R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 01-03-2010, 11:43 AM   #8236
Tech Fanatic
 
Join Date: Jun 2005
Posts: 900
Default

Quote:
Originally Posted by InspGadgt View Post
Even with those modifications the BMI springs will not properly fit on the CRC front end. The arm is just too thick to allow you to get any droop out of the front, you get too much pre-load on the spring. I originally had problems with my CRC front end using the long ball conversion as the ball would not thread in straight on one side causing different caster from left to right. So for awhile I went back to the AE front end. Then when I got tired of cracking lower arms I went back to the CRC front end and got the long upper arm which works much better. The front end squares up nicely now and once you glue in the axle and loctite in the king pin there is no need to hybrid the front end with the AE. Also if you want shorter steering arms on the knuckle, CRC is now making them in different sizes.
To fix the problem of snapping AE lower wishbones, drop them in boiling water for ten minutes, then take off the heat and let it all cool down.

They don't distort and they don't go soft. The nylon re-enforced plastic simply absorbs the water, and is more resilient. Never broken one I've treated like this, broken several I've fitted straight from the packet. HTH
SlowerOne is offline   Reply With Quote
Old 01-03-2010, 08:09 PM   #8237
Tech Champion
 
Join Date: Nov 2001
Location: Hawaii, USA
Posts: 7,168
Default

I wasn't talking about the regular AE arm but the IRS lower arm which comes with the BMI kit. It cracks right in the bolt hole even when I tap threads into the hole.
InspGadgt is offline   Reply With Quote
Old 01-04-2010, 10:48 AM   #8238
Tech Master
 
Join Date: Jan 2010
Posts: 1,837
Trader Rating: 32 (100%+)
Default

jason can you help, will be running bmi 12th scale at minnregg the 17th, need decent baseline setup for carpet, only run at adrenaline. thanks
fermanracer is offline   Reply With Quote
Old 01-04-2010, 12:12 PM   #8239
Tech Fanatic
 
Join Date: Jun 2005
Posts: 900
Default

Quote:
Originally Posted by InspGadgt View Post
I wasn't talking about the regular AE arm but the IRS lower arm which comes with the BMI kit. It cracks right in the bolt hole even when I tap threads into the hole.
Sorry Gadget, got the wrong end of the stick. And yes, they do... and that's why I stopped using them!
SlowerOne is offline   Reply With Quote
Old 01-04-2010, 02:33 PM   #8240
Tech Adept
 
Join Date: Jan 2008
Location: In a house
Posts: 218
Default

Irs used to do lowered ae front arms a few years ago
Quietman is offline   Reply With Quote
Old 01-04-2010, 02:48 PM   #8241
avs
Tech Master
 
avs's Avatar
 
Join Date: Jul 2006
Posts: 1,155
Trader Rating: 2 (100%+)
Default

Quote:
Originally Posted by InspGadgt View Post
I wasn't talking about the regular AE arm but the IRS lower arm which comes with the BMI kit. It cracks right in the bolt hole even when I tap threads into the hole.
interesting, i think i break everything else but the lower arm!

i bend the aluminum screw long before the arm cracks. are you using a steel or ti screw?
__________________
Tony Shimko
avs is offline   Reply With Quote
Old 01-04-2010, 03:07 PM   #8242
Tech Fanatic
 
Join Date: Jun 2009
Posts: 994
Trader Rating: 2 (100%+)
Default New to BMI

Hi Guys,
Got a new BMI for Christmas, put the car together which was no problem, love the quality of the parts. I've installed motor and electronics and did a quick tweak check, lifting the front wheels by the middle of the chassis. The right front lifts first, when I lower it back down the left front is down first. Checked the front end, everything is okay, tried a different front end but still the problem exists. Switched the flex plates from one side to the other, still the same problem. I'm not sure what I've done wrong. Any suggestions?
I currently run an Asscioated 12R5 and chose a BMI because of its reputation for not tweaking. I have the new carbon flex plates coming, maybe that will help.
Thanks Guys.
__________________
Cheers,

Kev
notsocrazybrit is offline   Reply With Quote
Old 01-04-2010, 03:45 PM   #8243
Tech Champion
 
Join Date: Nov 2001
Location: Hawaii, USA
Posts: 7,168
Default

Quote:
Originally Posted by avs View Post
interesting, i think i break everything else but the lower arm!

i bend the aluminum screw long before the arm cracks. are you using a steel or ti screw?
Nope...I use the aluminum screw. It's a known issue with the IRS arms...many people have had problems with them cracking. If you've bent the aluminum screw it is likely you cracked the arm and didn't realize it because the crack is under the caster block.
InspGadgt is offline   Reply With Quote
Old 01-04-2010, 04:45 PM   #8244
Tech Elite
 
SpraydbySprague's Avatar
 
Join Date: Jun 2008
Location: Conducting aggressive board meetings at my local track
Posts: 3,301
Trader Rating: 64 (100%+)
Default

Quote:
Originally Posted by notsocrazybrit View Post
Hi Guys,
Got a new BMI for Christmas, put the car together which was no problem, love the quality of the parts. I've installed motor and electronics and did a quick tweak check, lifting the front wheels by the middle of the chassis. The right front lifts first, when I lower it back down the left front is down first. Checked the front end, everything is okay, tried a different front end but still the problem exists. Switched the flex plates from one side to the other, still the same problem. I'm not sure what I've done wrong. Any suggestions?
I currently run an Asscioated 12R5 and chose a BMI because of its reputation for not tweaking. I have the new carbon flex plates coming, maybe that will help.
Thanks Guys.
Double check the sockets on the flex links. Make sure the set screws are not too tight on the pivot balls. The flex links should be able to flop under their own weight when detached from the front mounts on the chassis, yet have as little up and down play on the pivot ball as possible. It takes a delicate touch to get them just right.

