3d printers and robots
 

For those teams out there with 3d printers, how did you guys use them during the year (offseason and build season)? And more specifically, how did you use them with your robots during the build season?

Re: 3d printers and robots
 

Round belt pulleys have been things that we have printed in the past. They are bulky items that don't have to be too accurate.

Re: 3d printers and robots
 

Is it possible to post a picture?

Re: 3d printers and robots
 

We have printed a large variety of things in the last few seasons. Some things we've printed include:
Variety of spacers
Mini-bot
Wheels
wheel hubs
encoder mounts

Re: 3d printers and robots
 

Yes. Under "Additional Options" click "Manage Attachments". Then, choose which file to upload and click "Upload". Also note that a picture can be no larger than 2 megabytes.

Re: 3d printers and robots
 

I believe he meant "could the poster above post a picture". At least now I know how to post a picture :p

Re: 3d printers and robots
 

No, moved away. Team no longer exists, sorry :(

I know Team 3824 uses a quite large 3D printer to print several parts.

Re: 3d printers and robots
 

Here's a few pictures I took at the Michigan State Championships of some 3D printed parts one team used on their robot. Unfortunately I didn't catch which team it was in any of the pictures or video I took, but here they are anyways...

Re: 3d printers and robots
 

Along with pulleys(and excluding minibot), we've used all this with a 3d printer.

Interestingly, we've not only done round belt pulleys, but have printed round drive pulleys with the belt pattern(the name of which escapes me) with moderate success.

Re: 3d printers and robots
 

Looks like a portion of the Stryke Force (2767) logo in the background of the first image. Looks like their robot too.

Re: 3d printers and robots
 

There a few threads with this same question.

We started printing parts for our robot in 2011, more than a few parts. Most of them critical. We felt that it was a worth while effort for our team so we have continued every year since.

http://www.chiefdelphi.com/media/photos/38032
http://www.chiefdelphi.com/media/photos/38033
http://www.chiefdelphi.com/media/photos/38034
http://www.chiefdelphi.com/media/photos/38831
If you have any questions I am sure they will be answered.

My only true advice, understand the design limits of "your" 3D printer and apply your robot designs appropriately.

Good luck with it,

Re: 3d printers and robots
 

In the past, we have 3D printed pulleys, electronics mounting towers, gears, molds, potentiometer mounts, and even shooter wheels.

Re: 3d printers and robots
 

I usually hate on a lot of teams for really poorly using 3d printing, so this is great advice.

207 is the first team I saw at an event (in 2011) where I really said "WOW! they actually get it! They're using it right!".

Re: 3d printers and robots
 

What would the limits be then

Re: 3d printers and robots
 

It depends on the printer and the settings and the material.

For any 3D printed part, there is a size limit--can't build any bigger than the machine's build envelope, unless you're doing something where two parts mate into one.

Different materials print differently, and different temperatures can make a material act differently. For example, we once took a lot of warping out of medium PLA parts by cutting the print head temperature by about 30 C. (For that matter... if you plan to use a color on the robot, test it first. Some colors on the printer WILL act differently--we always had a problem with white PLA cracking, for example, not so much with any other color.)

Support structure can be a limiting factor, but I don't know much about that, so I'll pass on commenting.

The printers I'm used to--RepRap types--are sensitive to a level surface, condition of the heated bed covering tape, temperature of the print head and heated bed, tension of belts, height of the print head above the platform... In short, they HAVE to be dialed in. We'd check how dialed in we were every time we moved one from one location to another (though having it on a cart removed that for a while) and adjust if necessary. That's how sensitive they could be. We also did not have the ability to use support structure, so parts had to be printed in a certain orientation--actually, still an issue.

There's also the issue of precision--3D printers are only as accurate as their print heads' extruder tips in both travel and thickness of material--we'd always figure at least .003" oversize to allow for the tip running thick. Otherwise, holes would need to be drilled out.

Re: 3d printers and robots
 

A couple of additional tips - Understand how the part is going to be loaded. Generally, the material will be weaker in one direction than another. Also, use the software to your advantage. The automatic print setting features are great for parts that aren't going to see much loading, but if you have the ability to examine each layer and tweak the print settings, definitely do so. You can minimize the number of voids caused by the printer head changing direction around curves (see here for an example), which can help you in situations where you will have loading, such as around fastener holes.

Re: 3d printers and robots
 

1675 did some experimenting with 3D printing last fall and I'm sure we'll continue that this year. We were mostly experimenting with gears. Most of our tests help up just fine - it was when we hastily reduced material near the hub that we had a failure.

On our 2013 competition bot, we used 3D printed plates for custom gearboxes for our drive train. Our milling and pocketing capabilities are limiting so the ability to print two plates in 3 hours greatly increased our production. We had 8 printed plates and assembled gearboxes by the end of week 1 (normally we're looking at week 3 for assembly). Never had a problem with the plates through 5 competitions so far.

We also printed a guidewheel for our climbing mechanism, but the printer ended up having a breakdown after 7 hours of printing so the actual part on the robot is a lathed piece of acetyl donated by a local machine shop.

Previous to that (2006), one of our mentors printed a fully functional set of mecanum wheels for a Vex robot.

Our school has a Dimension 1200 BST and Stratasys donated some material to the team this year.

Stratasys also donated some polycarbonate printed gears for us that we briefly used to increase the speed of our robot (but ultimately removed in favor of more torque).

