bilinvic's R1 Build

[bilinvic]

I did have to get a new driveshaft to compensate for the extended wheelbase. For the front, I used the longer sections of the JunFac hardened (male and female) driveshafts from both the front and rear to create a longer driveshaft. I purchased the JunFac hardened Universal Shaft (120-155mm) for the rear. With this combination, there's a significant amount of the male shaft that fits into the female () which makes for less wobbling and much more strength.

[bilinvic]

Here's some pics of the R1 fully assembled. These pics are prior to any testing and tuning and there are some changes that I since have done to improve performance and reliability (those pics are coming!)

[bilinvic]

I couldn't use the upgraded GMade steering linkage kit because they are significantly larger in diameter than the stock steel linkages; they wouldn't fit in space behind the diff skid plate and actually caused less turning radius if they did fit....spare parts now!

[bilinvic]

Post first test thoughts: (all of which will be rectified)

1. The crawling performance is looking very promising...with some tuning.
2. The Holmes Hobbies 35t Torque Master Pro 540 isn't cutting it for me with 2S power.
3. The cut VooDoo U4 tires are OK, but better tires will improve performance.
4. Weight distribution and CoG in this configuration is looking VERY good.
5. Rollovers with a thin aluminum roof panel isn't a good combo.
6. Rollovers with the front shocks exposed will definitely cause a failure on the trails.
7. Rollovers with the steering servo exposed could potentially ruin your day!
8. The ground clearance from the Portal Axles and bent VP Wraith Ti lower links is noticeably better compared to my Wraith.
9. I wish there was a bit more turning radius....but I can live with it for now; the 4WS option is looking better!

[bilinvic]

A few updates to the "issues" noted above.

I replaced the HH brushed motor with a HH TrailMaster BL Pro 540 - 3300kv. This motor had proven itself and has outstanding power and torque. Even with only 2S power, this motor is awesome!

HPI Hot Bodies 2.2 Rover Crawler Tires on Gear Head RC 2.2 Five Star EZ-Loc Beadlock Wheels. Fronts are weighted with 84 grams each. Essentially the best crawling tire on the market (IMHO).

I used Wraith Lexan roof panel to cut out and form the R1 roof panel...much more durable than aluminum.

I used a Gearhead Wraith Droop Kit (rear) to get the front shocks leaned back and below the "impact zone". I added an additional Axial aluminum cross member to stiffen the shock mounts. This will definitely save the shocks from rollover impacts.

To protect the rear shocks, I fabbed up a pair of "winglets". Not only will this save the shocks, it will help to alleviate breaking the protruding upper shock mounts on the chassis.

I still have to fab up some protection for the servo.

Here's the pics:

[bilinvic]

FYI....the R1 now weights in at 7 lbs 7.5 oz with the batteries. The front weighs 4 lbs 1.4 oz and the rear is 3 lbs 2.6 oz.

[bilinvic]

I was surfing RPP today and came across a Servo Armor, from Vanquish....I had forgotten these were available. A black one was ordered.

[bilinvic]

I took the R1 out for a good 45 minute shake-down crawl to see how it would perform and what needed tweaking.

I have two incredible crawlers to compare it's performance with and I have to say, this R1 is already showing signs that it will be another very competent addition to my "fleet". I'm very impressed with the high clearance and low CoG.

The shocks "guards" I added work very well. I have fabbed up new version (v2.0) of the rear shock "winglets" out of sturdy 1/8" hardened anodized aluminum. This will take the abuse of bedrock rolls much better than plastic.

The R1 does exhibit some torque twist (passenger side front tire raises) which can ruin a good crawl. To combat this, I have added more ballast on the right front axle and stiffer springs on the left front and right rear shock. After some testing, this has definitely helped.

