XRAY - Model racing cars

I've been taking a few images of my build along the way and thought I'd document it and share my experiences. My intention is not for this to take over from the XB808 build tips thread, just provide an overview and review of the build in my eyes. Please feel free to comment as you see fit, or if you have other points that I've missed that could help others.

I'm doing it mostly in the evenings so the photo quality is a bit dodgy as the light isn't very good, and will be adding photos as I go.

Opening the box.






The box contents including the new, very narrow chassis.


All the contents laid out. Things that stand out are the BIG shock springs, the white inner air filter foam (at last!) and the generous selection of shock and diff oils. Oh, and a better quality, black anodised multi tool.


Diff components including the new moulded bearing shields:


Something I've always done is lightly sand the face of the diff cups to remove any high spots. It looks like XRAY are now doing some of this for you, but you can still see the glossy areas that are the low spots. It may not be necessary, but I've never had a diff leak. Sorry for the blurry photo!


Here's the after shot. You can see it's now all matt and completely flat. I do this by adhering a piece of fine glass paper to a board and sanding it an a figure of eight motion. Be careful not to take off too much material as this could affect the tolerances of the diff gears. Make sure you blow off all sanded material out of the diff cup.




All diffs done. The boring part is now over! I also used a 0.2mm washer to tighten mesh. (Please note the 0.2mm washer may not be necessary with the new '09 spec diff cases).


The stupidly thick and strong front shock tower. Until you hold it in yours hands, you've got no idea how strong it is.


To seal the edges of the carbon fiber parts I make a little cup out of tin/ aluminum foil to hold the CA and rest a cotton wool bud (q-tip!) on.


All the parts after they've been sealed. Notice how glossy all the edges are. The idea here is just to 'seal' the edges - don't go apply loads of layers as it will just chip off.


Front and rear diff casing components (with the seals of the two inner pinion bearings removed). Obviously with the new '09 spec car it uses the metal shielded bearings as standard so you don't need to remove this cover.


The two plastic inserts that fit into the pinions are extremely tight. They need to be pushed in really hard. My only theory as to why these are needed is so that material can be removed from the pinions to save weight and they are re-sealed with the inserts so no debris can enter the diff housings.




Remember to back these screws out a bit as recommended in the supplementary sheet to remove some pressure from the bearing. Again - on the '09 spec car it comes with the diff spacers so you don't need to back these screws out.


Both front and rear diff casings finished.


I think the material has been changed slightly for the casings as they now feel even stronger! Notice how far the inner mould protrudes out where the bearings sit inside it.


Everything sits very neatly inside the diff casings. Until you build them you wont appreciate how genius this design feature is.


Rear lower arms are symmetrical, and seem slightly harder/ denser than the EC's standard arms.


The rear arms installed. Notice how there's now two fixing points for the roll bar.


Other parts for the rear assembly. You'll need to delve into the bag containing the clutch parts to get the other set of moulded washers out as in this bag there's only a total of 3mm for each side and you need 4mm to remove more play between the hubs and arms (unless you're building the '09 spec car!). They now got rid of the c-type spacers and replaced them with circular ones, meaning there's no way to remove them without removing the hinge pin. Takes slightly longer but no more spacers falling off mid race!


No grub screws in the outer 'cvds' as the pins are captured in the inner hub bearing.


The captured pins. Also the rear hubs are symmetrical (identical) which is a nice feature.


Just the wing mount to go. Notice the markings on the anti roll bar to denote it's thickness. Yet another useful design detail!


So far so good. Superb XRAY quality as always. I'll upload more photos when I continue with the build this evening...

Don't you think that rear roll bar is a little bit to short?? If you put the rear on the chassis the roll bar not allowed maximum stand of the car

I did think it seemed a little short, but think it'll be fine once it's loosened up slightly. Wiggling the arms up and down a bit has already loosened it up and they now drop quite easily. The manual clearly states to insert the roll bar so it's flush with the end of the ball link, but you could always move the links further out. The down stop settings seem way off in the manual. They recommend leaving 4mm protruding from the bottom of the arm, but when you offer this up to the chassis the arms aren't even allowed to drop below the chassis!

Could this be due to the great big bores? They should soak up alot more
on the landing than the old shocks. Just a thought.