3D Printers in Robotics
 

Hi all!
I'm taking a Project Lead the Way course of Engineering Design, and our class is trying to get a 3D Printer to help with our rapid prototyping for the class. Part of this proposal is trying to find other ways it can be used around the school, and I, being an avid FIRSTer, mentioned that I had read about applications for 3D printing on robots from the all-important Chief Delphi.

So I was assigned to ask you all about them.
I know I've read threads about the applications of 3D printers, and that those threads already exist, but I want to know about the printers themselves.

How did you get one (Is it your sponsors', your school's, your team's, etc.)?
What model is it?
What can it do? (Features- multicolor printing, what materials does it print in?)
What features do you find essential for making parts for robots?
What other uses do you find for the machines?

If you want to include bits about some special ways you use 3D printed parts, that'd be cool, but I've read a lot about them already.
Thanks!

Re: 3d printers and robots
 

Apparently my thread was merged with this one, although the threads are meant to be about slightly different things. But no matter.
I'm still interested to get answers.

Re: 3d printers and robots
 

Off the top of my head, here are some printers:

Ultimaker
Makerbot
RepRap (Mendel, Prusa, Kossel, Rostock)
UP! (inventables.com has these)
Buccaneer
Stratasys


Things to look for: reliability, ease of maintenance, replacement of components, material costs.

Multi-color: This is not a requirement for most things. It will make your peices attractive, but at a huge increase in cost. There is a printer out there that can print any color on demand (I already forgot which company made it).

Extruders: There are two basic designs: direct-drive or Bowden. Many Bowden setups require fine-tuning to dial in the retraction rate. Direct-drive is basically a stepper motor on the print head which feeds directly into the hot end.

Hot end: This is the part that melts the plastic filament. Depending on how hot / how well the temperature is maintained, this will limit your material selection.

Heated bed: This is important for ABS plastic. It allows the first layer to adhere to the print surface and helps keep the next layers on target/aligned when printing up since the base layer has set well.

Materials: ABS, PLA, Polycarbonate, Nylon, Wood

Overhang:The overhang is basically how well the printer can print an "arch" without having to put support pillars under the arch.

Slicer/G-code: The software and firmware that convert the 3D model into paths, set the retract speed, print head acceleration and speed, as well as the thickness of the outermost wall (shell). Fine tuning in the printer software will result in huge variances in strength (more plastic is not always better), cost, weight, and durability.

Hopefully, this is some place to get started. There are so many printers out there you can easily find one. I would recommend against going for the cheapest ones out there and also against a large commercial printer (Stratasys) for a school setting. You may be able to get one with support and donated materials, so if it works out in your favor, there is no reason to immediately eliminate this. In the end, it needs to work or be repaired quickly. If you can get a sponsored service contract, this is something that might be worth looking into. However, expect to pay several thousand dollars for a repair call if there is no service contract. (And at that cost, you might as well just buy another Makerbot/Ultimaker/etc.)

You want one that will work, but also one that is maintainable, affordable, and cost-effective. I would not get an SLA printer due to the material costing $200+/liter. If it is for an engineering design class, why not have one that students and teachers can build, take apart, fix, and use. In fact, most of the videos are probably on YouTube already!

Re: 3d printers and robots
 

Our school's CTE department was awarded a grant to purchase a printer that one classes is now assembling. The second part of their grant is they will use it to print parts for making another printer that will be given to a middle school CTE program.

I will talk to the instructor and find out what make and model the printer is.

Re: 3d printers and robots
 

It's probably some form of RepRap. Wouldn't be surprised if it's a Mendel or a Prusa.

330 runs a modified Mendel. It can't do multi-material; that involves a 2-extruder head (though those are available). Prints PLA, can do ABS but haven't tried that. The one 330 runs has a heated bed and a heavily modified Y-axis from the standard Mendel. (Instead of being largely PLA/wood, it's mostly metal.)

Haven't found too many other uses for the machine yet, but printing random small stuff isn't too hard.

Re: 3d printers and robots
 

So we started playing with 3D printing last year after I built a Linear Prusa REPRAP. Didn't get a lot done for the robot but we did build some slides and electronics mounts. We also printed a ton of wrenches to hand out at competitions.

I taught a 3d Printer class (where everyone built their own printer) over the summer which was attended by both members of our team and some other teams.

We now know a lot more and know what we can print if we design it so I hope to see it used more this year with not just FRC but also potentially FTC.

That said to add to what folks said above - Calibrate, Calibrate, and Calibrate.

From a cost basis the REPRAP kits are affordable and from what I have seen if carefully assembled and CALIBRATED can print things as good as the lower end commercial models.

Plus if the kids do the assembly and calibration it is an opportunity to learn about a lot of different concepts.

Personally, of the REPRAP designs I currently like the Prusa I3 although there is a certain minimalist elegance to the Linear Prusa V2 which is made up primarily of Rods and printed parts. I have sponsored a Kickstarter which should deliver me a good Rostock (delta style) printer later this year.
A very reliable vendor of Kits who makes really quality stuff is MakerFarm
(http://www.makerfarm.com) and he offers both V2 and V3 Prusas kits at
really good prices.

There are lots of different host, slicing and firmware options out there. Look up the online version of MAKE magazine which recently reviewed a number of slicing programs. There are also several electronics options but not all firmwares will work with all electronics.

Currently my favorites are:
Electronics: RAMPS 1.4
Slicer: Slic3R
Firmware: Marlin
Host Program: Repetier

I am looking to offer the 3d Printer class in the Northern Virginia area again later in the fall. Contact me directly if interested.

