3d printers and robots

[Josh Drake]

Originally Posted by bs7280

Is it possible 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.

[cbale2000]

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...

[Calvin Hartley]

Originally Posted by cbale2000

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...

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

[Metalcrafters]

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,

[hammerhead_399]

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

[AdamHeard]

Originally Posted by Metalcrafters

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

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!".

[bs7280]

What would the limits be then

[EricH]

Originally Posted by bs7280

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.

[Lisa Perez]

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.

[Kevin Kolodziej]

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).