XV-01 Pro Rally (re)Build

[Big Jon 684]

5 hours ago, ThunderDragonCy said:

@Big Jon Interesting read. Thanks! Do you have a link to those CRC body mounts? I am interested in them for my touring cars. 

https://shop.stormerhobbies.com/product-p/crc1264.htm

[ThunderDragonCy 7877]

5 minutes ago, Big Jon said:

https://shop.stormerhobbies.com/product-p/crc1264.htm

Thanks! 

[Big Jon 684]

I was able to burn a couple of packs this afternoon out in the street. I'm all out of pavement tires, so I tossed on an old set of Rally Blocks for the time being to save the Losi Gravel Spec tires for dirt use. I'm very satisfied with the handling, although I have no idea if it's actually better. The car feels magnificent and does everything well. I blasted the sidewalk and the neighbors yard, and the expansion joints, root heaves, and grass didn't upset the car at all.

So, here are the last pics. I'm going to leave the rear body posts long in an attempt to save the wing in rollovers. The body was heavily reinforced with drywall tape and Shoe Goo to withstand future punishment. 

[KalEl63 695]

Cool thread with great info.

once you do get a chance let us know how the 120k feels on dirt

plus what oil wt and pistons are you using? (I hope I didn’t miss that in your thread)

[Big Jon 684]

9 hours ago, KalEl63 said:

 

plus what oil wt and pistons are you using? (I hope I didn’t miss that in your thread)

Right now, I'm using 30wt oil with Yeah two-hole tapered pistons. Someone posted an editable setup sheet on the Facebook; once I figure out how to post one here, I'll get it up.

Haven't gotten enough dirt driving in yet to get a feel for the diffs. It's really good on concrete, though. Acceleration out of tight corners is excellent, and I can get on throttle very early and hold my line. Very good on power steering.

[ACCEL 2014]

what did you use for the golden hue to the headlights?

i was thinking of using the transparent amber model paint for turn signals just the inner lenses.

we'll be Ebony and Ivory, i'm paint'n mine black thus the "Piano"

only problem is the black stickers will be mute

i think restro and remods seem to be way more involved, that's another reason i'm procrastinating the AWD Mugen Bulldog restoration.

Your Delta came out nice.

you musn't get it dirty right away or you'll be doing this again😮.................................

[Big Jon 684]

Thanks, man! 

I used Tamiya clear yellow on the headlights, rubbed the black with my thumb to bring up some highlights, then shot the whole grille with Tamiya gloss clear.

Been watching your build....

[KalEl63 695]

On 4/21/2020 at 11:25 PM, Big Jon said:

Right now, I'm using 30wt oil with Yeah two-hole tapered pistons. Someone posted an editable setup sheet on the Facebook; once I figure out how to post one here, I'll get it up.

Haven't gotten enough dirt driving in yet to get a feel for the diffs. It's really good on concrete, though. Acceleration out of tight corners is excellent, and I can get on throttle very early and hold my line. Very good on power steering.

You can fill it out and then save it as a jpeg

[Big Jon 684]

Well, this beater certainly doesn't look like this anymore...

After at least a hundred packs, I've changed the springs to Tamiya's soft Rally springs, broken off the rear wing, and smoked a whole bunch of tires. I've worn a nice groove in my front yard, too.

COVID cancelled this year's rally season for us, so no race results to report.

[Fabia130vRS 2098]

Can you explain the logic of the gyro in the compartment.

as far as I know it should be placed in the middle of the car somewhere after the front axle.

[Big Jon 684]

8 hours ago, Fabia130vRS said:

Can you explain the logic of the gyro in the compartment.

as far as I know it should be placed in the middle of the car somewhere after the front axle.

It fit there, honestly, and seems to work ok. I really have no idea if it would work better elsewhere, because I haven't tried. I'm always trying to make this thing a little better. At the very low gain I prefer, do you think that it would be more effective positioned up front?

This is the only gyro I've used on any of my cars, and it widens my setup window without getting in the way. Kinda takes the edge off on slippery surfaces. I turn it off if there's traction or I want more aggression.

[Fabia130vRS 2098]

2 hours ago, Big Jon said:

It fit there, honestly, and seems to work ok. I really have no idea if it would work better elsewhere, because I haven't tried. I'm always trying to make this thing a little better. At the very low gain I prefer, do you think that it would be more effective positioned up front?

This is the only gyro I've used on any of my cars, and it widens my setup window without getting in the way. Kinda takes the edge off on slippery surfaces. I turn it off if there's traction or I want more aggression.

Ifnit works ok. I have a MST 2.0 LSD gyro according to the manual it needs to be centered and in between the middle and fron of the car for best effectiveness.