Re: 3d printers and robots
 

How about a Modified Mendel Max using OpenBeam?

Here's one:
http://www.thingiverse.com/thing:33946

I have been trying to find some photos of a full-on OpenBeam Mendel (http://www.hive76.org/modified-mende...ing-wednesday), with only the injection molded OpenBeam components used for framing. This would allow you to build up from components without the need for a 3D printer to make the framing components.

Re: 3D Printers in Robotics
 

We recently got most of the DC Public School robotics teams Makerbot Replicator 2s. We started with the 6 PLTW engineering schools as an easy justification, and added in the 4 other schools with robotics. They have been used for a variety of projects, but not yet used on an FRC robot. Some things made have included parts for a quad copter, camera/Arduino enclosures, and cell phone cases. They only have one colour at a time, but we got multiple colours they can switch around the feed. They will be used in the PLTW engineering classes by non FRC students as well as FRC students.

It's really cool to talk about an idea with students, and then have them put something in your hand the next week.

Wetzel

Re: 3d printers and robots
 

Our FTC team used our 3d printer (uPrint SE) to print out a bucket for Ring it Up, due to the fact that it was three days before competition and they had couldn't get the legos to hold the weight of the rings without collapsing. I think it was about a 18 hour part, with the white build material running out halfway through. Our teacher then switched it to red, making it look like a magnet. The team won the design award at competition because of it, at least that's what they say.

As for FRC, we have yet to really use our 3d printer for anything.

During offseason, people have made cases or stands for their electronics using thingaverse.com, as well as someone using it to make parts for a hexapod and a 3d scanned toy lion. My school also says that they 3d printed a part that broke somewhere that would have cost $$$ for about $1 of material.

I personally have used it to:
*Make two lithophanes for my sisters for their birthday (found software online, can't remember where. Came out really well, especially when I remembered that lithophanes work better when held up to the light :] )
*Sculptures that were artwork from my aunt that I traced in Inventor
*A small print to ask a girl to homecoming last year (she said yes and really liked it. Someone else then copied it and also got a yes)
*Pieces for a tic-tac-toe game
*Two roller coasters of my own creation, one found online (see my instructions and pictures I posted to themeparkstudio.com: http://forum.themeparkstudio.com/index.php?topic=108.0) I mess with this a bunch because I want to be an Imagineer, fyi.

*Our school bought two when it opened, one more when a new department opened.
*uPrint SE is the main one we use, a powder one that doesn't have strong material that is used by the bioscience department for printing of dna strands that we have no access to (also not sure if the software on it supports inventor models or anything else we would want to make). The other (another department has it and doesn't like us using their stuff, but if ours is broken or is running something big, they will occasionally let us) is a uPrint SE plus. Our high schools have makerbots
*Support material (big thing for complicated parts that some don't do!)
*I personally think support material is a must, since it can make really complicated parts and models, like roller coasters
*See above

Re: 3D Printers in Robotics
 

I own a Makerbot Replicator 2X. My job also owns the same printer.

It can do ABS or PLA (I've heard tell of it doing Nylon but I haven't tried it and I likely won't) and can do 2 color printing (or mix and match materials if you want)

I've primarily printed brackets, PCB enclosures, and prototype parts for visualization. I've never tried to use it to print structural parts for FRC scale robots.

Other uses? I purchased it to prototype out parts for small scale educational robots. I use it for its intended purpose. Yes, I occasionally print out small trinkets as demos for people but this is a tool for me and I use it as such.


Overall, I've found the 2X to be a useful tool once it is dialed in. Being able to design a part, hit print, and wake up the next day having the part sitting in the printer is convenient and lets me iterate designs quickly.
Small issues I've run into -

Leveling the build platform is really important. It's not a set once and forget it. I tend to level it before every print or two.

Kapton Tape is a nightmare to apply. If anyone has any tips on this please let me know.

Living in Florida there is a lot of humidity, this shortens the effective lifetime of a KG of plastic as it wicks moisture out of the air. When these pockets of moisture hit the extruder they boil and it can cause the nozzle to spit plastic rather than smoothly extruding it. While this will rarely ruin a build it can make it look like crap. I recommend NOT opening filament until you have to use it. If you can store it in a low humidity area that might be better. I don't currently have that option, as such I'm more or less giving my spools a 6 month life time. There are things you can do to take the moisture out of them but they don't seem a) safe b) effective to me so I likely won't do it. Rolls that go bad will probably be relegated to "demo" rolls where I don't care about the quality of the parts just making lots of them for kids or giveaways.

I'd also have serious concerns about letting students run these devices without heavy supervision. Mine gets very hot (bed is 110C and the extruders are 200C+) and they stay hot for a while due to being fully enclosed. Burns are a serious concern.


Otherwise, I highly recommend this printer for prototypes. I wouldn't use it for structural members in FRC though.

Re: 3d printers and robots
 

Verdict is that it is a Rapman 3.2

Re: 3D Printers in Robotics
 

We check if the printer gets moved around, or we notice deteriorating build quality.

As far as the Kapton... It's much easier with an extra pair of hands. What we'll do is to stretch it across first, but only tack down one corner with your fingers. Then run across the plate on one edge, using the other hand to keep the stretching (or, the other person's hands). Then you get the fun part: start in the middle of the platform and smooth the tape down going away from the center/already smoothed area towards the edges that haven't been dealt with. Pick up if you need to get rid of a wrinkle or air pocket. Sometimes you may need to poke a hole in an air bubble with the tip of an Exacto knife to let the air out. Line up the next piece and repeat.

