Turbo Optima build - Project Barney: Finished

[Jay Dub]

Yeah, I don't think he knew what he was talking about . I could be wrong, but the only car I have ever seen these arm on is the Maxxum. In fact the description seems to indicate that those particular arms are a replacement (included in the kit at some point) for the kit MX-6 arms and are stronger. But it should wrk well on the optima. -Jeff

[Mr. ED]

I had seen a description along the same lines before (I only vaguely remember). So either there truely was a release with these arms by Kyosho, or it was the same seller, or the story has spread itself like a city-legend

[Coelacanth]

With some advice from EvolutionRevolution, I picked up some purple GPM front C-carriers (for Kyosho TF-3/4) for Barney's front arms. Thomas hadn't actually tried mounting these on an Optima, but sounded confident enough for me to take a chance...and for only $12, it was worth a try. The carriers came with everything I needed to mount the knuckles. Everything fit perfectly, no modding required! Thanks Thomas!

I still can't do any chassis building until the awaited RCScrewz kit arrives...

[EvolutionRevolution]

Good to see that they do indeed fit the arms, and that ZX-5 front uprights will also fit most previous Kyosho 4WD cars by extension.

[Coelacanth]

Good to see that they do indeed fit the arms, and that ZX-5 front uprights will also fit most previous Kyosho 4WD cars by extension.

Not to nit-pick, but the uprights (I think you're referring to the ZX-5 knuckles) come in 2 varieties; a version made by 3Racing which requires some careful filing down of one of the kingpin bosses, and a Duratrax version (shown above) which is a perfect swap. The C-carriers are for the Kyosho TF-3/TF-4--and would probably require aftermarket control arms (such as the Maxxum arms shown) with deeper notches than stock Optima arms. Only mentioning this in case anyone is thinking of doing the same mod.

I'm so stoked you put me onto these TF-3/4 carriers, I was surprised how well they swapped right onto those Maxxum arms!

[EvolutionRevolution]

The GPM c-hubs have three holes for the hinge pin. If you want to use them in normal Optima arms or TF-3 arms you use one of the inner holes instead of the outer hole. The outer hole is used on the TF-4.

Unless they changed the design since I bought them.

[Coelacanth]

You're right, I noticed the more inboard mounting holes but never thought to try mounting the carriers to stock Turbo Optima arms. Now that you mention it, I'm pretty sure they'd work.

[Coelacanth]

Unfortunately this isn't much of an update, but things needed to be done. I had to grind down the axle ends of the Kyosho Lazer CVDs because there was a lot of rubbing inside the rear alloy hubs. The top is the stock CVD; the bottom one shows the cut-down flange.

The first step of the assembly (according to the manual) is to assemble the rear gear-box. I have the belt drive diffs, pulley, shaft, 2mm screws and some washers, but those little Lexan dust-covers to keep dirt out of the modded rear gear-box are impossible to find. I didn't want to just leave a gaping hole for dirt & crap to get inside the gear-box and mess up the diff, pulley & final pinion gear, so I had to find a way to fabricate my own cover. Once this niggling detail is taken care of, the majority of the build should move along a lot quicker.

It seemed to me that making a "sandwich" with 2 side pieces and a curved center piece would be the easiest way to fabricate this thing. Here are some pics of the pulley cover progress. I'll cement the center piece to the 2 side pieces with a bit of Weld-On (hopefully it'll work), then trim down the corners of the side pieces. When the gear-box is done, I'll seal any openings with silicone.

[Mr. ED]

Are those the low-cost UJ's for the lzaer zx5? Do you have a partnr and address for buying?
(The CVD's are great but so expensive)

[jwscab]

Marc,

you can get polycarbonate glue if needed to glue together that dust shield, they make a few different types, one is very thin and it more or less melts the two pieces together, and then there is thicker stuff.

thanks for the photo of the zx5 universals.....how long are they from the face of the plastic on the axle to the bone pin?

[Coelacanth]

I'll find that info for both of you tonight. I paid maybe $20 a pair for those CVDs after watching eBay patiently and finally seeing a low price on them.

Back in the day when I was modding computers and doing a lot of custom work with acrylic, I bought a couple varieties of Weld-On, as Joe mentioned one is more of a goopy viscosity (in a tube) and the other is a runny liquid (in a can). I know it works fantastic to cement acrylic, and is supposed to work for polycarbonate as well...

Bought it from Ridout Plastics:

http://ridoutplastics.com/adandcem.html

[Coelacanth]

Are those the low-cost UJ's for the lzaer zx5? Do you have a partnr and address for buying?
(The CVD's are great but so expensive)

Mr. ED, I'm pretty sure this is what I bought, but this is even cheaper than what I paid. I bought them in 65.5 & 68mm lengths, as the GPM rear arms are approximately 5mm longer than stock Turbo Optima arms. Stock dogbones are 62.5mm so I figured one of those ought to work.

http://www.ebay.ca/itm/Kyosho-LA303-UNIVERSAL-SWING-SHAFT-65-5-PLASTIC-JOINT-/220789950245?pt=Radio_Control_Parts_Accessories&hash=item33681b4725

And another seller:
http://www.ebay.ca/itm/Kyosho-LA303-Universal-Swing-Shaft-65-5-P-Joint-Type-/130496829586?pt=Radio_Control_Parts_Accessories&hash=item1e62379892

[Coelacanth]

thanks for the photo of the zx5 universals.....how long are they from the face of the plastic on the axle to the bone pin?

Joe, from the face to the center of the pinhole, it's about 10.5mm.

[jwscab]

thanks Marc,

can you also measure from the face of the plastic part all the way to the end of the bone, at the center of the pin? I'm looking for overall length. These could be cheap replacements for yokomo 870c universals that can convert over to pin and nut arrangement for 2.2" wheels, I just don't know the dimensions, and you happen to have them and can measure them

[Mr. ED]

mmmm didn't we have a loooong thread with all this info allready in it?
I remeber building an 870C with white arms just to proove it can be done.
I have to look for it , but I think I used 68mm lazer CVD's for the rear or front.
(Depending on how your front is made up you need different lentgh Yok universals also)