R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 04-02-2007, 07:01 AM   #1036
Tech Master
 
billjacobs's Avatar
 
Join Date: Sep 2004
Location: Rockville, MD
Posts: 1,264
Trader Rating: 54 (100%+)
Default adding weight to 3200 lipo

To Rick Hohwart or Mr.Black,

I run the carbon lipo 3200s and 13.5 brushless in a ta05 and find that I need to add about 4.3oz to the battery to bring the car to the roar minimum weight. This weight also evens out the steering (without the weight, the car turns fine to the left, but to the right is an inside wheel lifting, spin out nightmare.) I am currently using tungsten carbide weights below the battery strap that sits in the cut out on top of the battery. (Tungsten because 1- tungsten is 1.7 times heavier than lead, 2- lead is toxic.) If Orion/Peak can create a tunsten blank (1" by 4" by 1/8" thick) to fit into the cutoff, this would add about 4 to 4.5 oz to the battery. In addition, because the weight is higher, less weight is needed than if the weight were lower (I think this is because in the corners having the weight farther from the roll-center makes it move more.) I have called tungsten shops, and the cost for the blank is about $50 if you buy 8 of them. Orion could have these made in china, korea, etc for about $15 each (maybe less,) and resell them to racers. This would fix a big issue with lipos, and still allow you to remove the tungsten blank for weight savings in cars with the battery down the middle, or in cars like the tamiya mini or f103gt.

Any thoughts?
billjacobs is offline   Reply With Quote
Old 04-02-2007, 08:45 AM   #1037
Tech Addict
 
Iceracer's Avatar
 
Join Date: Feb 2006
Location: Canada
Posts: 656
Trader Rating: 1 (100%+)
Default

What's the advantage in using any exotic material for adding weight? Weight is weight, whether its a stone or a piece of gold.
Iceracer is offline   Reply With Quote
Old 04-02-2007, 08:48 AM   #1038
TEM
Tech Regular
 
TEM's Avatar
 
Join Date: Apr 2005
Posts: 253
Default

Quote:
Originally Posted by Iceracer
What's the advantage in using any exotic material for adding weight? Weight is weight, whether its a stone or a piece of gold.
The higher weight density of a material; the smaller piece you have to use. That lets you target the weight "on-spot" where it's needed AND it also keeps the CG lower on the chassis.



Thanks to the guys who answered my question on current usage!
TEM is offline   Reply With Quote
Old 04-02-2007, 09:02 AM   #1039
Tech Lord
 
syndr0me's Avatar
 
Join Date: Dec 2004
Location: 5280 Raceway
Posts: 13,140
Trader Rating: 32 (100%+)
Default

Quote:
Originally Posted by Iceracer
What's the advantage in using any exotic material for adding weight? Weight is weight, whether its a stone or a piece of gold.
Lead is a nasty, nasty metal. It's highly toxic, and should be avoided if that's an option.

As someone else said, a piece of tungsten is 1.7x heavier than a piece of lead the same size. This is important in R/C since we have very limited space to place weights to begin with.

Rick mentioned in another thread that they're developing a "heavy" version of their LiPo battery.
syndr0me is offline   Reply With Quote
Old 04-02-2007, 09:23 AM   #1040
Tech Addict
 
MrBlack's Avatar
 
Join Date: Jul 2006
Location: OC
Posts: 746
Default

Quote:
Originally Posted by billjacobs
To Rick Hohwart or Mr.Black,

I run the carbon lipo 3200s and 13.5 brushless in a ta05 and find that I need to add about 4.3oz to the battery to bring the car to the roar minimum weight. This weight also evens out the steering (without the weight, the car turns fine to the left, but to the right is an inside wheel lifting, spin out nightmare.) I am currently using tungsten carbide weights below the battery strap that sits in the cut out on top of the battery. (Tungsten because 1- tungsten is 1.7 times heavier than lead, 2- lead is toxic.) If Orion/Peak can create a tunsten blank (1" by 4" by 1/8" thick) to fit into the cutoff, this would add about 4 to 4.5 oz to the battery. In addition, because the weight is higher, less weight is needed than if the weight were lower (I think this is because in the corners having the weight farther from the roll-center makes it move more.) I have called tungsten shops, and the cost for the blank is about $50 if you buy 8 of them. Orion could have these made in china, korea, etc for about $15 each (maybe less,) and resell them to racers. This would fix a big issue with lipos, and still allow you to remove the tungsten blank for weight savings in cars with the battery down the middle, or in cars like the tamiya mini or f103gt.