If you really need some advice in dealing with Kapton, find your local R/C aircraft club, figure out who their best monokote applier is, and ask him/her for lessons. Then treat the Kapton like monokote and your fingers like the iron used to apply it.

Re: 3D Printers in Robotics
 

My team has desperately been trying to get our hands on a 3D printer. We have a budget of less than $2500. Would a makerbot replicator 2 be the best option? I have heard about the makerbots for a while now, and they sound like the best option for a not-$5000-beast-3D printer.

Intro to Engineering and Design, or Principles of Engineering? If you are doing Intro, I still have all of my notes from last year if you need some of them for whatever reason. Also, those long definitions, word for word, man. One word off and you lose points.

Re: 3D Printers in Robotics
 

I've heard good things about Makerbots, but have never played with one. Try to get a decent-sized one, though--the small ones might not be worth it for robot parts, or they might be.

I would try the following experiment, regardless of what printer you opt for (and I might even go for a RepRap kit build to start with...).

If you have one 3D printer, you can build the plastic parts for a RepRap for cheap (if you're willing to put in the time)--definitely under $100 worth of plastic. It'll also help you with dialing in the machine. Now, with those parts... build another. (You'll need to get the metal, electronics, and possibly the print head--figure about $1K for the lot.) Nothing like building a machine to understand the nuts and bolts of how it works.

Re: 3D Printers in Robotics
 

Engineering Design and Development
http://www.pltw.org/our-programs/hig...eering-program
The last one here. I'm a senior and I've already gotten four PLTW college credit courses done.

That's some awesome information there, Tim. And I'll bring up building one. Is it more cost-effective than buying a COTS one?

I'll look into the kits. And emphasize calibration. :P
North Virginia might be a little far to go for our class, though :D .


Does the uPrint support importing Inventor models?
Is that a feature that is standard among a lot of 3D printers? Or is it only specific ones?


Thanks for your help, everyone! This could turn out really well for us.

Re: 3D Printers in Robotics
 

I would say that it's a better value. That's not necessarily the same thing as cost-effective, mind you.

For building one, the pros:
--You know the machine VERY well.
--You can do some mixing and matching of parts.
--Cost tends to be lower for a larger machine. A large one could be in the neighborhood of $2K, depending on exact size and features. A smaller one could end up closer to $1K or possibly even lower--again, dependent on features and exact size.
--Build one, build a dozen over the next 5 or so years. (could be faster...)
--Adaptable to new technology fairly easily.

And the cons:
--You need some basic tool skills going in, both mechanical and electrical.
--Still have to buy the parts.
--May get the fun of incomplete assembly instructions. Trust me, that's not fun.
--Calibration will probably take a lot of time--nothing is done for you.
--May need to spend extra $$ to replace parts.

Re: 3d printers and robots
 

I'd say get a COTS unit that has an open-source history so you can learn from it. Something like the Ultimaker would fit that bill.

There are mixed reviews on the Makerbot Replicator 2/2X, but that is probably a solid choice. With the recent acquisition (or sell-out, depending on who you ask) of Makerbot by Stratasys, I would expect to see reliability improvements and some commercial flow-down into the more mainstream printers.

In the end, you want it to just work and work most of the time or be repaired in a reasonable time and at an affordable cost. It's awesome to have a printer you can modify, but if that printer works three days out of the year correctly, then it's not much of a tool. That's not to say you can make an outstanding printer from a well-designed kit like the Ultimaker or Kossel Pro / Kossel Mini (expect these early next year).

While on the topic of the Kossel Pro, I have one coming in December (via Kickstarter), and it looks to be shaping up quite well. It has a 250mm diameter x 250mm height build area, heated bed, automatic bed leveling probe (software leveling of the print), linear recirculating ball rails, and a J-Head hot end for $1100. I'll give a full report once I get it up!

Re: 3d printers and robots
 

This is exactly the reason I have both a SoliDoodle and an Up! printer. The SoliDoodle has already seen heavy modification to make it more reliable. The Up! printer just works.

I've built several RepRap style systems entirely myself since before anyone was really into this. Back then it was the opposite side of the spectrum from the professional 3D printers like the Z Corp. I had access to but not $100k-$150k to buy.

A SoliDoodle printer is less than $1,000. I paid $1,600 for the Up! printer.
The SoliDoodle was already malfunctioning when I got it (early model the new ones have evolved).
The Up! printer had made a large pile of objects and was still going strong.

Now both models give me about the same productivity.

This is incendentally why I am one of very few people that own 2 of a particular LPKF PCB circuit mill.
The other was the prop designer for StarGate.
Sometimes things go wrong or you want to alternate to improve production speed.

Re: 3D Printers in Robotics
 

There are LOTS of high quality kits for under $2500. You could get 4-5 Linear Prusa Kits for that price.
While you can source parts and pieces yourself I like the full kit approach.
It makes it easier.
For example for the glass I teach my non-profit charges $750 per student. Each student gets a printer, spool of filament, glass, etc. and we make a small margin.

I don't use Kapton. Lately my choice is plain window glass, binder clipped to the bed, and sprayed with some pump based extra strength hair spay.
If the part has issues with warping I will resort to ABS juice (1 part scrap ABS plastic to 10 parts acetone) but that has safety issues (flame, fumes,etc.)

For the person who mentioned the class would be too far the non-profit will share it's materials and plans with FIRST teams. Depending on expenses I will also consider traveling to teach the class.

