R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro Off-Road

Reply
 
Thread Tools Search this Thread
Old 01-19-2009, 06:04 PM   #1
Tech Regular
 
markr04's Avatar
 
Join Date: Jan 2009
Location: TX
Posts: 421
Trader Rating: 1 (100%+)
Default Radio tray flex (or, are my brakes working right?)

I bought a used MBX5 Prospec a few weeks ago. The brakes are nowhere near as good as my 8ight buggy (RTR). Both the MBX5 and the 8ight had the same throttle servo (Spektrum 270). Same servo, the 8ight stopped a lot better.

My question is more about the MBX5. I'm only mentioning the 8ight as a comparison.

I tore the MBX5 brakes down and installed new pads. The discs look fine. I also installed a more powerful servo. It stops better now, but I also have the brake end point set to where the radio tray flexes a bit when I hit the brakes. Is this okay?

I'm frustrated with the braking on the MBX5. My 8ight RTR pwns it in that regard and that doesn't seem right.
markr04 is offline   Reply With Quote
Old 01-19-2009, 06:19 PM   #2
Tech Master
 
Join Date: Aug 2006
Location: Oceanside CA
Posts: 1,075
Default

Are you comparing the phenolic losi disc to a steel mugen disc? I dont know what the losi RTR comes with but my race rollers had the phenolics & you cant compare the 2 thats why you almost never see anybody use steel rotors anymore.First time you soak those new pads in fuel there pretty much done & the steel rotors will glaze easily. If thats not the problem maybe the fuel tube used as springs on the 2 are different of how far the brake rods are out from center on the 2 is different,basicly the closer the rods are to the center of the servo arm the stronger the servo acts & greater the resolution(brake feel) you get.All I can think of for now.

I just realized you are taking into consideretion the mugen weighs a lot more than the losi right?
butch man is offline   Reply With Quote
Old 01-19-2009, 06:22 PM   #3
Tech Elite
 
jamminnay's Avatar
 
Join Date: Apr 2008
Location: IL
Posts: 2,012
Trader Rating: 10 (100%+)
Send a message via AIM to jamminnay Send a message via MSN to jamminnay
Default

u do not want our tray to flex when the brakes are applied.. just back the epa off just a bit so the tray does not move.
jamminnay is offline   Reply With Quote
Old 01-19-2009, 06:36 PM   #4
Tech Regular
 
markr04's Avatar
 
Join Date: Jan 2009
Location: TX
Posts: 421
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by butch man View Post
Are you comparing the phenolic losi disc to a steel mugen disc? I dont know what the losi RTR comes with but my race rollers had the phenolics & you cant compare the 2 thats why you almost never see anybody use steel rotors anymore.First time you soak those new pads in fuel there pretty much done & the steel rotors will glaze easily. If thats not the problem maybe the fuel tube used as springs on the 2 are different of how far the brake rods are out from center on the 2 is different,basicly the closer the rods are to the center of the servo arm the stronger the servo acts & greater the resolution(brake feel) you get.All I can think of for now.

I just realized you are taking into consideretion the mugen weighs a lot more than the losi right?
You're right, the 8ight RTR brake disc is a different material. Is there a phenolic brake upgrade for the MBX5?

I'm trying to picture what you're talking about with the brake rods. I'm having trouble. I'm kinda new to much of this.

I considered the weight difference between the two, but I think the brake disc material you mentioned has more to do with it.
markr04 is offline   Reply With Quote
Old 01-19-2009, 06:37 PM   #5
Tech Regular
 
markr04's Avatar
 
Join Date: Jan 2009
Location: TX
Posts: 421
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by jamminnay View Post
u do not want our tray to flex when the brakes are applied.. just back the epa off just a bit so the tray does not move.
Thanks for that info. I'll do that.
markr04 is offline   Reply With Quote
Old 01-19-2009, 08:17 PM   #6
Tech Master
 
Join Date: Aug 2006
Location: Oceanside CA
Posts: 1,075
Default

Lots of rotors available for the mugen in phenolic,fiberglass,carbon fiber to name the most popular.Do a search here with a couple different wordings.

http://www.carolinasrc.com/Webstore/...?idcategory=24

or here

http://www.amainhobbies.com/

or where ever you normally shop. The MBX-5,5T,5R,brakes will all fit & I think so will any made for the MBX-6 but not totally sure on the MBX-6.
butch man is offline   Reply With Quote
Old 01-19-2009, 08:26 PM   #7
Tech Elite
 
ezveedub's Avatar
 
Join Date: Aug 2004
Location: Fort Lauderdale, FL
Posts: 2,411
Trader Rating: 14 (100%+)
Send a message via AIM to ezveedub Send a message via Yahoo to ezveedub
Default

I assume your using the Blue Mugen pads. They stop fine, provided you make sure the top brake bushings are not worn out and you don't tighten down the top center diff plate too much (binds the levers). If you want to, you can install the MBX6 brake pads instead. There was some on Ebay priced pretty good.

