Novak HV Maxx 4.5 Problems/Questions
 

I was running my electric revo on the Gorillamaxx G3R chassis with Novak HV 4.5 and 14 cells. Two old 7 cell packs (14cell 16.8v). The run time was low but still ran good for 5 mins. I probably ran it twice, then decided I needed better batteries. Everything is brand new (except for the old packs)

I just purchased two Venom 8.4v 7 cell packs (14 cell, 16.8v). I put deans on the packs and tested to see if they were charged from factory. They weren't and the truck ran for 7 seconds. Put a charge on them the next day. The truck ran for a total of 20 seconds, glitched and wouldn't move. Now, you have to push it with your hand to get it going and it doesn't travel for long. I backed the motor off the emaxx tranny and it sort of works if you push the pinion gear to get it going. It will run if you have some throttle on it but then it doesn't move. Sometimes a glitch. Pull the throttle and get two blinking leds on ESC, blue and green.

I am running spool in rear, diff in front. 16t pinion and 1/8th 51t spur both Module 1. A good airtronics servo and traxxas TC3 radio/receiver.

Not a good experience for my first brushless setup. I went with Novak because the setup seemed simple. What am I missing here? If someone can help, please do. Here are some pictures.

http://img181.imageshack.us/img181/2...3839ce0.th.jpg http://img297.imageshack.us/img297/9...3837gz5.th.jpghttp://img181.imageshack.us/img181/4...3790lq4.th.jpg http://img181.imageshack.us/img181/1...3789ma9.th.jpg
http://img181.imageshack.us/img181/9...3783hq8.th.jpghttp://img521.imageshack.us/img521/6...3798sk5.th.jpghttp://img521.imageshack.us/img521/1...3825zg4.th.jpg

The same thing happened to me. Your speed control is toast. Send it in and get it replaced.

I've been saying for the longest time that the HV ESC is just not up to the task of handling the HV4.5 motor...

Did you receive another ESC? Any problems now? I emailed two people at Novak on Thursday with no reply yet. Thanks for the heads up.

Yeah...they replaced it, and I got rid of it right after (sold it). The 6.5 was a great system - super reliable, it just didn't have that top seed I wanted. The 4.5 had the top speed I wanted, just not the reliability. When Novak comes out with a true HV (6S) setup thats reliable, I'll probably pick one up, as I love the sensored operation.

You could check the wires that go from the motor to the speedo; both the sensor and the main leads.

Everything looks good. No signs of overheating.

Must be the controller itself. You could contact Novak over this matter; they are very responsive to their email.

One cause of the problem could be that your waaayyy overgeared for the 4.5.
Someone who knows more about the novak's or has the manual might be able to tell you for sure, but I think novak recommended around 28:1 or maybe even 30:1 final drive ratio for the 4.5 on 14 cells. Yours is 15.6:1.
Check the HV manual to see if it gives you gearing recommendation.

Would that have caused internal problems in the ESC or motor? I only ran it a total of 20 secs on new batteries. I ordered 9t, 10t and 11t pinions today.That won't matter if the systemed is jacked now.

I backed the motor off the strobe clutch. Have to "push" the pinion with your finger to get it going. Once it's running you can stay on the throttle to keep it going.

It could be possible that it happened from over gearing.
Sounds like you'll have to send the esc in like the other guys said.
Just make sure you use the right gearing with the next one. A lot of people have bad luck when using the wrong gearing on the 4.5.

It does definitely appear that you're overgeared. I'm not sure what the loaded kv is for the motor, but if it's as low as 4000 (which I'm sure it is higher than that), you'd be looking at 70mph top speed. The HV ESC has a hard enough time with 40mph...

I picked the HV 4.5 system cause it looked simple and I was new to brushless setups. Yeah, I should be down on a 8t or 9t pinion with the 51t spur.

Now it's decision time. Keep the HV 4.5 or upgrade.

Well since the mamba monster maxx is due soon I would wait. Also, you should be able to trade in the hv system and for novak's 6s system when it comes out for a small cost.

Yes, you are way overgeared! Didn't noticed that.

The 6.5 would be a better option IMO, but if geared right, the 4.5 can be a strong/fast setup too.

You can simple download the gearing table of the novak site.

I have a G2R (I think, bought a used rolling chassis) running the Novak HV 4.5 setup. I have run 70/18 with no problems other than all it wants to do is flip over when I hit the throttle! I have upped the gearing a bit to 64/18 but had the same problem. I have actually pulled a complete flip on take off and kept going! I have now upped the gearing to 64/22 and am awaiting dry ground to test it. with 70/18 I was getting close to 30 MPH and 12-15 min run times on some cheapo 4500mAh 6 cell packs and pretty much the same with Venom 4200mAh 7 cells. If I burn mine up I will be waiting for the MMM as well. Good luck with yours!

I sent the Novak HV 4.5 system back to Novak's customer service dept today. Thanks to all who helped out.
To be continued...

Email message from Charlie at Novak
"I’ve gotten this push start problem from lots and lots of HV users, however, when we get their systems in, they don’t suffer from any issues. Meaning they run normally.

The one common thread between ALL of these are “stick packs’. Try some other “non stick packs” before you do anything else. Ask a buddy, ask a shop, ask some racers, just so you can do basic testing. No need to run it around or bash it, just see if it works.

If it doesn’t the system has a problem and will need to be sent in for warranty service. If it does, you’ll know it’s the packs that are causing the problems not the ESC/motor. Even if the packs charge up and look okay, that does not mean they are okay. Your ESC and motor “look’ okay too. "

This might be a dumb question but what are non-stick packs? I tried two sets of packs before I sent it back.

cells layed out end to end rather than side-by-side. The connecting conductor between stick pack cells are generally thin foil-like metal tabs. Side by side cells use actual bus bars for better current flow without voltage drop.

Do you have an example or link? I guess you are talking about the "flat" or "side by side" packs (see link below)

Here http://www.maxamps.com/proddetail.ph...68-Pair&cat=78

Thanks

I talked to Novak Today. ESC was busted, got a new one, should get it today.

Now, should I keep the 9t pinion/ 51t spur setup (1/8th strobe slipper, mod-1) or use the stock emaxx 32 pitch pinions and stock emaxx spur for more options.

The stock spur should put you in the right gearing-zone.

I don't like pinions in MOD1 smaller than 11-12, they seem to wear pretty fast. (they more rub the gear instead of driving it like a larger pinion.

Ha! I sold about $40 worth of stock emaxx pinion/spurs a few months ago.

The 9t/51t on 16.8v and 4800kv motor puts me at 27.8:1 final drive. That is super close to the recommended 28:1 for 14 cells (novak's chart). That sound right? Thanks for the help.

If i were to go back to emaxx set up would it be around 12/72 (29.4:1)? Revo diffs, emaxx 2nd 16.8v and 4800kv.

Got the truck up and running, finally.

Went back with the stock emaxx 12/72 gearing. Put on two Venom 7 cells NiHM's and it's rippin'. I did order some 9t mod1 pinions if I wanna switch back to the Strobe slipper and 9/51 gearing.

http://www.youtube.com/watch?v=JM77yy26X2M

Here is a quick video. Wouldn't you know it. I get this truck running and something breaks. rear cvd. End of video is front wheel drive.

Now the truck won't even turn on. Might got too hot or something. But I could touch the motor and Esc and it didn't burn me. Oh well. Fix it later, working the skin for a clodbustn' tube chassis crawler.