Looking at this thread, I could see a "best use of additive manufacturing" award related to design and functionality.

Re: 3d printers and robots
 

We used our 3d printer for numerous things. Our hopper, the plate that pushed the frisbees into out shooter was printed (and was replaced a lot due it the force of our pneumatics powering it) our mount for our kinect was printed, it slide into it, had rubber on the inside to reduce vibrations, our illuminator of 30 leds that was a cross section of a sphere (15 degree span left and right, ten up and down) was printed and screwing into our mount for the kinect, and lastly our mount for our onboard processor-o-droid x2. a case and platform were printed for a) installing a fan to cool it, and b) easier to put onto our electronics board. We also printed a holder for our hd camera on our robot, then when the match was over, we'd literally just plug in a cord to it, grab the video, delete it from the camera, and then unplug.

*note* all of our printed components were designed in autodesk inventor, transferred via a memory stick, then printed.

Re: 3d printers and robots
 

Right now there are many cheap 3D printer kit, so you can get a very good printer for $1000 or less. I believe that the OpenBeam Kossel Pro, the Kossel Clear and the Rostock Max are all very good printers in this budget.
Anyway, any advice for PLA vs ABS printing? Which is more reliable to use on our robot?

Re: 3d printers and robots
 

It depends on many factors: shear forces applied to the part, shell thickness, mesh, how the plastic was printed (layer/pass bond strength). If you are using SolidWorks or other similar software for design, you could do a materials load analysis to see what the forces on the part are. From there, you could select an appropriate material, using tables of material properties from the filmament manufacturer, Wikipedia, or comparable products. Be sure to have a safety factor as different manufacturers and printers do not create identical results! As a good practice, I would always design for ease of inspection and replacement of your 3D printed part.

I would also suggest looking at Taulman 618 and 645. There is also polycarbonate (PC) and high impact polystyrene (HIPS), BendLay (bendable plastic), Laywoo-D3 and LayBrick (for art use) filaments available. These are available from various resellers such as Amazon, SeeMeCNC, Rainbot3D, MatterHackers, and others (I'm not sure what is available in Israel).

I'd love some feedback on these materials if anyone has tried them. I'm going to start stocking up within the next few months and would love to have a good selection of filaments prior to the build season.

Re: 3d printers and robots
 

I got an e-mail from a friend of mine at Stratasys today... There's a free sweepstakes for one of their 3D printers going on right now. I don't really know anything about the specific printer being given away (and only know a little about the company itself), but with a "total prize value" of $13,900, it has to be pretty decent, right?

Naturally, I want my team to win... but if we can't, I'd prefer it to go to another team than some random hobbyist out there!

http://www.deskeng.com/3Dprinter/

Re: 3d printers and robots
 

Thanks for that!


Also, I figure I'd share this with you all... FREE CAD software DesignSpark Mechanical. I'm going to try this out over the weekend, but it might be a good option for those on a limited budget or do not have access to Autodesk/SolidWorks products for one reason or another.

Re: 3d printers and robots
 

We're going a little off-topic, but isn't solidworks and inventor (as well as PTC Creo, which we use here) free for all FIRST teams?

This is not really helpful...
Can you sharesome of your expiriances with those materials? (as well as any other material that you find worth checking out)

Re: 3d printers and robots
 

No, it's about as much help as one can be. You do need to take all those factors into consideration. In my experiences the biggest factor to using these as structural parts is what direction you print the part in. Any forces that are pulling layers apart are more likely to make the part fail.

As for PLA vs ABS - I've always printed ABS. My printer supports PLA but I've never bothered with it since, if I recall, it tends to degrade in the sun. (I live in what is known as The Sunshine State)

Re: 3d printers and robots
 

I've got some experience with PLA. Haven't done anything with ABS. PLA is to some extend biodegradable, but haven't tested that at all. I've found that the color of PLA tends to have a pretty hefty effect on how it prints and how it'll hold up. Set for one color, print a nice part, change colors and print the same part with the same settings and it might not be the same--depends on how close the colors are. (White tends to crack easily and without warning, for example; most other colors will at least warn you.)

Re: 3d printers and robots
 

Yes, but if you want to design and sell something, you can't use either of them in academic license form.

Great bit of information there. What colors tend to print "better"? When you say the other colors warn of cracking, I assume you're referring to the discoloration gradient when the plastic is nearing its yield stress?

Re: 3d printers and robots
 

I've never had this problem with ABS. Could it be a function of dye in the PLA changing the melting point? ABS seems to melt pretty much the same no matter the color. (Disclaimer: only used Makerbot supplied stuff on my own printer, work used 3d something or rather as their source, no major problems there either)

Re: 3d printers and robots
 

I think that's what we were thinking at one point, or something like it. We tend to run on the cool side of PLA's range, at something like 185 C or 190 C (after 220 C proved to be a little too warpy after the parts cooled), so that might also have something to do with it.

We have ABS, but haven't used it yet to my knowledge--IIRC, we were concerned about the smells/fumes we've heard it has.

Re: 3d printers and robots
 

It has a slight burnt plasticky smell and I wouldn't use it in an enclosed small room. However, nothing I've read says anything too bad about it. I will say that it warps even more and you have to print on the high end of things (I run my nozzles at 220C and the heated bed at 115C). Enclosing the build area is important, without the top enclosure I had some pretty major warping.

Re: 3D Printers in Robotics
 

Exporting as an .stl file, which is the standard for 3d printers.

