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need help with the twin force

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Old 06-27-2014, 06:17 PM
  #1
nitrosportsandrunner
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Default need help with the twin force

I did some running of my twin force today (see video in video forum) and it did well until the pin in the front center dogbone came out, leaving it RWD.

then while looking up parts, as well as a steering upgrade (the slop is bad) I found a pic showing the suspension setup.....which is NOT like mine.

see the 2 pics below. I then looked up the manual and sure enough the lower shock mount point should be the adjustable mount location near the wheel...not the tab where mine are mounted.

here is the problem, look at my shock and the location of the outer (proper) mount point....if I put the shock there it will surely hit the wheel! that mount is about a half an inch from the outer edge of the wheel, and as it sits the shock is already just 1/4 inch from the wheel.

what gives? should my wheels be mounted further out somehow? (I ask cause the front wheels can hit the lower links if I have my steering rate above 70%)

what am I missing? my current setup helps explain why the suspension is so stiff.





also, does anyone have pics of their axle mount steering mod? Ive looked at the thunder tech racing one but im not willing to pay $30 plus shipping for a small carbon fiber plate and 2 links.
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Last edited by nitrosportsandrunner; 06-27-2014 at 06:20 PM.
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Old 06-29-2014, 08:05 AM
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Well just looking at the pics you posted there is definitely something not stock on your truck. Your wheels and tires are further inboard than stock, I don't know if that's due to wheel offset or something like the wheel hex. Wheel offset seems the most likely if Giga Crusher wheels have less offset. But maybe your truck has shorter stub axles with shorter wheel hexes on it. The only other explanation is early MF had shorter axles with wider offset wheels but I doubt that. Either way it looks like you have lots of comparing part numbers to do, assuming you can find part numbers for everything.
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Old 06-29-2014, 08:24 AM
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Quote:
Originally Posted by Maj_Overdrive View Post
Well just looking at the pics you posted there is definitely something not stock on your truck. Your wheels and tires are further inboard than stock, I don't know if that's due to wheel offset or something like the wheel hex. Wheel offset seems the most likely if Giga Crusher wheels have less offset. But maybe your truck has shorter stub axles with shorter wheel hexes on it. The only other explanation is early MF had shorter axles with wider offset wheels but I doubt that. Either way it looks like you have lots of comparing part numbers to do, assuming you can find part numbers for everything.
wheel offset is my thought as well...but have no idea how to find out what is the stock offset.
I wish I could join RCMT.net as they have a good size forum on these trucks and id bet I could get answers from people who own them, but that site is messed up. every time I try to register I get a message saying the admin has blocked my email address....so, I am unable to register. and I have never registered there before, so something is screwy with the site.

but I have gone threw many of the threads there. most are making their trucks into crawlers, so I have seen a few different steering and linkage mods. some do use the same lower shock mount mine does but it looks like they could use the proper one but choose to use the more inboard mount. On mine, I don't have the option of using the proper mount.
If only I have $100....while the stock wheels/tires look good, I have seen some other tires that look amazing. But I know they are not cheap either.
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Old 06-29-2014, 12:12 PM
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some websites wont accept certain email sites. i have had this issue myself. i just opened a gmail for those sites.
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Old 11-20-2014, 10:26 AM
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The third picture is where both (sold one) of my nitro Mad Force's are. No rubbing. Was wondering how this build went cause I want to convert one to electric. Not being too familiar with electrics, I'd like to copy what you have done if it's not a problem. To me, everything is exactly the same between the nitro version and the electric one besides the power source, one way on the three speed, and the 3 speed. I just replaced my diff in one of them. It seems they came with aluminum pinion and ring but upgrade to Inferno steel #MA050. I watched your video and that is about enough speed that these things should run. If you could help, that would be great. It seems rcmt.net is no longer or they are not accepting new members?
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Old 11-20-2014, 11:04 AM
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I ended up selling the truck, but I did put a brushless system (low power, 1/10 scale on 2s lipo) and didn't have any problems with it.
As far as the steering is concerned, I left it stock and I used the EPA setting on my radio to adjust the steering throw...so the tires wouldn't rub.
There are kits that move the steering servo over to the axle....this in combo with a radio that lets you adjust the steering throw will give you good steering. The stock steering linkage allows for a bit of play, and a bit of play with large tires means the truck doesn't always track 100% straight.

