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?
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.
Is it possible to post a picture?
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
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.
I believe he meant “could the poster above post a picture”. At least now I know how to post a picture 
No, moved away. Team no longer exists, sorry 
I know Team 3824 uses a quite large 3D printer to print several parts.
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…
http://imageshack.us/a/img15/619/7cl8.jpg
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.
Looks like a portion of the Stryke Force (2767) logo in the background of the first image. Looks like their robot too.
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,
In the past, we have 3D printed pulleys, electronics mounting towers, gears, molds, potentiometer mounts, and even shooter wheels.
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!”.
What would the limits be then
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.
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.
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).
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!
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.
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!