R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 06-02-2008, 08:57 AM   #6226
Tech Champion
 
Join Date: Jun 2004
Location: St Louis
Posts: 7,868
Trader Rating: 198 (100%+)
Default

Now remember, a motor that is under geared means it is running at its highest RPM more often=heat. Gear up does not mean the motor gets hotter necessarily.
__________________
Please become an organ donor.
www.donatelife.net
Custom decals and Sno-Tee'z, T-Shirts by Sno Camel

Last edited by dodgeguy; 06-02-2008 at 09:07 AM.
dodgeguy is offline   Reply With Quote
Old 06-02-2008, 09:04 AM   #6227
Tech Regular
 
Rock'sTC3's Avatar
 
Join Date: Nov 2003
Location: MEmphis
Posts: 232
Trader Rating: 5 (100%+)
Send a message via AIM to Rock'sTC3 Send a message via Yahoo to Rock'sTC3
Default

well, seems to me my car reaches max speed about 2/3rds down the straight on our track. Which I thought was the perfect point. Since the guys running lower FDR are overheating and since when I rean a 5.2FDR my temps were much lower. I assumed going any lower on FDR would increase temps even more giving me a problem over heating. Maybe I am wrong here.
This is all still with the 13.5
__________________
Treasurer MSRA Drop out and failed that position
Rock'sTC3 is offline   Reply With Quote
Old 06-02-2008, 09:16 AM   #6228
The Evicerator
R/C Tech Elite Subscriber
 
Join Date: Sep 2001
Location: Irvine, CA
Posts: 4,142
Default

Gearing is difficult to recommend all the time due to differences between motors, track sizes, traction, temperatures, and driving style.

We recommend that you gear your motor so that it runs no hotter than 160 or 170 when using the recomended starting points I mentioned a bit earlier.

Motors can run hot when over or under geared...generally I see this more with the "modified" motors...but it can happen with the spec motors as well.

Also, check the condition of your rotor... if you have run it hot a number of times it may have been weakened slightly and need replacement.
__________________
Steve Weiss
TEAM ASSOCIATED -- REEDY -- SANWA -- PROTOFORM -- 1UP Racing -- ActivRC -- P1 BRAND -- TEAM KINWALD -- TEAM STEVE INTERNATIONAL
Steve Weiss is offline   Reply With Quote
Old 06-02-2008, 09:50 AM   #6229
Tech Elite
 
artwork's Avatar
 
Join Date: Sep 2004
Location: Thornton, CO
Posts: 3,112
Trader Rating: 62 (100%+)
Default

Steve-

Have a quick question for you abouyt my GTB...

This weekend I was running and I was thermaling my motor on every run. I have used this same combination in the past (Novak motor and speedo) with the same gearing without any issues. The thermal is only in the motor the speedo does not thermal.

Things I tried to resolve this:
1) I tired gearing down a few teeth (48P), but this did not help
2) I matched the gearing of a friend of mine (which was gearing up in fact) that I was racing with (we have the exact same setup), but this did not help
3) I tired a brand new Novak 10.5 motor, still thermaled
4) Got mad and went home.

I have been running brushless for a long time and I have never had issues like this...could the problem be with the Speedo?

Not sure what else to check...

Things to note:
Track was pretty big, but I have run on bigger with this same gearing without issues. Nothing bound up in the drivetrain. I pulled the original motor and checked rotor and bearings and did not see any issues. Windings looked fine in the can.
__________________
Sanwa | R1 Wurks | Avid | 2mm Designs
artwork is offline   Reply With Quote
Old 06-02-2008, 10:09 AM   #6230
The Evicerator
R/C Tech Elite Subscriber
 
Join Date: Sep 2001
Location: Irvine, CA
Posts: 4,142
Default

Hi Artwork,

Sorry to hear that you're having trouble with your equipment.

Did you happen to get some actual temperatures on the motors that you tried?

If the motor is not really hot (under 150 normally) you can try removing the blue wire from the sensor harness to see if this helps your problem at all.

We have seen some ESCs that have "touchy" thermal shutdowns...but usually they are like that from the get go and do not "catch" it later in life... but there is a possbility there could be something wrong with your ESC...and if the blue wire fix doesn't help I would recommend sending everything in for a good once over and replacement.


Quote:
Originally Posted by artwork View Post
Steve-

Have a quick question for you abouyt my GTB...

This weekend I was running and I was thermaling my motor on every run. I have used this same combination in the past (Novak motor and speedo) with the same gearing without any issues. The thermal is only in the motor the speedo does not thermal.

Things I tried to resolve this:
1) I tired gearing down a few teeth (48P), but this did not help
2) I matched the gearing of a friend of mine (which was gearing up in fact) that I was racing with (we have the exact same setup), but this did not help
3) I tired a brand new Novak 10.5 motor, still thermaled
4) Got mad and went home.

I have been running brushless for a long time and I have never had issues like this...could the problem be with the Speedo?

Not sure what else to check...

