RACING 1/8 BUGGY vid - Page 3 - RC-Monster Forums

02.12.2007, 02:19 AM

Quote:

Originally Posted by glassdoctor

About the electronics:

So it was back to the Neu. Now I didn't put the 1512 back in just as a trial, because last fall when I raced it with that motor and the MM that was still in the car, it would start shutting off (reboot, come back on) after a few minutes for no apparent reason... temps were low, not under big loads, etc.

So I tried the 1515 just to see if the motor was the problem. It did the same thing with the 1515 so something is wrong with the controller.
:013:

I have had a similar situation and it turned out to be the deans connectors. At first it seemed to have a lot of carbon on the male side of the deans so I kept cleaning it off, but in the end I had to change both the female side and male side. I'm not sure if this is the problem your having but it might be worth a check.

glassdoctor · 02.12.2007, 02:26 AM

Thanks for the tip... I will definitely check it out. Hmm, I'm pretty sure I did install this controller in a hurry at that race last fall.

JakeE · 02.13.2007, 10:41 PM

Greetings glassdoctor from one of your neighbors to the north, your buggy looks really good on the track!! I'm in the process of doing a buggy conversion and trying to spur interest for a class at a new track opening this spring in MN.

I have a question for you. I see that your average current draw is approximately 230mAH/minute in a race setting. Have you done any testing with a data logger to see what your peak current draw is? I'll be using a 5S A123 pack and a Neu 1512 2.5d and I'm curious if I can get by with a 1P or if I'll need to use a 2P configuration. I'll do some testing of my own once I'm further along in the conversion process but was wondering if you had any data to share.

02.13.2007, 11:24 PM

Cartwheels,

When I saw your post, I remembered that my buggy was cogging for no apparent reason the last time I was at the track. Since you mentioned it, I realized that the Deans on my ESC has been on there since the day I first got my MM, which was right after they were released. With the salty humid weather down here, I thought it might to change it and what do you know? No more cogging. This time I applied some electrical grease. This stuff actually helps conductivity.

Thanks.

02.13.2007, 11:42 PM

Quote:

Originally Posted by AAngel

Cartwheels,

When I saw your post, I remembered that my buggy was cogging for no apparent reason the last time I was at the track. Since you mentioned it, I realized that the Deans on my ESC has been on there since the day I first got my MM, which was right after they were released. With the salty humid weather down here, I thought it might to change it and what do you know? No more cogging. This time I applied some electrical grease. This stuff actually helps conductivity.

Thanks.

I'm glad I could help. I never had any problems with Deans on the 1/10 stuff but, I've seen it a couple of times now on my 1/8 cars. It must have something to do with the increased voltage and current. In time there gets be a black smudge on the contacts and it's hard to get off. It's easier to clean off the male side but very hard to clean the female side if not impossible.

BrianG · 02.13.2007, 11:54 PM

Quote:

Originally Posted by JakeE

...I have a question for you. I see that your average current draw is approximately 230mAH/minute in a race setting. Have you done any testing with a data logger to see what your peak current draw is? I'll be using a 5S A123 pack and a Neu 1512 2.5d and I'm curious if I can get by with a 1P or if I'll need to use a 2P configuration. I'll do some testing of my own once I'm further along in the conversion process but was wondering if you had any data to share.

I'm obviously not glassdoctor, but I recall him saying he got 120-130A peaks according to his Eagletree on one of his buggies (running 4s and a Neu motor). I think you'll probably want 2p on that A123 pack. A 1p pack at 30C would only be delivering ~60-65A and with a decent voltage drop.

glassdoctor · 12:24 AM

Yep... depending on gearing and traction, you can pull over 100amp spikes. My truggy with the 1515 hit over 120.
I think the highest I saw with the 1512/buggy was just under 120. But I don't use the eagle tree all the time.

But I have had runs in the street and lower traction tracks that showed peaks around 70-90amps.

At full speed the amps drop to around 30ish but every time you yank throttle and accelrate it will hit at least 50-60amps until the load drops (stops acclerating).

And average for the whole run is like @15amps.

JakeE · 02.14.2007, 08:23 AM

Quote:

Originally Posted by glassdoctor

Yep... depending on gearing and traction, you can pull over 100amp spikes. My truggy with the 1515 hit over 120.
I think the highest I saw with the 1512/buggy was just under 120. But I don't use the eagle tree all the time.

But I have had runs in the street and lower traction tracks that showed peaks around 70-90amps.

At full speed the amps drop to around 30ish but every time you yank throttle and accelrate it will hit at least 50-60amps until the load drops (stops acclerating).

