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RC10B4/T4 Forum

Old 03-22-2008, 07:57 PM
  #4351  
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I have the Mamba max 4600 in my B4 geared at 19/84 and after beating the ever living crap out of it today it was cool to the touch. I would kinda think that the thermal problem is being caused by something else. Just my .02
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Old 03-23-2008, 08:47 AM
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wow, my B4 with the Novak 10.5 is geared at 84/24. I don't understand why you guys run such low gearing. Everyone at my track that runs a brushless motor is gearing them at like 24 or 25 pinions with absolutely no one thermaling. My truck is also geared at a 25 pinion.
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Old 03-23-2008, 09:15 AM
  #4353  
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Im just starting to play with gearing so I was wondering would I lose bottom end with a bigger pinion?
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Old 03-23-2008, 10:01 AM
  #4354  
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Well, definately. It's the same with a brushed motor. The thing is that brushless motors have so much low end power that you won't really notice it. My T4 has got ALL KINDS of low end power, even with a 25 tooth pinion. It'll make it alot easier to drive with a higher tooth pinion, and it will give you more top speed.
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Old 03-23-2008, 10:31 AM
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From personal experiance with Novak motors in my TC, there a totally different gearing animal than the CC motors. I run a 10.5 in my losi sedan and it runs a 35/91, with a final around 5.8:1 I believe! Thats insane gearing for sure. The 13.5 needs even bigger pinions than the 10.5 I tried a Speed passion 13.5 in my B4 and had to use a losi 74 spur with losi slipper pads so that I could get a 33-34T pinion on it. Works extremely well though. These BL motors are all over the place, with no one right way to gear them.
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Old 03-23-2008, 10:39 AM
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They have so much bottom end compared to a brushed motor that you can gear them to the moon compared to the brushed. However, I have found that gearing them to come off at about 90-100* after your run will produce more power than if you gear them higher. This was on both Novak and LRP 10.5's and 13.5's.

If you're over heating running such low gearing it could be a few things. How long you're driving, how smooth your diff/transmission is. You could also just be geared to low.
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Old 03-23-2008, 11:38 AM
  #4357  
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I have a RC10 B4 and I have a few minor issues. I just came back to the hobby after a very long hiatus so please forgive my naivete.

1. Steering. I spend about a half hour setting all my turbuckles in the front for camber and caster and setting the trim on my radio. For whatever reason my steering becomes erratic. Basically I start off with it nearly perfect it goes straight with a little pull to the left. I trim that out and I am good. After a few minutes, it is pulling very hard to the right. So just to keep going, I fix the trim to get it back to center onbly to have it pull real hard to the left. I also notice the my caster and camber is all off from where I set it. Is this just bad turnbuckles? Or is my steering too loose. If my steering is too lose how do I get it to tighten up?

2. After a long run my battery was luke warm at hottest. My ESC heat sink was slightly hot to the touch and my motor was pretty hot. I am running TC 5400mah LiPo and Novak XBR ESC/8.5 EX brushless system. I am using a 22T 48P pinion and the stock 81T 48P spur. Is it running too hot? If so how should I go about getting it cooler with regards to FDR.

Any suggestions would be greatly appreciated.
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Old 03-23-2008, 12:17 PM
  #4358  
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Tomblaze, first pop off the ballcup from the steering servo, try to turn the bellcranks by hand, should be extremely easy. If its not you may have over tightened the 2 screws that hold the bellcrank linkage to the top mount. Its easy enough to take apart and loosen those screws 1/4 turn.
If its ok and turns easy, I'd look at the servo next. You didnt say what it is, but if its a standard budget servo, included with most radio systems, they tend to have problems staying "centered". You may want to try another one, or go to something such as a JR590M, something a bit better.

Gearing will vary with track, but how hot are we talking? Try keeping the motor temps below 150F, If you ran it till the pack dumped then that was probably 15min or so, which will make it hot. See what others are running if you frequent a track.
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Old 03-23-2008, 12:57 PM
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I have a Spektrum SR3000 Receiver and my steering servo is a Spektrum Z590 - High torque servo. (they came with my Spektrum DX3.0)
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Old 03-23-2008, 01:05 PM
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Originally Posted by hobbipro View Post
Tomblaze, first pop off the ballcup from the steering servo, try to turn the bellcranks by hand, should be extremely easy. If its not you may have over tightened the 2 screws that hold the bellcrank linkage to the top mount. Its easy enough to take apart and loosen those screws 1/4 turn.
If its ok and turns easy, I'd look at the servo next. You didnt say what it is, but if its a standard budget servo, included with most radio systems, they tend to have problems staying "centered". You may want to try another one, or go to something such as a JR590M, something a bit better.

