pic: 2175 Wheel v2
 

Re: pic: 2175 Wheel v2
 

What are the differences of the new version? Different type of plastic?

Re: pic: 2175 Wheel v2
 

Yes, the black wheel is made of Altem, a stronger 3D print material. We ran into the problem that after 2 regionals we wore the hex out on the wheels, so we asked our friend to make us some stronger wheels.

Re: pic: 2175 Wheel v2
 

Looks like your robot is going to need some re-inspection :D

Did your pneumatic arms ever get approved up in Duluth? I was the inspector that didn't actually do much because we were waiting on a ruling from the LRI.

Re: pic: 2175 Wheel v2
 

Yes, they did get approved, but we decided not to use them... We made passive climbers that were able to be actuated for North Star. A lot simpler and safer.

Re: pic: 2175 Wheel v2
 

The new wheels also have a stronger printing pattern around the hub. We did not start noticing wear on the origanal wheels until after a regional and a half. We also are using a much smaller hex shaft then we wanted (3/8) we ended up having to use this size shaft because all of the half inch bearings were out of stock.

Yes we got them approved, but ended up not using them because they would have crushed our new shooter we had installed. We added a passive ten point climber that actuated up for north star and it worked beautifully.

Re: pic: 2175 Wheel v2
 

Coming from a team that is planning on 3D printing some wheels next year, what material were you originally using?

Glad it was approved, but they seemed a little over-engineered to me for a simple 10-point climb. Glad you guys figured something else out! Congrats on the regional win at North Star and I am looking forward to stopping by your pits at champs!

Re: pic: 2175 Wheel v2
 

The original material if memory serves was abs m30, and the new material is Ultem about 2x stronger according to our printer friend

Re: pic: 2175 Wheel v2
 

Could you send me a picture of the worn out hubs you're describing?

Glad to see 3D printed wheels are working for you guys, in at least some extent. I think they've got the potential to open up custom wheels for a lot of teams that may have not had that option available before.

Re: pic: 2175 Wheel v2
 

I would be VERY careful with those 3/8" drive shafts supporting cantilevered wheels. Have plenty of spares ready and check them every match, and make sure they are a strong material (7075 AL or a nice, strong steel alloy).

Otherwise, neat wheels.

Re: pic: 2175 Wheel v2
 

I'd be willing to bet that the 3/8" hex shaft is also a factor in the hub wear as well. Figure a 3/8" hex shaft is transmitting the same amount of torque through a significantly smaller area on the wheel than 1/2" hex, so it should be more prone to stripping the hub out.

Also, for those of you that are curious, ABS M30* has an tensile strength of ~5,200PSI and Ultem* 9085 has a tensile strength of ~10,400 PSI.

*Assuming that these materials are being printed using a Fortus Printer.... AFAIK it's the only machine that uses both of these materials.

Re: pic: 2175 Wheel v2
 

Since our season ended, we have been doing some experimentation with 3D printed wheels, too. Here are a couple of our results:




More pics here:
https://picasaweb.google.com/1099928...eelDevelopment

The latest version has the spokes as internal structure, with fairings on the outer surfaces. We'll print some graphics or lettering on the outer fairing in a contrasting color.

Fun experiments, but we were so happy with our Colsons this year that we'll probably go that route again, unless there is a compelling reason to switch.

Re: pic: 2175 Wheel v2
 

Ill try and find the wheel at the shop tonight and upload it later. we believe the reason for the failure was because of the less then ideal shaft size causing the forces not to be distributed over a large enough area in the wheel. What size shaft do you guys use it looks like 3/4.

Also the 3/8 shaft is steel (not sure the exact alloy) and they have held up through 2 regionals plus practice in the shop, i dont expect to see any failures from them, but we have two spare drive sides that we can scavenge off of if they start to fail.

Re: pic: 2175 Wheel v2
 

I view these as a case of someone who has not yet realized the full potential of a 3D printer, my guess is you could use a fair amount less material, resulting in a lighter wheel, and also have it much more aesthetically pleasing.

Let your imagination run wild, I always have to re-jump the hurdle when I cad something I know will only be 3D printed, as past experience has taught me to CAD for whatever machining capabilities I've had at hand.
3D printers only recently joined this list, and its been fun.

go crazy, you're allowed to

Re: pic: 2175 Wheel v2
 

Notice the 7 spokes :P But in all seriousness we knew we could do some really cool designs and there were team members that really wanted to, but we decided to play it safe for our first year doing this with such an important robot part. Expect some much cooler wheels in future years if we continue printing wheels which i personally hope we do