Re: Academy Wyvern, 23 Mar 2013, suspension update

[Mr. ED]

Thanks Joey.

The build of the spare car has well advanced, but I came across an issue with the slipper setup. The spring to load the slipper doesn't have parallel front and back planes. And the back slipper plate has play on the axle => giant wobble on the spur when the slipper is even slightly tightened up.
I'm gonna try to solve it using my dremel on the spring. If it doesn't work out I'll have to look for a better spring.
While the dremel is out I'm gonna work on the front arms a little too. The upward travel of the arms is very limited as the arm quickly touches the outdrive of the diff.

[EvolutionRevolution]

Can't you sandwich the spring between two washers?

[Mr. ED]

It is sandwiched between 2 washers already : one on the nut end and the other one is part of the pressure bearing.
The problem is that the end faces of the spring are not perpendicalar too the spring center axis. So when you tighten up the spring the spring load is uneven on the pressure bearing.
I tried the dremel on it yesterday and it's better now. funnily it got even better when I tightened up the nut further ... puzzled.

Continuing the build I found the optional ball-diff uses the same spring. But here it didn't cause any problem.

[Mr. ED]

Just a teaser while I'm resizing and cropping the first batch of build pictures

[DennisM]

Holy cow, that´s quite a heist - can´t wait for pictures.

[Mr. ED]

Ok, here we go.
I didn't follow the instructions; having built the first car , I wanted to follow an order inverse to how I'd take it apart for a rebuild or repair.

As each part is new from the package I took a pic of each in its package. But I'm not going to post them all: would be a bit too much.
Here's the chassis. Unlike some of the other parts I only got 1 in those boxes. It's made of a very shiny composite with bakelite (an early plastic invented by a belgian called Baekelant in the early 20th century).
It looks a little more 'pro', but I guess it's not as good as the the blank GF10 chassis of the Wyvern. The Wyvern EX was priced a little higher than its pro brother, only because it contained the Mabushi 540 and an MSC Talk about poor marketing

A separate nose piece with built-in bumper in souple nylon

Mating can start

the nose piece adds a nice kick-up upfront and gives more clearance for landing from jumps: thumbs up

Check out these arms: nice and wide, made of fiber reinforced plastic

Hinge-pins with E-clipses, classic pain in the B

The front gearbox; they sure know their plastics and mouldings at Academy

The front end put roughly put together and ready to take the diff, but let's get on with the rear first

[Mr. ED]

The rear end: gearbox casing with built in arm mounts with fixed caster.

Another pair of nice arms (yes I know they look like yokomos). Note the spared-out area for the diff cups.

The rear carriers look like yok's too; but they have the axle nicely encapsuled

10x5 bearings and U-J's are optional here and these optional U-J's are way shorter than Yok's: the diffs outdrives are further apart= centering right above the hinge-pins

Getting that butt ready

the "center" gearbox:

and inside:

Far from the prettiest part in the kit, but metal and functional

Ok, I'm tired, we'll continue the story tomorrow.
I hope you're enjoying the ride

[JK Racing]

Truly jealous. I've had a soft spot for Academy cars since I first bought one and became one of the team drivers. I have always loved the yoke's and this puts 2 of my yearnings into one car But I would be way to temped to drop a 10.5 in there with you owning 90% of the parts on the planet, I wouldnt feel very comfortable.

[RichieRich]

I agree, I'd love to have one of these too. I have an SB along with a GV2 so I'm a fan of the Academy kits.

[Mr. ED]

Joey, there's worse places to have those stock parts; now at least you know where to ask
Richie, Stormer hobbies has the truck version of the GV2 still on stock and I was eye-balling them for a bit too.

When this build is over I'm gonna categorize parts and see if I can get some basic kits together while keeping some stock of the wear and tear parts.
They'll definitely miss the lower chassis and shocks, but those are 2 items that don't need to be original for a good runner.

I'm going to build a little more tonight, so a little more patience for the story to continue, sorry.

[Charlie don't surf]

Wow, it gets cooler!!

[Mr. ED]

Wow, it gets cooler!!