Don't think so wirtz, no doubt they'll soak up more but I'm fairly certain the measurement is wrong. I'll post more pics when I mount the back end to the chassis and you'll see what I mean.

awesome review so far Oli!!!! Keep it coming!!!

great pics oli..

you know what id like to see tho on the cvd's..some rubber gaitors,the mud and sand(in astroturf) over here plays havoc with them binding and jamming up,if there was an extra lip/shoulder on the stubaxle part you could hook a gaitor over there.

keep the review coming oli

dave

I use these on my XT8
http://www.dynamiterc.com/Products/Defa ... ID=DYN7687

why take the seals off of the bearings?

i believe they discovered that the inner seal could fall off in use so better safe than sorry and getting chewed up in the geartrain

x-r-a-y how do you keep them on? I place one on the CVD and one on the drive shaft can I place little zip tires and it will keep them there. This is what I mean I place mind on and when I was running the XT8 it slip off and got destroy same thing on the CVD is there away to keep them on??



Thanks
Felix

Never had a problem with the boots slipping off, they use to push back, but I pushed them down further the next time I cleaned the truck and they stayed in place.

I've never had mine come off but I only used these on the front.
On the rear and center I used these http://www.gmksupply.com/html/gmk0119.html

yes but you have nothing to lock them onto the cvd part,they would just push up and not really seal the cvd..heres what i meant,quick drawing if you see what i mean,is this possible?

the boot would then have a lip to hang onto,like the shock boots do

Very good point daveg, this would be a really cool feature. I think something similar has been designed into the RC8. The only problem I could foresee is that the extra material protruding out to enable the lip to be created would reduce the movement of the cvd?

A CVD boot will not fit. I bought some to fit but there is no possible way.

The entire CVD is with in the rear hub/upright. The bearing holds the CVD pins in place. It is a genius design, but no way to fit a boot.

We realise a cvd boot will not fit, daveg was just pointing out a design feature that might be able to be incorporated into the axel to enable a boot to be fitted. But looking at the front end I think a feature like this would limit the movement of the cvd too much.

your probably right oli,ill have a look when i get chance to see if theres someway to affix a boot..

how about making the hub with a shoulder on it to affix a boot?

The trouble is to machine that shoulder on it would result in the movement of the driveshaft being limited, which I think would be fine on the rear, but on the front would limit it too much to achieve full steering lock without it binding.

Well, I continued with the build last night, and finally got to admire the mouldings of the steering assembly...

First off I replaced the rear wing mount brace with the aluminium ones from the old XB8. IMO these offer a lot more strength than the plastic ones that come with the 808. These are the same as the ones that come with the XT8.


The rear assembly finished.




The front hinge pin holder with the stamped steel insert.


Only one option for where to mount the roll bar on the front lower arms.


Other components for the front assembly.




Interestingly the hubs have got steel inserts but the caster blocks don't. There is however more material for the screw to go into on the blocks. These really are lovely quality mouldings.




All steering block components installed.


I wasn't happy with the length of the screws that secure the upper link to the shock towers (both front and rear) so chose to use a slightly longer screw. In this image you can see the old screw (further away) barely goes into the nylon of the locknut.


Front and rear ends bolted to the chassis.




You can see the lack of droop the recommended downstop screw setting gives you! I normally set my car up so the shocks (when on the car!) are 104mm front and 114mm rear from the centre of each mounting hole.




The rear chassis brace is very short, and is also made of a very dense material. Much tougher with less flex than the old ones. The front one is identical to the old ones, made of the same softer material.


Steering rack and servo saver assembly components.


The servo saver is now much easier to assembly, and much easier to adjust as the nut sits about 6mm up from the chassis. THey have removed the o-ring so you now need to use threadlock, which is a shame IMO. (This has been rectified with the new '09 car!)


The posts now sit much closer together, which seems to be the theme with everything on the chassis!




The servo saver top plate feels reassuringly solid, and it's a bit a mission holding the front body post mount when doing it up. I'm surprised they didn't mould in a square section to the top plate and the underside of the body post to hold it still while doing it up. What is nice is that you can change the angle of it. Just the steering turnbuckles and centre diff assembly to go and the drivetrain is done...