Rustler 8s/9918: gearing/cells?

[captain harlock]

Well, probably shortening the blue wires is a good idea, but honestly, everything looks neat.

[Batfish]

PowerPole connectors are the best for me. I use them in all of my applications now. Best part about it for me is that I don't have to solder them :)

[captain harlock]

How much amps can it tolerate?

[Batfish]

Originally posted by captain harlock
How much amps can it tolerate?

It's nearly impossible to get accurate data from either WS Deans or Anderson, but as near as I can find both connectors are actually only rated for 35 Amps. However, we know that Deans can handle more than that.
Alternately, I've seen several references to PowerPoles handling over 60 Amps continuous and up to 200 Amps burst.
Here's a great article to help understand PowerPole connectors:
http://www.flyrc.com/articles/using_powerpole_1.shtml

[MetalMan]

I have read that Deans are rated at 60amps cont. and much higher in bursts. Powerpoles are good connectors, but they are rather bulky, and crimping the wires on will create higher resistance than soldering.

[Batfish]

Originally posted by MetalMan
I have read that Deans are rated at 60amps cont. and much higher in bursts. Powerpoles are good connectors, but they are rather bulky, and crimping the wires on will create higher resistance than soldering.

Not to be argumentative, but a crimped connection has less resistance than a soldered connection, all other things being equal. This is the best way i can describe it:
With a crimped connection, all of the strands of wire either touch each other or touch the connector directly, offering a direct path for the current to travel through.
With a soldered connection, the solder gets between the strands and connector as well as between the strands themselves. This puts a higher resistance substance (solder) between the current and it's destination.
If soldered wire was better, we'd put solder inside short lengths of wire to increase their capacity. Strand-to-strand is a better conductor and, generally speaking, the more strands the better. A soldered wire essentially turns all of the strands into 1 at the connection point.

However, you are correct in that the PowerPoles are larger connectors.

Yes, I have also read that the Deans are rated at 60 Amps. It's just impossible to get information from WS Deans themselves. Their website hasn't been updated in years and none of their products come with spec sheets, so all we have to go on is what other sources say.
As far as PowerPoles, since they aren't specifically designed for R/C use there are many, many people using them for a large amount of different applications. This makes quite a bit of data available about them. Here's a quote from the article I linked earlier: The actual rating for a 30-amp Powerpole is for a 30° Celsius (54° Fahrenheit) temperature rise at 30 amps (and 110 volts) using 12-gauge wire. This temperature rise spec is published in the National Electrical Code for building wiring and is more of a wire gauge rating than it is a connector rating. The power level noted in that standard is 3,300 watts.
I think the 30A rating on the PowerPoles themselves generally makes people think they are weaker connectors than Deans.

[captain harlock]

Hmmm, at first I thought it was made by acer racing, but it does say it is a powerpole connector. Check this page if you want: www.acerracing.com/connectors.html I also heard that the bullet type connectors like the ones made by Trinity and Orion are capable of handling up to 80 amps cont. The 3.5 mm like the Schulze ones are 50 amps or something like that. Also Chris Fine just imported a new type of bullet connectors that can tolerate up to 200 amps cont. Check it out here: www.finedesignrc.com/motors.asp

[kulangflow]

Originally posted by captain harlock
Okay, use 9-10 cells with a gear ratio 11.8:1 and watch the temp of the esc and your motor. Your 8s will take you beyond 58mph easily at 12 volts....

So, today I did some GPS testing. Here are the results:

10 GP3300 matched cells

18/84: 35.3 mph
20/84: 38.0 mph
22/84: 40.5 mph

9 GP3300 matched cells

18/84: 31.2 mph
20/84: 34.6 mph
22/84: 36.7 mph

8 GP3300 matched cells

18/84: 27.5 mph
20/84: 31.9 mph
22/84: 33.2 mph

The hottest my motor ever got was 115 F, and the hottest the controller ever got was 91.9 F (This was on 8 cells at 22/84).

What do I need to do to get to that 58mph you mentioned? Are these gear ratios correct?

18/84 = 12.69:1
20/84 = 11.42:1
22/84 = 10.39:1

I'm thinking that I'm gearing it way too low.

What do you all think?

Thanks ....

[Rtsbasic]

Sounds like your undergeared. 10 cells on the 8s should in theory fly. I run 8 cells on my 6s and it'll fly faster than any of the speeds you've posted with the right gearing. Your setup should rev the same as mine on 10 cells, but have more torque.

I have no experience with the rustler, but in theory, you need to run 25/84 (assuming normal 3.5" diamater tyres, adjust accordingly if your tyre sizes are different) giving a ratio of 9.14 and approx 55mph.

[MetalMan]

You should use something closer to 26/84! A 22t pinion just isn't big enough if you want a lot of speed! Also, if your slipper clutch pegs are worn down, replace those.

[SpEEdyBL]

More like a 30 tooth pinion or higher. The max efficiency at that voltage occurs at over 80 amps!

Wow, those sound pretty slow. I gps tested my Lehner 4200 on 6 matched cells in my stampede reached 39.6mph. It was geared 18/84 I believe. I have the 8s too now. Maybe it just doesn't have it. I've been disappointed so far as well. I'm thinking of gps testing mine on Sunday.

Originally posted by kulangflow
So, today I did some GPS testing. Here are the results:

10 GP3300 matched cells

18/84: 35.3 mph
20/84: 38.0 mph
22/84: 40.5 mph

9 GP3300 matched cells

18/84: 31.2 mph
20/84: 34.6 mph
22/84: 36.7 mph

8 GP3300 matched cells

18/84: 27.5 mph
20/84: 31.9 mph
22/84: 33.2 mph

The hottest my motor ever got was 115 F, and the hottest the controller ever got was 91.9 F (This was on 8 cells at 22/84).

What do I need to do to get to that 58mph you mentioned? Are these gear ratios correct?

18/84 = 12.69:1
20/84 = 11.42:1
22/84 = 10.39:1

I'm thinking that I'm gearing it way too low.

What do you all think?

Thanks ....

[captain harlock]

Hmm. As the others suggested, go for higher gearing and replace any worn out slippers and fully tighten your diff.

[kulangflow]

Right on ... thanks for all the help!

I'll try 24, 26, 27, and 28 tooth pinions sequentially while watching the temps of everything, then I'll report back to let you all know what happens.

It might be awhile though, 'cause my Integy 16x4 Pro went up in smoke again for no apparent reason. It worked perfectly for 6+ months, and now it's smoked twice in the past two weeks. I wish it didn't take so long to get it fixed, although mostly it's time spent in travel to and from Integy.

Word.

[aqwut]

you could get the Power polese which are 45 amp rated from robotcombat, since I had a whole bunch of the black and red covers.. I decided just to order the contacts....

the pole conectors 15 amps, 30 amps, and 45 amps both use the same housing.... And I do agree taht deans are good for 80 amps... but the solder is the week part... my Crimped 45 amp power pole stays cooler than my soldered Deans 80 amps...

So the batfish is correct, the solder is the week part.. well.. that's my opinion.. :)