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-   -   Baja 5b SS Brushless conversion (https://www.rc-monster.com/forum/showthread.php?t=17303)

gyn77 12.15.2008 10:06 AM

Baja 5b SS Brushless conversion
 
Hi everybody,
my dream of converting a big 1/5 HPI Baja to brushless is done!

Motor mount and pinion holder made by Serum (thanks!) :lol: :lol:

The photos

Motor: NeuMotor 1915 684 rpm/v
ESC: MGM 12018

At the moment, I run with little setup of 7s2p A123, but next weekend I will run with 9s lipo and Sentilon HV esc.

With 7s2p A123 the starting power was already enough, but the max speed was about only 62 km/h scryptasilum calculed (about 38 mph)

These are 2 video of the first on road run.
Video1
Video2

Eagle tree datas:
Max ampere 108
Max watt 1880
Max RPM 15200

Byte 12.15.2008 11:12 AM

I like it!

Very cool conversion.. Please make a video if you will run it on 9s LiPo!


- Patrick

othello 12.15.2008 02:00 PM

Congratulation on this built and your succesful maiden run.

Interesting motor choice, as it is rather lightwheight for the wheight of the car. With 3KW peak not the most powerfull one but as one can see in your videos with 2wd too much power will only spin the car. Motor temp in your videos was around 49-58°C (120-136°F) right? I guess your outside temp was at 12°C / 52°F while you made this run. With a more agressive driving style, 9s Lipo, a more powerfull ESC and hotter outside temperatures your motor temp might become critical.

7s2p A123 are able to provide far more peak power then 1.9KW. I would assume up to around 2.8-3.5KW peak which also represents the rated motor limit.

Expect considerable more power with 9s lipo which is comparable with an 11s A123 setup.

lutach 12.15.2008 02:21 PM

Awesome build. I would love to see the Eagle Tree data you got from the run.

lincpimp 12.15.2008 02:36 PM

Very nice!!! I like!!! (said in Borat voice)

Any idea what your running weight with batts is? 7s2p a123 is not all that heavy and your motor is not that heavy either. The stock gas motor must weight at least 4-5lbs and a tank of gas adds a pound or so (6lbs to the gallon, tank must be around 20oz). You may be lighter than the gas model, which will always help performance.

I would go with a 10-12s setup with 2500mah lipos and a motor of around 550kv. Possibly an outrunner, but I do like your use of the 19 series Neu. I have been wanting to do a 5th scale, may make my own with lst components... Or buy a used 5b, they go for around 4 bills...

One question, does the 5b have any sort of 1 way bearing in the gear reduction? I know it is a single speed, just wondering if you could use motor brakes for the rear wheels? I would do mech front brakes anyway, so most likely use the rear mech brakes too. I could run a set of channel mixes so that I could have selectable reverse with a reversing esc, like Lutach's 10s 150 amp model....

Any chance of some close up pics of the motor mount installed in the 5b?

gyn77 12.15.2008 03:41 PM

Weight RTR is 9,0 kg, I think about 2 kg less of nitro baja with full of fuel.
I'm sorry I don't have other pics of motor mount.

drkros3 12.16.2008 01:09 AM

thats sick!. i was kinda thinking about making my baja brushless. but i dont know yet.

rchippie 12.16.2008 01:16 AM

That looks real nice . :smile:

What's_nitro? 12.16.2008 02:11 AM

Sweet build. :yes: I think you could out-pull a diesel locomotive with that 8-pole Neu! :yes:

gyn77 12.26.2008 04:34 PM

New Test:

9s lipo zippy 5000 mah 20-30c

Max velocity: 80 km/h (gun releved)
Max watt: 4.933 watt
Max ampere: 175 ampere

Eagle tree printscreen

Other photos

Video1

Video2

Byte 12.26.2008 05:47 PM

Quote:

Originally Posted by gyn77 (Post 245609)
New Test:

9s lipo zippy 5000 mah 20-30c

Max velocity: 80 km/h (gun releved)
Max watt: 4.933 watt
Max ampere: 175 ampere

Eagle tree printscreen

Other photos

Video1

Video2


Nice speed! I like it! :smile:

Just one question, I want to buy a Eagle Tree system too. But I don't know which one to buy. Which one did you buy?

Thanks,

Patrick

othello 12.26.2008 08:47 PM

Nice. Thank you for sharing pics and videos. The sentilon ESC seems to perform very well in your car. Motor start up is impressive.

At some point in your second video i think i have understood that your motor temperature was 58°C ... correct?

As Lutach i'm very eager to see your eagletree data. Maybe you can attach your eagletree logfile from this run to your next post.

gyn77 12.27.2008 04:51 AM

1 Attachment(s)
to Byte:
I don't know which model of eagle tree I have used, because it is of my friend. I will ask him.


to Othello:
The sentilon works great (and is very cheap), you can see at about the third minute of the video2 the baja on 2 back road while starting at full gas.
Yes, max motor temperature was 58° (celsius) at about 16° of air temperature, sentilon was at a max of 50°.

I attach here the eagle tree log file.

My only doubt is about zippy lipos, they are rated for 20-30c, I got 172 ampere from them, that are about 35c. Do I risk to damage them?

Unsullied_Spy 12.27.2008 05:06 AM

http://lh5.ggpht.com/_GS-R7ugwb24/SV...204933watt.jpg

:surprised: That's a lot of amps!

I saw your videos the other day, Master Blaster has a thread on HPIBajaForum.com about his conversion and your vids are linked to a few times. Mike is working on a conversion for MB, hopefully he puts the finished conversion into production. I know I'd love to have a BL Baja but don't feel like custom-machining the motor plate.

EDIT: That's about 6.5 HP, stock 26cc engine out of an SS is about 3 HP I think :yes:

EDIT Again: What size pinion are you using?

azjc 12.27.2008 11:35 AM

I do like the use of a 19xx motor, a lot of torque and a 8 pole motor. Another motor that could be used is a Scorpion 4035...they have comparable performance to a Neu 19xx but a little cheaper

http://www.scorpionsystem.com/catalo...0/HK-4035-500/


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