That's why I chose for the pink dampers; don't want people to get jealous
More on the dampers later though: let's see some other pics first:

The center shaft: special edition as included and needed with the slipper kit. And the top pulley, and ... uh-oh: I had to dig in other stock to find a fitting E-clipse as that wasn't included

Strange: 2 different pulleys with the same part nr? I used the black one since the white one has a smaller inner diameter.
I think the white one is the alternative for the one-way front-belt pulley when using the slipper shaft. Still strange to give it the same partnumber as the standard rear-belt pulley though.

the one-way front-belt pulley:

IMG_8881.JPG (30.16 KiB) Viewed 1375 times

IMG_8881.JPG (30.16 KiB) Viewed 1375 times

Partial assembly. see that open window on the front of the gearcase? Beats me why it's there. Surely something I'll have to fix in the future.

Coming together nicely. Oh, and notice the spur actually sits behind the moter unlike the Yok's. This means the moter sits further forward: a feature copied by many of todays cars just kidding but I do like it

From another angle

The slipper kit parts, not very different of every other single-pad slipper design out there:

These sturdy covers will seal the gap between the center gearbox and rear gearbox.
Funny detail: behind the pulley on the lower side is a provision to put an axle and bearing: to put some tension on the belt I guess. But the Optional part was never released: didn't see it anywhere in the catalog with spares and options.

And this turnbuckle lets you adjust the belt tension by pushing the center and rear apart. That's the theory at least. I wish they had gone with that internal bearing instead.

Almost there... but not yet

[Mr. ED]

Once on the chassis I gave it a couple of turns to see if the transmission felt free. No problem, hooo: see that spur wobble.

As mentioned before I went at the spring ends with the dremel to solve that:

IMG_8902.JPG (24.36 KiB) Viewed 1374 times

IMG_8902.JPG (24.36 KiB) Viewed 1374 times

And while it was out I attacked the front arms too:

I don't have spare gears nor diff outdrives for the couple gear diff housings among the spares. So I'm going with the optional balldiffs on this car. A bit worrying as the ones in the griffin pro weren't working for me

Threadlock in the left part and diff rings glued in place with cyano.... I'm pulling everythin out the closet I can come up with

Allright! It actually feels well AND doesn't slip. What a relief; for the griffin it all failed and I had to chase up geared diffs.
In it goes: on a pair of 15x10 bearings

And that's how far I got with cropping and re-sizing pics.
More to follow, but first a little more building too

[RichieRich]

Interesting about the diff. For the older Academy ball diffs, we used the TC3 spring, t-nut, bolt and thrust bearing. This made the diff much better. Not sure if that will help you out here.

Excellent progress pictures. You're making everyone want to pick up one of these cars.

[Mr. ED]

Might be worth giving that a try, but for now it feels ok.
I found a nib wyvern in a danish webshop, but it is so expensive. Especially since it is the ex version.
The dealer in germany was pretty active back then , so your best bet would be finding a cheap used one on ebay germany and complete that with some of the option parts I have plenty of.

On with the build story:
I have the black bakelite towers on stock car, so I picked the white epoxy ones for this build. They are around 2.5 , maybe 3mm thick and lots stiffer than the black kyosho ones of the ultima pro etc. Multiple hole locations should make up for the only 1 shock position on the arms (both in back and front). But I have doubts about which are actualy usable. The ride height is big even with the relative short shocks in the rear... you 'll see that soon enough.
Cool thing to note about these spare part bags: all the hardware you see is included in the bags. So if you replave this rear tower , you getnew screws and pillowballs all included.

left-right threaded turnbuckles instead of the black rods to set it further off from the standard EX:

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IMG_8917.JPG (37.58 KiB) Viewed 1361 times

The pink stuff comes out !
I have several sets of this triplet in pink, some in green too and some yellow duo's only: no rear shock parts.
Pittty 'cause I'd have gone for yellow for sure. And green was my next choice, till I realised it would not go well with any of the potential bodies I have in mind to try on this. Yeah, I could have taken stock black ones, but hey that'd be boring.
Aside from fun I really can't see how Academy considered these shocks as 'hop-ups'. And to top it off you'd have to take your standard shocks apart and re-use parts to build these coloured ones as they don't make full shocks.

The pink turnbuckles give it a bit of a theme look

this is the stuff I had to open extra: everything on the right won't get used

and another bag:
(And this one is a little bit of a problem: I only have the one in the stock kit and 3 spares. But better than the front: for wich I only have the stock kit parts: enough for just 1 front shock pair. And since this is car 2 I need to find some alternative source for shockshafts.)