The front tires were also rubbing on full lock; driver side rubbing the servo and passenger side rubbing the shock. This will be alleviated with the new rims and rubber package I have ordered from RPP:

SSD 2.2” Assassin Beadlock Wheels
Vanquish Products SLW .600 Wheel Hub Black
JConcepts Ruptures - Green Compound Tires
Crawler Innovations Double Deuce 6.0” Standard Inner / Medium Outer

Since this machine is intended for pure crawling, I have also ordered a Tekin ROC 412 Professional Brushless Crawler Motor 1800kV. I have a few of the 3100kV ROC412 motors but decided to try out a motor with more bottom end torque.

As mentioned earlier, the turning radius isn't the best so I decided to see what I can do to improve it. Using spacers and minimal grinding, I have now drastically improved the radius. Axial 6mm spacers were added under the tie rod link ends to get the tie rod from bottoming out on the differential cover. I removed the lower hole on the Axial servo arm to provide clearance to the raised tie rod. The tie rod link ends were shaved on the inner surface that would hit the portal axle housing to gain even more precious radius. The end result is that my servo can now be maxed out to utilize it's full range of motion. For now I am using the steel SSD 2.2 wheels with Vanquish .450 SLW hubs and there is no rubbing.

I'll have the new parts this week and hopefully I will be able to get out this weekend for a good long crawl with our group.

[GTSLOW]

How's the brushless setup?

[bilinvic]

The HH TrailMaster BL Pro 540 - 3300kv motor is awesome....I stole it from my "Wroncho Bug" but as I mentioned above, I will be using a Tekin ROC412 1800 kV very soon. All my rigs are BL powered (sensored)!

[bilinvic]

I received my RPP order with upgrades, but they didn't all go to plan!

The new JConcepts Rupture tires are huge, too big for the R1....so these will go on my DMG Wraith along with the SSD 2.2 Assassin Wheels. I'll use HPI Hot Bodies 2.2 Rovers for now, which are great tires anyways. I will get some specific GearHead .375 or .500 hubs to get the tires out a little wider.

The Vanquish Servo Armor is on and looks great.

The Tekin ROC412 1800 kV motor is installed, but no tested yet. I did bench test it with 2S, 3S and 4S power...this motor is pure torque! I think I will go with 3S power combined with a 12t pinion & 56t spur.

On a bad note, I discovered the driver's side front CVA axle is already bent & broken; there's a crack on the ball section of the CVA because there's not a lot of "meat" on these parts!

With that being said, I ordered DravTech's Wrapter v2 from Shapeways. I'll use Vanquish Wraith Scale Chubs (Clamping) and Knuckles with the modified Axial Wraith Universals. Should make for a superior set-up compared to stock. I was going to say the heck with it and throw some AR60 axles under this rig, but the unique attribute to the R1 is the portal axles....so I will retain them for now.

[Sancho]

Dude, great build.
I specially like the front shock mounts, I think the car handles like crap when you mount the shocks all the way by the bottom of the "windshield" as suggested in the "more articulation" thread. I've been working on a custom shock mount that will mount them in the same exact spot as yours so it's encouraging that I'm going in the right direction. I think that is the sweet spot for mounting the shocks on this car.
I also stripped out the stock wheels and I got the SSD steel wheels from RPP, did you happen to notice any wheel slop on the axle?
Mine look like the axle is too thin for the wheel hole, I read about the hexes being suspect but I'd like to hear your opinion.
Thanks!

[bilinvic]

Thanxs Sancho. I agree with the shock location, it's terrible location way down by the lower windshield pillar. The R1 handles very good with this new front upper shock mount location and the articulation is great. The rear doesn't need to articulate as much as the front...it should be stiffer to keep the the rig "planted". No, I didn't notice wheel slop from the 12mm hexes...cheap and easy to swap out if you think they are bad. Get clamping hexes though. When I convert the front end, I'll use the Axial aluminum hexes that have a protrusion that inserts into the wheel's axle hole; I feel this gives more support.

[NitroRampage13]

Where did u get the scale car jack?

[bilinvic]

It was a gift several years ago. I'm not sure where it was purchased. It's kool eh?

[bilinvic]

I have everything for the DravTech Wrapter front end conversion now....except for the Wrapter conversion parts from Shapeways. First time I have ordered from there and it seems to take a while.

