Project SR-71: A Stealth R1 Build

[derb]

Went on a social train run today and decided to throw up some pics afterwards. The carbon fibre panels aren't installed as I have run out of small cable ties and haven't been bothered to pick some more up. I've also swapped to the black versions on the G-Made Transition shocks to keep the 'stealth' theme, and I reset the rears to a droop setup. As you can see the ride height is greatly improved.

Some of those with a keen eye may spot that the front wheels look a little wonky, this is because I lost two step screws on the trail run. Thankfully only one from each side, but I did not notice until I got home and gave it a close inspection. I also snapped my plastic servo horn on the trail, but I got a nice alloy one off one guy, which I proceeded to break also, and then another off another guy which seems to be staying in good health.

I ran my big 5000mah battery across the front axle for the trail and I am ecstatic about how the rig handles now. Only rolled it over about 3 times in 2 hours and it actually side hills now, even with my GoPro strapped to the roof. Before the changes above it would roll over if you looked at it funny. I was honestly a bit upset with the rig so far, but after today I'm so glad I kept at it and tried some different settings. Once you lower these rigs they are amazing!

As for parts, the rear steer controller has finally shipped, along with the HPI servos. I'm going to rip my other BEC out of my currently off the road CC01 and give each servo its own boosted power feed. I've ordered two alloy, clamp-type servo horns after the breakages today. And finally I've ordered another low CG servo and battery plate and a couple of sets of replacement step screws from Junfac. I was going to use the factory plastic servo mount on the rear axle but I want it to look as sexy as the front. I doubt I'll install the second battery plate, but you can't order them separately.

 

[derb]

I've got the PunkRC dual steer computer installed with the new servos and its AWESOME! It's turning circle has come down from the size of an entire street to no more than 1m/3ft. I need to rename it with a snake name as that is exactly what it looks like doing slow crawls and lock to lock turns. And the crab walk mode is actually pretty cool, not just for looks, but because I can definitely use it to crawl across the face of a large rock/dirtpile/etc. I think I'll leave it in rear steer/crab walk mode as locked rear is just awful after feeling the response of rear wheel steer. Will grab some pics tomorrow and a quick vid of the snake-like motions.

 

[derb]

Finally got some pics. I have plastidipped the controller after setting the trim and select options.

 

[bikerzee24]

looks good man, quick question...what does the controller do? I have seen some people with them, but haven't fully understood what they do?

 

[Smithysride]

rigs looking good. axles are looking phenominal. love the 4WS. Hows it working for ya?

 

[derb]

I will find out just how well it performs tomorrow, I'm going on a nice big crawl at one of the best places in my town. It's a big, long riverbed with stones and boulders literally everywhere for miles. The weather has been really crap here lately so I'm itching to get out and crawl. I'll try and get a video of the turning circle as well since it's a little hard to hold a camera and drive at the same time.

 

[dextan22]

nice! i'm torn between 4WS or DIG... DIG for me is more cost efficient as i've extra servos but 4WS looks like fun!

 

[bikerzee24]

I will find out just how well it performs tomorrow, I'm going on a nice big crawl at one of the best places in my town. It's a big, long riverbed with stones and boulders literally everywhere for miles. The weather has been really crap here lately so I'm itching to get out and crawl. I'll try and get a video of the turning circle as well since it's a little hard to hold a camera and drive at the same time.

I so agree with you Derb on the video taping part, as much as I love to do my videos it is hard to carry the camera and get good angles while you are actually trying to crawl. I have been using my tripod with my camera and just having it posted up in the areas where I am crawling at...I wish I could have it zoom in an out on good crawl spots, but its the best it gets without getting a gopro and mounting it to my rig somehow. Even with that, as much as my flip my rig over the gopro would just be getting all scratched up everytime I flipped it over.

 

[derb]

I have a GoPro actually, it comes with a waterproof case which is also pretty shockproof too. I just use a few cable ties and it stays pretty solidly right on the roof, and the footage is pretty good since it's nice and close to the ground. It won't really capture how tight the turning circle is though, but it's a very cool device, can be controlled via a free app on my phone and is no heavier than a 1500mah lipo so it doesn't affect the abilities of the rig at all. If you can afford one, or see a used one for sale, grab it.

