Show off your machining!
 

I've always had a liking for some of the nice machine work that goes into FRC robots. I'm one of those people who comes into your pit area and really takes a close look at your robot, because I have an eye for the details. It's disappointing to see that many students don't have an eye for the details, especially when it comes to machined parts. We all know a handful of teams that do really nice work in this area, but I don't think we've ever had a Chief Delphi thread for teams to show off their nice machining work.

So, show off your machining! It can be mill or lathe, manual or CNC. For now, let's leave waterjet, plasma, saw cutting, and sheet metal forming out of it.

If you have a description to go along with the picture, that would be awesome. I'll come back later with a few of my own if I can dig up some pics.

Re: Show off your machining!
 

Heres a picture of my teams new swerve drives.
They have a one peace frame milled from 3" by 6" extrusion.
I would consider it to be quality machining.

Re: Show off your machining!
 

They look really nice. Do you make new ones after kick off?

Re: Show off your machining!
 

Interesting gearing choice- The sprockets are about as large as the wheels.

What do they weigh?

Re: Show off your machining!
 

Very interesting design with the 4-sided extrusion. Could you share what the weight is per drive module?

Re: Show off your machining!
 

Pictures Here

The first is of the majority of our 2010 drivetrain components. Impressive just because of sheer quantity.

The bearing mounts are cool because we 3D surfaced them in the machine. Previously we were hanging a long bar out the side of the vise, machined the contour in from the side, then sending a kid to chop the semi finished part off the raw bar so that the backside could be machined. Switching to the 3D surfaced part eliminated all secondary handling and allowed the parts to get done way faster.

The rest of the pictures are of my favorite part I've ever machined. It was the yoke that held the wheels for our grabber onto the end of the grabber arm in 2011. It was a pretty subtle part when looked at on the robot, but it required a ton of machining and looks really cool on it's own. I like it so much because everything about it came out perfectly, when I was worried that some features wouldn't match, that there would be chatter on the inside walls of the part, etc.

Re: Show off your machining!
 

What was this? 40 wheel tank drive!?! :p

Re: Show off your machining!
 

An oldie but a goodie: http://www.chiefdelphi.com/media/photos/26323
That was before my time on the team -- we tried to do away with excessive machining...

Re: Show off your machining!
 

that was 7 robot's worth of wheels.

Re: Show off your machining!
 

Do you mind sharing how you made these/how much the aluminum cost you? These are really cool.

Re: Show off your machining!
 

The aluminum alone should only cost you between $1-6 bucks per part. Aluminum isn't too expensive compared to the cost of the retail version of the part.

Also, great thread. Keep putting up cool pics!

-RC

Re: Show off your machining!
 

We chose this mostly for footprint size. They are 6" by 6" square. They're pretty light as wel though. 7.5 lbs each.
A whole drive base, including fame but no electronics weighs 37 lbs.

All of the drive gearing is in the lower box chain to save space on top.
There's a picture of the frame as it was weighed.

Re: Show off your machining!
 

Here was a little 2079 project from Luncay. Unfortunately the swerve drive wasn't as effective as we wanted it to be, but the machining is pretty cool.








Here's a link to more pics.
http://alarmrobotics.wikispaces.com/Swerve+Design+09

Re: Show off your machining!
 

I have always thought a circular swerve would be cool. My next disign iteration has an octagonal pivot for space savings and strength.

Did you have trouble with your cim motor wires tangling?

Also, did you have a special tool and a 4 axis cnc mill to cut the sprockets?

Re: Show off your machining!
 

Beautiful. I knew there was going to be some good stuff when Cory came on the thread.

We've milled some semi-cool things on 100 (Throwback time, like these), but the only decent looking and recent thing I had a photo of was this:



They weren't super tricky parts, but they do have a lot of very cool looking pocketing. Those parts were the siderails of our offseason intake, heavily inspired by (read-cloned from) 1538's intake.

Now, if we were allowed to submit waterjetted parts, these might fit the bill nicely:

Re: Show off your machining!
 

Just so! Even his brackets are things of beauty! :)

Re: Show off your machining!
 

Unfortunately I don't have a better picture, but these were pieces done for our 2013 competition chassis. All sparring was no-contact.

http://i.imgur.com/egUATAB.jpg

I give up. This whole image thing really isn't working out.

Re: Show off your machining!
 

This was our first year with real machining resources (that arn't woodshop tools) and it went pretttty swell if you ask me.

