SLU-70 Lugs

[The Lucas]

Originally Posted by sanddrag

I've tried every iron and soldering gun I have to solder Anderson Contacts onto 6 ga wire and I just cannot get it anywhere near hot enough. The best thing that I've found is a small butane pencil torch, but mine broke so now I use the big propane torch. It gets hot enough but it is a real pain because the flame is so large.

While working with Team 1495, we soldered these with the only soldering iron available, a 25-watt Radio Shack iron. It took about a half an hour per connector. These stupid things make an excellent heatsinks.

[sanddrag]

Originally Posted by The Lucas

While working with Team 1495, we soldered these with the only soldering iron available, a 25-watt Radio Shack iron. It took about a half an hour per connector. These stupid things make an excellent heatsinks.

I'm worried that in this case all you have done is created a "blob" (for lack of a better term) of solder. A good solder joint is a hot one, and hot solder joints happen quickly. You may have just filled in the gaps without providing any increase in mechanical or electrical integrity.

I have a question, assuming you only screw down the lug, do you get a better connection on more finely stranded wire? Like good welding cable as opposed to the junk battery cable they give us?

[activemx]

Originally Posted by sanddrag

I have a question, assuming you only screw down the lug, do you get a better connection on more finely stranded wire? Like good welding cable as opposed to the junk battery cable they give us?

You will get better conection with the thin stranded copper cable. It is more expensive but it is easier to solder and crimps better then those wires that have barely any flexibility.

[eugenebrooks]

Originally Posted by sanddrag

I'm worried that in this case all you have done is created a "blob" (for lack of a better term) of solder. A good solder joint is a hot one, and hot solder joints happen quickly. You may have just filled in the gaps without providing any increase in mechanical or electrical integrity.


I have a question, assuming you only screw down the lug, do you get a better connection on more finely stranded wire? Like good welding cable as opposed to the junk battery cable they give us?

If the solder flows through the wire and joint you have a good solder connection. Someone practiced at soldering will know what good solder flow looks like. I would not try to solder the SLU-70 lugs with a 25 watt iron, however.

We use #6 welding cable for our power wiring for its flexibility and high quality rubber insulation. The problem with this cable on the SLU-70 lugs is that the wire is fine enough to work its way through gaps in the clamping mechanism. You can end up with a connection that loosens. Solder the connector after clamping the wire it in order to remove this possibility. I would never use the SLU-70 lugs without soldering them.

[The Lucas]

Originally Posted by sanddrag

I'm worried that in this case all you have done is created a "blob" (for lack of a better term) of solder. A good solder joint is a hot one, and hot solder joints happen quickly. You may have just filled in the gaps without providing any increase in mechanical or electrical integrity.

I have a question, assuming you only screw down the lug, do you get a better connection on more finely stranded wire? Like good welding cable as opposed to the junk battery cable they give us?

Originally Posted by eugenebrooks

If the solder flows through the wire and joint you have a good solder connection. Someone practiced at soldering will know what good solder flow looks like. I would not try to solder the SLU-70 lugs with a 25 watt iron, however.

That is a valid concern especially when working with a 25-watt iron. I can confirm it is a good hot solder joint. I had a student hold the iron on the bottom of the lug and I applied the solder directly to the top of the wire. As soon as the whole system heats up, the solder flows through the wire and down to the bottom of the lug. The result is a thoroughly tinned wired and bottom of the lug. We even avoided soldering the screw and clamp so we can still screw that down. It was also a good lesson on what it takes to make a good hot solder joint, and that student's small wire soldering skills improved.

Team 1495 works in a school metal shop and has few electrical tools. Soldering with a 25 watt iron is fairly dangerous, since you have a very hot wire and lug near your hands for about half an hour. However it is possible, so you could do it in a pinch. A micro torch is a better idea and that is what Team 365 is going to use on all the new SLU-70 lugs we had to use after we found out that rule at Pitt.

