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R/C Tech Forums Thread Wiki: Official Xray XB2 2WD Buggy Thread
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Last edit by: dgrobe2112
Instruction manuals: (C/O BentKa)

Xray XB2 Carpet Edition Instruction Manual
http://www.teamxray.com/xb2/2016/dow...ual_v2_low.pdf

Xray XB2 Dirt Edition Instruction Manual
http://www.teamxray.com/xb2/2016/dow...w.pdf?update=2

BentKa: Carpet Edition 4 gear to 3 gear laydown conversion parts:
  • Gearbox #323014
  • Motorplate #324012
  • 36T idler gear #324236
  • Brace for waterfall #324031


Socket: Bodies Available:

Xray has two OEM bodies, the .75mm and the .50mm light weight:
light weight: https://www.amainhobbies.com/xray-xb...329701/p492942

OEM .75mm: https://www.amainhobbies.com/xray-0....329700/p477762

Also, I've fitted the yz2 body, both the light and regular fit fine, just make your own cut lines:
https://www.amainhobbies.com/yokomo-...z2-101/p417674


[i] J Concepts S2 Body [i]


Penguin Racing makes a high grip body that fits the DE and CE:
http://www.ebay.com/itm/X-Ray-Xb2-Hi...oAAOSw1S9WewHV



Socket: Wheel fitment:

According to some, you'll require different offset rear hexes to use B5M wheels. According to my Hudy setup board, B5M wheels are the same offset. I measured the overall width of the car with XB2 wheels, and then again with B5M wheels, same measurement.

On the front, B5M wheels were 1.5mm wider. Xray offers hexes to reduce width -.75 on each side, or you could spend 3-5 minutes and sand your OEM hexes down .75mm.

edit by dgrobe2112
here are the hubs for losi and AE

for AE Front 365354 -0.75
for Losi rear 365358 +3.00 (4 stripe)
for AE rear 365359 +3.75 (5 stripe)



Socket: Flex and the XB2:

Flex screws are as follows:

Plastic bulkhead between motor and waterfall. Can remove screw in chassis, or remove bulkhead altogether.

Waterfall has 4 screws, can remove the inner two or outer two. IIRC, removing the inner two provides more flex, and thus more bite.

Removing the battery brace. This gives a tremendous amount of flex on the middle of the car, and can sometimes be inconsistent. I do this for outdoor racing on low bite. I like the feel over the 4 gear in 17.5 racing, since the 4 gear will take some snap away off the corner.

Rear C block - has inner and outer screws. I haven't played with this, as it's a crucial pivot point of the car.

Medium arms and towers -> I don't believe the carpet car has the rear medium tower available, however the DE DOES have an optional hard part. I think the hard parts are more consistent, especially when it gets hot (90+ degrees F). However, the medium parts do NOT break unless you're severely talented. They also don't wear out.



Socket: Avid/Schelle Slipper mod:

Credit to WillS, Matt Trimmings, and myself for figuring this out months ago.

Parts you'll need:

B5M V2 3gear compatible top shaft.
TKO Special 5x13x5 bear OR 5x13x6 bearing Either can work. This replaces the spur side bearing on the top shaft.
5mm shims, same shims used in 1/8th scale clutch bells. Look for protek .1mm and .2mm kit.
Avid or Schelle b5m top shaft kit, with spur gears of your choosing. (DE can't handle a 69, the CE can)

Shimming: You'll need to install the bearing in the front portion of the removable piece for the shaft. Make sure the bearing is pushed all the way in. With the TKO bearing, you'll need to shim approximately 1.4mm on the front side of the top shaft. Roughly .3-.5mm with the other bearing. This is a "feel" and tolerance setting. I urge you to watch videos about setting clutch bell play in 1/8th scale to get an idea of what yield you want for end play. Too tight, it'll eat bearings.

Outside of trans case: Use Avid/Schelle top shaft spacer plus .2mm shim to offset slipper from motor plate perfectly. Install slipper as instructed, and use Avid/Schelle spring and XB2 slipper nut.