Things to note:
Track was pretty big, but I have run on bigger with this same gearing without issues. Nothing bound up in the drivetrain. I pulled the original motor and checked rotor and bearings and did not see any issues. Windings looked fine in the can.
__________________
Steve Weiss
TEAM ASSOCIATED -- REEDY -- SANWA -- PROTOFORM -- 1UP Racing -- ActivRC -- P1 BRAND -- TEAM KINWALD -- TEAM STEVE INTERNATIONAL
Steve Weiss is offline   Reply With Quote
Old 06-02-2008, 10:25 AM   #6231
Tech Regular
 
Rock'sTC3's Avatar
 
Join Date: Nov 2003
Location: MEmphis
Posts: 232
Trader Rating: 5 (100%+)
Send a message via AIM to Rock'sTC3 Send a message via Yahoo to Rock'sTC3
Default

okay, so if it can overheat in either direction then how would one know which direction to take the gearing?

Memphis track info
Outside temp 85-100 degrees, Track temp 90-130 degrees.. Very humid
Layout is small fast and technical, lots of short straights and hard braking..
Grip is very slippery at best.
__________________
Treasurer MSRA Drop out and failed that position
Rock'sTC3 is offline   Reply With Quote
Old 06-02-2008, 11:17 AM   #6232
The Evicerator
R/C Tech Elite Subscriber
 
Join Date: Sep 2001
Location: Irvine, CA
Posts: 4,142
Default

It's hard to guage sometimes with the "spec" motors... but generally when the ESC temp is very low but the motor temp is high, the gearing is too short.

When both ESC and motor temps are "high" that tends to lead me to believe that the gearing is on the tall side.

But because the "spec" motors aren't that hard on the ESC it's hard to guage this.

I would say that if your track has alot of "short straights" then a lower/shorter gear ratio is probably what you need to keep your motor cooler overall.

Again, check your rotor's magnet as well, as that degredation with this is usually slow and sort of creeps up on you.
__________________
Steve Weiss
TEAM ASSOCIATED -- REEDY -- SANWA -- PROTOFORM -- 1UP Racing -- ActivRC -- P1 BRAND -- TEAM KINWALD -- TEAM STEVE INTERNATIONAL
Steve Weiss is offline   Reply With Quote
Old 06-03-2008, 04:27 AM   #6233
Tech Adept
 
xraysteve's Avatar
 
Join Date: Feb 2008
Location: blissfield,mi
Posts: 146
Default

hi i killed to lipos this weekend. they were over a yaer old. they seemed all right last week. old but ok. the track that a race on had just been resurfaced. so there was more traction. maybe the more traction swelled up my lipos. the motor was 140f the speedo was about 130f and the cap was some were in there. nothing to hot. i may have a bad bearing some where in the car. i just don't want to ruin a new pack. anything you could suggest. could i be running to fast of a motor for the lipo packs. they were max amps 6000 and now i just got smc 4000. i run a 4.5. if the motor and speedo and cap are not hot then they are running just fine right.
__________________
lazer speedway everything else is a parking lot
xraysteve is offline   Reply With Quote
Old 06-03-2008, 07:36 AM   #6234
Tech Elite
 
Yeti35's Avatar
 
Join Date: Sep 2004
Location: SL, UT
Posts: 2,804
Trader Rating: 5 (100%+)
Default

Steve, I got a question for yah. When you are temping the motors where should you take the temp from? I went to temp a motor this past weekend out of curiousity and when I temped the ring it was 169 but when I temped the can it was 129. Which area is more accurate to be reading temps from? Speedo was cool since I was only running a 13.5/10.5. I am not having any issues with my setup, just more interested in what area to check for temps.
__________________
JRXS Type R, I have four of them!! ;) ( Yes, I still have them!!)And racing one of them again!!
22 3.0SR
22T 2.0 w/ Exotech chassis
Yeti35 is offline   Reply With Quote
Old 06-03-2008, 07:50 AM   #6235
Tech Champion
 
Join Date: Jun 2004
Location: St Louis
Posts: 7,868
Trader Rating: 198 (100%+)
Default

FYI on temp guns, Silver will not give accurate readings. Due to emissivity that happens. Most good temp guns in the instructions will explain this and recommend that the surface color is black for accurate readings.
__________________
Please become an organ donor.
www.donatelife.net
Custom decals and Sno-Tee'z, T-Shirts by Sno Camel
dodgeguy is offline   Reply With Quote
Old 06-03-2008, 08:17 AM   #6236
Tech Master
 
timmay70's Avatar
 
Join Date: Dec 2003
Posts: 1,701
Trader Rating: 5 (100%+)
Default

Another thing on those pretty purple rings, if the rings aren't in full contact with the laminations at all points, I.E. if there are air gaps, then they are serving to insulate the core part of the motor (the motor's highest temp). So, if you can spin the sleeve with ease, congrats - you have a motor insulator. Same goes with the purpose built heatsinks. I have removed all the rings from my motors, and have been temping right on the laminations.

