First one I ever had... 2019 Turbo Optima re-re build

[emerilnut]

OK, last steps and now the car is DONE! Electronics. This step had to wait because I went on the advice of XLR8 and got the GoolRC motor/ESC combo. The problem was that the motor shaft is 5mm thick, so I had to order a new pinion gear with a 5mm bore.

But that guy's in now, and meshed perfectly...

After that the receiver went in near the hole for the antenna tube

Then the ESC taped down so that the motor wires are nice and neat.

And, lastly the receiver wires from the servo and ESC, and mounting the power switch. VOILA! Complete!

This build was SO fun to do. Kyosho really has some quality stuff. From the fit and finish of the metal parts to the way they plastic parts come off the tree. Just good stuff. Everything lined up, and nothing seems out of place. In some ways I'm glad that I built this car now instead of when I was 13, because I was an idiot then and would've completely messed up the build. But with age comes experience, and it was really fun to take this slow and do things right. Especially painting the body.

[XLR8]

Well, the car looks great -- and it should run GREAT as well.
5mm shaft??
Oh man, I am kicking myself right now because I may have sent you the wrong link. My motor takes standard 1/8" shaft pinions.
I went back and looked and the motor I have is model 3650, 3500kV with a 50mm can but I think I sent you the link to model 3660, 3300kV, 60mm can (It's sorta like a 550 class motor).
I am so sorry - I should have checked that link more closely before sending it to you.
Man that TO is gonna rip with that motor.
I have a Reedy motor with similar specs in my TOMS tribute car and it's an ANIMAL.
Anyway, the motor prices are about the same but unfortunately it required you to buy a new pinion. I am sorry about that.

[emerilnut]

No worries at all. I didn't know any better. The way I looked at it, I should have known better when I ordered it. I read the entire Amazon page on it before ordering and even saw some people in the Q & A section mention the 5mm shaft. It should have hit me then to source another pinion. AND since this is my first motor purchase of the KV variety, the numbers around the motor didn't alarm me at all like a low turn count would have. I was just excited that the combo was so cheap.

I'll get it out for the first run soon. I don't think I'll get a chance on Sunday since I have family stuff all day. But I'll report when I get the chance.

[sundevil67]

Arg. 3 out of the 4 screws are able to be tightened, but for some reason (I definitely didn't over-tighten/strip the threads) I just can't seem to get the 4th to catch the threads. The diff-halves seem pretty secure & I could probably get away with just leaving it out, but it'll bug me & I want this to be a 'perfect' build... The fact that I'm stuck on step 1 doesn't inspire confidence, but I'm wondering if anyone else ran into this or had any suggestions. Thanks!

[XLR8]

I don't recall having this problem with any of the re-release kit's I've built.
The front diff case is plastic so maybe there is some flash that is preventing the screw threads from biting? I would suggest disassembly and checking the hole and if there are no obstructions, take an sharp xacto knife and lightly run it around the hole to form a small chamfer, then test-fit the screw before re-assembly.
The rear diff case is sintered metal so this could point to an untapped hole - you could disassemble and confirm. If so, then this is a faulty part and I would suggest contacting Kyosho customer support and request a replacement part. Kyosho provides excellent customer support.

[sundevil67]

Thanks for the reply! There's no flash or obstruction I can see... I did drop a note to Kyosho America earlier in the week...no reply yet, but maybe they'll get back to me with some guidance. If all else fails, would some threadlock be out of the question here? It doesn't seem like it'd interfere with the smooth operation of the diff.

I don't recall having this problem with any of the re-release kit's I've built.
The front diff case is plastic so maybe there is some flash that is preventing the screw threads from biting? I would suggest disassembly and checking the hole and if there are no obstructions, take an sharp xacto knife and lightly run it around the hole to form a small chamfer, then test-fit the screw before re-assembly.
The rear diff case is sintered metal so this could point to an untapped hole - you could disassemble and confirm. If so, then this is a faulty part and I would suggest contacting Kyosho customer support and request a replacement part. Kyosho provides excellent customer support.

[mikea96]

Are your other 3 screws tightened down already? If so back them out and make sure all 4 screws are started before tightening any of them down.

[XLR8]

I've always phoned Kyosho and they've always answered my questions - no delay.
I would not use thread lock since it would be virtually impossible to keep it from contacting the plastic and this could lead to problems down the road.
I also would not run the car with only three screws in the diff cases. If all else fails, simply explain the problem to Kyosho and they will send you replacement parts, they may even send them via next day air.

[XLR8]

Are your other 3 screws tightened down already? If so back them out and make sure all 4 screws are started before tightening any of them down.

That's an excellent suggestion Mike.
I've always just started all the screws then tighten them after all of them have been installed.

[TRX-1-3]

"would some threadlock be out of the question here?"

If you go with threadlocker, make certain it is formulated for use on plastics. There are some different kinds out there. Good luck and happy modeling!

[mikem65d]

You could also use a longer screw in that hole if parts are not available. 2mm longer will work.

[sundevil67]

I'll post when I get back into it...I took the E-Revo out in some serious mud & I've gotta get that sucker cleaned up before I can dive back into the Optima build.