- NEW - Schelle now sells Xb2 Topshafts. They include a spacer, so no need for shims in gearbox, and comes with the smaller bearing. Both methods work.

Socket: Yokomo Differential or MIP pucks:

Credit to: WillS for figuring out pucks, and as well fitting the Losi 22 diff with the same mods.

Parts needed: Yokomo Bmax2 or YZ2 complete diff OR Mip PUCKS outdrives
Xb2 diff gear
Bmax2 V3 Worlds rear dog bones, or Bmax 2 pucks dog bones
You'll use XB2 axles, and will require no other mods for the axles or dog bones.
You'll need .2mm outdrive/diff shims. Shim approximately .5mm on each side of the diff, behind the bearings. The top portion of the transmission is what "sets" the diff in place, not the bottom half. A little play back and forth is fine, the stock diff has some play from the factory.

dgrobe2112: CE to DE conversion:
along with the parts needed.. you MUST have these following hardware, or it wont work

https://www.teamxray.com/xb2/2016/do...conversion.pdf

(3) XRAY 902340 M3x40 button head screws. these are the screws that mount the motor mount to the tranny
(4) XRAY 903322 M3x22 counter sunk screws. these are for the rear diff case, to mount to the chassis. i think i used some M3x18 and they worked ok.

Socket: Best method for setting up the XB2 ball diff:

The XB2 diff is stellar when setup correctly. The spring is too short and soft, allowing the diff to slip. You'll need to glue the rings to the outdrives with just a drop of CA, then add a 1mm shim between the spring and the outdrive. This preloads the spring and stops the diff from slipping so easily.

OR, you can run the AE diff spring, which is both slightly longer, and stiffer. The overwhelming issue is the stock spring allows the nut to bottom out on the outdrive before the diff is tight enough.

This shim:
https://www.amainhobbies.com/xray-al...a303122/p12070

This diff spring (don't need a shim, then.)

https://www.teamassociated.com/parts...thrust_spring/

Functional Aftermarket parts: (Not just bling!)

Servo Horn: (The B5M sized horns are too short to get full throw)
https://www.amainhobbies.com/protek-...800-bk/p273496


Socket: Exotek has a full suite of parts, some bling, some not. Here's a list (all fit DE and CE, unless otherwise noted):

Titanium front axles: http://www.exotekracing.com/xb2-titanium-front-axles-2/

Rear Hanger, HD (Adds 4 grams): http://www.exotekracing.com/xb2-rear...75-heavy-duty/

Brass C block, 18 grams added: http://www.exotekracing.com/xb2-rear...-brass-weight/

Alloy front camber mount: http://www.exotekracing.com/xb2-fron...er-mount-7075/

Carbon Fiber Chassis: http://www.exotekracing.com/xb2-carb...m-plate-2-5mm/

Alloy rear hubs:http://www.exotekracing.com/xb2-allo...ub-set-2-7075/

Alloy servo mounts, allow for use of LP servo:http://www.exotekracing.com/xb2-xb4-...-alloy-1-pair/

Titanium shock mounts: http://www.exotekracing.com/xb2-xb4-...shock-posts-2/

Slipper Eliminator: http://www.exotekracing.com/xb2-direct-spur-mount/
Xray eliminator is #324100

dgrobe2112: 2016-2017 new 3 gear laydown
Gearbox #323014
Motor plate #324012
36T idler gear #324236
Brace for waterfall #324031

dgrobe2112: Xray Spring Rate Conversion:
front C WHT
368174 2 str 0.65-0.85 3.71-4.85

358184 2 dot 0.65 3.71
368185 3 dot 0.72 4.11
368186 4 dot 0.80 4.57


Rear
368273 2 str 0.35-0.45 2.00-2.57

368284 1 Dot 0.35 2.00
368285 2 Dot 0.40 2.28
368286 3 Dot 0.45 2.57
368287 4 Dot 0.50 2.86

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Old 12-17-2015, 12:08 PM   #556
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Originally Posted by symmetricon View Post
Alright, my first race race report. lol

I built the car box stock minus the pistons and oil setup. I wne with 1.6/1.7 35/30wt oil. For reference, I race on high bite clay, the track is sealed with dirt glue and is really grippy. The tire of choice are clay slick. However, when it starts getting cool which it the weather has started to do here in houston the track gets a bit slick. At the moment our lap times are approx 1/2 sec per lap off due to the colder weather.

