LavaCapCrawling My First Micro Build

[LavaCapCrawling]

I saw the Trail Trekker on the shelf at the local hardware/hobby store and had to get it. I did not know the can I was opening. Purchased this thing like a month ago, been coming here for a bout six weeks. This forum has been super helpful, thanks.

So far I have done the quick "Phase One" mods.

To the mods,
-Trimmed .187 from each spring.
-Removed factory limits.
-Hot Racing aluminum bead locks.(+11 grams per wheel)
-m2.5 steel lock nuts.
-Trimmed .125 off body all the way around.
-Milled .021" off each servo mount to make room.
-Hitec 65mg, no saver.
-Custom made weights/wideners(+9 grams)
Available at
New Product Trail Trekker Wheel Wideners
-experimenting with 5mm aluminum spacers on axle side of upper arms, seams to cause a soft bind or soft limit at full flex about .1 before shock limits and reduces torque twist. I remain undecided.



In the Mail,
-Roc Lox.
-HR 56t Spur.
-3pc brass pinion set.

All due to arrive Thursday.

[LavaCapCrawling]

I finally got my goodies installed. Running a 10 tooth brass pinion and Hot Racing 56 tooth spur. The Roc Lox makes my crawler climb like it wants it. I had trouble with the foams that came with the Roc Lox, they seemed too stiff. I had stock tires with no foams and they sealed like a balloon tire in the bead locks. The Roc Lox did not seal as well and stayed flat when the air got pushed out. So I decided to remove some of the foam and came up with this.

I used a hole punch to punch a hole in the foams every 1/4 inch or so. I had to pull the punch apart a little to get the foam in there. It was easy to tear the foam if I tried to move the foam without pulling the punch apart a little. The tires have good give across the tire and stay in shape well.

[LavaCapCrawling]

I installed a Predator 90t motor. Way more torque, my trekker climbs out of the stuff now. In the process of the motor swap I flipped the transmission.

I decided to to try to tilt my servo back to give me more clearance. I took a second set of servo mounts and milled them to fit onto the bottom of my first set of servo mounts. Then glued them together creating a riser that tilts my servo back. When I did my first test drive with the new mounts the steering was weak to one side. I then flipped my servo over and the stock linkage fit between the servo horn and diff, I had to carve just a bit off the diff. It clears good and after a bit of servo corner trimming articulates fully. The steering is strong in both directions. Next I think I will try to create a higher cross linkage.

[spoo76]

Nice! I really like the foam tuning with a hole punch

[Mastah Kyler]

interesting... good idea!

[LavaCapCrawling]

After driving the truck for a while I found it to be a little more tippy going down hill. It also seems to have excessive twist when I turn the front wheels. I decided to move the battery back to the front, it was in the back after the tranny flip. After finding a place that it fit, I marked for holes and clamped my two side plates together and drilled a screw hole for the the battery box. I drilled just the lower hole for now. While the plates were together I drilled some holes in the frame to lighten it a little. No machine shop stuff this time just a drill motor.

While the Plates were off the truck I filed down some corners on the bottom.

[LavaCapCrawling]

After some More test driving the truck was still tippy and twisty. When I modified the servo mounts it raised the link position up about .25 of an inch. This seemed like something that could cause a change in the driving characteristics so I drilled a hole in the new servo mounts in the original position for the links to connect to. Once it was put back together it drove much better. Moving the link position up just a little killed stability bad.

While test driving I broke my bumper mount on one side, then I decided to to make an entire bumper out of shapelock. In the process I make more room for the servo horn which was hitting the crossbar after the links got repositioned. I have to deburr completely before painting it but it seems to work alright.

I have a new video too. I filmed this with my phone between my knees, I edited out moving the camera and never touched the truck.

Trail Driving - YouTube

Shorts is a compilation of several short crawling maneuvers.

Shorts - YouTube

[elsewhere]

Looks good!

[LavaCapCrawling]

Just roached my first Hitec 65mg, just dead. Before that I decided to build a bumper that looks like I have some sort of assembly ability. I cut the molded bumper off the body just under the lights and tried to copy it, much better.

[spoo76]

I wonder if Hitec's quality is going down the drain. I keep hearing and reading about the Hitecs in all sizes dying out.
BTW thats a hell of a Macro mode! that thing looks like a 1/10!

[Ebola Zaire]

Looking good! I might have to try the hole punch mod to the foams, never seen that before.

