Blackjack Baseline Test

[ApacheDude]

So I have been running my Blackjack a few times and figured I should baseline a few runs to get an idea of what improvements I get over time. I bought an EagleTree logger and love it...

My results for stock setup
27.4 MPH (via Garmin Fortrex 201)
16,500 Total RPM
Motor Temp maxed at 80.6F
Prop angle set low
NiMH batteries in fair shape, not new.

I was surprised to see that this setup was pulling almost 60 amps? 57 on one run and 58 on another run (different day). I have attached the screenshot from the logger to show.

Comments?

[Meniscus]

Are you sure you didn't install an anchor? LOL, J/K

For those of us that do not have a data logger, this is great info. Are you using the stock prop?

[ApacheDude]

Yes, stock prop. I thought it would be in the 30's but I think the batteries are the weak link at the moment. Plus I am going to adjust the prop angle up.

My goal is to do one thing at a time, make a few runs, and compare.

[Steven Vaccaro]

What packs were you running? 28mph is about on par with a 12 cell nimh system.
On the next run log consider adding the voltage also. That will give you an indication of cell quality.

[ApacheDude]

2 Trinity 6 cell packs. After the holidays I am going LiPo. Just having a tough time trying to figure out which packs are going to suit me.

I also logged the voltage and noticed large drops but I figured that was part of the large current draw. I think it dropped to around 10 volts under heavy loads. I can post that graph for this same run if needed. What should I be looking for? What indicates a better pack vs. a crappy set?

[Steven Vaccaro]

2 Trinity 6 cell packs. After the holidays I am going LiPo. Just having a tough time trying to figure out which packs are going to suit me.

I also logged the voltage and noticed large drops but I figured that was part of the large current draw. I think it dropped to around 10 volts under heavy loads. I can post that graph for this same run if needed. What should I be looking for? What indicates a better pack vs. a crappy set?

A better pack under load will have less of a voltage drop. If you are dropping to 10v with nimh a set of lipo will easily give you 3-4 volts more. Which directly translates to at least 3000 to 6000 more rpm. You will be amazed at the speed difference.

[Meniscus]

ApacheDude, you are going about this the right way, trying one thing at a time. Its nice to see someone that is patient enough to do just one thing at a time, test, log, and best of all, share their experience and knowledge gained.

I wish I could stick to the trying one thing at a time mentality. LOL

[scoota]

With a stock drive system apart from relocating he water pick up ,im running a Feigao 11L motor , found the XL motor over kill & an ETTI 125 amp speedy with a x440 prop a cheap way of getting speed out of that hull rides well & has been bullet proof . I have been GPs speeds between the 47 & 49 mph mark .....as for running high amps make sure the drive system is not pushing up motor shaft to hard or against the drive cable tube that can cause extra load on the system & make sure the flex drive is well lubed !!!!

[Meniscus]

Cool, what are you testing next? Your post is one day after Christmas...and it looks like you have your lipos.

A true FE boater!

[ApacheDude]

I think you are confusing my posts with scoota?

but... I did order my lipos!!! Could not pass up the deal from cheapbatterypacks.com this time around. rclipos.com did not come close for packs in this range.

Next up to test in order (hopefully this weekend):
Prop angle
switch to lipos (Elite 2s 4800s)
Octura x642
Motor timing

If this does not satisfy my needs then I am on to:
Fullers or similar hardware
new props (any suggestions after x642?)
3S lipos
New motor

I am quickly becoming a FE addict with no desire for a cure...

[Meniscus]

My mistake, LOL!

Hardware: I'm thinking about trying the Head of the River (HTR) hardware on mine.
Prop: My Blackjack is running well on a Prather 220.

[ApacheDude]

OK, went to the model boat pond today here in San Diego. Nice day and a good run.

Today's mission was to test the new lipos. I will admit that I adjusted the prop angle up a bit as well, so I changed two things from my last run. Attached are the voltage drops during the run. NIGHT AND DAY difference with lipos. I was using Elite 2S, 4800's.

Previous run was 27.4 MPH
Todays run was 32.4 MPH

Motor temp 86.9
Max AMP Draw : 68.75!!!


WOW. The boat was running great. It held the voltage much better than the NIMH runs. I knew I would be, but I have to say it: I AM SOLD ON LIPOS.

Next up: Motor timing set to high.

Then my X642, sharpened and balanced.

Then Fullers

then... ?

[rc123]

First this is a great post so keep it up :)

From what I've learned in the last few months with the BJ
- X642 prop on the current z drive may be a challange I've just managed to put an X640. Still it's worth I was doing close to your current speed on 4200 nimh with the X640
- New hardware - may look into the Head of River stuff I think it's a copy. I've got the Fuller one (different from the one Propnut has) and it looks quite the same. The quality should be different at least the price was..
Next for me was a larger esc and 6s lipos and then my fishing skils improved :)
Then bigger and faster I think are the key words...

[Meniscus]

Note: the Head of the River hardware has water pickup on both sides of the rudder.

Again, this is what I was going to grab in the future for my BJ. If I'm not mistaken, User: "Spot Me 2" has had this hardware in the past and could probably attest to its quality. Send him a PM, unless he happens to read this and he can confirm or deny that he has owned.

[rc123]

So it's better to search the forum before you buy
One thing still is that the prop shaft and strut is on 4mm but they may work with the 3/16 props.. (based on my limited knowledge)...

[ApacheDude]

Went to the pond model boat pond again today and had enough juice for two tests.

Motor timing on high, then added x642 prop.

With Motor Timing high:
33.2 MPH (+.7 MPH compared to low timing)
89 degrees
78 Max amps


Added x642
36.1 MPH (+2.9 MPH)
94.6 degrees
83.15 Max Amps



What is a good range for motor and battery temps?

[Duclover]

While on the topic of changing to lipo from nimh I was told that the stock esc wouldn't handle two 7cell packs. That being under the 21v max why would that be? I expect mine via UPS tomorrow and have been looking at 2s-4s lipo Vs two Nimh 4500+ packs. Any advice for someone who has yet to even receive the darned thing?

Thanks- Duc

[ApacheDude]

You are looking at 17 volts total compared to 14 volts. I wouldn't worry if you are running stock.