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Old 01-08-2009, 02:46 PM   #61
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Why can't the conversion keep the original two-speed and brake set-up? There's room still left for the throttle servo to serve as braking purposes only. Just take all the brake out of the esc and mix the servo as third channel braking on the radio.

Also why can't the conversion include a redesigned radio plate to accommodate the new 5000mah 30C batteries?

Imagine brushless with two-speed and 5000mah, very fast and long lasting. No need for battery change to last at least 15min. or more.
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Old 01-12-2009, 10:40 PM   #62
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Why can't the conversion keep the original two-speed and brake set-up? There's room still left for the throttle servo to serve as braking purposes only. Just take all the brake out of the esc and mix the servo as third channel braking on the radio.

Also why can't the conversion include a redesigned radio plate to accommodate the new 5000mah 30C batteries?

Imagine brushless with two-speed and 5000mah, very fast and long lasting. No need for battery change to last at least 15min. or more.
Well take it from someone who actually built one of these. (The MRX3 in the youtube video). http://www.youtube.com/watch?v=5N176o-JueE
The motor diameter at the location where the brake rotor sits does not leave enough room for the rotor. Secondly, the motor has full torque at start up, unlike a nitro motor that needs to get into it's powerband to make equal power thus needing a two speed. I can tell you that I have never had better brakes than with this BL motor compared to the conventional friction brakes. it's like having anti-lock brakes that are far more aggressive at slowing down the car. Simply doing a conversion is not going to get this class going. Too heavy and not enough room for cells much larger than 2500mah. We need a ground up design that will provide enough room for a pair of off the shelf 5000 hard case lipos. After my testing I found that the best runtime I could get (on the track) was about 5 minutes with the pair of 2400mah 3s packs wired in parallel which gave me 4800mah @ 11v. and they were VERY warm afterward.

I think that the only way 1/8 electric on road will gain any footing is if 1 or 2 US based companies decides to design and manufacture a 2wd 1/8th pan car. Similar to the CRC Gen-x10 but bigger or the DXF Megatron from France.

I do plan on building another car to prove the concept but after seeing that DXF already has a series going, I'd have to say that it has potential, real potential. The euro cars are too damn expensive but if CRC can produce a 1/10 for $250 (Stormer Hobbies) why not an 1/8th for less than $400 (street price)?

I'll post pictures as soon as I get the ball rolling...
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Old 01-14-2009, 11:09 AM   #63
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Yodog - Thanks for your reply. Just how heavy is a 1/8 onroader compared to a 1/10 TC? I just can't believe that you can only get 5min. Also, if you were running the two 2400 packs in parallel you would get only the same voltage as a single pack because your voltage only doubles if it was wired in series.

About your suggestion on a ground-up electric, I thinking that it would be a stretched 1/10 TC especially one with centralized battery using only a single hardcase lipo like 5500 or maybe 6000? with 30C rating.

Platforms to stretch would be:
  • Team Magic E4
  • Team Losi JRXS series
  • Old HPI Pro 3
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Old 01-14-2009, 12:05 PM   #64
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Yodog - Thanks for your reply. Just how heavy is a 1/8 onroader compared to a 1/10 TC? I just can't believe that you can only get 5min. Also, if you were running the two 2400 packs in parallel you would get only the same voltage as a single pack because your voltage only doubles if it was wired in series.

About your suggestion on a ground-up electric, I thinking that it would be a stretched 1/10 TC especially one with centralized battery using only a single hardcase lipo like 5500 or maybe 6000? with 30C rating.

Platforms to stretch would be:
  • Team Magic E4
  • Team Losi JRXS series
  • Old HPI Pro 3
You're right about expanding an electric TC. This is one of the reasons I've decided to run the TM E4. I intend to borrow some of their design ques since their battery is centrally mounted and they run a 3 belt drive train.
weight is only one of the problems with the nitro 1/8. The drive train is not very free. as far as the batteries go, I miss quoted, I tried a few different configurations that would fit into the chassis without raising the CG too high and the 4s packs in parallel worked the best with my Novak HV speedo.
It gets kinda flakey with voltage over 16v. The biggest problem with the batteries was that the car only has space for cells that are under 100mm long. This is the main reason I believe that a ground up design is needed.
We can use the suspension and bulkheads and most of the drive train from the nitro car but a new chassis and top plate will have to be redesigned at the very least. A pan car is likely to be a more practical place to start, then we will start to see suspension cars get developed. Don't get me wrong, as you can see in the video, my car hauls ass but I don't think it's the final answer.

