What would a safe robot look like?

You have some great input on labeling and connectors. These are important to electrical safety.
However, I’ve chosen to disclude those from this particular thread in order to have a narrowly defined topic that facilitates thorough and comprehensive discussion of the topic.

If you’d like to create another thread covering these topics and move your post there (or ask a mod to), I’d be happy to participate.


A few thoughts from someone who works on 12v electronics all the time as a automotive/MD truck technician.

Speaking of wire the best is cross-linked polyethylene it is the only type of wire endorsed by SAE for underhood automotive use and has much better heat and abrasion resistance. Even the newest solder’er can’t melt nor damage the insulation, Ok maybe if you use an open flame. It is called out as *xl with TXL having the thinnest insulation, SXL the thickest and GXL in-between. SGX is super heavy insulation available in 6ga or larger for “battery cables” and is what is used on the more recent Anderson Power Pole pigtails. It is identifiable by the slippery waxy feel to the insulation if it isn’t marked.

The translucent PVC “stereo” wire is the worst stuff you can get. The reason it is thicker and heavier yet more flexible than standard PVC wire marketed as “primary wire” (GPT) is because the transparent insulation has a lower melting point and abrasion resistance due to its’ softness.

There are boots designed to provide insulation for contacts such as the main breaker and PD, I use them all the time, and they are available from companies such as TSC.

I’m not sure what is meant by “motor protectors” any motor protection needs to be internal to the motor in the form of a thermistor. Fuses and circuit breakers fall under the category of circuit protection. They are not to protect what ever the load is but instead are to protect the wire from the load.

Again, great post.
For this thread please trim it down to the parts about insulation, wire, and heat shrink.
However, don’t just delete the rest. Copy it, and save it on your computer as a text file. I’m hoping Larry will start that other thread, at which point you can repost it over there.

Would you happen to have a picture of your robot that shows the TXL wire, Delphi connectors, and insulation boots?

I’m heading to bed so I’ll trim it down tomorrow.

I wish I had pics of our Robot with the mentioned items alas we attempted to get our head wiring student to do the leg work on those items and come up with a list of items to order before the season began, but he didn’t do so. So we didn’t have the items in time for this years Robot and worked with GPT and the resultant melted insulation. I could show you them on some of my trucks if you desire.

I am not sure what your statement is about soldering. We solder every connection. We use uninsulated crimps, then solder and add heatshrink. We do this because we lost to Beatty in the Champs finals many years ago when a crimp failed. We will not lose to Beatty for this reason ever again. They are too good!
The last crimper in your post is also meant for uninsulated terminals. It is the very one we use for those terminals.

please save this for another thread.

On second thought, as a mod, don’t you have power to move and delete posts?
Does someone else need to create that new thread first?

Marshall, Not sure what you are asking of me?

I’m asking that the posts on connectors and labeling be moved to a seperate thread. This thread is about insulation, motor protectors, and battery protectors.

Is there any more that should be said about insulation?

If not, lets move on to motor protection.

Is it reasonable to say “any motor that gets hot enough to smoke presents a safety hazard”?
Or is there a more stringent requirement, that we must stay within 135% of normal load to prevent abusing our motors?

What sort of electrical device should be used to prevent damage in an overload situation? Are we going to find a NEMA class 20 overload relay for low-voltage DC?