New School losi: Comp Crawler bug

[aconsola]

My latest build. Haven't gotten to run it yet. waiting for the sensor cable for the brushless system.
got it painted up today and took some pics, can't wait to hit the rocks.
It is basically stock except for the dig servo mount, aluminum steering servo mount, and aluminum motor clamp.
The only RPM parts I could squeeze onto this one so far are the shock up travel limiting clips.

[bearrickster]

that looks cool, I have thought about building one. but I see it on all of the crawlers why do the put the servo on the axle houseing? I am sure it works better their but IMOP it takes away from the looks of the scale rigs?

[Lowgear]

Straight axle vehicles that have a lot of articulation need the servo on there for a number of reasons.

If it was anywhere else you would run into binding issues.

If it was anywhere else it would be in constant competition with the axle.

You want to keep the steering links as short as possible like on anything else.

Theres almost no slop.

More room on the chassis for other electronics.

More weight over the axle for better traction.


Did I forget anything?

[markt311]

That looks really cool, pardon my ignorance, but I know nothing about crawlers. What is a dig?

[aconsola]

That looks really cool, pardon my ignorance, but I know nothing about crawlers. What is a dig?

I'm not sure how it got the name, but dig refers to disengaging the power from one axle while allowing the other axle to continue to propel the vehicle.

On a shaft driven vehicle like this it is the transfer case that can be shifted between 4wd, front wheel drive, and rear wheel drive, hence the need for the servo.

on dual motor vehicles like a clod, it is accomplished either by onboard electronics electronics/relays that cut power to one motor, or by having 2 seperate speed controls that are run from 2 channels on the radio so they can be controlled/mixed as needed.


I've not driven a dig equiped vehicle yet, but I believe it allows tighter turning. By letting just the front wheels have power with a locked rear axle you can get the tuck to turn/rotate with no forward movement.

[Doc J33P]

Love the Losi Comper but I am out of it for now. I was so into it that I traveled all over the US last year competing. I got burnt out too quickly.

Rick - the servo on the axle housing is better placed there for comp crawlers as you get all the throw/torque from the servo on the axle. The scalers who compete have to have a frame mounted servo for steering.

Mark - the dig allows you to turn on the axles radius or even a wheels fixed position to make it around obstacles. Dig also assists in keeping the rear axle from moving while climbing steep verts. A couple years back when digs became more prevalant in comps they made it so you had to have one. The shaftys with digs soon lost out to Bergs with MOA axles and the the rigs like Losi has now with worm gear axles. You get the benefit of worm gears (no drivetrain movement under dig) and the dig like a shafty. The Losi rig has turned the tables on MOA rigs to say the least.

Anthony, you will love competing as it is a completely different rush. Your first time out will be a blast as you will be inexperienced and having fun. Go practice and learn the dig very well!!!

Enjoy!

[Doc J33P]

OH and..................

Tear those front wheels apart and add a few ounces of stick on weights............
Tear the rears apart and add about 1/2-1/3 that amount of weight..........
Get some memory foams up front for climbing and some regular full foams for the rear to hold your rear up on climbs.......
See if you can get your lipo mounted on the front upper control arms..........
Move the esc to the rear axle.........
Slam the body more........
Rip the diffs apart and make sure they are properly lubbed - many were not in the beginning...........
Upgrade or sipe those CLaws. The version 2 claws are taller and have offset lugs. Most tires nowadays are taller than those stock Losi ones. Believe it or not that matters a lot!!!!

[bearrickster]

I get it, I just dont like it. they dont do it on the real ones they work it out.

[Doc J33P]

Professional comp rigs in the 1:1 use dig all the time?! Go to any WeRock or XRRA (sp?) race and you see it constantly. A lot of the rigs have independent dig per wheel now?!

It is far too common in comps and casual crawling real or r/c.