Quote:
Originally Posted by InspGadgt View Post
I wasn't talking about the regular AE arm but the IRS lower arm which comes with the BMI kit. It cracks right in the bolt hole even when I tap threads into the hole.
I've developed the small stress crack in the IRS arm as well, but the arm still holds. As long as the screw will tighten down I'll run it until it completely breaks. Two seasons on my 12RR, and I have only broke one arm completely.
__________________
How would I describe my holeshots?

Three words...

Ready... Steady... Confetti!!!! (gonna need a new one of those)
SpraydbySprague is offline   Reply With Quote
Old 01-04-2010, 05:03 PM   #8245
Tech Elite
 
oeoeo327's Avatar
 
Join Date: Oct 2008
Posts: 3,343
Trader Rating: 70 (100%+)
Default

Quote:
Originally Posted by Quietman View Post
Irs used to do lowered ae front arms a few years ago
CRC still sells lowered front AE 12L3 lower arms - CRC part # 1247...
__________________
Founding member of the Solid Gold Racing Team - Mediocrity, redefined...
✯Jackson RC✯Horsham RC✯SJCCR✯
oeoeo327 is offline   Reply With Quote
Old 01-04-2010, 05:13 PM   #8246
Tech Adept
 
-showtime-'s Avatar
 
Join Date: Oct 2007
Location: Kittanning, PA
Posts: 163
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by Quietman View Post
Irs used to do lowered ae front arms a few years ago
BMI sells the lowered associated arms also.

Quote:
Originally Posted by notsocrazybrit View Post
Hi Guys,
Got a new BMI for Christmas, put the car together which was no problem, love the quality of the parts. I've installed motor and electronics and did a quick tweak check, lifting the front wheels by the middle of the chassis. The right front lifts first, when I lower it back down the left front is down first. Checked the front end, everything is okay, tried a different front end but still the problem exists. Switched the flex plates from one side to the other, still the same problem. I'm not sure what I've done wrong. Any suggestions?
I currently run an Asscioated 12R5 and chose a BMI because of its reputation for not tweaking. I have the new carbon flex plates coming, maybe that will help.
Thanks Guys.
If your car isn't balance side to side it will act that way.
__________________
Greg Dobrosky
Showtime Designs

BMI - Parma - The Raceway at Beaver, PA
-showtime- is offline   Reply With Quote
Old 01-05-2010, 07:09 PM   #8247
Tech Fanatic
 
Join Date: Jun 2009
Posts: 994
Trader Rating: 2 (100%+)
Default

Quote:
Double check the sockets on the flex links. Make sure the set screws are not too tight on the pivot balls. The flex links should be able to flop under their own weight when detached from the front mounts on the chassis, yet have as little up and down play on the pivot ball as possible. It takes a delicate touch to get them just right.
Quote:
If your car isn't balance side to side it will act that way.
Thanks very much for the advice guys. Looks like it was the balance of the car. I'm now in the process of adding weight to the right side of the car, it seems like that will fix the problem. What a shame having to add weight.
__________________
Cheers,

Kev
notsocrazybrit is offline   Reply With Quote
Old 01-05-2010, 07:17 PM   #8248
Tech Adept
 
-showtime-'s Avatar
 
Join Date: Oct 2007
Location: Kittanning, PA
Posts: 163
Trader Rating: 1 (100%+)
Default

Have you tried rearranging your electronics? Moving the components around, in and out on the chassis, ect. Most of the time you can get things pretty close that way without having to add weight.
__________________
Greg Dobrosky
Showtime Designs

BMI - Parma - The Raceway at Beaver, PA
-showtime- is offline   Reply With Quote
Old 01-08-2010, 07:59 PM   #8249
Tech Master
 
CarlosG.'s Avatar
 
Join Date: Jul 2004
Location: Falls City,TX
Posts: 1,145
Trader Rating: 12 (100%+)
Send a message via Yahoo to CarlosG.
Default

Jason, any chance you would make a 0.026 linear spring. I checked the website and you go as high as 0.024.
CarlosG. is offline   Reply With Quote
Old 01-10-2010, 08:41 AM   #8250
Tech Elite
 
SpraydbySprague's Avatar
 
Join Date: Jun 2008
Location: Conducting aggressive board meetings at my local track
Posts: 3,301
Trader Rating: 64 (100%+)
Default

Jason, I'm having a bit of an issue with the 12rr. I sent you a PM and Email. I'm hoping you can help.
__________________
How would I describe my holeshots?

Three words...

Ready... Steady... Confetti!!!! (gonna need a new one of those)
SpraydbySprague is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
NEW IN BOX BMI DB12R bigb11 R/C Items: For Sale/Trade 47 10-09-2008 04:36 PM
-BMI DB12R- joey R/C Items: For Sale/Trade 11 05-18-2008 09:25 PM
BMI DB12R wallstreet R/C Items: For Sale/Trade 17 02-15-2008 05:04 PM
BMI DB12R D-Bizzle R/C Items: For Sale/Trade 2 12-21-2007 03:48 PM
WTB BMI DB12R chris moore R/C Items: Wanted to Buy 8 06-29-2007 06:25 PM



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 08:45 AM.


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