1st pack: I threw the car on the track without saucing, big mistake. The car had zero traction and was un drivable.

2nd pack: I sauced the rear tires and threw it down. The car was hard to drive, the rear end had very little grip and washed out everywhere. However i could feel the car had potential. Also, the dampening felt a bit too soft.

At this point I realize that the car needs some serious setup work with regards to the stock setup. To gain rear traction I decide to remove as much anti squat as possible. I change the car from 2 deg to 0 deg of anti-squat.

I put some sauce on the rear and throw it on the track. Bingo, the rear is hooked up. I finish the pack and am very happy with the change, however the rear is still a bit lose on exit, but mid corner the car actually has a bit of push to it.

I decide to reduce the caster and change from the 2.5 deg insert to the 0 deg insert. I re-sauce the rear and throw it down on the track. The rear is even more locked on exit and I can drive the car hard. Im still missing some mid corner steering though.

I shorten the rear camber link and remove one shim on the hub to adjust the roll center. I test the car again and its better, Im now about 1/2 sec off pace. Now the quals have started and I have also been helping my bro set his XB2 up.

The quals go OK, I' m right on pace but a bit slow and take 3rd where I ultimately finish int the main.

I then decide to reduce drop in the front and add another 3mm of limiters with a total of 4mm of limiter shims inside the shock.

I throw it on the track and BINGO! the car is strapped. I run 1/2 a lap faster than with the previous setup.

All in all, the car as a ton of potential, its super stable and the car feels like it would be impossible to traction roll with (unlike my RB6). The current setup actually feels very similar to how my RB6 was except much less tippy. My setup is getting very close. All my bros were very skeptical of how the car would perform due to the weight distribution.

Bottom line is the car is excellent, tons of potential. I'm very satisfied and I believe this car will be a world beater...


FYI, the pre-assembled ball diff doesnt have lube in it. Make sure to take it apart, clean it and lube it... Also, the gear diff is hands down the best ive built PERIOD.

Thank you for the report I have heard similar reviews about the stock setup being too loose at the back.

One thing to note though is that if you reduce antisquat you will reduce rear weight transfer (the more the car squats the less you transfer weight, it is counter intuitive).
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Old 12-17-2015, 12:13 PM   #557
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Thank you for the report I have heard similar reviews about the stock setup being too loose at the back.

One thing to note though is that if you reduce antisquat you will reduce rear weight transfer (the more the car squats the less you transfer weight, it is counter intuitive).
I tested back to back 0 deg vs 2 deg of anti squat and 0 deg yielded significantly more rear grip everywhere... I may try and add some more back in and then add some more toe and/or narrow the width in the rear also via hinge pin inserts.
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Old 12-17-2015, 12:13 PM   #558
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Originally Posted by BentKa View Post
For carpet and astro running Stagger front tires we don't use foams.

Bent
+1

Foam sucks!
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Old 12-17-2015, 12:47 PM   #559
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Originally Posted by shannow View Post
Thank you for the report I have heard similar reviews about the stock setup being too loose at the back.

One thing to note though is that if you reduce antisquat you will reduce rear weight transfer (the more the car squats the less you transfer weight, it is counter intuitive).
I think ya got that backwards: Anti-squat prevents the weight shift to the rear so less anti-squat increases weight shift thus increases traction.
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Old 12-17-2015, 12:51 PM   #560
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Originally Posted by symmetricon View Post
I tested back to back 0 deg vs 2 deg of anti squat and 0 deg yielded significantly more rear grip everywhere... I may try and add some more back in and then add some more toe.
I don't want to interfere if you feel it's good, then it's good .
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Old 12-17-2015, 01:01 PM   #561
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Originally Posted by BentKa View Post
For carpet and astro running Stagger front tires we don't use foams.