And average for the whole run is like @15amps.

Thanks for the info

glassdoctor · **UPDATE... race #2 -** 03.05.2007, 03:36 PM

Ok, here's dome stuff from last weekends race. (2nd time racing with the 8ight)

Setup changes from before:
Different MM esc... other one cogging bad... I think I killed it. :036:
Direct hardwired the motor wires...no stock 4mm gold cons.
Replaced the 1515 1700kv with the 1512 1900kv.
Dropped the gear from 16/46 to 14/46 with the motor swap.
Ran the new maxamps 5000mah 4s pack in quals... 8000 pack in the main, to be safe.

Ok... biggest mistake was not working on the car, checking ride height, etc. It was riding low in the rear already and when I put the bigger pack in for the main it messed things up on some of the jumps... bad nose over from chassis slap. Also, the shocks needed rebuilt bad... they had been leaking and I never got that done.

Anyway... I did ok in qualifying but not great. Some bad runs and dnfs by some fast guys helped me qualify 4th out of 28 buggies. But the main was rough for me... one jump wrecked me almost every lap, lol...

Gotta go get some 3's... brb

glassdoctor · 03.05.2007, 04:15 PM

The awesome thing was that the setup I ran was getting great runtime.

I could have geared up a tooth to get a little more top end and may hurt the runtimes a bit. But here's what I got:

first run 1350mah
second run 1225mah
third run was around 1300ish... didn't write it down.... hectic day. :019:

So I was using about 180mah per minute on average based on a 7 or 7.5 minute run. Last time it was using 1400-1600mah per run with the 1515.

I'm surprised to see the efficiency improve. Gearing was just barely lower (when adjusted for kv change... the 16/46 @1700kv would equal 14.25/46 @1900kv... I ran 14/46) The esc settings may have something to do with the improvement.

ALSO, the temps were even lower than before also... I only checked it once, after the last qualifier and I was surprised:
Motor: 97*F
ESC: 115*F

Track temps were probably in the 50's I would guess... no fan on motor/esc.

glassdoctor · 03.05.2007, 04:25 PM

Oh.. and I ran the 30 minute main... should have been almost 32 minutes total track time. The 8000pack charged back 5440mah... 170mah per minute.

I wish I could always count on that! The 5000mah pack just might have done it if I skipped the warm up laps!!!!

I should have run the 5000 pack.... the car would have handled better too so maybe I would have done better.

One last thing:

With the 8000mah pack it weighs about 2oz. more than my buddy's nitro 8ight full of fuel. He also has a heavier body... probably a good 2oz more than the stock one.

With the 5000mah pack it only weighs 7lbs 3.6oz... a full half pound less than the nitro.

I did see another guy on rctech say his (nitro) 8ight weighs 7lbs 3.3 oz wihtout fuel (would be @7lbs 7.5oz. with full tank).

The 8ight is so light, some guys are putting lead weight in the rear... but it's cool to have an BL that weighs less than a nitro and can run almost 30 min.

skeeler · 03.05.2007, 04:32 PM

glassdoctor,

Could you give us any more information about your setup, other than what's in your signature. I'm just getting into the world of BL conversion, and I like to see as many examples as I can, in as much detail as possible, of good conversions. Also, could you post some recent photos, or point us to some that are already online?

Thanks again for your patience.

glassdoctor · 03.05.2007, 04:37 PM

http://www.rc-monster.com/forum/showthread.php?t=5572

start there.... plenty of stuff to look at....

skeeler · 03.05.2007, 04:41 PM

By the way, glassdoctor, would you recommend the Mamba Max/New 1512 combination? I'm thinking I'll probably use a 1512 on my buggy project.

Oh, I see you just replied to my previous query. Thanks.

glassdoctor · 04:52 PM

Hmmm.. that's a big topic here... the MM and Neu combo.

I'm doing it... but it's tough to recomend it due to the potential cogging problems.

EDIT: I did just take the MM out of the CRT and put in a 125b... which seems buttery smooth.

With the motor wires direct soldered, I'm having pretty good results. But there is still a bit of cogging occasionally. So far it's not bad and I could recomend it if the other advantages outweigh this flaw.

But I'm concerned that a bad episode of cogging could ruin a MM. That happened to me recently. (before removing the 4mm connectors and hardwiring it)

IF Castle comes through with a software update to fix it... then I will absolutely recomend this setup to everyone!

BTW, I have heard from more than one person that the MM works awesome with a Pletty Maximum... zero cogging so they say. So i have faith that CC can fix this issue.