Fallen's RC4WD Miller Motorsports #4421

[Fallen]

It's a valid question either way. When parts that shouldn't fail, do fail, the question of user error needs to be answered.

I also have the recurring problem of the front ring gear failures. I've yet to hear of anyone else having that problem.

Maybe my opinion of "realistic driving" is unrealistic. I doubt it, but it's possible.

 

[themountain]

How are your LX shocks holding up ? I am thinking about to do the plunge and get those.

 

[Fallen]

They've been great. No leaks at at all.

I've changed the fluid in them several times during the tuning process and everything is still nice and tight.

The adjustment on the bypass tube actually effects the damping.

You do need to build the shocks correctly though, but it's not difficult and the instructions are easy to follow.

When you build them, the floating piston in the bypass tube calls for 2 O-rings. I found 1 O-ring works better, and allows more free movement of the piston inside of the bypass tube.

 

[Fallen]

Apparently I was wrong. Not about the cracked plastic part, that is definitely cracked. But there's some other problem apparently.

I replaced that cracked part, and reassembled. The "click" is still there.

Something else in the transmission that I haven't detected yet must also have failed. Fortunately RC4WD sent me about $150 worth of parts for free. Even though I told them all I needed was that one plastic piece, they sent me an entire transmission, a free shirt and stickers.

Now I just need to build the new transmission into the new housing. The problem there is that I might never understand precisely which parts have failed. And that bothers me.

But let's see if the new transmission even solves the problem first. I suspect that it will. If I get the transmission built this weekend, we'll at least have that answer.

 

[themountain]

You are there reference on this board for them...they should support you let's see how all pans out.

 

[Fallen]

Well, still no good news. New transmission assembled and installed.

The click is still there. Along with no drive.

It's either user error (bad assembly of transmission) or something other than the transmission.

Something interesting I noticed is that with the Spektrum 2300KV motor, the gear mesh with the transmission input gear is too tight. As in zero play. Gear mesh on this motor plate is not adjustable, but fixed.

I'm going to go back to the stock motor / ESC and try that with this new transmission. Maybe a slight variance in how centered the motor shaft is in the motor housing is causing the gear mesh to be wrong enough to cause transmission problems.

 

[ferp420]

is it posable the motor is bad maybe the shaft isent tight to the rotor ?

 

[Fallen]

Certainly, as I didn't check for that. I did run the motor with finger touching the shaft (don't laugh, it's not funny!). The shaft spun true, as far as my finger could tell.

I didn't try to move the shaft in relation to the motor though. I assumed it was secure.

 

[Fallen]

I anticipate that there won't be any updates on this truck for some time. I'm waving the white flag.

What that means is I've locked the truck in low range, removed the shift cables, disconnected the shift servos and am leaving the differentials locked. It's just a crawler now.

I've replaced the stock electronics and put the 2300KV system back in my Bronco. This truck will now be my 5 year old son's crawler.

You win some, you lose some. I'm not mad at RC4WD, they stood behind their product and tried to get it working. I'm just not willing to spend more time trying to fix this. I'm glad RC4WD made (or attempted) to make such a versatile vehicle. That's no easy feat, as the KOH race has proven.

I'll just hang on to this thing and let my 5 year old son drive it while I see if others have similar problems and a solution is developed.

I might also make use of BGRedjeep's designs to start with a new skid plate using a different transmission, driveshafts & axles. We'll see...

 

[JimrC]

That sucks ... but least yer kid now has a cool looking crawler

 

[Fallen]

Oh, and some good news. I traded my LMT to Mudbeast for a GCM CMax LC70 chassis w/ an LC70 hardbody.

So there will be a build thread for that soon as I start working on that project.

 

[bgredjeep]

I might also make use of BGRedjeep's designs to start with a new skid plate using a different transmission, driveshafts & axles. We'll see...