Bent
i am new to carpet so what is stagger front tires? do i just glue the tires on with no foam for the factory xray rims that come with the kit? what about rear foams?

i am running proline pin points z3 in rear and proline wedge front tires on factory xray kit rims

thanks for helping a carpet newbie out
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Old 12-17-2015, 01:03 PM   #562
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I think ya got that backwards: Anti-squat prevents the weight shift to the rear so less anti-squat increases weight shift thus increases traction.
The car squats more hence your rear roll center drops significantly while cornering and accelerating. That will make the car a lot more stable. Especially exiting a corner.
But on a dead straight line you'll have less weight transfer on the rear.

The weight transfer depends only about 3 items :
- The wheel base
- The center of gravity position
- The force applied to the CG.
That's it. (this is what we call in french B.A.M.E: bilan des action mécanique exterieur).
There's only 2 points of physical contact with the "outside" and one representing the outside "non contact force" with the CG. Anything else is "inside job" and doesn't effect the picture at a given moment.

The antisquat effect itself basically determines how much % goes direct through the chassis (geometric weight transfert) and the % that goes into the shocks (elastic weight transfer). But it doesn't actually transfert weight by itself.
When the car squats you don't create traction even though the spring crushes, it is only part of the force that goes through the chassis which it converted into elastic force. But what indeed happens is that the car squats. In other words the CG drops. If the CG drops the lever effect for the weight transfer diminishes, the lower the CG the less weight transfer you'll have.

But I'm always open for any correction or input if I'm wrong .

Edit: One of many sources I spent time reading (bottom page) :
https://www.hyperracing.com/pages/te...ed_theory.aspx

Last edited by shannow; 12-17-2015 at 01:37 PM.
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Old 12-17-2015, 01:45 PM   #563
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Originally Posted by corn_bread View Post
i am new to carpet so what is stagger front tires? do i just glue the tires on with no foam for the factory xray rims that come with the kit? what about rear foams?

i am running proline pin points z3 in rear and proline wedge front tires on factory xray kit rims

thanks for helping a carpet newbie out
We typically run these on the turf and carpet tracks:

Fronts: Sort of a pain to glue but the premounts are awesome.
http://www.amainhobbies.com/rc-cars-...61780?v=232422

Front Premounts:
http://www.amainhobbies.com/rc-cars-...48144?v=445448

Rear we typically run v1 or v2(softer) Schumacher mini pins with Schumacher blue open cell foams:
http://www.amainhobbies.com/rc-cars-...61778?v=170808

http://www.amainhobbies.com/rc-cars-...hu6734/p170824

You can get the mini pins in premounts as well and they are very good.
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Old 12-17-2015, 02:16 PM   #564
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alright then. i will mount my rears with red aka soft foams with the proline Pin Point tires and do no foam for my proline Wedge tires. should this be about right?

are the xb2 front rims slim?
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Old 12-17-2015, 02:19 PM   #565
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The car squats more hence your rear roll center drops significantly while cornering and accelerating. That will make the car a lot more stable. Especially exiting a corner.
But on a dead straight line you'll have less weight transfer on the rear.

The weight transfer depends only about 3 items :
- The wheel base
- The center of gravity position
- The force applied to the CG.
That's it. (this is what we call in french B.A.M.E: bilan des action mécanique exterieur).
There's only 2 points of physical contact with the "outside" and one representing the outside "non contact force" with the CG. Anything else is "inside job" and doesn't effect the picture at a given moment.

The antisquat effect itself basically determines how much % goes direct through the chassis (geometric weight transfert) and the % that goes into the shocks (elastic weight transfer). But it doesn't actually transfert weight by itself.
When the car squats you don't create traction even though the spring crushes, it is only part of the force that goes through the chassis which it converted into elastic force. But what indeed happens is that the car squats. In other words the CG drops. If the CG drops the lever effect for the weight transfer diminishes, the lower the CG the less weight transfer you'll have.

But I'm always open for any correction or input if I'm wrong .