Any thoughts?
Hi Billy yes we have actually been working on a "heavy" battery since last fall and have a 98% finalized design waiting for final production testing. Yes you are correct Tungsten is heavier this is why we have in the past suggested it over Lead for those with higher budgets. We would still keep the lighter 4800 as the majority of users prefer the weight savings and would only add the Heavy battery as a further option in a growing line of LiPo solutions.

Thanks for the input.

By The way thank you to all of our customers for voting the Platinum 4800 Lipo as the Car Action 2007 Reader Choice winner for Batteries .
__________________
TEAM ORION - AVIONICS - KYOSHO - KO PROPO - PEAK

"Racing is about the journey not the destination if it wasn't it would simply be called Arriving"

"The solution is people need to spend more of their efforts on promoting and finding more people to race with, rather then a personal quest to form a class that they can win at."
MrBlack is offline   Reply With Quote
Old 04-02-2007, 09:28 AM   #1041
Tech Master
 
billjacobs's Avatar
 
Join Date: Sep 2004
Location: Rockville, MD
Posts: 1,264
Trader Rating: 54 (100%+)
Default heavy 3200

The problem I see in a heavy 3200 is that it doesn't give the option of 1 lipo battery with 2 different weights. I am assuming you will take out the top recessed area and put weight at the bottom and move the lipo's up. The reason I attached the tungsten to the battery strap is so that the weight would not rest on the plastic 3200 case, and because you don't have to use as much weight if it is higher up. A tungsten blank would do the same thing except that it would be a cleaner solution and:
1) you could remove it easily for lighter running
2) you could attach it to the graphite battery strap
billjacobs is offline   Reply With Quote
Old 04-02-2007, 09:35 AM   #1042
Tech Master
 
billjacobs's Avatar
 
Join Date: Sep 2004
Location: Rockville, MD
Posts: 1,264
Trader Rating: 54 (100%+)
Default lead concerns

As for lead, a couple of things:
1) it is toxic, but only if ingested or inhaled, it is difficult (but not impossible)to absorb lead thru the skin. That is why eating while using lead solder is a bad idea.
2) 10% of the lead ingested or inhaled is absorbed and retained in adults, 90% of the same lead is absorbed and retained in pregnant women and infants.

I wouldn't worry so much about handling lead if you wash your hands thoroughly afterwards, and if you wear a respirator if you sand it. If you are working with molten lead (casting, forming, etc,) then at high temperatures it can vaporize and you could breathe it in (soldering isn't hot enough.)

But all in all, especially around kids, using lead is a bad idea. (Including solder.)
billjacobs is offline   Reply With Quote
Old 04-02-2007, 05:25 PM   #1043
TEM
Tech Regular
 
TEM's Avatar
 
Join Date: Apr 2005
Posts: 253
Default lipo, weight, etc

Towerhobbies got them at 84.99 and you get a 10bucks off with a purchase of between 100 to 150, etc, etc. I got one coming in the mail with some other junk. I'll be real pleased if the 3200 behaves like the 4800PE.

Assuming in a 19T touring car. 3 to 4 runs a day; Almost every Sunday. How long before the battery is "done"?

For the weight thing; does anyone make any tungsten "pucks" that you can secure to the chassis? Somehow I feel it's better to do that than sandbag batteries to make them heavier.

I would be PISSED if all of a sudden they say you have to use the new weighted lipos when they come out! (among all the other bs rules in the hobby!)
TEM is offline   Reply With Quote
Old 04-02-2007, 05:45 PM   #1044
Tech Lord
 
Hebiki's Avatar
 
Join Date: Aug 2003
Location: Chino, CA
Posts: 12,919
Trader Rating: 26 (100%+)
Default

Quote:
Originally Posted by TEM
Towerhobbies got them at 84.99 and you get a 10bucks off with a purchase of between 100 to 150, etc, etc. I got one coming in the mail with some other junk. I'll be real pleased if the 3200 behaves like the 4800PE.

Assuming in a 19T touring car. 3 to 4 runs a day; Almost every Sunday. How long before the battery is "done"?

