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Old 04-05-2009, 04:54 AM   #1
Quarry Creeper
 
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Default Lowering COG Help Needed

I am running an Axial AX 10 RTR. I have replaced the standard stick battery with a split pack on the front axle. I have moved the ESC and Receiver to top links. What else can I do to lower the COG of my crawler? I have read about using droop shocks, but I want to try a regular shock set up first on my crawler. Are there shorter shocks that will work on my RTR Axial? If so how short of a shock can I use on my RTR? I have attempted to flip my schocks without sucess due to my bent links. Looking at getting a different chassis at some point in time. Any suggestions on which chassis will help with performance and low COG,

Is there anything else I can do to lower my crawler's COG?

http://www.flickr.com/photos/42427526@N00/3411705791/

http://www.flickr.com/photos/42427526@N00/3411707373/

Last edited by BMFOTP; 04-05-2009 at 04:58 AM. Reason: added info
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Old 04-05-2009, 05:40 AM   #2
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You're off to a good start.

Try adding stick-on weight to the inside of your wheels. You'll have to take the rims apart, but it's well worth the effort. Add 7 oz. to each front rim and 2 oz. to each rear rim. Some guys use far more weight, but this place to start.

Next, slam the body as much as possible. Most new crawlers overlook this because the body is light. Cut out the fenders as much as needed and get that body low. It makes a big difference.

I've run droop for a few years, and I'd recommend sticking with tradition sprung suspension. Droop has some advantages, but it is very time comsuming to get dialed in perfectly.

Try Traxxas Stampede front shocks at all four corners.

Last edited by MattH; 04-05-2009 at 06:01 AM. Reason: added info
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Old 04-05-2009, 06:05 AM   #3
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I would recomend getting a new chassis like the Swx. I wouldn't waste much time in the stock chassis.
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Old 04-05-2009, 08:31 AM   #4
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Quote:
Originally Posted by MattH View Post
You're off to a good start.

Try adding stick-on weight to the inside of your wheels. You'll have to take the rims apart, but it's well worth the effort. Add 7 oz. to each front rim and 2 oz. to each rear rim. Some guys use far more weight, but this place to start.

Next, slam the body as much as possible. Most new crawlers overlook this because the body is light. Cut out the fenders as much as needed and get that body low. It makes a big difference.

I've run droop for a few years, and I'd recommend sticking with tradition sprung suspension. Droop has some advantages, but it is very time comsuming to get dialed in perfectly.

Try Traxxas Stampede front shocks at all four corners.
Thanks for taking the time to respond to my question.

How does adding weight to my tires lower my crawlers COG? I have only been able to add 4 oz of weight. Should I just wrap another layer of weights on top of the first layer of weights?

Why Traxxas Stampede front shocks?
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Old 04-05-2009, 09:26 AM   #5
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Originally Posted by Shaun (yota) View Post
I would recomend getting a new chassis like the Swx. I wouldn't waste much time in the stock chassis.
Thanks for taking the time to respond to my question.

Why do you suggest the Swx chassis over the others that are available?

The HaVoc Chassis

http://www.jpcustomrcs.atomicshops.c...89/6697097.htm

Ares chassis from AKRCC

http://www.akrcc.com/product.html

Thees are the only two I can think of off the top of my head.
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Old 04-05-2009, 10:03 AM   #6
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Originally Posted by BMFOTP View Post
Thanks for taking the time to respond to my question.

How does adding weight to my tires lower my crawlers COG? I have only been able to add 4 oz of weight. Should I just wrap another layer of weights on top of the first layer of weights?

Why Traxxas Stampede front shocks?
Adding weight to the rims lowers where the largest amount of weight is on the vehicle, same moving the battery and other electronics. That's the whole thing center of gravity. Lower is more stable. Go ahead and wrap another layer around the front rims.

The Traxxas Stampede shocks will do a few things. They are short, so they will lower your vehicle and its center of gravity. They will also reduce articulation which will help the truck handle better. Too much articulation usually hurts a lot more than it helps.
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Old 04-05-2009, 12:04 PM   #7
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The Traxxas Stampede shocks will do a few things. They are short, so they will lower your vehicle and its center of gravity. They will also reduce articulation which will help the truck handle better. Too much articulation usually hurts a lot more than it helps.
Thanks for answering those questions with simple answers.

What is the best shock length to use on an Axial AX 10 RTR?

Any idea where I can find the best deal on Traxxas Stampede shocks?

Are there other shocks like the Traxxas Stampede that are as good or better for my crawler?
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Old 04-05-2009, 01:14 PM   #8
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Quote:
Originally Posted by BMFOTP View Post
Thanks for answering those questions with simple answers.