Nifty CIM mount for our shooter, cut from a piece of 3x2x1/4
Okay, these were Akash's idea, but its still awesome.



Mmmm parts



Assembly


All parts generously donated by our sponsor, Gaum Inc.

Re: Show off your machining!
 

This was our bot the 2nd week.

http://ultimate3647.tumblr.com/post/...kend-machining

Was done by myself on an CNC bridgeport and Tormach mill.

Re: Show off your machining!
 

Well I saw this beautifully machined ratcheting PTO winch gearbox at IRI with pretty tool paths and beautiful attention to detail. You can see the really nice toolpaths on the gearbox plate in the background.

And oh yeh, it's 696's. :cool:

Re: Show off your machining!
 

Is that an Electrathon car on the wall in the background? Good to see another group involved in electric car racing out there. We do NECA (National Electric Cart Association) here in Michigan but borrow a lot of Electrathon rules.

Re: Show off your machining!
 

Supermileage, actually. And sadly we don't compete any more-- many of the students who used to compete in Supermileage moved over to FRC when the team started in 2007. Due to a lack of funds (and shop time), for better or for worse, the Supermileage team faded and eventually folded into our FRC team.

Re: Show off your machining!
 

I present to you Kyle in his natural environment:


I'll see if I can dig up our arm transmission from Rebound Rumble. It was manufactured using the gears out of a Harbor Freight worm gear winch, which were lightened and placed in a custom aluminum housing.

Re: Show off your machining!
 

Here's some shots of our drivetrain siderails and our new intake we built for champs. The intake was made my me on a cnc controled bridgeport and the siderails were cut at a mori seiki rnd facility on a prototype machine.

Sorry for the poor image quality.

-Adrian

Re: Show off your machining!
 

Those parts are a thing of beauty. What thickness of metal did you use? Looks like 3/8"?


Here's some of the various machining we did last build season, everything is .120" aluminum cut out using a laser.
These are parts for 1038's feeder system we cut out for them:
http://i.imgur.com/aKJhftH.jpg?1

This is a prototype uni-body chassis. It's a single piece of aluminum cut out and bent using an automatic break and welded with a robotic welder:
http://i.imgur.com/Dy47Hjw.jpg?1

And this is our 2013 bot towards the end of the build season, most of the machining was in the shooter, I couldn't find a picture of just the shooter only.
http://i.imgur.com/7ewsI3D.jpg?1

Re: Show off your machining!
 

Really neat looking sideplates you've got there!

Re: Show off your machining!
 

A frisbee shooter we built for the off season based on the awesome design by team 67:

SAM_0224 by Hotbotz 2640, on Flickr

Re: Show off your machining!
 

Thanks! All the plate in those pics is 1/4".

Re: Show off your machining!
 

Any reason for the custom 1/4" plate drivetrain? I've never seen one like it before. Worked beautifully for you guys.

Re: Show off your machining!
 

Could you elaborate on how you did the surfacing on the bearing mounts?

Also, I love that yoke. I wish I had a chance to make something that complex. It looks like you chose to pre-drill your bearing bores with a twist drill then finish with and end mill. If that's what you did, why'd you chose to do it that way instead of just milling the hole?

Thanks,
-Adrian

Re: Show off your machining!
 

It puts a lot of load on a end mill to dive or spiral into a part, even for center cutting end mills.

For teams with ATCs, it's generally faster to just drill a quick hole and dive your cutter into the part rather than taking a while to spiral down through the part. Of course, if you have to manually change tools, its probably faster just to spiral in.

Re: Show off your machining!
 

Was going to ask this as well. It looked as if they were tumbled afterwards.

Re: Show off your machining!
 

Interesting story, glad you asked.

I got the sideplate idea from 125, I could be wrong but I believe they've been doing a sideplate style drive since 2007.

Anyway, as for why choose a sideplate style drive was because it lined up best with what machining resources we had. Last year our resources were mainly me using a sponsors shop with cnc controlled bridgeports, engine lathes, and basically everything you could want in a shop. In addition to my shop use we had some basic hand tools at the school and I talked to one of our sponsors (Mori Seiki) to cnc some parts for us. So essentially we had two machinists in two shops making our robot.

The original plan for 2013 was to make a WCD. I talked to my contact at Mori Seiki and went over some WCD part drawings with him. He felt that it would be a waste of a resource to make WCD siderails on their equipment, as they can be machined manually pretty easily. So we settled that if we were to do a WCD the only parts Mori would make would be the wheels, which left everything else for me to make which I thought was less than ideal. Thus was born the siderail design, which was designed to be easily made given our resources. We had Mori do our siderails and wheels and all I had to make was standoffs, assemble the wheels and make the bellypan.

