Electrical Connectors
 

With a desire to keep several of our robots past the season for demonstration...but the high cost of supplying each with a complete control system...I want to suggest that the team design and build a "modular" control unit this season with the Creo, sidecar, power distribution board, jags, and spikes. We could then modify the previous robots to accept this module and be able to switch it back and forth. They would need some kind of multi-conductor plug and jack system - and I haven't had much luck with reliability. Is anyone doing something like this? What kind of connectors are you using?

Re: Electrical Connectors
 

For signals, you could use something like a parallel port DB-25 to make a harness for that robot's sensors and pwm connections. You would solder all the leads to the appropriate pins on the plug(s). Last season, we used an aircraft-grade DB harness plug for our shooter deck.

For the cRIO and digital sidecar, you would keep them plugged together with a regular harness set. For power, we've put Anderson Power Poles between the motors and motor controllers for ease of rewiring.

We've used velcro on Baltic birch plywood to hold down all our motor controllers, cRIO, and digital sidecar.

What you are asking is actually a fairly good design practice for a competition robot, even if you had extra control system in your inventory. The ease of access and serviceability will save you a huge hassle later on.

Re: Electrical Connectors
 

Plus, we usually create our drive base first, then we find that we have to cover everything up with a big towel when we drill or cut on a new superstructure. It would be nice to pull all the sensitive electronics out for protection.

Thanks for those suggestions...I'll look into that.

Re: Electrical Connectors
 

Please remember that the Anderson Power connectors can be assembled into blocks and are also available in different colors. We have assembled a connector with more than 15 circuits in the past for removable appendages.

Re: Electrical Connectors
 

For the past few years, we've used Anderson PowerPoles between the electrical board and the rest of the robot. It lets us build the board separate from the robot, so it only gets attached at the very end of the build season with a couple of bolts and plugging the connectors together. This is also making it easy for us to swap out the board this fall as an Alpha Test team, so we can hook up a completely new control system!

Re: Electrical Connectors
 

One of the TechnoKats' best-designed robots in recent memory indeed used a DB25 for sensor connections. That even let us use an extension cable between the control box and the robot a few times when we wanted to test some code while the robot was surrounded by people doing mechanical work.

A couple of blocks of Anderson PowerPole connectors were the disconnect for the motor power wires. If we do that again, we'll make sure the person responsible understands the importance of using the little locking pins between them.

Re: Electrical Connectors
 

Here is a link to some of the Anderson Power Connectors we have used. You can order new pins (contacts) and reuse the cases on wires no longer being used to help offset costs for future builds.

The crimper that we use for these connectors is a great one.

You can also connect the blocks in such a way that they only fit in one orientation instead of using different color cases. This eliminates the "need" for stocking different color cases.

Re: Electrical Connectors
 

Interesting problem here.

Designing a control board (sizes, mounting holes ect) before kickoff to be used on a competition robot doesn't appear to satisfy R16 per 2013 rules.

You can get around this by say, posting a CAD model on Chief Delphi, but be aware of it.

Re: Electrical Connectors
 

No one says that the board will be the in terms of layout and components. Rather if you know the old robot's control board mounting configuration, you can design a new board that incorporates both the old mounting configuration and the new mounting configuration. It may even be possible to use the same mounting holes for both robots. I don't think this violates the rule, or the intent of the rule.

Now if you were taking last year's (old) board and installing it in the current season's (new) robot, this would be an issue. Although, I see nothing wrong with you using an old board on the robot for testing purposes until you can get a finalized design for the new board.

Re: Electrical Connectors
 

My plan is to do exactly this...with a twist, Use the design project as a CAD training activity in November and December. Post the design for all to use, modify, improve - then adapt it as necessary when the new game is revealed. Hopefully we can come up with something that will work with the new robot, but still operate Logomotion and Ultimate Ascent - the two bots we're keeping for demonstration purposes.

Re: Electrical Connectors
 

To fully conform to the rules: Your design can be published & reused. Physical parts (non COTS) have to be made during build season. So your mounting board can be used for development, but you should make a new board for competition.

Re: Electrical Connectors
 

Exactly...wouldn't want to build this before kickoff anyway - it might have to be waterproof! My hope is that it can be backward compatible...not that something we make now becomes forward compatible.

My main concern was finding some way to create the modular connections that would allow us to plug it in and remove it easily and reliably. The PowerPoles look like the answer!

Re: Electrical Connectors
 

I'll second Anderson Power Poles for power, but we've also been using Tyco CPCs (Circular Plastic Connectors) for signal connections with great success. You can see the catalog page here:

http://ca.mouser.com/catalog/catalogcad/646/1576.pdf

In the past we've used DSub connectors, but they required good soldering skills and weren't very forgiving. They can be found cheap though, while the Tycos will cost upwards from $10 for connectors and pins. You'll also want to get their crimping tool ($225).

Our design for the last two years has split the electrical board in two - a signal box (cRio, digital sidecar, etc.), and a power box, each of which can be removed quickly from the robot. The system still needs some work, but it has been a big plus for modularity, and showing students how things should be done in the "real world".

Re: Electrical Connectors
 

One option is to use D-subs that work with ribbon cable such as the example below. I have always used a vise to gently "crimp" connectors such as these for the prototypes I have worked on.

www.digikey.com/product-detail/en/1658612-3/AFR15B-ND/825359


If I recall correctly, many of the cRio interfaces will work with connectors that also take the same type of ribbon cable.

Re: Electrical Connectors
 

Link not found...