Peterbilt 6x6 Medium Hauler

[Tommy R]

Well, in an effort to make it easier to integrate the DIYGuy999 light/sound controller, I decided to pick up this Flysky i6X. I also picked up an additional receiver and between the two of them I hope to have a solution to be able to fully control the MFCU to its full extent. In time I hope to be able to migrate to a pistol grip transmitter of some sort.


So I've been having issues with the Lesu transmission. I believe I've mentioned how I've burned through a micro shifting servo and the replacement servo tends to run hot. It hasn't failed, but I think it's only a matter of time. The reason? Well, the springs are pretty strong so when you're in low or high gear there's a lot of stress on the servo to hold that gear. In middle gear there's no strain because the springs aren't at play.

After a lot of thoughts on how to deal with this I decided to tear it apart to move the shift linkage toward the front. Moving it from the rear to the front means I'll have room to use a full size servo to shift. It'll still be under load, but a full size servo should be able to withstand the load much more easily. So here's some pics of the Lesu 3 speed 4WD transmission cracked open.










So here's the shift linkage now at the front.


Now to get this full size servo set up to shift it. Hope this works like it should! I may instead mount a low profile servo with the servo horn up top. I'll experiment with a few options tomorrow.

[frizzen]

So with the FS-I6X, i'm assuming you still have a menu for setting 'End Point Adjustments' like the fs-i6?
If so, you can back off the servo throws to a lower percent of travel to keep from having the servo fighting at full power to reach beyond the mechnical stops on the trans.

If it really is the servo fighting too strong of springs, you might also be able to move a locking collar or trim a turn off the coil to reduce preload toward 2nd gear.

[Tommy R]

I'm currently using a Sanwa MT4-S, but yes, it has all the endpoints adjusted properly. But the spring tension is significantly stronger than those in the Tamiya trans. I hoped to remove the springs, but they're necessary for the trans to function. Before I cut or replace the springs I decided to move the linkage so I can use a full size servo. If necessary, I'll look into softer and/or shorter springs. I also looked into just using the Tamiya trans with a front output. That would work out great except for the fact that the output is 1" higher than the front axle's pinion and it's only 1" forward.....so that yields a super steep driveshaft angle.

[Tommy R]

I now have a full size servo controlling the shifter. It's so much stronger than the micro servo I tried and doesn't heat up at all. I think that issue may now be resolved.


I also put this stuff in one rear axle to try out. It looks like it'll work better than the 2.5M weight oil I was using and shouldn't leak out. Now to do the other rear axle. No need to do the front axle, though. I have something different planned for it!


I'm also starting to make some progress with the ESP32 MFCU. I have the steering worked out, but that's all. I still have quite a bit of configuring left to do. Having to also learn a new transmitter just adds to the complexity!

[egronvold]

Looking at the ESP32 myself, just a million other projects to finish first...

[Tommy R]

Originally Posted by egronvold

Looking at the ESP32 myself, just a million other projects to finish first...

I can definitely relate to that!

So here's why I didn't bother with putting the new diff grease into the TLT front axle. Lesu locking diff with a 2.6:1 ratio. It's narrow so the tires will tuck as far as I want, they bolt up to the F350 leaf springs I'm using, they're shorter in height which will lower the ride height a bit, and with the option of an open diff and higher steering angle, it should turn much sharper. That being said, the narrow width of the axle means the tires will get into the leaf springs. Add spacers to gain more throw and the scrub radius increases, possibly causing fender clearance issues. We'll see, though! Time for test fitting soon.




Here it is with the diff lock cable attached. It also included a tie rod, which I wasn't expecting. Nice!


It's substantially narrower than the TLT it's replacing.


I almost forgot this came with my axle order! I'm really excited about the level of detail this unit will add. I think it looks pretty amazing.

[Tommy R]

With that narrower Lesu front axle the tires tuck waaaaay more than before. And this is shown with wheels that have much less backspacing than the ones I've been using. I would actually like to space them out a bit more. The issue is the scrub radius is pretty bad and at full lock the tires get into the back/inside of the fenders. I either need to do some clearancing and/or raise the fenders up a bit.




Loving the new AC unit!


And I've got a bit of good news to report on the ESP32 sound unit. I have it operating the lights like it should, but am working on the sound now. Fingers crossed I can get it all working properly!

[Tommy R]

Meet Fred.

[Tommy R]

So I hit a bit of a milestone yesterday. You see, a very daunting task that's been lingering over my head is the wiring for the lights for this truck. And that was on hold while I determine what solution I want for the light/sound unit. I was working on the DIYGuy999's homemade unit, but I haven't fully figured that one out just yet. I'm not giving up on it, but in the meantime decided to try a Beier USM-RC-2 sound/light unit. Since it's an off-the-shelf unit and available in the US through Bob at Hobby Concepts, I figured I'd try it out.

WOW! This thing is powerful! It can do so much. It took me awhile to learn it and get it all sorted, but I managed to make it happen and I'm super excited about it! What does that mean for the truck? Well, it means I can finally start wiring everything up and begin......dare I say it......final assembly??

Yeah, yeah....I know no project is ever "done", but you know what I mean. I also have a few more goodies for the truck that I'll be installing along the way. I'm so stoked to have this thing finally nearing completion!

[Tommy R]

In the process of wiring lights, it dawned on me that I never shared what I'd done with the dash lights. I did pretty much what Bob from Hobby Concepts does.

[skeeter]

I'm loving the lighted dash!

[Benni]

It's amazing what a couple of LEDs can do...

[groom3]

how did you get the sift linkage to the front?

[Tommy R]

The trans came with a second shaft for front shifting. When I had it disassembled I swapped them out.

[groom3]

Wondering if you reversed the longer shaft or put it in the same way? I am trying to change mine but having difficulty.