[LavaCapCrawling]

Quickly vid just before servo fry. Added a variation of the hair tie thing. I'll do write up when the final setup is finished. I call the vid it's a setup because I had to place the truck on the slope it did not drive there just up from there.

It's a setup - YouTube

[LavaCapCrawling]

I got a servo, Hitec 65mg as before. I did some work on the servo link to ease a slight loading of the link. My servo would hum just a bit when I was not inputing anything from the remote, I believe this was because the link was not aligning well enough.
The rebuild consisted of cutting the ball ends off the stock arm then drilling small holes into the cut end just a bit smaller than my wire that I had to work with. I also drilled very small holes intersecting the hole for the wire. Then I cut and shaped a piece of wire and glued the ball ends onto the ends of the wire. I used shapelock to cover the wire and build the piece up a little. The shapelock covers the wire and cut ends of the ball ends. over and into the small holes creating little rivets that keep it al from pulling apart. The link ended up way high and out of the way.

[LavaCapCrawling]

I decided to drill a tight pattern in the case of my esc instead of a total decasing. I used packing tape to cover the holes after I drilled them. Then I drilled every piece of plastic that came on the rig.

[LavaCapCrawling]

I came up with a variation of the hair tie thing. I made small brass hooks and used small pull springs to connect the lower shock mount (on axle) to the upper suspension link (on frame). It would take forever for me to describe the process, there were several prototypes before the current hook design. I also put brand new stock springs on the shocks.

In the first photo you can just see the upper brass hooks peaking out.

In the second you can see the whole assembly, it's bolt on.

The result is a truck that sits at full droop when set down. When the truck is picked up the shocks extend about 75% of the travel and when I lift one wheel the opposing wheel drops to full extension. The truck does not do the "push the frame up" thing when the truck is going up slopes. The frame resist rocking to the low side while cross hilling. The rear resist lifting on downslope driving. Changing the spring tension can allow a really tight lifted axle or a lower more animated axle. I really have been impressed with the performance.

One more thing I added a Losi 7.4v 300Mah Lipo. It's nice to have the first half of the trigger do more than make my esc hum and it runs for nearly an hour.

[TekmoCrawl]

Wow. You have really put in some work. Nice job man.


Sent from my DROIDX using Tapatalk 2

[LavaCapCrawling]

I was thinking about cutting out a new frame. Something like this. I'm trying to decide if a different tranny mount style might gain a little ground clearance. The origin is where the stock skid sits. The mount would use the screw holes in the metal plate where the gear cover screws on. The slanted side in the first shot is distortion the sides are vertical plates. I'm having a hard time finding screen shots in my program and took a photo of the screen with my phone. All the mounting holes are in stock locations except the lower links are a little higher. Any thoughts and critiques are welcome before I start cutting.

[Demodude]

You got me thinking of more ideas for mine now! Love everything you've done. I never thought these little trucks would be so much fun!!

[RcLee]

Can you do pros & cons of....no springs, your springs & stock, your springs & pull springs that you said you like the performance on. Anything you didnt like about that setup.

See your trying to go way above just solving the hang up prob on the trans mount & rear lower links & frame lift prob.

I like your wheel wideners/weight kits

Ever think of providing a spring & spring pull back kit.

Any other spring setup on here work better?

[LavaCapCrawling]

Originally Posted by RcLee

Can you do pros & cons of....no springs, your springs & stock, your springs & pull springs that you said you like the performance on. Anything you didnt like about that setup.

See your trying to go way above just solving the hang up prob on the trans mount & rear lower links & frame lift prob.

I like your wheel wideners/weight kits

Ever think of providing a spring & spring pull back kit.

Any other spring setup on here work better?

The spring set up is pretty sweet. Before I made those I tried full droop(no springs), wrapping the ends of the springs around the ends of the shocks, the hair tie thing, and a rubber band. I feel for my type of wheeling the springs as I have them are the best way to go. I don't sell them because interest hasn't been there. I would love to sell them. I can check with our sheet metal house and see what stamping out few hundred of them would cost. I made them with brass strips from my lhs. Cut four pieces off the stick, super glue them in a stack and drill the thru hole and shape the outside with them glued together. Then do the same for the other four hooks. That makes two sets of four parts that are nearly identical. I can make a custom set but that's gonna be pricey. Oh, springs are from mcmaster, I bought three types and settled on the black oxide .093 in diameter I think. I use small chain to adjust tension, just a few links on one end of each spring.