What is the best shock length to use on an Axial AX 10 RTR?

Any idea where I can find the best deal on Traxxas Stampede shocks?

Are there other shocks like the Traxxas Stampede that are as good or better for my crawler?
You can limit your stock shocks to 4 inches with some simple spacers from Home d/ lowes like this.
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Old 04-05-2009, 03:00 PM   #9
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Why would I want to limit my stock shocks with a spacer? From what I see it would only limit the movement of the shock. Doesnt seem like the spacer would help lower my COG. Wouldnt it be easier to buy short shocks to lower my COG?

Remember I am new to this hobby so please explain in simple terms.

I appreciate you taking the time to post a reply to my question.
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Old 04-05-2009, 03:47 PM   #10
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Quote:
Originally Posted by BMFOTP View Post
Why would I want to limit my stock shocks with a spacer? From what I see it would only limit the movement of the shock. Doesnt seem like the spacer would help lower my COG. Wouldnt it be easier to buy short shocks to lower my COG?

Remember I am new to this hobby so please explain in simple terms.

I appreciate you taking the time to post a reply to my question.
It will make the shock shorter, Lowering COG. You can take a stock axial shock and reduce it to 4 inches eye to eye. When i did this on my rig i was able to crawl 3 degrees steeper on my slope test board.

Yes it will also limit articulation some, which is a good thing for comp rigs. To much can actually hurt your crawling ability. Around 70 degrees is plenty for me. I like my rig to only lift its front tire a little above the rear tire. But thats what works best for were i crawl the most.
I am using front slash shock all the way around on my wifes dna rig and it works awsome.They are barely 3 inches eye to eye and this thing crawls great.

Last edited by rottenbelly; 04-05-2009 at 03:49 PM.
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Old 04-05-2009, 04:27 PM   #11
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It will make the shock shorter, Lowering COG. You can take a stock axial shock and reduce it to 4 inches eye to eye. When i did this on my rig i was able to crawl 3 degrees steeper on my slope test board.

Yes it will also limit articulation some, which is a good thing for comp rigs. To much can actually hurt your crawling ability. Around 70 degrees is plenty for me. I like my rig to only lift its front tire a little above the rear tire. But thats what works best for were i crawl the most.
I am using front slash shock all the way around on my wifes dna rig and it works awsome.They are barely 3 inches eye to eye and this thing crawls great.
After looking at the pic with the shock several times I understand what the spacer is doing in the shock. The spacer isnt allowing the shock to return to it normal lenght by blocking some of the inner shaft travel.

Can you tell me how to diassemble my shock so I can get the washer inside the shock? Or do you know a thread where I can find the information?

What lenght spacer should I use in the shock?

Do you have a link to the right size tubing I should get from Lowes?

Any help is appreciated.
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Old 04-05-2009, 04:38 PM   #12
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Originally Posted by BMFOTP View Post
After looking at the pic with the shock several times I understand what the spacer is doing in the shock. The spacer isnt allowing the shock to return to it normal lenght by blocking some of the inner shaft travel.

Can you tell me how to diassemble my shock so I can get the washer inside the shock? Or do you know a thread where I can find the information?

What lenght spacer should I use in the shock?

Do you have a link to the right size tubing I should get from Lowes?

Any help is appreciated.
I took the ball end off the shock, (after the spring cup and spring), Then take shock cap off. This would be a good time to have some towels or a little cup to put the shock oil in. Pull out shock shaft and it will look like that pic with spacer.(without spacer.)
I took shaft with me to lowes and checked which spacer would fit.( I think they were 1/8th inch) Buy the one inch ones. I cut them down to 3/4 inch and that gave me a little over 4 inches eye to eye.
The spacers are called hillman they were like 53 cents for 2!. And were in the isle with all the nut in bolt in a drawer. Package looks like this. But these are the wrong size. These were for a mini crawler shock.

Last edited by rottenbelly; 04-05-2009 at 04:51 PM.
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Old 04-05-2009, 04:45 PM   #13
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to disassemble your shock you take it off the truck, then thread the ball end off the shaft. Next remove the shock cap, drain oil and install your spacer. I would recommend fuel tubing from a nitro rig. cheap and easy to work with. as far as length you can just cut it, test, and refit until you reach the desired length. next assemble the rod and ball end back through the shock body and fill your shocks back up with oil. Reassemble cap and install in truck.
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Old 04-05-2009, 06:44 PM   #14
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What are the correct size for the Axial AX 10 RTR? I would like to pick some up tomorrow.
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Old 04-05-2009, 06:50 PM   #15
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Originally Posted by BMFOTP View Post
What are the correct size for the Axial AX 10 RTR? I would like to pick some up tomorrow.
1/8th inch x 1 inch. If you cut them down to 3/4 inch it will give you a shock length close to 4 inches eye to eye. I put 80 weight oil in rears and 50 in fronts. Works good for me. Some run 50 rear and 30 front.
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Old 04-05-2009, 07:00 PM   #16
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Default Disassembeled Shock

Okay here is the right rear shock disassembled, properly I hope.

http://www.flickr.com/photos/42427526@N00/3415834917/

What do I do with the black spacer on the shock shaft?

