16-12-2012 23:06

kgzak

Re: pic: 4183 Testbead Chassis

How strong is this frame? Could it hold up to an actual competition? I ask because 4392 builds their robots out of wood. Last year we used the kit frame but maybe our frame this year will be wood, if it could hold up.

16-12-2012 23:14

kuraikou

Re: pic: 4183 Testbead Chassis

This chassis is just our prototype so it will not be able to withstand competition, it is just for attaching various parts to to see if they work for this year's game. Because we don't know this year's game we decided to make out of wood and make it compatible with just about anything we need it to do.

16-12-2012 23:25

z_beeblebrox

Re: pic: 4183 Testbead Chassis

To clarify what kuraikou posted, this chassis would likely be able to withstand competiton but will never have to. The chassis we use in competition will be somewhat more sophisticated...

Also, 4183 is proud to be the first team to post a drivetrain with Talon speed controllers on Chief Delphi!!

16-12-2012 23:33

kgzak

Re: pic: 4183 Testbead Chassis

Alright. So it seems sturdy. That's good to know. we'll see what we do when kickoff comes around.

16-12-2012 23:38

JosephC

Re: pic: 4183 Testbead Chassis

Quote:

Originally Posted by z_beeblebrox Also, 4183 is proud to be the first team to post a drivetrain with Talon speed controllers on Chief Delphi!!

16-12-2012 23:38

ttldomination

Re: pic: 4183 Testbead Chassis

For anyone wondering if the wood will hold up in FRC, look up FRC 1771 in the CD images. They've used since 2009, and have never really had an issue with it "holding up".

- Sunny G.

16-12-2012 23:46

Nuttyman54

Re: pic: 4183 Testbead Chassis

Quote:

Originally Posted by ttldomination For anyone wondering if the wood will hold up in FRC, look up FRC 1771 in the CD images. They've used since 2009, and have never really had an issue with it "holding up". - Sunny G.

16-12-2012 23:52

z_beeblebrox

Re: pic: 4183 Testbead Chassis

Quote:

Originally Posted by JosephC I take it those are the optional fan mounts? Any reason for attaching those?

16-12-2012 23:54

MrForbes

Re: pic: 4183 Testbead Chassis

neat chassis!

In case no one here knows....Gary (GUI) was the chassis lead for team 1726 in 2008 and 2009...the wood chassis he designed and built in 2009 won the Motorola Quality award (and the blue banner) at the 2009 AZ regional.

I woodn't diss the concept of a wood chassis for the final robot, and I sure like how this prototype looks in the photo.

17-12-2012 00:25

GUI

Re: pic: 4183 Testbead Chassis

I wouldn't use this specific layout for competition only because the outer frame rails are only supported at the ends. However, the basic "kitchen drawer" design is strong and rigid. This particular chassis has about eight hours of labor to this point, and most of the work was done by students with very little manufacturing experience. We chose wood for this chassis because it is readily available and allows for multiple axle holes and easy mechanism attachment without compromising the structural integrity.

17-12-2012 00:27

Bill_B

Re: pic: 4183 Testbead Chassis

Quote:

Originally Posted by z_beeblebrox To clarify what kuraikou posted, this chassis would likely be able to withstand competiton but will never have to. The chassis we use in competition will be somewhat more sophisticated... Also, 4183 is proud to be the first team to post a drivetrain with Talon speed controllers on Chief Delphi!!

17-12-2012 00:56

AdamHeard

Re: pic: 4183 Testbead Chassis

Quote:

Originally Posted by GUI I wouldn't use this specific layout for competition only because the outer frame rails are only supported at the ends. However, the basic "kitchen drawer" design is strong and rigid. This particular chassis has about eight hours of labor to this point, and most of the work was done by students with very little manufacturing experience. We chose wood for this chassis because it is readily available and allows for multiple axle holes and easy mechanism attachment without compromising the structural integrity.

18-12-2012 13:37

alb4h

Re: pic: 4183 Testbead Chassis

What is the metal 't-shaped' piece mounted between the power distribution board and the CRio?

18-12-2012 14:18

MrForbes

Re: pic: 4183 Testbead Chassis

It looks like a plastic wire duct. A cover snaps over it. Keeps the wires organized and protected. But that's just a slightly educated guess.....

18-12-2012 17:05

z_beeblebrox

Re: pic: 4183 Testbead Chassis

Quote:

Originally Posted by MrForbes It looks like a plastic wire duct. A cover snaps over it. Keeps the wires organized and protected. But that's just a slightly educated guess.....

