JRH, maybe you can answer this for me but I am having a hard time understanding how dig and the worm gear setup will work together. When using Front Wheel Drive only how wheel the rear wheels free wheel and allow movement. It would appear to me that with the worm drive it would lock up the rear end. Don't get me wrong, I like Losi's new truck, I am just trying to see what I have missed in the equation.

Sure, but when your crawling you want them locked all the time. Its flat ground we are reffering to.

That is the idea - The front wheels drive whilst rear locked pulling you around - this gives you a tighter turning radius.

You don't necessarily want them locked all the time when crawling.

On the courses, there are often flat parts (like plateaus, etc) on the rocks where you need to make the U-turns for the gates. It's hard to explain, but I'll see if I can find a picture unless someone else finds a better way to explain it.

Edit: This is the best I could do:

http://i192.photobucket.com/albums/z...1Largeedit.jpg

On the top part of the picture (the u-turn between gates) it's a flat section where an unlocked diff would work wonders. It's kinda hard to see the grade of the terrain from the picture, but several of us mentioned wishing we could unlock our diffs for those two gates.

Anyone know how long it would take to lock/unlock a diff? Like 1 second or???

It should just take a second. It's just the flip of a servo.

When the dig engages, it will cut power to which axle you wish. So lets say you engage front dig, which disengages rear power. The rear will totally lock up since it is a worm gear (on the losi), and drag ass behind. This allows you to turn the front and "burn" or dig around. If the rear has any traction it will allow a tighter turn. Here is a perfect video showing normal locked turning vs dig turning. http://www.youtube.com/watch?v=m_cZ_pwTczo On higher traction flat surfaces with even weight distribution you could get tighter turning still.

It only works well on flat or surfaces where the front is up hill. When you are facing downhill you must engage rear dig and lock the front axle. This will make the rear axle fall down the slope if the front has enough traction to stay put.

Then newest, yet to be available item is the unlockable diff. It would allow tight turning without dig as long as all four tires are on the ground. It would be much more predictable until a tire lost traction or lifted from the ground. If I had to choose, I would take dig over unlockable diffs for a comp crawler, mostly because I have been using dual ESC dig in comps for over three years now. I would choose unlockable diffs on a rock racer.

Thanks JRH, I understand the dynamics now. I knew I was missing something in my head when trying to wrap around it.

I really like the idea of the remote locking diffs for the trail scaler I want to build and am now contemplating trying the Venom crawler with the x-trail chassis when it comes out. From what I can see it looks close enough to work with maybe a few minor mods. I saw another guy who put the x-trail in a CR-01 which gave me the idea. Of course I may wait and try the C-frame chassis from the SCX10 when it comes out. I am deep into my tanks now which has my time taken up this month.

There are so many options for piecing it together, it is surely the fun of it.

I would like to use the losi tranny with the venom axles for the ultimate trail rig. Maybe put a three speed divorced tranny into the lower half of the losi and use my 5 channel radio :lol:

That would be slick! Part of what draws me to trail rigs is that there is really no limits and so many different ways guys do them. The scaleness is obviously the other factor. Crawlers have some variation but most of the comp formulas are very similar in design from what I see.

That would be very cool. Make sure you make a build thread! :party:

Any updates on this. Hows the losi performing?

The Losi hasn't been released yet. They're still working on the worm gears to get them just right.