1:10 or 1:12 scale project wanted... - Page 10 - RC-Monster Forums

BrianG · 03.24.2007, 03:30 PM

Yeah, I might just do that. But I still need to find a replacement outdrive yoke because it is too short to use the Kyosho spur.

The easiest solution I think would be to shave all the teeth off the stock spur and use the plastic spur the way I did in the pic below. Then, use several 2-2.5mm screws and screw the stock steel spur to the Kyosho spur. This would let me use the stock bearing and stock outdrive. All I would need to do is shave the chassis a little so the gear won't rub.

Sylvester · 03.24.2007, 06:20 PM

Seems like a good idea, but since it would be pushing the gear closer to the servo assembly, wouldnt it be hard to get the pinion on the motor since its already near the end of the shaft?

BrianG · 03.24.2007, 06:51 PM

I thought that at first, but after measuring and test-fitting, it looks like it will work with a whole 2-3mm to spare. :)

I responded to Mike asking if he had some 1/8" bore Mod1 hardened steel pinions, or sleeves to use with the 5mm bore ones. I also showed him the dual spur thing. Maybe he can make an adaptor plate for the diff cover and then attach the plastic so it's like my idea...

Sylvester · 03.24.2007, 06:54 PM

Or just like you said round off the stock spur gear and drill your own holes - i wouldnt see a problem in that, id personally countersink the stock steel spur for 4 screws, and use nuts on the plastic end of the spur. I cant wait to order my crt .5 up!

BrianG · 03.24.2007, 06:55 PM

LOL. I would do that, but the stock spur is hardened and I don't think I can drill the holes nor shave off the teeth. :)

Sylvester · 03.24.2007, 06:57 PM

Thats true, but i have a mill which will make it easier, yet still, i hate working with hardened material, really messes up my drill bits:mad:1 ..

BrianG · 03.24.2007, 07:00 PM

No such luck here - just an overworked dremel. :)

nieles · 03.24.2007, 07:05 PM

if you drill first a 1mm hole and then go up every time with .5mm till you have a 3mm hole I think that will work

because i drilled bigger holes in my hardened rear wheel axle of my buggy (2,5 to 3mm)

BrianG · 03.24.2007, 07:10 PM

I tried it with a 1/16" bit and I couldn't even get it started. It's one of those DeWalt Ti bits too and it was brand new.

BP-Revo · 03.24.2007, 08:37 PM

Yea...hardened steel is a PITA to work with.

I'm hoping someone finds a solution by the time I get my CRT .5 :p

skellyo · 03.29.2007, 03:04 PM

Whoever does pricing at Tower sure is on crack:

http://www2.towerhobbies.com/cgi-bin...&I=LXPRF3&P=ML

$420 for the same truck you can buy from Ultimatehobbies.com for $275

BrianG · 03.29.2007, 03:41 PM

Wow, I guess! I thought they would've lowered the price to a more marketable level once they got it in stock. Maybe the pricing people are pricing the KIT like a RTR and don't realize it...

rhinopole · 03.29.2007, 08:47 PM

So have you come up with a solution to the spur gear problem yet?

BrianG · 03.29.2007, 09:51 PM

Quote:

Originally Posted by rhinopole

So have you come up with a solution to the spur gear problem yet?

Yes and No. Time for more pics I guess...

OK, so the stock outdrive wasn't long enough. I got an 1/8th scale Ofna outdrive set. It fits, but there was too much length after the pin, so I ground down the end until it was perfect. Man, the Dremel tool is totally indispensable! Anyway, the pic below shows the size differences.

Then I noticed the hole for the pin is bigger on the modded cup, but luckily, the stock gear has spots for two sized pins. And even more lucky is that a Revo wheel hex pin is the perfect length/diameter to fit. :)

The 1/8th scale outdrive mounted on the Kyosho spur:

The assembled diff. Fits perfectly! I did have to use two Ofna gaskets to get the right amount of play in the diff though. Note the stock 10x13x4 bearing on the 1/12th scale side and the 8x16x5 bearing on the 1/8th scale side. More on this later.

So now I am going to have to get/make some type of dogbone adaptor that will have a larger end for the now larger diff cup and the stock smaller end for the rear-end cup. You can see the size difference below between the stock shaft and a Sportwerks dogbone set. Not much difference in shaft diameter - only 0.06mm.

I figure I can either cut both shafts and use some type of collar to join the ends (grinding a flat spot and using a set screw), or have a new dogbone made to size. Below are a couple of examples of what I mean. Note; these are doctored images...

Remember the size difference between the bearings on the diff? Well, I ground 0.5mm all the way around one of the plastic diff mounts to accomodate the larger bearing. Took a while to get perfect, but not difficult.

However, with the Kyosho spur, the diff is physically about 3mm longer. So, I have to drill new mounting holes in the chassis. Not a big deal really, but the new holes would be VERY close to the existing holes and I don't like that. So, I think I'm going to enlist Mike's services once again to machine an integrated diff mount and motor mount. There really is not much room to play with between the front and rear braces so options are limited. The good news though is that he also has a CRT.5 so I won't have to ship mine out for test fitting. :)

glassdoctor · 11:56 PM

Nice work... what would be sweet is to find a CVD type center shaft that is the proper length. The diff end would fit the modded center diff outdrive and the other end would have the u-joint, which I'm guessing would work on the other end? (assuming the .5 is made like big brother...)

But... you can probably make the custom shaft like in your pic. I cut a dogbone and shortened it for my Kyosho conversion. I used whatever material I could find that fit the bill... I think it was an aluminum handle from a pick. And I used a piece of steel tubing also, then put pins through it. Amazingly it's worked great... it's not the prettiest thing, but it has not failed yet. :)