[ChrisRx718 4470]

Your wiring job is very neat and your thread has been a great guide for me re-building mine. What are those spacers called fitted along the length of your motor wires? The ones which link them together - looks brilliant and I want to be a copy cat!!

[Fabia130vRS 2098]

8 hours ago, ChrisRx718 said:

Your wiring job is very neat and your thread has been a great guide for me re-building mine. What are those spacers called fitted along the length of your motor wires? The ones which link them together - looks brilliant and I want to be a copy cat!!

Inoticed that too, I believe zip ties and O-rings 

[ChrisRx718 4470]

13 hours ago, Fabia130vRS said:

Inoticed that too, I believe zip ties and O-rings 

I thought you were kidding but now I see it on my PC screen... That is genius!

I already have both of those things too 

[Big Jon 684]

On 10/19/2020 at 3:41 PM, ChrisRx718 said:

Your wiring job is very neat and your thread has been a great guide for me re-building mine. What are those spacers called fitted along the length of your motor wires? The ones which link them together - looks brilliant and I want to be a copy cat!!

Thanks, man! It's just black zip ties and o-rings!

[Toad16v 282]

@Big Jon, what tyres do you use for asphalt with this?

[Big Jon 684]

On 8/6/2021 at 6:39 AM, Toad16v said:

@Big Jon, what tyres do you use for asphalt with this?

I use Gravity USGT spec tires on all my on road stuff. They're relatively cheap, work well (or at least good enough) on all surfaces, and last forever. Also, they are premounted on spoke wheels, not boring dish wheels.

[Tal00 1]

Hi.

I could use some advice. 
I want more ground clearance so I ordered 70mm shocks and adjustable carbon shock towers. See pictures below. I also intend on using sway bars to compensate a bit.

What shock oil do you think I should use with them. I’m not sure if I have different hole options. But they do come with three springs. Which springs should I use to drive around a grassy park and bumpy parking lots?

 

Thanks a bunch for your advice. 
 

Cheers from Canada,

 

Tal

[Big Jon 684]

I'm not familiar with those towers, but be careful with your ride height. The steering tie rods will foul on the front rear suspension mounts at full droop if the ride height is too high. I'd start with the softest springs all around and maybe 25wt oil with two-hole pistons. Those shocks are very nice quality.

[smirk-racing 253]

 

On 3/31/2020 at 8:38 AM, Big Jon said:

With all of the parts clean, it's time to begin with the chassis assembly. This next part addresses the only real weakness this chassis has: rocks getting stuck in the steering, the #1 reason for a DNF in our rally group.

You'll need a set of MST low profile servo mounts.

Drill three holes in the servo compartment with a 1/8" bit and countersink. Measure twice, cut once. I managed to drill the holes in random locations despite careful measurements, so they are oversunk to compensate.

Install the mounts upside down, with the locating lugs facing up. Leave the lower screws until you install the servo.

Of course, you'll need a low profile servo. I'm using a Turnigy TGY-159BL, an aluminum brushless unit, which is the only Turnigy servo I've been happy with, a High Torque servo saver, and a 3Racing horn. Using a servo saver on the XV01 is a must, as it'll break steering parts and knuckles with a solid horn and very rough use.

With the servo mounted upright, stones will no longer get wedged between the front of the electronics box and the servo. Definitely leave the hole in the bottom of the chassis open to allow the debris to pass through.

@Big Jon Thanks for these awesome write-ups. Your posts are such an incredible resource for other hobbyists. You inspired me to make a contribution to the community as well.

I liked your idea about moving the servo orientation, and I recently bought a 3d printer, so I took this as an opportunity to learn how to make a servo holder for myself and for others. 

I'm a beginner with 3d printing and with CAD in general, and this is the first part I've ever designed. I have tested it, and it works well enough for my needs, so I thought I'd share it with the awesome TC community. Note: this part is probably way over-done, but I was having fun and learning, so here it is....

Some goals:

-- re-use existing holes in chassis, no drilling required

-- make part strong without much stress on the screws (biting into the 3d part seemed iffy). This part slots into place and there's hardly any real stress on the screws (the part itself takes most of the forces).

-- cheap and quick (45 min print, few grams of material)

-- use standard low-profile dimensions

Everyone is free to do whatever they want with this part. If you do improve it, please consider sharing it back with TC. I've included the Fusion 360 file (amazing software, and free for individual users) as well as the STL file which you can directly load into your slicer. Here is what it looks like:

 

 

 

Enjoy.

XV-01 Serv0 Simple v15.f3d XV-01 Serve Simple v15.stl