All of my tests and suggestions are based in racing, not bashing so please keep that in mind when I may downplay the ideas of others. I'm not trying to piss in anyone's cornflakes.
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Old 01-14-2009, 12:25 PM   #65
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Quote:
Originally Posted by YR4Dude View Post
Why can't the conversion keep the original two-speed and brake set-up? There's room still left for the throttle servo to serve as braking purposes only. Just take all the brake out of the esc and mix the servo as third channel braking on the radio.

Also why can't the conversion include a redesigned radio plate to accommodate the new 5000mah 30C batteries?

Imagine brushless with two-speed and 5000mah, very fast and long lasting. No need for battery change to last at least 15min. or more.
YoDog basicly sums it up (well done), but I will share my opinion...

Why would keeping a 2-speed tranny is any FASTER then this Speed Passion convertion when it is already running the SECOND SPEED SPUR from the serpent 960...? Take a closer look at the pic, it is using the Serpent 960 2nd gear (spur, choice of 44,45,46) along with SP option pinion (18,19,20). So, when the motor is rev to it max, the gearing is EXACTLY the same as the car is running nitro engine with the 2nd gear engaged.

Electric conversion don't need 2-speed cause electric MOTOR has the "GET GO"....unlike Nitro engine, has very low pick up rpm (compare to elect motor). And need to big spur/small pinion to launch the car. Electric motor just need a pinion and one spur and can get the job done.

Look at all the electric TC now...you don't see 1 with a 2-speed, but you do see the 2.5 or even 2.0 speed brushless motor. Electric motor will handle the torque and the RPM.

Like wise...you DO NOT need that fancy braking system no more. The electric motor will do the brake just fine. Why add the extra weight, then another servo, plus the 3rd channel to do the Brake part? Pointless.

Last...why another radio deck when the idea of the 4800 pro packs will fit the existing fuel tank location just fine with some SP hardware to mount the LIPO...? SP try to provide something that is needed, not try to create more BLING when you don't need to....

SP claim 2400 startup 4 cells lipo (beginner package) will last 8-10 minutes...the 4800 will be close to 15 minutes.

I have personally seen a 2-speed gear conversion 1/8th...it is NO FASTER, just extra hardware to screw up the motor more. Not to mention a custom 2-speed pinion that no one is making but custom. Overall, 2 speed is not needed for electric motor.

Again, stay tune...SP is in final stage of testing.
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Old 01-14-2009, 02:21 PM   #66
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I thought that I'd point out that when it comes to the 1/8 on road conversion.
I've pretty much tried it all. 2 speed: (more complicated with little to no benefit).
Disk brake: (not enough room and no benefit)
Batteries: (not much room unless you build the pack taller, high CG) like the SP pack.

The batteries that I experimented with were not that great so I'm sure I could get better run time with newer 30 or 35c rated cells.
If I could get a hold of one of the SP packs, I can give more feedback on run time on my car. (Hint,Hint)
Here are a few pics of the car...
Attached Thumbnails
Will there ever be a 1/8th scale Electric onroad car-dsc_2993-small.jpg   Will there ever be a 1/8th scale Electric onroad car-dsc_2991-small.jpg   Will there ever be a 1/8th scale Electric onroad car-dsc_finished-car-comp.jpg  
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Old 01-14-2009, 02:28 PM   #67
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Here's some pics of the custom parts I made.
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Will there ever be a 1/8th scale Electric onroad car-dsc_3025comp.jpg   Will there ever be a 1/8th scale Electric onroad car-pic-0002.jpg   Will there ever be a 1/8th scale Electric onroad car-pic-0003.jpg   Will there ever be a 1/8th scale Electric onroad car-pic-0004.jpg  
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Old 01-14-2009, 07:38 PM   #68
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I'm in the midst of an Evolva conversion. I'm using the Novak 4.5 and HV sc. I'm also going to use 4s A123 cells side by side.(yes I'll have to do some grinding) What pinion and spur did you use? I've come up with a spur by using the 1st gear spur(49T) and the center collet from the 2nd gear. Don
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Old 01-15-2009, 02:53 PM   #69
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Originally Posted by YoDog View Post
Here's some pics of the custom parts I made.
Whoa!! Looks like you did explore that 2-speed concept. So going with a single speed gear, which direction should it be; a motor with an extremely high rpm range and hopefully the bearings will hold; or a motor with extremely high torque where you would gear it extremely tall?

