6x6 Peterbilt Semi Truck
 

Hey y'all,

It's been a while since I've done a build. My Class Zero rig is still gathering dust. I picked up and built an SCX10.2, but I've been lazy mounting the Jeep body to it. So why not start a whole new project, right? :mrgreen:

I've always wanted to build a Tamiya semi truck. They're just so cool looking and I've been a fan of big rigs since I was a kid (maaaaany moons ago!). I've spent hours and hours watching those incredible expos in Europe where people build and drive their amazingly detailed trucks through scale cities, but sadly, it doesn't seem to be very popular here in the States. :cry: So that means if I were to build a semi truck, I would likely have to run it with my crawler buddies. Now make no mistake, converting one of these trucks to all wheel drive will absolutely NOT make it a crawler. However, I should be able to do mild trails with it and honestly, that's all I care about for this truck.

So which one to buy? The Euro cabover trucks like the Scania, Mercedes, and Volvo look fantastic, but all the front overhang and such a short wheelbase would combine to make an already ill-performing offroader nearly useless in our terrain. I would really need something with a slightly longer wheelbase and minimal front overhang. So I looked into the US trucks like the Globe Liner, King Hauler, Aeromax, Grand Hauler, etc. Some had a wheelbase that was just ludicrously long so they got ruled out. I also figured this truck would have a bit of a "heavy hauler" or "construction" type look so that ruled out the trucks with tall sleeper cabs. That left me with the Globe Liner and the King Hauler.

And after months of researching them and what it would take to make them all wheel drive, I opted for the King Hauler. The longer cab would likely give more options for drivetrain and the mandatory sound system! :mrgreen: Tower Hobbies hooked me up with a generous gift code and I already had a gift certificate so they got the order. Three days later....

BAM!
https://photos.smugmug.com/Hobby-Stu...MG_7249-XL.jpg

The first order of business is to do a stock 6x4 build with RWD only. It's crazy, but after being in the hobby since the '80s this will be my first Tamiya build! I can't believe they still use philips screws, but oh well. Once it's built I plan to convert it to a 6x6 and I'm still trying to decide which method I want to follow because there are plenty of options! I also figured I'll do some bodywork during this time. Since the King Hauler isn't really a Peterbilt or Kenworth or any other specific brand, I would like to put some effort into making it a Peterbilt. I'm not yet sure how far I plan to go with that, but it may include front fenders, a grill, and some badges. That would likely be all I'd consider, though there's certainly more options available to make it more accurate. Specifically, I'm after the look of a Peterbilt 359. Now let's build!!

Chassis all done!
https://photos.smugmug.com/Hobby-Stu...MG_7250-XL.jpg

For the axles I had something in mind. I didn't want to fully lock the axles because I'd like the truck to have a reasonable turning radius on concrete. However, it needs a true 6 wheel drive to get anywhere and open diffs just won't cut it. So I decided to try an experiment with some Gravity RC 2.5 million weight diff grease. My hope is that offroad it will lock up enough to spin all the tires, but allow diff action when turning on grippy concrete. Time will tell if it works! Here's the goop going in.
https://photos.smugmug.com/Hobby-Stu...MG_7257-XL.jpg

Roller status!! I also installed a Savox 1256 servo for the steering. It's only got about 277 ounces, but I think that might be fine for this type of rig.
https://photos.smugmug.com/Hobby-Stu...MG_7259-XL.jpg

Transmission coming together. I'll lock it into first gear for now, but eventually I'll have a servo to shift it.
https://photos.smugmug.com/Hobby-Stu...MG_7265-XL.jpg

Trans and an Integy 55t motor installed with the stock 10t pinion. I hear these things are way too fast with the stock gearing so I'll have to address that for sure.
https://photos.smugmug.com/Hobby-Stu...MG_7268-XL.jpg

Now the body and accessories. The base build is pretty much done. 8)
https://photos.smugmug.com/Hobby-Stu...MG_7278-XL.jpg

Re: 6x6 Peterbilt Semi Truck
 

And Bamm she done..haha..
Looking forward to see how you make it a 6x6...was thinking of one of these toys in the future tamiya fan as i am and a 80's fan also..."thumbsup"
how many Hrs or days did it take for you to get it to looks as it sit right now..Can you tell me the WB looks big....
subscribe now...."thumbsup"

Re: 6x6 Peterbilt Semi Truck
 

Check out that crazy articulation!! LOL
https://photos.smugmug.com/Hobby-Stu...MG_7279-XL.jpg

My plan all along has been to run a Tamiya TLT front axle in this thing. Same gear ratio as the semi rear axles and a good width. They're increasingly more difficult to locate these days, but I found one on ebay and guess what arrived from Canada over the weekend? :mrgreen: I gave it the same treatment as I did for the rear axles.
https://photos.smugmug.com/Hobby-Stu...MG_7301-XL.jpg

Then I greased up the gears, along with a coating on everything else in there to prevent rust since it may see some light water crossings.
https://photos.smugmug.com/Hobby-Stu...MG_7302-XL.jpg

And so much for an assembled truck! I yanked the front axle so I could figure out how I want to attach the TLT axle.
https://photos.smugmug.com/Hobby-Stu...MG_7304-XL.jpg

I am now at a crossroads. I need to determine how to mount the TLT to the leafs. The stock leaf spring has no holes in it. That would mean I'd need to drill two holes in order to attach it to the axle. Not sure how well this steel will drill since I suspect it may be spring steel? I also have Hi Lift springs, which has three holes in it. I may look into installing it, but am not sure if it will be stiff enough to support the weight of this truck. If anyone has thoughts or suggestions, I'm all ears!