 

[bikerzee24]

Yeha I working on it for sure, Ive been using my ladys HD camcorder and it works well but it is hard to mount it on anything like a gopro can. I will have to wait a while before I am able to invest in one though.

 

[dextan22]

derb, are you still running the Axial lower links? how long is it compared to stock R1 links (110mm eye to eye)? and what length driveshafts are you using with the Axial links?

 

[derb]

They are about 90mm long as measured along their curve, but mine are not the Axial hopup option, they are made by a local guy and are just cheaper copies. I'm using the R1 option driveshafts from Junfac which are 95-130mm.

 

[derb]

Had an excellent weekend, 'Stealth' won it's class outright against 4 other competitors! But not before putting a scare in me twice.

Firstly, I don't have my own battery charger and rely on a mate to charge them up for me. He only got my main battery charged the night before and I foolishly only hooked it up and tested the rig on the morning of the comp. Turns out my motor was somewhat dead. Applying throttle in forward or reverse just wouldn't kick the wheels over. As soon as I gave the wheels a little spin with my hand, the motor would keep them going, but then fail to move them again once I got off the power. So I swapped my previous el-cheapo RC4WD 55t in which worked perfectly. Buggar all torque or wheel speed, but at least it moved the rig without assistance.

Secondly, I turned up at the comp and after spending about 30 seconds just playing around before any of the classes started, I broke a rod end. Thankfully a fellow competitor had a spare that fit my ball end and set screw size and got me back on deck. I'm very glad to be with the other people in our local comps, they are never afraid to lend a part or a tool even if it might advantage them to just deny you and let you flounder about.

Still waiting on my offset rod ends and M3 rod for the steering linkages. Rear steer is totally awesome, but you can never have too much steering angle and the stock 'heavy duty' links foul the diff covers without proper bending. Once that gets sorted out I'll get some metal rod ends and some Crawler Innovations foams and be pretty much done until I get the cash to buy some more JunFac hop-ups for the rear end.

 

[cytogen]

Derb,

Glad to hear you made it through despite your issues

Debating on either 4WS or a Dig on my rig. With what you see at the comps; what's more common and more useful? 4WS or Dig?

 

[derb]

I'll be putting up some videos of my runs, but with the way our class is set up, rear steer would work better. We're calling the class 'Outlaw', but you could call it Scale - Class 3. It's definitely not even close to the Sportsman classes in terms of courses with insane angles and one wheel holding you up. We set it up initially for people with Wraiths and AX-10 type rigs. Of the five entrants we had, there were 2x Wraiths, 1x AX10, my R1 and another guy with a frankenstein rig that is basically Axial SCX10 axles on a custom CF body. None of these rigs would even get past the first gate on a Sportsman course.

 

[derb]

Here are the vids from the weekend. First course was pretty easy, but the last one was much more technical.

20130414 GMade R1 - CANZ Bragging Rights Comp - Outlaw - Course 1 - YouTube

20130414 GMade R1 - CANZ Bragging Rights Comp - Outlaw - Course 3 - YouTube

 

[bikerzee24]

Looks like a good time, the course didn't looks too bad. The first one looked like it was more meant for a speed run than a tech crawl, looks like some more practice may be needed with that new rear steering capability. The second run went much smoother, I'm loving the part where you had to cross the the tree bridge. That 4ws has its benefits and its very fun to watch and see how well it works when getting up and around obstacles. Great work

 

[derb]

Installed the Junfac alloy 7-degree c-hubs and alloy knuckles in the rear today, finalising this build for a while I think. I did find a destroyed bearing in the rear left when I swapped the c-hubs though. Cleaned it all out and checked all the others which were spinning cleanly. It's been taking a back seat lately to my SCX10, but a couple of mates are building 2.2 rigs for trailing and river work which is what this beast does these days. So I'm looking forward to getting it nice and dirty again.

 

[Ricky G]

Looks cool! Great work.

 

[derb]

It's been a while, but this is what my R1 is looking like as of today. Custom carbon fibre chassis from a local guy with links modified to suit the new 335mm wheelbase, a pair of the new Savox 20kg waterproof servos, a set of Traxxas Big Bore shocks and a 27t motor. In these pics it's mechanically complete, I just need to work out the electronics mounts and wire it back up.