Build Complete: Vaterra Slickrock

[doodahoops]

Fyrstormer you are an inspiration . Thank you from a converted newbie. I have just bought my son who's 19 with learning difficulties, a SlickRock for his birthday which is over a month away. We have a couple of HPI Firestorms which we use for bashing but they require too much space to run, are fast and we do tend to break them a lot as a result. I saw some crawling videos and this I think is the way forward as we have loads of great places to crawl nearby. It seems to be somewhat over looked in the UK - why?

So the SlickRock is on the dining table and I have been measuring it up. The mods I have ordered so far that we will build in together are:

LED Light Bar Kit
HB Rover Red 1.9 tyres
Axial 1.9 beadlock 8 hole wheels
Axial wheel weights (2x 43g)
Turnigy 7.4v 2200 mAh LiPo (fits 1/16 traxxas) 119g

The plan is to tidy up the wiring and move the esc, build a platform for the battery like you have done (105mm x 30mm). I presume putting it at the front is better for weight distribution, initially I may cut the battery box so it fits in there. Is 180'ing the motor fairly easy?

Later changes will be the shocks and high clearance links. Out of interest how long would the standard motor run for on a 2200mAh lipo battery? Anything I have forgotten...

Thanks Again

Hoops - possibly more excited than 'hoops-son' will be

 

[fyrstormer]

Yes, putting the battery near the front is better for weight distribution. Putting it as low as possible is even better, but it's hard to make room for the battery lower than where I put it. The only other viable option is to put it down the side of the "passenger compartment", opposite the motor. Several people have done that, but I'm not sure their battery-retention straps have been as secure as mine are.

Yes, 180-ing the gearbox is easy. Unbolt the gearbox support plate, turn it around backwards, and reinstall it. The stock battery box won't fit anymore, but the hardest thing about making a new battery plate is taking a deep breath and actually starting to do it. Once you've made the basic measurements and drawn them on a sheet of Lexan, it's all just cutting, test-fitting, and cutting some more. Go slow and test-fit after each cut. You'll need to make notches in the front of the plate to allow clearance for the suspension ball-ends, but it's not a big deal. Honestly I spent more time cutting-down the battery strap and sewing it back together than I spent cutting the battery plate.

The Axial wheel-weights are really bulky and will ruin the tires' ability to squish and conform to the rocks the vehicle is driving on. Save yourself the pain of disassembling and reassembling the wheels, and get some lead tape and wrap it around the wheels before initial assembly. You will want about 2oz/57g of weight per front wheel (about three rolls of tennis-racquet balancing tape per wheel), and optionally about 1oz of weight in each rear wheel. This is the single best grip-enhancing improvement you can make, except for replacing the stock tires of course.

Making the rear links is pretty easy. It's the front links that are hard. You could probably 4-link the rear suspension to start with and worry about 4-linking the front suspension later. As I noted, it's easier to fit the 4-link suspension if you get some extra shock pivot-balls and some longer screws, and you attach the lower shock eyelets outboard of the shock mounts. I think it also helps to stabilize the vehicle.

When you get around to making the front links, if you attach them to the back of the servo plate like I did, be forewarned that the servo plate is slightly asymmetrical, so you'll have to measure an equal distance to the left and the right from the servo-plate mounting holes to make sure your front-upper-link mounting holes are spaced symmetrically.

Even if you don't want to tackle the 4-link suspension right away, I strongly recommend building a steel steering linkage with a low-profile clamping servo horn. (the servo horn I used was made by OFNA.) The stock linkage and servo horn are so bulky that they are constantly slamming into rocks and keeping the front wheels from getting a good grip. When you replace the steering linkage, flip the servo around so the upper link is longer; the longer length means it will stay closer-to-parallel with the lower link as the servo horn moves through its arc.

