BL MBX-5 Near completion. Pics - Page 3 - RC-Monster Forums

lxmuff · 04.09.2007, 11:11 PM

Just a reminder for all about the KV, rpm, pinion size, spur size, which can contribute to cogging. Keeping the pinion smaller in size helps reduce cogging with the MM. Having a large pinion forcing the ratio lower is like starting your pickup out in 3rd gear from a stop. Factor in the low kv and you have a slow buggy. There is a balance between speed, rpm/v, cogging and motor/esc temps.

I use a quark 125B with a Plettenberg Maximum 3100rpm/v. This is on a Mugen MBX5 12/46. Does over 40 mph in the short straight easily. The motor never gets hot and the Quark can last a 5 minute race before the thermo MOD. I just did the mod and it makes a lot of sense why it has these thermo problems.

I used the same motor on a MM with no cogging and the same 12/46 setup. The MM is just not as smooth as the quark, but what is?

I will be running my new 8ight with 12/46, MM, Neu 1512/1.5D(american made) @ 3200rpm/v and 4s 5000mah LIPOs. I am expecting the same performance as the other buggy.

Hopefully I'll be running at Stateline soon.

jtracker · 04.09.2007, 11:18 PM

Quote:

Originally Posted by lxmuff

Hopefully I'll be running at Stateline soon.

Thats awesome that you will be running at Stateline. It should be a really kool track layout this year:027: Silentmonster,YJ-7 and myself(jtracker)are the only ones that run electric there so hope to see you there this summer!:027:

lxmuff · 04.10.2007, 07:31 AM

Do you run electric 1/8th scale?

Quote:

Originally Posted by jtracker

Thats awesome that you will be running at Stateline. It should be a really kool track layout this year:027: Silentmonster,YJ-7 and myself(jtracker)are the only ones that run electric there so hope to see you there this summer!:027:

jtracker · 04.10.2007, 08:55 AM

Me and my dad(yj-7) are in the process of converting ours. YJ-7 did the motormount and all the machining for silentmonster. :)

SilentMonster · 04.14.2007, 09:12 PM

Well I got a Neu 1512/1.5Y/F for the buggy today. Went to the Toledo RC show today and DMA was there with one so I bought it. Swallowed hard and went with the 1900kv. I really was tempted to go with the 2600kv against most of your suggestions but listened to the motor gods here. HA. It's freaking snowing so I don't think it will get ran real soon. Excited to try it out with the new Neu motor. Stephen.

squeeforever · 04.14.2007, 09:36 PM

Its snowing...In mid-April???

glassdoctor · 04.15.2007, 12:07 AM

Quote:

against most of your suggestions

HA! We win, lol. You will not be disappointed. Today I raced my buggy with the same motor you bought... :004: :004: should have seen it :027: oh my lord...

Sometimes even we (bl owners) forget how fast a bl can be. I had it geared 18/46 this time. It was stupid fast.. there were a lot of dropped jaws :005: Sometimes what doesn't appear crazy fast in the street or on paper (like 40-45mph) is just ridiculous on the track...

I actually gelt kinda guilty about having such an advantage as I wiped up the competiton (the faster local guys were not there today)

So... if you aren't smiling ear to ear when you run yours, just gear up...

jtracker · 12:32 AM

It was a hard decision for Silentmonster to make. I think what made it harder for him was that we stuck my 7XL in it with that freaking flywheel that he was running with the neu 1515 and ran it on our track and it was just stupid fast.:005: We knew it was way overgeared but I wanted to see how fast it went!We chased cars up and down the road and stayed with them. Got in the car and silent drove it in front of the car and it did about 57mph!! Hopefully he will be happy with his choice and if he needs more he will have to gear up:004:

glassdoctor · 04.15.2007, 12:35 AM

hee hee.. the 1900kv will have a hard time doing 50mph+ on 4s, due to the gearing. It's completely capable but need big pinion... at least 20t...