Re: 3D Printers in Robotics
 

Just check your units to make sure you're exporting it properly.

Re: 3d printers and robots
 

Sorry for digging up a old post. Having been to Hive76 when that Mendel unit was there, it's a nice setup. There also were some specialty heads for it (to print sugar), but that's more of a novelty thing. Unfortunately, the person who had it got a job out of state and moved, so that's not at Hive76 anymore (here's a piece about his work). I'll poke around and see if I can come up with a few pics.

I will say that the MakerBot Replicator 2 is really nice, I've had the opportunity to see one in person and in action. A prof here at temple has one, and uses it to make mounting brackets for a few sensors (among other things). It's just about as good as the Statasys printer that the engineering dept has (minus the Stratasys having a full oven). EDIT: didn't realize the Makerbot printed PLA. It's a nice setup, but other than that probably not really useful as much in a robotics application.

Just my $00.2

Re: 3d printers and robots
 

Thanks!

BTW, this thread is far from "old", so I don't think you have any need to apologize, even if my post was two pages back :)

Re: 3d printers and robots
 

Out of curiosity, has anyone played with any of the delta style printers like the Rostock?

Re: 3d printers and robots
 

We do not use ours too much (as per what I know). We do, once in a while, print a CAD Model of our entire robot. However, I think that 3D Printing is quite a great idea for FRC Robotics. ABS is very strong, strong enough for many heavily-used things. It also makes a great substitute to going to the shop to find the exact part. However, the technology has tremendous areas of improvement required. The resolution is not good enough for many applications where absolute accuracy is required. Also, the process is slow. The ABS is also dangerous. If it goes through too much stress and catches on fire, three toxic vapors are released, CO2, CO and HCN. A 3D Printer is just a very expensive injection moulding system that doesn't require a mould. I came up with the idea of a 3D printed stirling engine, running backwards, to test my design. After some research, this idea has been erased because of danger.

In Short: Do not use 3D printing in high friction or heat. Do not set alight on fire, and only use it where you know it will work. A milled aluminum piece will work way better.

Re: 3d printers and robots
 

BTW, according to the previous post, I was referring to ABS thermoplastic (just to ease any possible confusion)

Re: 3d printers and robots
 

I do not know what "color" is most discolor resistant because I have never used colored ABS, but however, white seems the best because even under deformation, there will be no effects. However, I thing a liitle bit of color could be helpful because it acts as an indicator for stress/strain/deformation.

Re: 3d printers and robots
 

The plastic 3D printing (additive manufacturing) is not a "very expensive form of injection molding". These are two entirely different manufacturing processes. A 3D printed part will not have the same strength characteristics of injection molding. The most beneficial aspect of additive manufacturing is the production of complex geometries. There are some things you cannot make with injection molding since it is a process that relies on subtractive machining.

On a per-part prototype production run in low quantities, 3D printing is far more cost-effective, and for the hobbyist, the cost of most printers and a fair bit of material (dozens or hundreds of spools of filament) is cheaper than one mold.

Aesthetically, there could be improvement on the output of many of the 3D printers. Most are able to print at 0.1mm layer resolution. The accuracy really depends on the user calibrating the machine and fine tuning the machine for consistency. From a part design perspective, this may or may not be required. Like all manufacturing technologies, you have to understand the requirements for the part you are producing and its use to determine the best production technique.

I would sure hope no one intends to burn their plastic part.


The comment on color is focused on the effects on plastic strength due to the dyes added. ABS is naturally a white color, so if the dyes reduced strength, the natural ABS would be the best choice for part strength in most cases. There is obviously more to the filament strength than the dyes: manufacturer, batch, moisture absorption, time on shelf, etc. all have an effect.

Re: 3d printers and robots
 

What I am thinking about to boost accuracy and resolution is to make it more "smart." If it is printing a cylinder, the printer should move the head in a circle to improve upon the resolution. Also, instead of printing a thin layer at a time, print thinker layers where the shape isn't changing and print small layers where accuracy is required. Our school's ten grand 3D printer doesn't have those features!

Re: 3d printers and robots
 

Gcode doesn't exactly do well moving in anything other than a straight line. Most machines, including 3D printers, use Gcode. What this means is that for most machines, the circles are simply very small straight line movements.

Also note: You're talking about simple X-Y movement here. You move a distance X, you move a distance Y, you can do both at once by going point-to-point... but moving in a circle is pretty tough. Not impossible, just tough. You're dealing with two quadratic variables instead of just one or none...

There's a really good reason for this, that maybe you don't quite realize. One of THE key definers of resolution is the tip size--how thick the material can come out. That does NOT change. It can be changed between builds, true, but then you have to reset the calibration of the machine--there's been previous discussion on the impact of having the tip too high for the tip size or vice versa. Changing during a build means a dual-head model, with both heads having a different tip, which means changing the calibration on the fly, if I'm not mistaken. That could get ugly pretty quickly--imagine rebooting the gyro while it's processing data, because you need to change the zero point.

I bet the reason that $10K printer doesn't have those features is quite simply that the cost/benefit analysis showed that the cost of the company's time and any parts needed for extra resolution/speed would far outweigh any benefits to the consumers, and drive the price up to $15K or higher, which means fewer customers pick that company.

Re: 3d printers and robots
 

Isn't circular interpolation via the G03 command actually quite good on most CNC machines, ie better than just linking a bunch of small line segments? Maybe I'm incorrect, but it seems like it would be more effective, accurate, and efficient for a 3D printer to read a G03 command rather than a huge block of G01 X Ys. Perhaps most 3D print controllers aren't advanced enough to do this kind of interpolation though, and need to run through a bunch of segments instead...