18-12-2012 17:08

CalTran

Re: pic: 4183 Testbead Chassis

Quote:

Originally Posted by z_beeblebrox It's a very good guess. The duct should help keep the robot's wiring much neater.

18-12-2012 18:04

Conor Ryan

Re: pic: 4183 Testbead Chassis

Great job for some rookies!

I work on the fields at competition, I see a lot of really weird things done with electronics. If you want to make them last, and fairly maintenance free, don't mount them face up like you did in this picture. Mount them standing or face down (just rotate the crio 90 degrees). It keeps all those pesky metal/wood shavings and dust from causing lots of issues down the line.

It certainly doesn't look as nice quickly, but if you take the time you can figure out a way to make it look real good. (And don't forget your Radio too!)

This step is crucial if you use jaguars also, but the victors and talons can probably get away without.

19-12-2012 19:43

kuraikou

Re: pic: 4183 Testbead Chassis

Quote:

Originally Posted by alb4h What is the metal 't-shaped' piece mounted between the power distribution board and the CRio?

20-12-2012 00:00

nixiebunny

Re: pic: 4183 Testbead Chassis

Here she is, all wired up and power applied. Still need to write some code... the programming team is learning Java robot programming this year, so they now have a nice, big, dangerous toy to work with.

20-12-2012 08:27

MrForbes

Re: pic: 4183 Testbead Chassis

looks good bro! With a few cross braces, that would be a stout chassis.

21-12-2012 09:27

Nathan Streeter

Re: pic: 4183 Testbead Chassis

Looks very clean - great job doing some educational, practical off-season work... best earmark of an improving team, in my opinion!

I second those who have mentioned teams using wood drivebases... it can be done very well and can be significantly easier to fabricate. I recall 173 - at least on their 2007 robot - used a many-ply (9 or 11?) birch plywood of about 3/8".

I don't have any experience with wood drivebases personally; however, our team (especially in it's early days) tended make things way too beefy and heavy. I know Oak is surprisingly dense, so I recommend intelligently experimenting some with using thinner/smaller parts in lower-load areas (it's easy to use a heavier member than needed just because you use it elsewhere... we've done this with 80-20, when many components could be 1x1x1/16 box alum, which is half as heavy). Speed-holing can also provide some weight savings... although I have also seen teams over-speed-hole a critical points. All that to say, "Be careful of surprisingly heavy drivebases... a 6WD doesn't need to weigh >50 pounds without electronics."

Also, if you're looking to save weight, switching to #25 chains or timing belts can be a good way to do it. The larger your sprockets are compared to your wheel diameter, the less tension they're subject to... A small change I recommend with little/no cost is to make the longer chain runs between the center wheels and the end wheels #25 chain instead. With a >3.5" sprocket, I would be surprised to see a failure on that chain run, but even then you'd still have 4 or 5 driven wheels.

It looks like you're using a 3/8" bolt for your axle... which I like using for dead axles... although be careful not to over-tighten them! I would recommend you make sure it's a Grade 8 bolt, though. From our team's experience, a standard (Grade 5) bolt is unlikely to hold up in competition.

I would strongly recommend implementing now the stiffness modifications you expect to make... Drive Bases - particularly 4, 6, and 8WD ones - take a surprising amount of internal load. A particularly important degree of stiffness is bending along the diagonals (when viewed from above). Drive Bases with insufficient stiffness can make a 6WD base with plenty of "center drop" hop. It's important to have a sufficiently strong drive base if you're going to be testing and comparing different drive trains, so you can get useful experience with each.

Best of luck this year!

21-12-2012 10:01

JamesCH95

Re: pic: 4183 Testbead Chassis

OP, great looking chassis! That's an awesome off-season project.

95 used wooden chassis almost exclusively until 2005, then a few more times since. Mostly in the pre-bumper days. It's a great what to make a chassis. We typically used 9-layer birch plywood connected with 1"x1"x1/8" aluminum angle and bolts if memory serves.

21-12-2012 10:09

Bill_B

Re: pic: 4183 Testbead Chassis

All good advice from the responders here. Useful ideas for the construction of your competition machine. I'm sure the team is mindful of the rule concerning modifications of COTS parts prior to kick-off. I'll be showing your pictures to my team so they can see what they should have done with their last two months.

23-12-2012 00:00

nixiebunny

Re: pic: 4183 Testbead Chassis

We got the bot driving yesterday using Java at our new build facility - a high school that we'll be doing a co-build with. As the manipulator subteam mentor, I'm looking forward to testing the new game ideas with it. The wooden bot's name is Stormageddon, as I as informed yesterday.