uses that method. The line makes multiple turns as in more than 5 and possible more than 10 around the wheel. It is very difficult for there to be any slippage with that many turns.
http://watercolorbot.com/
There is an elegance to their design, it’s quite attractive. Looks like it would be easy enough to give it a stiffening cage. I do wonder about the fishing line (is there not a better marketing term, like “synthetic nano cable”?), but if it works, it works.
Gel-spun, Ultra-high-molecular-weight polyethylene cable.
High-tensile polymer monofilament
65lb line is most likely braided.
I see that the motors are tucked under the glass sheet. It may be easier to curb noise with a design like that. If the dev team is reading, have you done any tests to lower noise using foam or some other material? A low/no noise 3D printer would be a strong selling point, because you could then run it at night even if you sleep in the same room.
Hey Red, good question! While I am not the electrical engineer on the team, I will try to answer this to the best of my ability. Because the voltage currents (pots on the stepper drivers) are well tuned to the specifications of our motors, there is almost no noise. The noise usually has to do with motors drawing too much current (more than they need). A good example of this would be the extruder of any 3D Printer where the user increases the current thinking that the motor is not able to push the filament, where in reality it is most likely the setup of the extruder (ex: something jamming it or causing friction)
If you have any questions, email us at info@deltaprintr.com. While I happen to be reading the comments at the moment.. I can’t promise to see everything everyone posts :)
Interesting that they limited the rewards, this might help them actually make their schedule, but hurts in getting to the goal. Still, not sure I’d trust my money to a bunch of college kids getting their act together and actually producing something.
Slick, and though I like their product, I will not be backing this campaign.
Why?
Look at their team. Not one has a bio mentioning any experience working with vendors, overseas partners or design for manufacturing. On the Risks and Challenges section they write:
“Before launching this Kickstarter, we made sure to get all of our logistics worked out. Like with any Kickstarter project, delays or minor mishaps are always a possibility. We’ll try to keep them at a minimum, and if anything does pop up, we’ll be sure to keep you guys updated.”
What logistics have they worked out? What vendors are they working with? What is their manufacturing plan? What is their fulfillment plan? Do they have an operations person? Do they have any engineers WITH EXPERIENCE?
This part galls me the most:
“We’ve done extensive research to make sure that production goes as smoothly as possible and we already have suppliers waiting for us to transfer the necessary funds to them.”
I am sure that they have had no problem finding people to take their money. . . but until they have cut tooling (which they have not) and received samples that pass muster, they do not deserve my money and they DO NOT have logistics “worked out.”
Get a loan from friends and family, cut tooling, get samples and demonstrate that you can deliver. . . THEN go to kickstarter.
– Robot
I would like to add that what prompts my tirade is that they are asking for a lot of money and offering little information in return.
All campaigners have an ethical obligation to deliver what they promise and to go into such a venture, with other people’s money so naively is negligent.
They are offering a product, for their own profit. It is not a charitable venture.
If they were asking for a small amount of money then I wouldn’t be so critical.
– Robot (again)
Is this your first encounter with a Kickstarter project?
Ha! Fair point.
Managing complex supply chain logistics was, until recently, my day job. Presently I consult to crowd funded projects with the aim of getting their products to market cost effectively. It takes years of networking and building relationships to get many vendors to even consider quoting your jobs. So, I am a skeptic.
If this group accomplishes what they aim to; there is good work for them in startup land.
@Brian, what makes this KS so outstanding that it merits a post on HaD?
Well, 125 of them were sub-$500. Right now they’re $655.
jwwearther4 is right: By the time I got on KS, all the sub-500 packs were gone. I wonder why they only have so limited sub-500 packs.
I also wonder if the machine can deliver such nice prints as shown on the KS page. Whenever I read about a 3D printer, I get the idea that the results might not be as good as the developer says it will be.
An no, it’s NOT always because the printer has the wrong settings, or is badly calibrated, etc etc.. It’s always the users fault.
limiting reward numbers is a wise move in terms of generating a lot of initial traffic and capitalizing on the excitement with higher cost rewards. That is sort of the logic behind loss leaders for Black Friday sales. Also, the RFQ process is based around set numbers of units so this makes managing the supply chain easier.
As for print quality; my PrintrBot Simple (which is not at all rigid) makes very nice prints with 0.1 mm layer height and 0.2 mm nozzle ID. The trick is to slow the machine down a lot.
Hopefully the delta printer is better.
sub-$700 is more like it now. add shipping and that price point fails. I had my hopes up for all of 30 seconds lol
Old technology repackaged to look good and make a buck. There is nothing new here.
The kossel or mini kossel by Johann is already open source and features a much superior design:
http://deltabot.tumblr.com/
They’ve taken the design, and replaced everything they could to lower the cost. Cheap 60 Watt PSU, fishing line, laser cut parts and house electronics.