Re: 3d printers and robots
 

I'm not entirely familiar with Gcode, just what I've been able to decipher off one of 330's machines. No G03 that I can recall even on a curved part.

I think it's more that the 3D printers aren't there yet, and as I said, it may be that there isn't quite the demand for it yet, at least at the low end. (A $10K machine is kind of cheap, mind you... compared to some of the six-figure ones out there! Admittedly different processes, but that's a matter for another day.)

Re: 3d printers and robots
 

the fact that you are not seeing and G03s makes sense. Its not due to the controller of the printer rather I would excpect that it is due to the file format.

The STL file spec is a faceted model. Thus it doesn't carry b-splines or nurb surfaces. Therefore a circle is really just a n-gon. Which is exactly what you are seeing.

Re: 3d printers and robots
 

I don't know if it matters to anyone, but RadioShack is now selling a 3D printer. http://www.radioshack.com/product/in...uctId=23160006

Re: 3d printers and robots
 

Dat is Expensive!!! Just get an Up! Mini for a third the price, or upgrade to the MakerBot for $500 more.

3d Printer Reccomendations
 

Hi everyone,

I'm currently looking for a well priced 3d printer for the team this year, any suggestions on brand, model or company would be incredibly helpful.

In the past 2013 season we used a Stratasys uPrint SE (not ours) to create belt sprockets, wheel hubs, spacers and mounts. Anything similar to this quality, but at a lower price would be worth suggesting.

We are not intending the printer for extreme precision work, that being said build strength and durability is a must. Solidworks 2013-2014 is the CADing software were using, compatibility would be helpful. Any and all suggestions are welcome.

Thanks!

Re: 3d Printer Reccomendations
 

In response to Vupa's query:

First let's see if anyone has done a head-to-head comparison of something from a Stratasys uPrint and say a Reprap Prusa:

Yeap someone has and that's not lion.:rolleyes:

So how's under $800 for your budget?

Second let's compare the build volumes:

Third with the Prusa you don't get a heated cabinet (most of us can buy a plastic storage box and put the printer in it).

Forth, the lion heads shown at the first link in this post printed *much* faster on the open source software.
(Read the comments at the link.)

Re: 3d Printer Reccomendations
 

This would be my list. Add to that the OpenBeam Kossel Pro (est. March 2014) and the OpenBeam Kossel Mini using the reprap Kossel mini with OpenBeam extrusions and linear recirculating ball rails.

Re: 3d printers and robots
 

There are tons of really good 3D printer models out there for under $1000.
I agree with several of the other posters that the Prusa I3 is currently likely the best value on the Open Source side.


I personally like the kit from MakerFarm: http://www.makerfarm.com/index.php/3...-8-i3-kit.html

Picture attached. For Under $650 (after shipping).

I have been dealing with Colin there for over a year and his product is quality and the service is good. I buy the kits for the 3D Printer camp I teach from him for just these reasons.

If folks in the Greater Metro-DC area I am doing session at the DC FRC workshops on 3D Printing where I will be covering a lot of these type questions.

I am also doing another printer build camp on Dec 16-20 in Mclean, Va. PM me or email 3dprinting@usstem.org for more details.

Re: 3d printers and robots
 

Thanks for all the great suggestions guys! I have been looking at all the options ya'll have supplied and am still deciding. Great news though, my budget bracket has now been upped to around the $2500.00 thus the range of 3d printers the team can afford is now slightly higher.

I started a little bit of my own research and came up with two possible, albeit poorly informed results. The TAZ 3d printer by LulzBot and the Replicator 2 by Makerbot. If anyone has more information on these models and whether or not they're worth their price please inform me. Also more suggestions are absolutely welcome.

Thanks!

Re: 3d printers and robots
 

I would say that you can spend $1600 on a great pre-assembled printer (that just works) like the Up! Plus 2 (with auto bed leveling probe) and buy or build a second printer with the additional $900. Having two printers is better than one very expensive printer for a number of reasons, including: print speed, production capacity, and reliability/redundancy.

I am a fan of the Open Source Hardware projects, as the support is plentiful on the web and the systems can be modified/repaired with ease. The Prusa is a great printer and is available in several derivations. Also look at the Mendel series. You can get a kit and assemble it or use the RepRap wiki parts lists and accumulate the parts piecemeal.

Is filament covered in the $2500 budget? I'd expect to budget $300 a year on filament, including PLA/ABS and a variety of exotics (Nylon, Polycarbonate, High Impact Polystyrene, Carbon Fiber PLA etc.). Do you have access to an oven? Some filaments have short shelf lives once opened before they need to be baked for several hours to remove absorbed water.

Re: 3d printers and robots
 

What Stinglikeabee said plus:

Please be aware that the MakerBot Replicator 2 prints PLA. MakerBot's PLA. Not ABS. Do not extrude anything else unless you want to deal with the MakerCare support issue your group is opening the door to. MakerCare is not a warranty. It's parts replacement agreement you can only use once you precisely follow the directions MakerBot provides you. Those directions can take many hours to follow and there are no estimates for the durations of any of the repairs.

The extruder assembly is several hundred dollars on the Replicator 2.
It's very possible for other extruders to be half that cost.
If the extruder does not work you are not printing anything.
So if you really have issues with the MakerBot extruder expect to potentially be looking at $500 to entirely replace it.
The hot-end alone is around $200.