As for temping on black, it doesn't have to be anything special, just sharpie a black spot on your motor and temp that spot all the time.
__________________
Speed Merchant Rev7, Tekin, TQ Racing (wire), Team Tamale
RC Excitement - Buy where you race, support your local tracks.
ROAR #105242
timmay70 is offline   Reply With Quote
Old 06-03-2008, 08:51 AM   #6237
The Evicerator
R/C Tech Elite Subscriber
 
Join Date: Sep 2001
Location: Irvine, CA
Posts: 4,142
Default

It's hard to say... it depends on the C rating of the lipo and it's condition. Brushless systems in general have the ability to pull alot of current and this could be too much for certain lipos.

We've used maxamps packs here alot and haven't run into the type of problem you are describing... are you sure that the lipo cut off was activated in your GTB?

Also, how hot was the battery?

Quote:
Originally Posted by xraysteve View Post
hi i killed to lipos this weekend. they were over a yaer old. they seemed all right last week. old but ok. the track that a race on had just been resurfaced. so there was more traction. maybe the more traction swelled up my lipos. the motor was 140f the speedo was about 130f and the cap was some were in there. nothing to hot. i may have a bad bearing some where in the car. i just don't want to ruin a new pack. anything you could suggest. could i be running to fast of a motor for the lipo packs. they were max amps 6000 and now i just got smc 4000. i run a 4.5. if the motor and speedo and cap are not hot then they are running just fine right.
In regards to temping the motor I usually do one of a number of things:

Temp the black end cap/end screw... while this might not be the absolute hottest part of the motor it is oftentimes very consistant.

The purple/black/blue band on the motor is generally another decent spot to temp as well. Like some mentioned if the ring is loose then the readings you will get will not be consistant.

Someone mentioned putting sharpie on your motor endbell to give it some color for the IR temp guages to work properly... this or a small sticker will work to get a better readings as well.

Quote:
Originally Posted by Yeti35 View Post
Steve, I got a question for yah. When you are temping the motors where should you take the temp from? I went to temp a motor this past weekend out of curiousity and when I temped the ring it was 169 but when I temped the can it was 129. Which area is more accurate to be reading temps from? Speedo was cool since I was only running a 13.5/10.5. I am not having any issues with my setup, just more interested in what area to check for temps.
__________________
Steve Weiss
TEAM ASSOCIATED -- REEDY -- SANWA -- PROTOFORM -- 1UP Racing -- ActivRC -- P1 BRAND -- TEAM KINWALD -- TEAM STEVE INTERNATIONAL
Steve Weiss is offline   Reply With Quote
Old 06-03-2008, 09:19 AM   #6238
The Evicerator
R/C Tech Elite Subscriber
 
Join Date: Sep 2001
Location: Irvine, CA
Posts: 4,142
Default Timing Confusion

Since there seems to be some confusion about how to identify timing in your motor I posted some pictures here as examples.

I appologize if in the past I have made a mistake when trying to explain this to someone... guess sometimes I'm a little rushed when answering these things !
Attached Thumbnails
Ask Steve "The Evicerator" Weiss-advanced.jpg   Ask Steve "The Evicerator" Weiss-reduced.jpg   Ask Steve "The Evicerator" Weiss-factory.jpg  
__________________
Steve Weiss
TEAM ASSOCIATED -- REEDY -- SANWA -- PROTOFORM -- 1UP Racing -- ActivRC -- P1 BRAND -- TEAM KINWALD -- TEAM STEVE INTERNATIONAL

Last edited by Steve Weiss; 06-03-2008 at 09:31 AM.
Steve Weiss is offline   Reply With Quote
Old 06-03-2008, 10:03 AM   #6239
Tech Champion
 
Join Date: Jun 2004
Location: St Louis
Posts: 7,868
Trader Rating: 198 (100%+)
Default

Steve, could you make a reference mark on the blue ring? I really can not tell which direction advance and retard is.
__________________
Please become an organ donor.
www.donatelife.net
Custom decals and Sno-Tee'z, T-Shirts by Sno Camel
dodgeguy is offline   Reply With Quote
Old 06-03-2008, 10:05 AM   #6240
Tech Master
 
c-lyon's Avatar
 
Join Date: Aug 2001
Location: Calgary
Posts: 1,724
Trader Rating: 7 (100%+)
Default

Steve, private message. Thanks.
c-lyon is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
STUFF FOR SALE """"LQQK """" EZRC R/C Items: For Sale/Trade 1 03-13-2007 07:20 PM
"""NEW""" Collari .21 3 port buggy motor lc21-b3 goneRVing R/C Items: For Sale/Trade 7 12-20-2006 06:25 PM
STUFF FOR SALE """"LQQK """" EZRC R/C Items: For Sale/Trade 11 10-22-2006 09:49 PM
""" XRAY FK05 """ excellent cond/super clean/stock evostyle R/C Items: For Sale/Trade 9 06-29-2006 10:04 PM
Let's send Steve Weiss (Evicerator) to Cleveland!!! TeamButter Electric On-Road 8 11-02-2004 11:32 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 08:50 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net