For the weight thing; does anyone make any tungsten "pucks" that you can secure to the chassis? Somehow I feel it's better to do that than sandbag batteries to make them heavier.

I would be PISSED if all of a sudden they say you have to use the new weighted lipos when they come out! (among all the other bs rules in the hobby!)
TEM not sure what you're asking exactly about the 3200's being done. But after my practice runs (usually 6-7 mins with a 19T), i take the pack and throw it immediately on the charger. it takes another 30-35mins to "top it off". I actually have to wait for the motor to cool down. Having two 3200s lets me practice non-stop.

My wait now really involves finishing my set up changes, the motor to cool down or if im running with a friend, for their battery to finish. it really does give me more time to wrench and more driving time.
__________________
Hebiki Design Works
Custom R/C Vinyl Graphics & Apparel: Your gear, your way!
Web Design - Web Development - Logo Design - Graphic Design
www.facebook.com/HebikiDesignWorks
Hebiki is offline   Reply With Quote
Old 04-02-2007, 05:51 PM   #1045
Registered User
 
Join Date: Sep 2003
Location: Chicago area
Posts: 47
Default

Quote:
Originally Posted by billjacobs
The problem I see in a heavy 3200 is that it doesn't give the option of 1 lipo battery with 2 different weights. I am assuming you will take out the top recessed area and put weight at the bottom and move the lipo's up. The reason I attached the tungsten to the battery strap is so that the weight would not rest on the plastic 3200 case, and because you don't have to use as much weight if it is higher up. A tungsten blank would do the same thing except that it would be a cleaner solution and:
1) you could remove it easily for lighter running
2) you could attach it to the graphite battery strap

DUDE! Stop eating the lead! WTH do you mean by "and because you don't have to use as much weight if it is higher up" Are you insane allready? If you need to add weight to make minimum as raced weight, the scale don't know the height of the weight. The chassis sure knows the diferance between low weight and high weight when in comes to chassis dynamics. Did you ever take High School Physics?

To all saine readers, please mount the weight as low as possible and do yourself and your chassis a favor.

You read the damndest things on the iternet, thank you Al Gore...
Don't get me started on Global Warming. Al Gores company will sell you carbon credits that they just print up for lotsa your excess cash. (that is if you are gulible enough or have to much cash and feel guilty...)

Radar... ping.....

Still laughing very loudly...... ping....
radar is offline   Reply With Quote
Old 04-02-2007, 06:27 PM   #1046
TEM
Tech Regular
 
TEM's Avatar
 
Join Date: Apr 2005
Posts: 253
Default

Quote:
Originally Posted by Hebiki
TEM not sure what you're asking exactly about the 3200's being done. But after my practice runs (usually 6-7 mins with a 19T), i take the pack and throw it immediately on the charger. it takes another 30-35mins to "top it off". I actually have to wait for the motor to cool down. Having two 3200s lets me practice non-stop.

My wait now really involves finishing my set up changes, the motor to cool down or if im running with a friend, for their battery to finish. it really does give me more time to wrench and more driving time.
By "done" I mean significant decline in performance. As good as it may sound; everything dies eventually. Just different things die at a different rate. I got a 4800PE but haven't had much chance to use it yet. Got a 3200 coming but I don't like to keep much more than I have to before rule changes or something better comes out. The idea is I can get away with 1 in each car? But for how long is what I want to know.
TEM is offline   Reply With Quote
Old 04-02-2007, 07:01 PM   #1047
Tech Elite
 
andrewdoherty's Avatar
 
Join Date: Jan 2005
Location: ★Wylie, TX★
Posts: 3,776
Trader Rating: 47 (100%+)
Default

I've ben racing my 4800 PE since June of 2006 nearly every week. Just a week ago I qualified third in our local big race with that 9-10 month old 4800 in stock rubber. I'd say you'll get tired of it before you "use it up".
__________________
"Whether you think you can, or think you can't, you're right." -Henry Ford
"[Driving] Genius is 1% inspiration, and 99% perspiration" -T.A. Edison
|◤Hobbywing◢|◤SpeedzoneUSA.com◢|◤Pro-One◢|
|◤ReflexRacing.net◢|◤Protoform◢|◤AVID R/C◢|
andrewdoherty is offline   Reply With Quote
Old 04-02-2007, 08:38 PM   #1048
Tech Elite
 
Rick Hohwart's Avatar
 
Join Date: Sep 2003
Posts: 3,935
Default

Quote:
Originally Posted by TEM
For the weight thing; does anyone make any tungsten "pucks" that you can secure to the chassis? Somehow I feel it's better to do that than sandbag batteries to make them heavier.
Hudy sells weights of various sizes that can be attached to your chassis with normal screws. You will have to drill and countersink a hole, but in the end the ballast installation is much cleaner.