Long story short, everything took really long to make and we didn't have a drivetrain till around week 4. This was mainly because we didn't have the time to test a siderail style drivetrain during the offseason, so we ran into a lot of issues with machining and assembly. But it all paid off and last year was the first year the drivetrain didn't fail during a match! It lasted two regionals, made it to Einstein, and won two offseasons before it finally popped a chain. The only other issue it had was when an ethernet cable got tangled in the chain, which was fixed.

Anyway, this year we've lined up a million machine shops to sponsor us and are going to make a WCD. As well as our drivetrain worked last year it took too long to make and design. I can design a WCD in my sleep and we can send off parts to be made quickly giving us more time to focus on subsystem design. Designing an original drivetrain was great, but this year we're sticking to our team motto: steal from the best and invent the rest. WCDs are proven and easy to make when you have the right sponsors, which we do now.

Sorry to threadjack.

Thanks,
-Adrian

Re: Show off your machining!
 

True. I'm used to using a cnc controlled bridgeport so predrilling isn't as fast as milling and with a helical ramp spindle load is minimal when you plunge (I use a super slow z feed). But with an ATC I can see the advantage of predrilling. Makes sense.

Re: Show off your machining!
 

Besides for being really awesome and a neat piece of machining, what is the advantage of a uni-body chassis? Is it stronger or lighter?

Re: Show off your machining!
 

I doubt they are tumbled (finish isn't dull), I'd go with a really nice face mill (2" or larger) with a very light pass for surfacing.

But Cory would know!

-RC

Re: Show off your machining!
 

Same. We've had some parts come off after using a 2in face mill with a similar finish.

Re: Show off your machining!
 

The surfacing was done with a ball end mill. I don't remember what specific toolpath I used, but essentially when looking at it from inline with the top "ridge" the endmill just follows the contour from the side, up and over the top, and back down to the side. It then steps over a very small amount (probably .010 to .015") and repeats the same motion until it machines the entire profile.

After machining they were hit real quick with a scotchbrite wheel.

I like to pre-drill when convenient (as long as the drill is in the machine) as it eliminates any chance of packing up the flutes or chipping the edge of a flute when plunging.

I think RC is talking about the yoke for the arm, which is shown as machined. It was scotchbrited later, but the finish you see on the outside of it is from a 3" aluminum specific face mill.

Re: Show off your machining!
 

Ah, that makes sense. Thanks!

Re: Show off your machining!
 

We never did any official impact testing with it or stress analysis on the CAD file but i can say it's strong enough to withstand being sandwiched between two bots (that was our unofficial test, for fun :D ) without bending at all. Weight is the biggest advantage to using a uni-body chassis though, as pictured it weighed 7lbs compared to our 2013 robot's frame at 20lbs, which was made from C-channel and extruded aluminum. We've since ditched the uni-body chassis concept as we found it to limiting, but it's still a pretty piece to display.

Here it is compared to our 2013 chassis:
http://www.chiefdelphi.com/media/photos/38612

Re: Show off your machining!
 

We had an issue with being under weight with our bot & added like 9 or 10 pounds of steel to our bumpers (and we were still under weight) ;)

Anyway, I would say our chassis last year took a lot of skill... Plus it's so holy, it could be a priest (sorry, couldn't resist the pun). Luckily, our 2 side chambers (that held our drive trains) that had the most holes, I tossed into our CAM model that we ran. Each face actually took 2 passes (one for the left & one for the right) as our CNC mounting base wasn't large enough. The other cross bars we drilled on our XY CNC Bridgeport.

Re: Show off your machining!
 

We've done alot but three of my favorites are

The 2006 robot wheel

http://www.chiefdelphi.com/media/photos/22626

and 2008 side drivetrain plates

http://www.chiefdelphi.com/media/photos/29983

2007 ball bearing shifter gearbox

http://www.chiefdelphi.com/media/photos/26986

I want to post a newer set of parts also once I get the photos together.

Re: Show off your machining!
 

This our shooter wheel this year. It weighed a little over 4lbs and had a diameter of a little over 12 inches. This started out as a 14x14 in piece of aluminum. The outer circumference was milled out, but the spokes were cut out with a wire EDM. This is very simple compared to some of the other things on this thread, but this was the first time our team had anything EDMed and it was very cool.

http://i.imgur.com/d2bTPPE.jpg