Is this allowed? -- DSC directly on 9403
 

Trying to shave every bit of weight possible, and wondering if we can legally do this. The DB-37 cable by itself is 0.5 lbs!
See attached...

Re: Is this allowed? -- DSC directly on 9403
 

I have no idea if it is legal or not, but I certainly wouldn't recommend it. You can easily damage the d-sub connectors that way. An early DSC concept was similarly cantilevered, but it was quickly dismissed for many reasons.

Why don't you just use a ribbon cable instead of the provided one?

Re: Is this allowed? -- DSC directly on 9403
 

I was actually planning to support it with a strap of metal. The ribbon cable is a great idea though, so I will investigate that.

Cheers,
-Neil.

Re: Is this allowed? -- DSC directly on 9403
 

can anyone reccomend a place to get 37pin male to female ribbon cable?

thanks,
Samir

Re: Is this allowed? -- DSC directly on 9403
 

6' Multicolor:

http://search.digikey.com/scripts/Dk...A7MFB-3706M-ND

6' Gray:

http://search.digikey.com/scripts/Dk...A7MFB-3706G-ND

These are not listed in stock because they have to assemble the cable for you, but it takes very little time for them to complete and ship, from past experience with 15-pin cables.

I'm sure you could also order the consituent components (see the product description details) on Digikey if you wanted to make a shorter custom cable.

Re: Is this allowed? -- DSC directly on 9403
 

just remember that the cRio is grounded to its casing, so any metal around it is probably not a good idea.

Re: Is this allowed? -- DSC directly on 9403
 

That Sigital Sidecar is currently overhanging Slot 1 where the required 9201 Analog Module with Analog Breakout and Battery Monitoring jumper must be installed per <R64>.

Re: Is this allowed? -- DSC directly on 9403
 

wow is this a joke? You want to shave weight from the cable?

I really really dont recommend doing what you posted in the picture... Maybe try getting a lighter cable if you are that concerned from the weight.

Re: Is this allowed? -- DSC directly on 9403
 

We saved 5 or 6 ounces by using a 37-pin ribbon cable. Not to mention the nicer-looking connection.

Re: Is this allowed? -- DSC directly on 9403
 

I missed that R64 -- we are not using that module or it's breakout. So we have to have it on there anyway??? Or does the rule imply that if we're using it, then it must be in that slot?

Either way, we could've shuffled the other modules so the digital sidecar clears.

I'm looking at the DB37 w/ribbon connector option now. Yes, every bit of weight savings helps, because we don't want to comprimise the design.

Cheers,
-Neil.

Re: Is this allowed? -- DSC directly on 9403
 

The orange box after <R64> makes it clear that it's required for every robot (and even explains why it's required).

Re: Is this allowed? -- DSC directly on 9403
 

Okay, I'll check the docs when I get back tonight. Thanks!

Re: Is this allowed? -- DSC directly on 9403
 

Yes, you must have the analog module in slot 1 with a 12-volt supply connected from a 20 amp breaker on the power distritution and the analog breakout's jumper set to read battery voltage.

No, you can not shuffle modules. They must be in the defined slots. Mandatory analog in slot 1 (with battery monitor jumper) and digital in slot 4 (with attached sidecar connected to Robot Signal Light). Optional analog in slot 2, digital in slot 6, and pneumatic in slot 8.

Re: Is this allowed? -- DSC directly on 9403
 

Okay thanks. I'm going to leave the connection changes to the controls sub-team folks. I'm just trying to re-do the mount layout and board today for weight savings.

Re: Is this allowed? -- DSC directly on 9403
 

the scale doesn't care where you lose the pounds, and the wiring of a robot certainly holds a lot of weight. We lost 6 pounds when we re-imagined our electrical board.

Re: Is this allowed? -- DSC directly on 9403
 

Switching to the 37 pin ribbon able will save weight, along with changing the material you are mounting your electronics to. 1/4" hardwood plywood works great and weighs next to nothing. It's less than lexan and very strong.

Re: Is this allowed? -- DSC directly on 9403
 

One of my problems with ordering from places like Digi-Key is too many choices that I can't tell the difference between. For example, is the above cable any different/better than this one for $9 cheaper?
http://search.digikey.com/scripts/dk...C7MFG-3706G-ND

6' is a bit longer than we need. If we wanted to make our own to a custom length, can anyone recommend specific connectors and ribbon cable?

Thanks.

Re: Is this allowed? -- DSC directly on 9403
 

Well, it's done. We lost 10lbs 2oz with the mods, and only 2 unused cRio modules and 1 digital sidecar were dropped. We'll lose a bit more by changing that DB37 cable. I'll have our controls guys re-check it tomorrow for legality, etc.