Edit: One of many sources I spent time reading (bottom page) :
https://www.hyperracing.com/pages/te...ed_theory.aspx
A good explanation I'd say.... I just try to think in terms of forces, not weight. Force transfer would be a more helpful term in the world of vehicle dynamics.
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Old 12-17-2015, 03:25 PM   #566
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I don't want to get into a debate about anti squat but if 2 springs have the same rate:
Spring A compresses 10 cm
Spring B compresses 20 cm
Which spring has more force or weight applied on it?

Is this not the same reason why a softer spring in the rear will allow more rear grip?
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Old 12-17-2015, 03:29 PM   #567
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I'm not sure I understood your question.
But from the spring perspective spring B will have double the force applied on itself.
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Old 12-17-2015, 03:39 PM   #568
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I'm not sure I understood your question.
But from the spring perspective spring B will have double the force applied on itself.
If car B is squatting twice as much as car A doesn't car B have twice as much force being applied to it?

As far as I know, and the only reason why you would lose grip with less antisquat would be from all the camber gain, but that's easily fixed via camber link setting. See video below.

https://youtu.be/peKl1THfQXY
https://youtu.be/hGZRairqHNI
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Old 12-17-2015, 03:48 PM   #569
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Originally Posted by symmetricon View Post
If car B is squatting twice as much as car A doesn't car B have twice as much force being applied to it?
To simplify it you could imagine putting elastic bands from the arms to the shock towers thus compressing the springs and doing it on all 4 ends.
All the springs on the car are then more compressed but the car itself doesn't way one gram more (except the elastics of course ).

You could imagine that the elastics on the rear represents the converted forward force though the geometry of the car.

It is a force that does compress the springs but it's a force that goes from the arm through the geometry to the springs and it doesn't go outside this circle.
The compression of the spring by shear weight is outside and just adds the compression.
It's as if someone on the car while riding it was lifting the arms and making the car squat by pulling them by hand, the weight one the car is still the same but the spring compress anyway.

edit: I saw the video's earlier there's a few mistakes. One of witch is the drawing of the antisquat. One of the comment on the video is correct by stating that the line that goes from the rear tire patch to the IC is wrong and should go the line axis of the front wheel. The CG should be represented on this line as well such as this :
http://www.pro-touring.com/attachmen...5&d=1322684983

Otherwise the front end would lift and the rear squat and the CG wouldn't change, just pivot. No change to the weight transfert.
Again not inventing anything there. It was through reading forum and stuff that some guys discovered that a reference book had a mistakes that was never corrected and many people had issues with % antisquat.

Anyway we're going a bit off topic to the xb2 sorry
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Old 12-17-2015, 03:58 PM   #570
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Originally Posted by shannow View Post
To simplify it you could imagine putting elastic bands from the arms to the shock towers thus compressing the springs and doing it on all 4 ends.
All the springs on the car are then more compressed but the car itself doesn't way one gram more (except the elastics of course ).

You could imagine that the elastics on the rear represents the converted forward force though the geometry of the car.

It is a force that does compress the springs but it's a force that goes from the arm through the geometry to the springs and it doesn't go outside this circle.
The compression of the spring by shear weight is outside and just adds the compression.
It's as if someone on the car while riding it was lifting the arms and making the car squat by pulling them by hand, the weight one the car is still the same but the spring compress anyway.

edit: I saw the video's earlier there's a few mistakes. One of witch is the drawing of the antisquat. One of the comment on the video is correct by stating that the line that goes from the rear tire patch to the IC is wrong and should go the line axis of the front wheel. The CG should be represented on this line as well such as this :
http://www.pro-touring.com/attachmen...5&d=1322684983

Otherwise the front end would lift and the rear squat and the CG wouldn't change, just pivot. No change to the weight transfert.
Again not inventing anything there. It was through reading forum and stuff that some guys discovered that a reference book had a mistakes that was never corrected and many people had issues with % antisquat.

Anyway we're going a bit off topic to the xb2 sorry
Does a softer spring not yield more traction?
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