I honestly have no idea how long a 2200mAh 2S LiPo pack will last on this vehicle. I've never driven mine long enough to hit the LVC. The tiny motors that fit in this vehicle sip power. I'm pretty sure the stock motor doesn't even have carbon brushes though, just bare copper leaf-springs that press against the commutator, so you should at least consider getting a motor from the Associated Mini Rival -- it at least has proper carbon brushes so it will last longer before it burns out.

 

[fyrstormer]

If/when you decide crawling is the right kind of RC fun for you, I highly recommend getting an Axial Wraith next. It's an awesome truck: http://www.rccrawler.com/forum/axial-wraith/507688-build-complete-axial-wraith.html

Or, if you want something less-expensive than a Wraith and more suited to general trail-driving and light crawling, the Traxxas Telluride is a solid option that doesn't get the respect it deserves: http://www.rccrawler.com/forum/traxxas-maxx-crawlers/531010-build-complete-traxxas-telluride.html

Or failing all that, if you don't care about cost and you just want a truck that works all the time with no mods required, the Traxxas Summit is great. I've had one for six months and the only mod I did was installing stiffer springs, and the only breakage I've had was a single axle that cost $4 to replace.

 

[doodahoops]

Fantastic again. Thanks. Will get onto the lead tape. The Wraith would be the ultimate goal but I do like the look of the Telluride - so will keep a look out of fleabay for one of those. One step at a time though. Not having used Lexan before, what mm did you use?

 

[fyrstormer]

For the ESC tray? I used a scrap that a guy at my LHS gave to me. I think it was 2-3mm thickness.

 

[doodahoops]

Wow. We have had the truck out a couple of times now and it is very good in standard set up. I've not had a crawler before it is amazing to see what it will climb / get over and also how real world 4x4 practices work on scale too.

I can also see where the thoughts come about quality and mods. We have already lost one of the shock bottoms and as said the shocks aren't great in themselves. 4 replacements on their way. Round two of presents will be the weighted wheel / tyre combo and then can see it will almost be unstoppable.

At the moment we have spent just less that a SCX10... :roll: do love the smaller size though.... but can feel a Wraith for me coming on

 

[fyrstormer]

That's a cool Lego truck. I'd like to see more info on how you built the suspension and how you got it to be remote-controlled.

The Slickrock is not, and never will be, a Wraith, but when properly kitted it can climb just as well as the Wraith as long as the obstacles aren't physically too large for the Slickrock to get its wheels over. Here's a quick demo of how well my Slickrock climbs now:

https://www.youtube.com/watch?v=6HUWjmV1Am4

I wish I knew how to embed videos on this site.

 

[doodahoops]

Here is the link to the Lego model - http://shop.lego.com/en-US/4X4-Crawler-9398. The slick rock looks very good. Once the mods done will try some of our own clips.

 

[doodahoops]

Can I just say thank you. Here is a quick video we shot this afternoon of Rocky in the back garden. New wheels & tyres, weighted, and suspension fitted.

http://youtu.be/wEa2hbPhb6M

Waiting for some rain now as it's been so dry round our way.

It's so much fun I've bought one second hand off eBay cheap. Want to put a different body on it but will post questions on that later.

 

[fyrstormer]

Looks good! Now you just need to build a stronger steering linkage, and ditch the bulky plastic servo horn.

 

[fyrstormer]

Tiny update: I found a store that still has the aluminum rear lockouts and single-piece steel axles for the TLR MRC Pro, so I picked up a set and put them on my Slickrock. It was a mostly drop-in replacement; I had to shave off the built-in spacers on the backs of the rear wheel hexes, but that's all I had to do to make everything fit properly.

Now it has aluminum hubs front and rear. I like when things match.

 

[fyrstormer]

Fixed all image links in this thread.

 

[Lugnutt]

do you know what bullet size the original esc was

 

[fyrstormer]

As I recall, the original ESC didn't have bullet connectors, it had cheap stamped-metal connectors that were kinda like bullets but not nearly as good.