Gearing will vary with track, but how hot are we talking? Try keeping the motor temps below 150F, If you ran it till the pack dumped then that was probably 15min or so, which will make it hot. See what others are running if you frequent a track.
Sounds like you might have your gearing spot on. As long as it's not thermaling you're doin ok.

As far as the steering, I agree with hobbirpo. If the steering moves freely when not connected to the servo, then your server is probably the culpret. As far as the camber is going, not sure what to say there. I know that when i built my FT B4 and T4, i never even used the stock ball cups. They are way too week. I went with the RPM ones right away. He is correct with the servo not wanting to center itself though. Your best bet is to spend a little extra ching and get a digital servo. If you wanna say some, look on ebay for a decent Hitec 5925, very fast servo and very good servo for the $50 i spent for it. I'm sure you might even be able to find one here someone is selling. Hitec servos are very good servos for the money. I run all hitec servos in my cars except for my truck, which has a futaba 9451, which is also an excellent servo for the money. That's where i'd look first once you've confirmed that you didn't tighten those two bolts too tight.
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Old 03-23-2008, 02:43 PM
  #4361  
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Thanks guys. I checked the steering bell crank and it was fine. So I will buy a new servo this week. As far as the motor getting hot I guess as long as the battery stays relatively cool I should be ok. Maybe a heat sink on the motor?

A few other questions:

- I tend to run this car hard (wherever there is dirt and a way to get air I put the car down and speed into it). I don't really race so weight is not a concern. I just want it to take a beating and love it. I am thinking of going with aluminum shock towers, aluminum trailing arms and titanium turnbuckles as well as a few other aluminum replacements. I was even thinking of going with the aluminum tranny case but I think that would be overkill. How will these changes affect the way my car handles and what adjustments should I make when/if I do this upgrade?

- I am thinking of buying the sintered rotor and large endbell magnet for my Novak EX 8.5T motor to upgrade it to an SS. What is confusing is that people say to never open the motor for any reason. So should I not do this and just get a new motor in time?
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Old 03-23-2008, 03:27 PM
  #4362  
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You can open the motor. Alot of guys upgrade to the sintered rotor. your motor may already have it. If the rotor is grey in color, then it doesn't, but if it's aluminum in color it does. As far as the aluminum upgrades go, i've said it once, i'll say it again. Anytime you replace a plastic part with an aluminum part, you transfer the forces of a crash thru the aluminum part and into the other plastic parts which will in turn break. Your best bet is to replace the turnbuckles and leave the plastic parts alone. If it isn't a factory team truck, then it has the regular plastic parts and not the graphite plastic parts. The graphite parts are stiffer and therefore break easier then the regular plastic parts too. Aluminum parts will only make you break parts that don't normally break (i.e. bulkheads, chassis....)
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Old 03-23-2008, 03:28 PM
  #4363  
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I'm not a big fan of aluminum suspension, unless it is a shelf queen and spending cash on cool looking display items is your thing.

The problem with aluminum is it has poor memory, so a hard hit means a bent arm, or the stress is passed to other suspension items, like mounts, chassis, hubs, etc. It's impossible to stop these cars from breaking in some hard crashes, so a $6 pair of arms seems better to me, rather then moving the broken parts to something that could be mor expensive.

Titanium turnbuckles though are a good idea.


For brushless, the motor can easily be opened up, in fact it should be for maintenance/cleaning. If the Novak motors were not able to be opened then they would not likely sell the items your looking at seperate, .

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Old 03-23-2008, 06:12 PM
  #4364  
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I see your point about the aluminum. Titanium turnbuckles good. Aluminum other stuff bad. Motor mod is go. Have spares of stuff.

Maybe I should Invest in this:

http://www3.towerhobbies.com/cgi-bin...?&I=LXEAJ2&P=7

I figure I will need to replace it all at one point my as well get my pain over with. Hell at the rate I am going it may be wise to get 2 sets.

OK you guys are awesome! I am off to break something else.
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Old 03-23-2008, 06:24 PM
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Originally Posted by TomBlaze View Post
I see your point about the aluminum. Titanium turnbuckles good. Aluminum other stuff bad. Motor mod is go. Have spares of stuff.

Maybe I should Invest in this:

http://www3.towerhobbies.com/cgi-bin...?&I=LXEAJ2&P=7

I figure I will need to replace it all at one point my as well get my pain over with. Hell at the rate I am going it may be wise to get 2 sets.

OK you guys are awesome! I am off to break something else.
Like I said before, unless you're racing, you don't want those carbon parts. They are stiffer and WEAKER then the standard plastic parts and will break alot easier. Good for racing, BAD for bashing.
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