SilentMonster · 04.30.2007, 03:19 PM

I've got an update. First off let me just say that the 1512 motors are more that enough. There is no need to even consider the 1515 series. I'm waiting on an order of pinions from Mike, so I ran it with the 24/44 gearing. Obviously it is stupid fast but here is the kicker: The hottest the motor ever got was 155 degrees. Wow, that is impressive to say the least. The MM was not too happy though. After about 10 minutes it was shutting off. I assume it was thermaling. I had the Nomadio Sensor on the motor but not on the ESC but it was hot. I didn't expect the ESC to get hot. When I ran the XLT-4 motor it was just warm and the motor was cooking. I can't figure that one out. It would shut down and then after about 10 seconds it would reboot and run. I'm sure the MM will like the 16, 18 or 20T pinion much better.

lxmuff · 04.30.2007, 05:18 PM

I raced the 8ight Saturday and in the 10 minute main with other 1/8 conversions and the motor got to 155 and the esc to 165 with a fan on it. I have the esc ontop of the diff. The motor didn't have a fan on it too. My friend was running my MBX5 with quark and Plettenberg Maximum with fan and it got to about 160 on the motor. The Neu is a little better than the Plett. I used the 1512 1.5D/F with 11/46. This is the track
http://www.rcracingextreme.com/forum...pic.php?t=3426
To give a relative idea, the 8ight went about 10 feet further than the fastest nitro on the largest jump(made me look like I knew what I was doing while landing great). I could go no further than half throttle anywhere on the track. I think I'll try the quark out on the buggy next. A friend of mine is going to be getting a new tekin mt for beta testing on his conversion sometime soon. Between that and the MMM, a large portion of the esc capability should be settled.
Silent, let me know when you'll be going to SL next.

MetalMan · 04.30.2007, 10:34 PM

Quote:

Originally Posted by SilentMonster

I've got an update. First off let me just say that the 1512 motors are more that enough. There is no need to even consider the 1515 series. I'm waiting on an order of pinions from Mike, so I ran it with the 24/44 gearing. Obviously it is stupid fast but here is the kicker: The hottest the motor ever got was 155 degrees. Wow, that is impressive to say the least. The MM was not too happy though. After about 10 minutes it was shutting off. I assume it was thermaling. I had the Nomadio Sensor on the motor but not on the ESC but it was hot. I didn't expect the ESC to get hot. When I ran the XLT-4 motor it was just warm and the motor was cooking. I can't figure that one out. It would shut down and then after about 10 seconds it would reboot and run. I'm sure the MM will like the 16, 18 or 20T pinion much better.

If with the XLT-4 motor the motor was getting hot and the MM wasn't heating up much, then the motor was undergeared. Are you using a fan on the MM? If not, I would say that the MM is running at a pretty acceptable temperature if it lasted 10mins. before thermalling.

SilentMonster · 05.01.2007, 02:25 PM

No fan on the MM. The gearing was the same at 24/44. Top speed was about the same at 57MPH. I know it's over geared but that is the only pinion I had. I'm assuming that just the 4 pole motor is just harder on the ESC. I expected the motor to heat up, not the MM. Other than the cogging issue with the Neu/MM I am really happy with the Neu. I really didn't want to have to run a fan. I built this for running a 30 min. main so I hope the sane gearing will make the MM more comfortable. I'm gonna put a temp Sensor on the MM also so I can see what's going on better.

SilentMonster · 05.14.2007, 03:59 PM

Got to run my first race Sat. Geared it at 16/44. ESC thermalled about 4 min in at 230 degrees. I missed the second heat as I was trying to get a fan on it. Ran the third heat and qualified 2nd for the B main. Finished 1st in the main. There were 24 entries so I was happy considering It was my first time on the track with a 1/8th buggy and I was on my lid countless times. Cogging was a problem due to being on my lid so often. Almost every time I was marshaled I had some problem getting going again.

After the races I was out just running it around and the ESC took a dump. I can only assume the cogging issue was the culprit. It didn't smell or smoke it just lost power and it will just kinda run intermittently with no speed or power. BOOHOO

The motor never got above 160 degrees though.

lxmuff · 05.14.2007, 08:45 PM

Hi Silent. We ran our first race at Pheasant Runn and we made 10 min mains. So far there is no cogging on the new Losi 8ight with the Neu 1512 1.5D. I had a 30mm fan on the MM. I have fixed a 40mm fan over the MM now and it runs even cooler. The motor with no fan never got over 155F. These motors do rule. I think it's better than the Plettenberg. I was running an 11/46 and could only hold down half throttle on the straight away. The tires I had were too stiff and I couldn't get enough traction. Here is a clip of practice early before the racing started.

http://www.rcpics.net/media/Losi_8ight.wmv

As of now, the nitros do not want us to race with them. Go figure. We don't have any problems running with them.