I am going to start with 1/4 inch tubing I found in Lowes.
I will go back tomorrow and get the right type of spacer.

Thanks for all your help guys.
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Old 04-05-2009, 07:00 PM   #17
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What are the correct size for the Axial AX 10 RTR? I would like to pick some up tomorrow.
Just get some fuel line tubing from the hobby store. You can cut it to any length you want.

If you're serious about making the truck work well I'd look into a SWX. I'm not gonna say it's the only way, but it's definitely a good way. The SWX was designed for 4" shocks, and I like the Losi Crawler shocks, but the traxxas ones work well too, as long as you get the aluminum ones.
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Old 04-05-2009, 07:20 PM   #18
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What makes one chassis better than another chassis? I am asking because I am new and dont know what to look for in a chassis.

Here are the chassis I have looked at so far in my research:

Ares chassis from AKRCC

http://www.akrcc.com/product.html

The HaVoc Chassis

http://www.jpcustomrcs.atomicshops.c...89/6697097.htm

Bender Customs SWX

http://www.rcnitrotalk.com/bender-cu...x-chassis-kit/

What is your opinion of these three chassis?

Will fuel tube start to deform after a time in the oil?

Which set of Traxxas shocks? There are several different models to chose from on the Traxxas website.
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Old 04-05-2009, 07:58 PM   #19
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Originally Posted by BMFOTP View Post
What makes one chassis better than another chassis? I am asking because I am new and dont know what to look for in a chassis.

Here are the chassis I have looked at so far in my research:

Ares chassis from AKRCC

http://www.akrcc.com/product.html

The HaVoc Chassis

http://www.jpcustomrcs.atomicshops.c...89/6697097.htm

Bender Customs SWX

http://www.rcnitrotalk.com/bender-cu...x-chassis-kit/

What is your opinion of these three chassis?

Will fuel tube start to deform after a time in the oil?

Which set of Traxxas shocks? There are several different models to chose from on the Traxxas website.

First and foremost I look for a chassis that will hold up to my rather abusive driving style. Secondly I look for adjustabilty, thirdly I look at chassis width, and I also look for a design that I think will work well with my setup.
The SWX
Pros:
Notched on the side to allow the motor to hang out. No real threat to the motor, makes the chassis narrower which is definitely good
Design is based on years of experimentation by Bender, among other highly knowledgeable drivers. I drove a SW3 for a long time and loved it-I know it works from experience
Comes with links
Braced on one side, which adds strength
Room for most any dig
Room for a cobalt puller
Not a huge amount of adjustment (what's there is what works best; less to confuse you, will work good sooner)
Cons:
Not a huge amount of adjustment (might not work well with every axle. Non issue with axial axles)
tall-ish. Some people prefer shorter chassis and shocks. I don't, I'm just throwing it out there

Ares Pros:
Lots of adjustment
a lot went into developing that chassis, used by many knowledgeable drivers
Notched on the side for width
plenty of room for dig setups
Cons:
Lots of adjustment
no links
Neither side plate is braced on the top. If it was a problem 666 probably wouldn't use it (he's harder on his rigs than I am) but it still makes me nervous

The havoc was really intended for a MOA rig such as a berg, bully, HR MOA. You'll have to use your stock skid to fit the trans, which is a drawback in my mind, the stock chassis is really too wide for my taste. I'm also not crazy about torsion chassis setups, but to be fair the kind I've used are very different than the Havoc. I'm sure you could make it work, I just probably wouldn't.

In short, if I was building a shafty 2.2 I'd build a SWX, becuase I know it and like it. Matter of fact, it works pretty well with berg axles too.

At the end of the day you can make your rig work really well with a stock chassis too.

Last edited by chrisjlittle; 04-05-2009 at 08:01 PM.
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Old 04-05-2009, 08:08 PM   #20
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The real thing I noticed was not so much adding weight to rims, but rather to focus on weight balance. Adding lead weight can help and hurt you at times. For me it was putting more strain on driveshafts and making the rig tip easier on verticles. Then I messed with link geometry and found it far superior to overall performance. So key things are weight placement, and balance and link geometry. Once you get the rig were you want it then practice with that as much as possible. That is my 2 cents.
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