Granite Jerry-rigged's Granite Mega 4x4

And after a bit of internet'ing, I am finding out that I pretty much MUST do the yeti mod, as there are no Mega 4x4 spur gears available...

I think I found the problem...

@Jerry-rigged How did you get the electronics "module" off/open? All I managed to do was get access to the transmitter, but that's all. I wasn't able to access the servo....

4 screws on the bottom of the chassis, plus the one screw in the steering link. Then you can take the whole electrics module off. There is a video, le me go look...

@zoldos - here you go-

Oh nice! Thanks!!

Jerry-rigged said:

I think I found the problem...

View attachment 16952

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Don't you know? All the serious racers do that to their spurs. It cuts wind resistance so the spur can spin faster.

Geez.

Kinda off topic but kinda not. My daughter and I drove her Granite in 3 inches of snow today at about 28-30 degrees and if did awesome. The chassis filled up with snow causing it to get pretty heavy but it did great. I was impressed with the durability after it ran head on or clipping one front wheel at full speed into trees and paver stones without breaking. It really slings the snow lol.

Edit - somehow packed with snow and 30 degree weather it still managed to reach thermal cutoff. All electronics are stock with the stock battery.

Mongoose said:

Kinda off topic but kinda not. My daughter and I drove her Granite in 3 inches of snow today at about 28-30 degrees and if did awesome. The chassis filled up with snow causing it to get pretty heavy but it did great. I was impressed with the durability after it ran head on or clipping one front wheel at full speed into trees and paver stones without breaking. It really slings the snow lol.

Edit - somehow packed with snow and 30 degree weather it still managed to reach thermal cutoff. All electronics are stock with the stock battery.

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Have you tried a LiPO? I ran everything stock except with a 2S 50C LiPO for like 30+ mins and everything was barely warm to the touch.

I ran mine only on lipos... After watching Vas's Granite video, I can't help but wonder if the issue is either a bad batch of motors or bad ESC's. My truck had nowhere close to his speed. No driveline binding either. It did have decent of the line punch, though. BUT - 15 minutes into every run, the ESC would thermal cutoff at 175f. Motor even hotter. I have no plans on perusing a warrantee claim with Arrma, as I never planned on running the brushed motor setup up very long. But for those of you that bought this truck for your kids, and want it 'tamer' then I would contact Arrma over this issue.

In other news, I have my yeti spur slipper assembly complete. Now just waiting on the mail man to bring me a 5mm bore 32p pinion. I screwed up my first order, didn't pay attention to the Amazon seller, and bought a set of pinions with 4-6 WEEK shipping from the far east... LOL Saturday I re-ordered a single gear from Horizon. Hopefully, it will be here soon, and I will get to run the truck again this week.

My current spur/slipper build -


Also, for those in the know for metric threads, I think the spur shaft threads are M8, but they are NOT the M8x1.25 that my local big box store has. They look like a fine thread. Any one know the specs for fine M8 threads? The stock nut is getting loose, after being taken off and put back on 30 or 50 times test fitting the clutch stack...

So a bit of googling later, I see there are apparently three M8 threads - 1.25 (what I have), 1.0, and 0.75. Just from looking, I'd guess these are the 0.75. But as luck would have it, apparently no nylon lock nuts exist in that size. There are lock nuts in the 1.0 size. Guess I'll e-mail Arrma.

On, and tracking shows my pinion at my local PO, so hopefully I will be running tomorrow!

Jerry on the slipper nut, I think my two granites came with a spare in the bag with the few tools.

Might be a little tighter than the one you wore out.

I gave up on trying to find the nut. Too many other issues needed to be addressed. That slipper is not designed to handle real power so it needs to be super tight. So I cranked on it as tight as I could get it then cranked it a little more Then I drilled a hole straight through the nut & shaft & secured it with a locking pin.

I got the truck back together, and did a quick run in the yard. With the taller gears it wheelies even easier now. Still has loads of power. Tried to do a tree flip, but the truck just climbed the tree about 6' up, didn't want to flip... LOL

Also, I added the optional wheelie bar. Looks well made, hopefully it will hold up.

I put together a short vid to talk about the Yeti Spur conversion -

Jerry-rigged said:

I put together a short vid to talk about the Yeti Spur conversion -

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That pin is a PiTA. I use some very thin needle nose pliers I found at Menards. The strip of pop can is ingenious. I have a very large bag of bearings to screw around with so I used the races for everything.

Yeah, I though I had gotten pretty good getting that pin in there, till I tried to do it on video. I edited out about 10 tries that I dropped the pin, and one that the pin just when clean thru the hole. Then fell on the floor and rolled into a hiding spot... LOL took me 10 minutes to find it. Grrr... LOL

Do you have to drill or mod the mounting holes for motor or did you guys get lucky and find a gear that fit stock motor holes? Obviously the number of teeth will be different.

I just cut the motor mount. I've done this successfully in the past, so I didn't even try to find a gear/hole combo that worked. With the plastic mount, it is easy to oval one of the hole (if you just want to bump 1-2 teeth bigger or smaller - I did this to the 27t hole when I wanted to run the 25t) or just join 2 holes into a groove. (if you need more adjustment - I did this when I swapped to 32p). After you cut on the motor mount, though, I recommend longer motor mount screws, and a flat washer under the screw head. Both times I did the mod, I was done in about 10 minutes. And only about 30 seconds of that was actually cutting on the mount.

Next time I have the motor out of my Granite, I'll get some pictures of the motor mount. But hopefully that won't be any time soon. (It is really an easy mod)

Cool thanks sounds easy enogh just didnt want to get ahead of myself and make more work thats not needed but it probably wouldnt hurt to do it since even stock 48p gears its a really huge jump with no options between. Any suggestions on gear sizes. I might even already have them since i have a yeti xl and other axial 32p gears already.