Since it doesn't sound like you are in a rush, I'll plan to draw another skid as a more direct replacement for the miller skid to run the 3gear trans. All the suspension locations on the current one are to mimic my bomber so it wouldn't work with any of the stock miller links.

 

[Fallen]

Killer, then I'll definitely wait a bit to get this stuff printed. I'm not afraid to use new links, but if I can keep the stock links / axles it'd be nice.

The stock front axle and trailing arms have dual shock mounts which I'd like to keep using.

 

[bgredjeep]

I got the skid posted. It matches the stock skid I have aside from the trans mount. Lmk if you see anything obvious that I missed since I don't have the complete car to test with.

Miller Rock Racer 3 gear skid plate by BRJDesigns

This is a skid plate for the RC4WD Miller Rock Racer to swap to a standard axial style 3-gear transmission. This should maintain the stock suspension mounting and geometry, links, etc. I do not have the complete Miller rock racer RC, only the cage, but I expect this will not allow you to...

www.thingiverse.com

 

[Fallen]

Thanks man! I'll get this printed soon. With a nice brushless set up, I should be able to get high and low speeds without the 2 speed transmission.

 

[Fallen]

We're moving in the right direction again.

I had a local waterjet company print up the skid bgredjeep designed. They did it in resin, and boy is it stiff compared to the stock, wet-noodle of a skid plate.

The stock suspension link rod ends fit perfectly in the mounts.

I ordered a cheap ($40) version of the Axial 3 gear. The idea is that's just for making sure everything works. It'll fail sooner rather than later, but once I know everything works I'll upgrade to the Vanquish transmission.

So far it looks like the only stock part that won't work with the skid is the interior. I suspect the motor / transmission will foul on it, so I preemptively removed it.

Once my transmission arrives I'll just need to figure out driveshafts, and this thing should be fun to drive again!

 

[bgredjeep]

Looking good.

 

[Fallen]

Once again, the Spektrum 2300kv motor / ESC is set to go in this truck. While the old "transmission click of doom" existed prior to me installing this motor, once I installed this the transmission failure became obvious.

Currently running a 22t pinion. I'm shooting for enough speed to make the suspension work hard. I'll likely end up using a smaller pinion.

I painted my rear lightbar lenses. The stock lens color was too dim. The white LEDs blew through the color & looked pale.

I used Tamiya clear red, yellow & blue. This lightbar is a reference to when Ultra 4 trucks were required to run one rear facing amber and rear facing blue light. That was the era during which I got into watching Ultra 4, so this lightbar is painted to remind me of that.

Just waiting for a rear driveshaft, and a replacement skidplate now.

 

[Fallen]

Good news, bad news, good news, bad news; overall, good news.

My driveshafts are here. Wraith / Bomber length driveshafts will work perfectly with this transmission conversion. The skid plate will need slight, slight clearancing to allow dropout of the rear driveshaft.

RC4WD designed the truck with counter rotating driveshafts. Ugh. So this transmission won't work unless... I can flip one of the differentials in the axle housing.

Which I can! But that also means sacrificing the selectable differential for that axle. So the front diff will have to say hello to my little friend... Silly Putty!

My front ring gear has lost two teeth. The locking tabs are still there, but clearly this pot-metal gear isn't up to the task. Hopefully the silly putty will result in less force being put directly into this ring gear.

And that means the only selectable function left on the truck would be the rear diff. Which I'll probably just lock with hot glue, or maybe silly putty also. Then I can just run a 2 channel radio in this thing.

It should all work, and should be fun to drive fast offroad. It obviously won't be a great crawler, but it never was. Even with the diffs locked it needed momentum to get over obstacles. With momentum it climbs great, but low speed crawling never really worked. The silly putty diffs should be a good match for this truck.

 

[ferp420]

they sell counter rotating 3 gear transmission

| AXSPEED 48P All Metal Transmission Box Reverse Gearbox with Motor Gear Protective Cover for 1/10 RC Crawler Car Axial SCX10

https://a.aliexpress.com/_mKIlEm8