As for the radio tray, you don't want it to flex too much under braking. Back off the EPA for the brakes. Also, if you using the fuel tube on the brake rods, make sure its Mugen fuel hose or hose of the same type of hardness. Normal hose may to be too soft to apply the brakes properly. On my MBX5T, it has the stock blue brakes and the truck has a lot of brakes, enough to pull an end-o at the end of the straight.
__________________
Kyosho, Mugen Seiki, Maxy's Fuel, KO Propo
O.S., Ninja JX, Novarossi, RMV
ezveedub is offline   Reply With Quote
Old 01-19-2009, 08:31 PM   #8
Tech Lord
 
Oasis's Avatar
 
Join Date: Dec 2002
Location: * Sin Cal *
Posts: 10,332
Trader Rating: 36 (100%+)
Default

Quote:
Originally Posted by markr04 View Post
I bought a used MBX5 Prospec a few weeks ago. The brakes are nowhere near as good as my 8ight buggy (RTR). Both the MBX5 and the 8ight had the same throttle servo (Spektrum 270). Same servo, the 8ight stopped a lot better.

My question is more about the MBX5. I'm only mentioning the 8ight as a comparison.

I tore the MBX5 brakes down and installed new pads. The discs look fine. I also installed a more powerful servo. It stops better now, but I also have the brake end point set to where the radio tray flexes a bit when I hit the brakes. Is this okay?

I'm frustrated with the braking on the MBX5. My 8ight RTR pwns it in that regard and that doesn't seem right.

Pretty much the 270 is NOT a good choice for throttle/brake..just not strong enough..
Here's the numbers..
Torque: 43 oz/in @ 4.8V, 49 oz/in @ 6V
Speed: .23 sec/60 @ 4.8V, .19 sec/60 @ 6V
Dimensions (WxLxH): 0.73" x 1.55" x 1.46"
Weight: 1.50 oz
Motor Type: 3-pole ferrite
Gears: Nylon
You can get cheaper servos that work pretty good for throttle/brake applications..both are not real fast but they do work..and both are under $50
Futaba 3305..6.0V 123.5 oz-in.
0.20 sec/60
JR 650..142 oz/in @ 6V
Speed:17 sec/60 @ 6V
__________________
I didn't say it was your fault, I said I was blaming you.
Oasis is offline   Reply With Quote
Old 01-20-2009, 08:01 AM   #9
Tech Regular
 
markr04's Avatar
 
Join Date: Jan 2009
Location: TX
Posts: 421
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by ezveedub View Post
I assume your using the Blue Mugen pads. They stop fine, provided you make sure the top brake bushings are not worn out and you don't tighten down the top center diff plate too much (binds the levers). If you want to, you can install the MBX6 brake pads instead. There was some on Ebay priced pretty good.

As for the radio tray, you don't want it to flex too much under braking. Back off the EPA for the brakes. Also, if you using the fuel tube on the brake rods, make sure its Mugen fuel hose or hose of the same type of hardness. Normal hose may to be too soft to apply the brakes properly. On my MBX5T, it has the stock blue brakes and the truck has a lot of brakes, enough to pull an end-o at the end of the straight.
I wish I had the bushing info last week, lol! I tightened everything down nice and solid and my brakes wouldn't release. I looked at the center assembly for a good two hours trying to figure it out. Then I took it to my LHS and they told me about the bushings (that I didn't even know were there). I oiled them and left a little bit of play when I tightened everything down.
markr04 is offline   Reply With Quote
Old 01-20-2009, 08:02 AM   #10
Tech Regular
 
markr04's Avatar
 
Join Date: Jan 2009
Location: TX
Posts: 421
Trader Rating: 1 (100%+)
Default

I appreciate your info guys. I'm glad I joined this forum.
markr04 is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 10:31 AM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net