I've been thinking a converted E4 with a 3.5 or if it exists a 2.5 and possibly a 5500mah or maybe soon a 6000mah battery with 30C or better rating. If made light enough with just stretched suspension and chassis, it may be possible to attain 1/8th like speed.

However, I am opposed to going with a pan style straight axle direct drive version because its just not the same level of sophistication as the 1/8th nitro (4WD & full susp.)
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Old 01-15-2009, 03:26 PM   #70
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To be honest with you guys,
I have the Novak 4.5 in my car at the moment. I had to run 14/48 to get decent top speed. Maybe it can handle a little taller gear but without better batteries I did not want to push it. I think that it's a good winding to run once the bugs have been worked out but perhaps the 6.5 would have been better and then run closer to the stock 2nd gear ratio. Something like 18/47.

At 14v I got about 37,000 rpm out of the motor(free wheel'n)
I used an eagle tree data collector to validate the power system.
If you are going to experiment and tune your car I strongly recommend getting one. It's only about $70 and the additional sensors are pretty inexpensive.
Get the brushless rpm interface and maybe the temp sensor.
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Old 01-15-2009, 06:51 PM   #71
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Quote:
Originally Posted by YoDog View Post
To be honest with you guys,
I have the Novak 4.5 in my car at the moment. I had to run 14/48 to get decent top speed. Maybe it can handle a little taller gear but without better batteries I did not want to push it. I think that it's a good winding to run once the bugs have been worked out but perhaps the 6.5 would have been better and then run closer to the stock 2nd gear ratio. Something like 18/47.

At 14v I got about 37,000 rpm out of the motor(free wheel'n)
I used an eagle tree data collector to validate the power system.
If you are going to experiment and tune your car I strongly recommend getting one. It's only about $70 and the additional sensors are pretty inexpensive.
Get the brushless rpm interface and maybe the temp sensor.
What would you estimate your top speed? The 4.5 HV is a 5000Kv motor and will turn, at least as rated, 74,000 rpm on a 14.8v 4S LiPo. That speed is serious if you ask me!
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Old 01-16-2009, 09:44 AM   #72
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What would you estimate your top speed? The 4.5 HV is a 5000Kv motor and will turn, at least as rated, 74,000 rpm on a 14.8v 4S LiPo. That speed is serious if you ask me!
It would be nice if it actually did that but from what I measured... I don't think so, especially if it's installed and your batteries can't maintain voltage under load. I believe Novaks numbers are very inflated or not under real world conditions.
I ran tall gearing and short gearing, 11v to 22v and never reached anything near 74,000 rpm.

So far under race track conditions I'd estimate that the car topped out at 70mph down the back straight.
I could probably gear taller but my batteries can't handle it.
The Eagle tree logger showed about a 5 to 8 volt drop during hard acceleration.
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Old 01-17-2009, 04:00 PM   #73
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Originally Posted by YoDog View Post
So far under race track conditions I'd estimate that the car topped out at 70mph down the back straight.
I could probably gear taller but my batteries can't handle it.
The Eagle tree logger showed about a 5 to 8 volt drop during hard acceleration.
Dang! 70mph is pretty fast Yo! I will start out geared at ~60mph on a Neu 1512/1.5D geared 16/51 on 4S LiPo. Attached is a photo of the conversion I am doing currently . . .

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Old 04-22-2009, 01:07 PM   #74
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bump because I am interested. I would love to see some 1/8th TC.

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Old 04-22-2009, 01:30 PM   #75
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Our MRX3 with SP ESC and 3.5T motor hit the carpet track this morning for it's first test. everything is fitting nicely with our solution using (2) 5200mh
40C SMC packs to get our 4s 14.4v. we did not see the limit of 4.5T motor with the SP ESC at 14.4v so I think we had a thermal issue and may have killes the speedo, but WOW this is going to be cool.

We have more speedo's and (2) 5.5T showing up tomorrow, and we'll get them in and share our results.
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