Exceed mad torque 1/8 to 1/10 scale budget build!

[Crawlin' Lobster]

I've ran the bfg krawlers now on a bunch of different terrain and I really like them. They grip great on almost all surfaces except really loose dirt.

On Mon I had a wire disconnect from the board inside the hitec servo I was running. Went to the lhs and the ones they had were way over priced. So I ordered a stock exceed 9kg servo from nitrorcx and added a couple sets of axle tubes since some of the hub holes are a little stripped. Total cost $32 after regular usps shipping. They got delivered today and the lhs finally got in the 55t axial motor I ordered a couple weeks ago. They seem to not be the best run shop imho.

Put in the motor with the other stock 12t pinion and now I have equal gearing f/r. Thought I was liking the od/ud but now that it's back to even I can see it was hindering me some. Made dirt climbs easier and better grip at steeper angles.

I swapped out the new servo for the stock axial one a friend gave me and the difference is night and day. The exceed has about the same torque rating as the 645mg I previously had. I have my wheels/tires all closely weighted at about 260g front 255g rear. Turns them just fine. Have yet to try my treps which all weigh 280g. Stock madtorque 2.8 wheels/tires weigh about 245g each.

 

[Crawlin' Lobster]

The new axle tubes will get put on in the next few days. While I have everything pulled apart I'm goin to cut the frame down some. May narrow it as well, still undecided. Have an idea for a new skid with integrated bottom link mounts and a new upper link mount for the axle I wanna try. Will probably have to make new bottom links or alter mine a little as I want to mount the shocks to the axle. Kinda wanna try a dual servo setup similar to this one too.

Will post pics when I make some progress.

 

[beomagi]

The dual servo setup does increase turning power, but I've found that even if you think you aligned them perfectly, they're usually fighting each other. With two high powered servos, fighting for position you'll drain the battery, just sitting there.

 

[shahram72]

Yeah, seems complicated, although I have seen 3D planes with multiple servos on one control surface. Seems easier and cheaper to just use one strong servo.

 

[Crawlin' Lobster]

The dual servo setup does increase turning power, but I've found that even if you think you aligned them perfectly, they're usually fighting each other. With two high powered servos, fighting for position you'll drain the battery, just sitting there.

Thanks I'll keep that in mind.

 

[Crawlin' Lobster]

Yeah, seems complicated, although I have seen 3D planes with multiple servos on one control surface. Seems easier and cheaper to just use one strong servo.

I most likely will only use one just thought it would be interesting to try.

 

[axial 4x4 crawler]

If you're running dual servos up front then simply make sure that there both aligned well and the trims are 0 percent on both of them before you put the horns on. Or to save time, you could get one single servo and be done with it. Here's a link to a servo that just might fit you well: Solar Servo D772 High Voltage 0.17sec@7.4v 64g Digital Metal Gear
Its a great budget servo and has plenty of torque for the price. For 20 bucks I'd say its worth a shot.

 

[Crawlin' Lobster]

If you're running dual servos up front then simply make sure that there both aligned well and the trims are 0 percent on both of them before you put the horns on. Or to save time, you could get one single servo and be done with it. Here's a link to a servo that just might fit you well: Solar Servo D772 High Voltage 0.17sec@7.4v 64g Digital Metal Gear
Its a great budget servo and has plenty of torque for the price. For 20 bucks I'd say its worth a shot.

Thanks for the info. That servo might just be worth a shot.

 

[RockBiter]

I got to work changing out the servo then started on switching tires. Off with the axial rock lizards and on with the Baja claws.
The wheels are a little skinnier and have less offset so it made my axles a little wider but I can deal with it til I narrow them.

Also got some plastic axial rock sliders a buddy had layin around and used them to mount the body for a cleaner look with no body pins showing. Covered all the other holes in the body with e-tape so it looks cleaner. Then went out and tested on the course.

Look they work! I kinda like em but they need to be a little longer.

And a poser shot.

Sent from my 4gLTEvo

I wanna come over and play, you'r course looks like a blast.

 

[Johnnysplits]

You really need a servo programmer along with programmable servos if you are to use multiple servos to control one thing. This way the will work together 100% with no interference with each other. Two steering servos do look cool though!

 

[Crawlin' Lobster]

I wanna come over and play, you'r course looks like a blast.

It's takin some time and work to become what it is. If your ever in Wa I'm in olympia if you wanna check it out.

 

[Crawlin' Lobster]

You really need a servo programmer along with programmable servos if you are to use multiple servos to control one thing. This way the will work together 100% with no interference with each other. Two steering servos do look cool though!

Know of any good cheaper ones?

 

[Crawlin' Lobster]

Made some changes to my truck. Got a 5 ft stick of 1/4" alum rod and a plate of .090 alum for less than $3 from a local machine shop. Got to work makin my new skid.

Amazing what you can do with a vice, hacksaw and file.

Did this at a friend's sisters house and her bf pulled out a case of random parts from some nitros he used to have. Told me to take anything I might be able to use. Had more than a whole set of one piece stainless links with what I believe are revo ends and a hitec 5997 titanium gear servo.

Tested and it works great. I think I'll save this as a backup for the stock exceed.

 

[Crawlin' Lobster]

Stripped down the frame and cut about 1" off the bottom. Bolted one the new skid and changed out the cuttingboard links for some of the stainless ones. Shocks now mount on the axle inside of the bottom links. Took the pieces I cut off my rear bumper mount and drilled a hole and bolted it to the front axle ylink mount. For the back I used a link end mounted the same, now it's kind of a 4 link. Used 2 more of the stainless links for the rear uppers and took off the y end off the front and added ends from my stock bottom links. Had to play with mounting positions a little but got it workin good.

 

[Crawlin' Lobster]

How it looks with the body.

Did a little testing on the course.

Flex comparison with a buddies deadbolt.

As much as I liked my first homemade links, I gotta say metal ones look much better on the truck.

 

[Crawlin' Lobster]

After testing decided to start making new custom links with the 1/4" alum rod. Went and got a pack of revo rod ends and a 8-32 bottoming tap and drill bit. Cut some pieces of allthread and tapped the rod ends.

Again only used basic hand tools. Next I cut some pieces of the alum rod to start bending my links. Clamped them by pairs in a vise to keep the bends even. That part was somewhat simple the hard part was making the opposing bends. Came out pretty dang close.

The rears have the more extreme bends. Marked out how long I needed than after the bends and cut. I used a small socket as a guide to drill out about 1/4" down in the ends of the links the threaded the hole. Was easier than I expected it be. Threading these holes was a little tedious as it required backing out and clearing the hole every few threads but not hard to do.

Sorry for the bad angle on the pic but they are even.

 

[Crawlin' Lobster]

They mount inside of the frame now and closer to each other f/r. Had to mount the upper links higher as well.

With the bends they clear the frame nicely when flexing.

Made a plate for the battery to mount right over the skid out of a piece of roof flashing then installed electronics.

Then the body.

Wood pile test.

Lemme know what you guys think.

 

[beomagi]

Any rub on the body?

 

[Crawlin' Lobster]

Any rub on the body?

There is some but I do have the body sittin as low as possible. I may raise it a little later on but I'll leave it for now.

 

[Crawlin' Lobster]

Had an idea for a bottom link/shock mount adapter plates so I made a some mock ups using a heavy duty washer. It will allow the bottom link to mount almost below the axle and the shock will be above.

First attempt didn't quite have enough room for the link ends to smoothly function so I made another one.

Should work good but I think I'll try to make the rest out of alum. Any thoughts?