Now if only *I* could lose 10 lbs in 8 hrs too... :eek:

Cheers,
-Neil.

Re: Is this allowed? -- DSC directly on 9403
 

It is on much thinner lexan than before, but with a thin strip of aluminum angle under it for support. It's very solid now. Wood would not have been a good option for my mods, because I used captive studs to mount the Jaguars under other components.

Wireless adapter not shown because that will be mounted elsewhere, but it was included in the final weighing. One spike was also included in the final weighing, but it will probably be deleted, as we will most probably eliminate the compressor and use 4 accumulators instead.

Cheers,
-Neil.

Re: Is this allowed? -- DSC directly on 9403
 

i don't know if this is allowed but i wouldn't recommend it. if there is a shift in the chassis from the violent ramming in this years game it could damage the pins which will be hard to fix.

Re: Is this allowed? -- DSC directly on 9403
 

You will have to leave that spike on there, even if you are using accumulators. The rules require that the robot must be able to charge the accumulators with the compressor attached to the spike and the pressure sensor working as a cutoff, even if the compressor is off-board.

Re: Is this allowed? -- DSC directly on 9403
 

Please quote the rule that enforces this.

Re: Is this allowed? -- DSC directly on 9403
 

Emphasis mine.

The offboard compressor must be run from the robot which means that the robot must have the electronics to properly run it installed which includes a Spike relay and properly installed pressure switch.

Re: Is this allowed? -- DSC directly on 9403
 

It does NOT say that the Spike and pressure switch must be on the robot. They may be with the compressor, on a compressor board. At least, that's the way I see it. (Note: if you do this, make sure that you make it easy to connect the Spike and pressure switch.)

Re: Is this allowed? -- DSC directly on 9403
 

Thanks Kevin. I had the same confusion that EricH states in the above post (Eric minds think alike?). Perhaps there is some Q&A that clarifies whether or not the spike can travel with the compressor.

Re: Is this allowed? -- DSC directly on 9403
 

The Pressure Switch must be on the robot per <R73-C> and <R77>.

If you are planning on trying to ditch the Spike I would certainly submit it as a question to the Q&A. Based on the note accompanying <R74> stating that the only difference is the physical location of the compressor, I believe the Spike must be left on the robot at all times (however, my opinion doesn't really mean squat).

Re: Is this allowed? -- DSC directly on 9403
 

In 2006 the rules were written about the same, it seemed clear you needed the pressure switch, but the spike was unclear.

Through two regionals and champs, the inspectors made sure we had a spike on the robot, pressure switch on the robot and a manual release valve on both the robot and compressor side.

I'd say play it safe and put everything but the compressor and a manual release on the robot. The spike and sensor do weigh something, but just be happy you already saved the 5+ of the compressor.

Re: Is this allowed? -- DSC directly on 9403
 

Or must it? Pardon me, but <R77> specifies that it must be connected to the "high-pressure" side of the system, of which the compressor is a part. If the entire high-pressure side is on a compressor board, including the regulator (which is legal by <R75-D>), then the pressure switch must by rule <R77> be with the compressor.

It must also be connected to the DSC, and the cRIO must be programmed to handle it.

Re: Is this allowed? -- DSC directly on 9403
 

Good point Eric, that brings up an interesting conflict with the rules as written.

If the regulator is kept off the robot per <R75-D> then the pressure switch must also be off the robot per <R77> however, <R73> requires that the pneumatic system on the ROBOT must contain a pressure switch.

Re: Is this allowed? -- DSC directly on 9403
 

There is one more thing in the picture that has not been mentioned. You have a label on your cRIO indicating that port #2 is on IP address 10.18.98.3. This is incorrect and will not work. Port #2 is hard coded to 192.168.0.3 and is used specifically for the Axis Camera.

The 10.xx.yy.3 address is not actually used in the systems as we are currently configuring them.

Re: Is this allowed? -- DSC directly on 9403
 

I had originally hoped to put the spike (and related components) on a separate board with the compressor, but Adam is correct -- it's relatively quite light, so I don't mind leaving it on the robot.

BTW, actual weight savings is 2.3lbs ... 4.3lbs for the compressor, minus 2 extra tanks (13.9oz each) + mounting (~4oz).

Mr. Bill -- thanks! I haven't done any work with the controls/software yet, but I know the controls guys are still bashing heads with tech support to resolve some basic operational issues. I'll pass this along.

Cheers,
-Neil.