I can not recommend altering the extruder on the MakerBot because again you'll pretty much be throwing away your MakerCare and MakerCare alone costs $500. For that $500 you could build an entire printer. So if you have a MakerBot if you really want to use other materials then you should build another printer. Don't spoil the pot or else that printer you probably stretched to afford might just get even more expensive.

Keep in mind that this technology is quickly evolving. There are 4 extruder printer designs out there. There are filament mixing systems that can use a single extruder and hot-end with multiple filaments. Committing to whatever today's technology is might impact funding future opportunities for the next generation of printers which will come.

PLA is rigid but more brittle unlike ABS which is more flexible and for FRC part purposes ABS is more likely to survive bending without cracking on a wearable component (it wouldn't matter on say a decorative cover). Since there is a tolerance at work here you'd be better off with ABS flexing than PLA cracking unless you can glue the resulting damage easy enough.
Be aware that PLA better holds the dimensions of the print but if you are planning on acetone washing or sanding the part that's not relevant anyway (measure twice cut once).

There are lots of other filament materials for the RepRap style extruders. MakerBot sells lots of PLA filament colors.

Please keep in mind: generally 3D printing ABS/PLA is slow. Team 11 just printed a smartphone shaped item laying flat on the bed of their Replicator 2X. It is merely 3/8" tall and it took 2+ hours between setup, printing and cleanup. Going to make wheel hubs at 1" thick laying flat on the bed? The wheel hubs probably take up more surface area on the printer bed and are taller that that smartphone print. Consider the time involved and that it is probably not wise to leave a heated printer unattended. Going to move the printer if you run out of time? Then you need to consider that you are interrupting the print and risking the print quality plus if you move the printer you need to level it again. I know that if I need to print anything large I sleep next to the printer in a ventilated area with fire alarms and my phone alarm to wake me up every once in a while.

With delays like this owning a single printer might be someone's undoing.
I personally own a SoliDoodle 3 (RepRap style printer) and an Up! printer.
I use the SoliDoodle 3 (which I heavily modified) for most things.
I reserve the Up! for sensitive things or overflow production capacity.
I have parts for at least 7 Prusa printers laying about.

I support the idea that this technology should teach a person to fish. Not give them a fish.
I would rather my students learn to build a cheaper printer they can keep at home and use on their schedule:
than create consumers that know little about their printer than if I click >this< button it 'usually' works.
The promise of the RepRap project is a printer in every home for anyone that wants it.

To extend my last point: what impacts students more? A laptop they can do as they please with or a desktop at the school everyone is afraid they might break and there are 100 students in line to touch? This is about creativity and access to enable that creativity.

Re: 3d printers and robots
 

I think stinglikeabee and techhelpbb have covered what you need to look for.
As they said, this is a quickly evolving technology. I got my printer 7 months ago. Since then, I can think of at least 6 different materials that have been released. I knew I didn't want to lock myself into a single material. I wanted something that gave me options. There have also been many printers released since I received mine.

I have been running a Makergear M2 since last April and it has done very well for me. I purchased the kit version ($1475.00) and it was very easy to assemble. I had it up and running in about 6 hours. The hardware itself is very robust. Linear slides on the X and Y axis and a lead screw with guides on the Z axis. My only complaint so far is that the Z axis end stop is tricky to adjust. Once it was set, I haven't had a problem with it.

The hot-end is rated for temperatures up to 230 degrees C so it can print PLA and ABS and uses the same mount that many RepRaps use so it is possible to use third party hot-ends. I have purchased an all-metal hot-end from E3D which will allow me to print nylon, polycarbonate, and many other exotic materials (with proper ventilation). Makergear is also in the process of developing their own all-metal hot-end and dual extruders.

Support through email and the Makergear Google group seems to be very prompt, although I have not needed it yet. Their website can be lacking at times.

On the software side, I use Simplify3D to do the slicing of the .STL files (exported from Inventor) and generate the gcode. It also works with the open source software packages such as slic3r and pronterface. While there are default settings for the slicing, it is worth it to tweak them to see what each setting does. Some settings need to be adjusted depending on what you are printing.

Re: 3d printers and robots
 

First concur that multiple printers is a really good thing. Some prints can take hours.

On filament, PLA is likely too brittle for many robot applications.
ABS is most common.

If you are doing exotics you will really need an all metal hotend to get the temps you need. Check out the new exotic filaments project that is on Kickstarter.

Re: 3d printers and robots
 

I am cross-posting this on a couple threads for maximum visibility. Hopefully, someone needs a printer and at less-than-regular price!

11 AM Eastern tomorrow, Amazon.com will be selling this printer (Up! Plus 2) at a discount. It is presently listed at $1612, and I've seen it as low as $1599 regularly.

Re: 3d printers and robots
 

It is $1290!

Re: 3d printers and robots
 

Posted another deal here:
http://www.chiefdelphi.com/forums/sh...=121433&page=7

Re: 3d printers and robots
 

Last year, we integrated 3D printing into over half of our robot. With the privilege of working with Oak Ridge National Laboratory, our team had the chance to use incredibly strong plastic such as Ultem, and we also printed a couple parts out of titanium. For support, our robot mainly used woven carbon fiber to complete the frame of the drive train. Two years ago, we had the first all-printed robot, so our team is definitely experienced in the area of additive manufacturing. This year, we have various consumer printers such as the Cube and the MakerBot Replicators, and we plan to utilize these printers for various FIRST motors, brackets, etc. so we can show how versatile this technology is.