There are several parts from the updated Mad Force Kruiser VE (lengthed version of the twin force with a 1/8 scale brushless system) that can add durability to your truck. And since kyosho still sells the Kruiser VE as well as the new Foxx VE version that also uses the same axles and trans, finding parts shouldn't be too hard. The new Foxx VE version is really sweet looking, and for the most part differs just in the chassis and intergreated body. From my understanding, the gears, driveshafts and such from either new version will work on the twin force. I think the mad force uses the same chassis (seems I recall the twin force chassis had lots of extra holes that would have been for a nitro motor and other nitro parts)
I know some who convert a nitro to an electric just lock the trans so that the electric motor can move the truck forward and stop it. You could wire in a servo to use the stock brakes, but locking the trans is easier. Or you can buy the trans from the Kruiser.
I had a Kruiser VE as well (sold the twin force for over $300, bought a used Kruiser for $280) and running it with it's 1/8 scale system, longer chassis and on 4s lipo was pretty crazy. more like 40mph and instant wheelies. It could do a backflip from a standstill. The gears in it are meant to take punishment.

If you go brushless, spend a little extra and get a 1/8 scale system. While a 1/10 system can work, you will be working the motor a bit hard. On 2s lipo, my motor was as hot as it would be in a regular truck running on 3s. If I was going to stick with a 1/10 system, the traxxas vxl might be the way to go. The vxl motor has more power than the team associated motor I was using. But, if you go with a 1/8 system, you could run a pair of 2s lipos in series...so you would still get 8.4v but have twice the runtime.
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Old 11-21-2014, 07:52 AM
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Sounds like a plan. I've figured it will cost roughly $50.00 in the parts I need to convert it plus the brushless system and batteries, charger... Everything I take off is usable on my other Mad Force that is still nitro with an OS .12 RG. So, the dumb question, do I buy a 1/8 system that will come with the ESC and motor? I'm sorry, but I don't know what KV is. I think the lower the KV the faster it is or less windings in it? I don't need a super fast motor/ESC but would like something that would be kinda moderate. Should I be looking at Mamba or Castle or something else? Last question, it has a radio and receiver that is old style with crystals, is that okay to use with these systems?
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Old 11-21-2014, 09:10 AM
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Quote:
Originally Posted by pcarluvr View Post
Sounds like a plan. I've figured it will cost roughly $50.00 in the parts I need to convert it plus the brushless system and batteries, charger... Everything I take off is usable on my other Mad Force that is still nitro with an OS .12 RG. So, the dumb question, do I buy a 1/8 system that will come with the ESC and motor? I'm sorry, but I don't know what KV is. I think the lower the KV the faster it is or less windings in it? I don't need a super fast motor/ESC but would like something that would be kinda moderate. Should I be looking at Mamba or Castle or something else? Last question, it has a radio and receiver that is old style with crystals, is that okay to use with these systems?
A 1/8 system is best, it is possible to get by with a 1/10 system....but it may only cost $30-$50 more to buy a 1/8 system.
There is the ezrun 80amp and 100amp brushless 1/8 systems. These are decent, but lower cost systems.
The Castle 1/8 systems will certainly work well.
KV refers to the number of RPMs per volt. If a motor is rated at 3300kv, then it will spin 3300 times a minute if 1 volt is applied (this is with NO load)
The motor mount on the truck does not offer much leeway when it comes to gearing options. You can work with any motor in the 1800 to 3000kv range. But, based on which you pick you will need to use a larger or a smaller pinion gear. I used the smallest I could fit (either a 15 or 16 tooth) because I had a small, 1/10 motor that was 3300kv.
The safest bet, look up the KV that the Kruiser and FOXX version uses. Buy whichever brand 1/8 motor you like that is the same KV rating. Then, look up what size pinion gear those versions use and buy that size pinion gear. This would take the guess work out of it.

With mine, since I used a smaller motor of higher KV, I bought a few pinion gears and tested each one while checking the motor temps with a temp gun. Once I found a gear that allowed the motor to run at a safe temp, that was what I used.

When it comes to KV, due keep in mine that lower KV motors generally have more torque. 1/8 scale motors can usually also handle 4s lipo (14-16 volts) as opposed to the 1/10 motor I was using that was higher KV but could only be run on 2s (7-9 volts) While the math may make it look like the higher KV motor would make the truck faster, you also have to factor in that the larger and lower KV motor will handle a larger pinion gear (taller gearing)

Radio....what you have you can certainly use. However, 2.4ghz radios are now very affordable and do offer some very nice features. My Flysky GT3S radio has 10 model memory, EPA, Duel rates and other adjustments that are nice. I can with a few clicks on the radio set my 35mph short course truck to do only 10mph...I do this some times so I can let my son drive the truck. The duel rate adjustment would allow you to change the steering angle so that the wheels don't rub (if yours do)
That radio is $60 and comes with 1 receiver. extra receivers are $10. Since the radio has model memory, you can program it to work with several trucks and go between the truck with just a few clicks on the radio.
The radio also has a rechargeable built in battery.
There are other 2.4ghz radios that are under $100 that offer similar benefits.
And, with 2.4ghz there is no chance of interference. With the older radios, there is some chance that high-power brushless systems can cause glitching. If you stick with your radios, make sure to mount your antenna up high and as far from the motor/esc as possible.
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