This is a better solution than adding weight to the battery. Why? Because adding weight to the battery is not necessarily balancing the car. An IB4200 weighs more than most electronics, so if you ballast the LiPo to equal an IB pack, you are contributing to the imbalance. If you must add weight tot he battery, you want to add enough so that the weight of the battery and electronics are equal. Then ballast the chassis equally on each side and front to back.
__________________
www.reedypower.com
Rick Hohwart is offline   Reply With Quote
Old 04-02-2007, 08:39 PM   #1049
Tech Regular
 
Join Date: Apr 2004
Posts: 352
Trader Rating: 6 (100%+)
Default

Quote:
Originally Posted by MrBlack
Hi Billy yes we have actually been working on a "heavy" battery since last fall and have a 98% finalized design waiting for final production testing. Yes you are correct Tungsten is heavier this is why we have in the past suggested it over Lead for those with higher budgets. We would still keep the lighter 4800 as the majority of users prefer the weight savings and would only add the Heavy battery as a further option in a growing line of LiPo solutions.

Thanks for the input.

By The way thank you to all of our customers for voting the Platinum 4800 Lipo as the Car Action 2007 Reader Choice winner for Batteries .
Will there be something we who have 3200 now do to get the "heavy" batteries? Perhaps send them in for an upgrade.
Goggles Paesan is offline   Reply With Quote
Old 04-02-2007, 09:42 PM   #1050
Tech Master
 
billjacobs's Avatar
 
Join Date: Sep 2004
Location: Rockville, MD
Posts: 1,264
Trader Rating: 54 (100%+)
Default position of weight

Geez, now my education is being called into question by Radar: an unidentified user who mixes physics wisdom with al gore rants and sprinkles in misspelled words and "dude".

If you mount the weight higher up, you increase the center of gravity. Since the roll center is lower than the center of gravity, you are increasing chassis roll (same thing as lowering the inner a-arm pivots.) My problem with a light battery was turning to the right, since the battery is on the right side. When you turn to the right, the left side gets the weight shifted to it, and because the right side is so light, the right wheels were almost lifting off the ground when you turned right. Adding the minimum weight to the right side higher up increased the roll and stopped the right side tires from lifting off the ground. I wanted to add the least possible weight to meet the roar minimum. To balance the car and put the weight as low as possible, I would have to add another 4 more ounces to the right side, which I didn't want to do.

Before you question someone's education, understand what the problem is and if their solution makes sense. If my understanding is wrong, then fine, I will listen to someone who knows better. But my reasoning is not: always mount the weight low, because that's what everyone says.

By the way, I am not a fan of Al Gore, but if carbon emissions trap the suns rays from reflecting back into space, it will cause a greenhouse effect, which will cause "global warming." The major initial signs of this are unpredictable weather, not necessarily a 20 degree hotter earth. Before you believe Rush Limbaugh's BS, read a little. And yes, carbon credits are a sham.

Last edited by billjacobs; 04-02-2007 at 09:57 PM.
billjacobs is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
NIP Team Orion 3200Mah Lipo Race Pack limbohz R/C Items: For Sale/Trade 0 05-30-2008 10:36 AM
Peak 3200mah carbon spec lipo aus jd 2703 Australia For Sale/Trade 8 04-23-2008 09:12 PM
Team Orion Carbon Edition 3200mAh LiPo squearl R/C Items: For Sale/Trade 7 03-11-2008 06:35 AM
Team Orion Carbon Edition 3200mAh lipo batteries dido41 R/C Items: Wanted to Buy 3 07-26-2007 04:10 PM
2 Team Orion Carbon Edition 3200mAh LiPo Batteries CCristo R/C Items: For Sale/Trade 1 05-04-2007 11:48 AM



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 06:53 AM.


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