The conversion adds approximately one inch of total width, so I ordered .500 Gearhead 6-Lug Aluminum Hubs for the two rear wheels to align everything up front to rear. Total width is the same as my Wraith now @ 12.5" wide (outside edge of tires).

I removed the front CVA that was bent and cracked...it's now shrapnel from crawling in my backyard!

I'm not sure if the SSD Ti steering links will work with the R1, but I can swap them out for the VP Ti steering links from one of my Wraiths if needed.

[bilinvic]

More parts and update:

I received the DravTech Wrapter conversion parts; these are my first 3D printed components and they look and feel very nice....hopefully they are torture tested!

Parts list:

DravTech Wrapter Conversion Kit
Vanquish Wraith Scale Chubs (Clamping)
Vanquish Wraith Steering Knuckles
Fast Eddy Bearings including the larger 5x9x3 and 5x10x3 bearings for the Wrapter parts
Axial Wraith Universal Axles
Axial Aluminum Hex Hubs (12mm)
Axial Flange Pipe (4)
K&S 5 mm x .45 mm Aluminum Tube
Vanquish Wraith Titanium Upper Link (Drag Link)
Unkown brand Tie Rod (from my spare parts)
Traxxas Jato and Revo Rod Ends
Misc shims, spacers and hardware

The front end conversion was pretty straight forward, the most time consuming part was modifying the universal axles. Taking your time here will yield a tight fit on the lower portal gear. I used J-B Kwik to affix the the aluminum tube to the axles IOT achieve an OD of 5 mm.

FYI, here is the link to DravTech's instructions: DravTech presents... The Wrapter for the Gmade R1 Portal Axles

It took a while to configure the tie rod and drag link, luckily my parts box has quite a few options. With the parts I used, the steering radius is maxed out and there is absolutely zero tolerance issues - Mission accomplished! At the same time, the axles are drastically stronger with proven Axial Universal Axles.

The overall width is now 12.5 inches using HPI Hot Bodies 2.2 Rovers on Gear Head RC 2.2 Five Star EZ-Loc Beadlock Wheels with stock hubs. The rear width is also 12.5 inches using the same tires and wheels but using Gear Head RC 6-Lug Aluminum Hubs, Plus .500 to achieve the extra width.

I also performed the underdrive mod for the rear differential using the Sawback ring and pinion. 32t/17t front ration and 32t/14t rear ratio. This link shows how: Underdrive for the R1... Finally

Now I just have to get out and test everything before I get 'er out for a full day of crawling with the guys.

[bilinvic]

Test session # 1 was cut short...within a few minutes the torque of the 1800 kV ROC 412 killed the stock plastic idler gear in the transmission! The lower gear was already swapped out for a Robinson Racing one piece steel diff gear (Wraith). I had a RR steel idler gear on my parts shelf for this transmission but never got around to throwin' it in.....I guess I'm getting around to this now!!! lol

After a transmission rebuild, test session # 2 commenced.....initial results are outstanding. My testing lines that are normally extremely difficult did not stop the R1, and in fact did better than my other crawlers in some spots because of the high Portal axle clearance. With the combination of an under drive rear diff and the complete Wrapter front axle mod, this machine turns on a dime now. I was testing with 2S power, but I will be getting some small 3S LIPOs for the R1.

I'm very stoked to get out on the crawling trails now!

[Sancho]

Originally Posted by bilinvic

I was testing with 2S power, but I will be getting some small 3S LIPOs for the R1.

I'm very stoked to get out on the crawling trails now!

Nice!
That's a lot more throw, I'm actually trying to get narrower or I would try the DravTech whatchamacallit


E-Flite 1350mAh 3S 11.1V 30C LiPo, 13AWG EC3


I've had awesome awesome luck with these, I mounted mine on the axle so they may not be to your liking, they are small but I get a solid 1.5 hrs. of slow speed crawling and maybe 1.25 on the trail at hiking speed.

[bilinvic]

Thanxs for the battery info Sancho, I'll look into them. If they are small enough to fit side by side in the custom battery position, I can run two at time in parallel to get 2700 mAh.