[Doug G]

We over looked that rule as well and this year we thought we're on top of it by soldering all our 6 gauge crimp connections - oh well - we replaced them with the SLU-70 lugs and all was well they held up through 15+ matches. I did notice a couple of rookie teams that had their lug screw pressing onto their wire instead of the screw pressing onto the V shaped clamp and then agaist the wire. Perhaps this might be why some teams had them coming loose.

[Al Skierkiewicz]

Originally Posted by Cory

It should have been enforced across the board at all regionals.

This rule will be enforced at Boilermaker and Midwest Regionals over the next two weekends. If you are attending either or both, please plan now to have a supply on hand if you didn't check the rule.

In case this missed your attention, each team needs to name a team inspector (student) whose responsibility it is to check through the inspection list for their robot's compliance before meeting with the inspector(s). Please check the FIRST site for the latest update to the checklist.

[Rombus]

Since im going to be doing wireing next build year, what about soldered lugs?

[Justin_302]

Originally Posted by Rombus

Since im going to be doing wireing next build year, what about soldered lugs?

I soldered lugs. They were very nice connections, shrink wraped and all. We couldnt pass inspection until we got the SLU-70 lugs.

[BrianBSL]

Although at first I was not a fan of these - they are a large improvement over what most teams were using in the past, particularly now that FIRST no longer includes a crimping tool truly capable of crimping 6 gauge connectors in the kit. I'm pretty picky about electrical connections, and every non-signal connection on our robot is crimped then soldered and heatshrinked, including the SLU-70's. We also put a little bit of solder into the setscrew of the lug to add something to prevent it from loosening. Solder isn't really good at doing mechanical things, but its an improvement over just leaving it. All of this, of course, requires that you have a soldering iron capable of heating up the copper connector and 6 gauge wire.

[Daniel]

Originally Posted by BrianBSL

Although at first I was not a fan of these - they are a large improvement over what most teams were using in the past, particularly now that FIRST no longer includes a crimping tool truly capable of crimping 6 gauge connectors in the kit. I'm pretty picky about electrical connections, and every non-signal connection on our robot is crimped then soldered and heatshrinked, including the SLU-70's. We also put a little bit of solder into the setscrew of the lug to add something to prevent it from loosening. Solder isn't really good at doing mechanical things, but its an improvement over just leaving it. All of this, of course, requires that you have a soldering iron capable of heating up the copper connector and 6 gauge wire.

An important point that you missed is "Strain Relief". That is, tie wrap your wires to a piece of the frame near the SLU70 so that part of the #6 wire will not move. This is the biggest problem with any mechanical connect, and it can be solved so easily. I'm trying to find a lug with strain relief to solve all of out problems.

[Al Skierkiewicz]

I thought it important to resurrect this thread and remind everyone that although the rules were relaxed for this last weekend (difficulty in obtaining the parts) SLU 70 connectors will be required at nationals. Home Depot, Menards, Lowes, Ace Hardware and of course Terminal Supply are all sources of this connector. Please watch for changes from FIRST, until then, Be Prepared!

[cbolin]

Our team came in last evening and changed out the connectors on all 9 batteries. Our electrician had done a good job crimping and taping (lots of it) so it took us a lot of time to get the battery plugs off of the battery. Whew!

We also connected those Anderson plugs on all four of our battery chargers to make charging easier, safer and less likely to reverse charge the batteries.

Remember...only 9 more days to get this done!!

Regards,
ChuckB

[Jack Jones]

Originally Posted by cbolin

Our team came in last evening and changed out the connectors on all 9 batteries. Our electrician had done a good job crimping and taping (lots of it) so it took us a lot of time to get the battery plugs off of the battery. Whew!

We also connected those Anderson plugs on all four of our battery chargers to make charging easier, safer and less likely to reverse charge the batteries.

Remember...only 9 more days to get this done!!

Regards,
ChuckB

OMG - Outside the window! Get ready to do-it-again, 21-April?

PS: Does FIRST honor the FIFTH Amendment?

[Al Skierkiewicz]

Originally Posted by Jack Jones

OMG - Outside the window! Get ready to do-it-again, 21-April?

Jack,
This isn't a robot part and it is not subject to the construction rules. Batteries can be kept by teams and brought with them to the competition.