Lastly, I still need to determine my transfer case choice, as well as my gear reduction method. But whatever I choose, it's looking more and more like I'll need to run the TLT upside down.....or maybe run my rear axles upside down if that's easy enough to do. Haven't looked into that yet, though. Again, any input is appreciated, but I've giving strong consideration to this transmission/transfer case:
1/14 rc car truck for tamiya 2 position 2wd/4WD Metal Transmission Planetary gear box
http://www.wtbcar.com/shopping/image...hv-600x600.jpg

Re: 6x6 Peterbilt Semi Truck
 

I'd say it's got about a full day of building in it, but this was also the first time I've put together one of these Tamiya 3 speed transmissions so I took my time. Making the diffs a limited slip also added some time. The only bad part is the use of those stupid philips screws!! LOL

The wheelbase from front axle to rearmost axle is 450mm. So what's that, about 18"? Definitely not short! :mrgreen:

Re: 6x6 Peterbilt Semi Truck
 

could always try these if your into taking it apart again......:lmao:I hear good hings about this company....

http://imageprocessor.websimages.com...m/teamknk2.png

http://www.teamknkhardware.com/apps/webstore/

Re: 6x6 Peterbilt Semi Truck
 

That's a great resource! If they had a hex head conversion kit for the Tamiya trucks, I'd have bought it in a heartbeat! I did replace some of the hardware as I was doing the build, but they use a shoulder screw in much of the suspension that couldn't be replaced with anything I had on hand.
https://photos.smugmug.com/Hobby-Stu...IMG_7315-S.jpg

Re: 6x6 Peterbilt Semi Truck
 

Been thinking about how to mount the TLT axle to this truck. The stock leaf springs are a multi-leaf arrangement with a rivet holding it all together and no through-holes. This would mean drilling through the stock springs in order to get them to attach to the TLT. Not ideal, but not problematic, either. Then I remembered I had some Hi Lift springs I'd bought years ago. They have three holes in them and the outer holes lined up perfectly with some of the holes on the TLT. Behold!
https://photos.smugmug.com/Hobby-Stu...MG_7308-XL.jpg

Note that I think I will run the axle upside down most likely. That will be required to get the drivetrain to all rotate the same direction. If need be, I think I could instead flip the rear axles. Looks like that would be easy enough, as well.

Before mounting it up, I measured the side-to-side spacing of the stock leaf springs is 74mm. The TLT's spacing is 79mm. So I'd need to space the leaf spring hangers and shackles out 2.5mm per side. I just used some 2mm spacers because that's what I had.

Front (hanger):
https://photos.smugmug.com/Hobby-Stu...MG_7312-XL.jpg

Rear (shackle):
https://photos.smugmug.com/Hobby-Stu...MG_7313-XL.jpg

And installed! I'm just using 6mm long screws (4 total), but the axle really feels secure. That could be sufficient, but I will likely drill all the way through it for a little more peace of mind.
https://photos.smugmug.com/Hobby-Stu...MG_7311-XL.jpg

Re: 6x6 Peterbilt Semi Truck
 

Wow, awesome Tommy! Your front axle setup looks way better than mine did. What wheels and tires you going with?
http://www.rccrawler.com/forum/non-c...ml#post3192356

Not sure if you know but here are some good resources for Semi Parts.
Accessories Product List | GardenTrucking.com

http://stores.ebay.com/RC-Parts-Bone-Yard

R/C Truck's Manufacturers/Venders/Retailers - RC Truck and Construction

Re: 6x6 Peterbilt Semi Truck
 

Thanks, Justin! I'll be going with some Lesu all terrain tires all around with their aluminum wheels, as well. I'll run standard size in the rear, but will run the wider version up front for more grip/flotation.

Thanks for the links. I think the only one I had not yet bookmarked was the middle one. In fact, you should check your build thread on RCT&C. LOL

Re: 6x6 Peterbilt Semi Truck
 

Well. That escalated quickly. Sold the stock wheels/tires and removed the body to do some work to it while I wait on the new wheel/tires to arrive.
https://photos.smugmug.com/Hobby-Stu...MG_7317-XL.jpg

Re: 6x6 Peterbilt Semi Truck
 

your first tamiya kit? no way!? i love tamiya kits, they have some pretty cool/unique engineering in them at times. just ordered a tamiya kit myself today.

looking forward to this thing.
what tires you thinking?

Re: 6x6 Peterbilt Semi Truck
 

Yep! In fact I've only owned two Tamiya cars my whole life. In the early '80s I had a Sand Scorcher and then in 2017 I bought a King Hauler. LOL! I'm glad I'm finally getting to build one. Really neat engineering involved, but I want to slap them for continuing with philips head hardware!

Anyway, onto wheels/tires. Here's what I'm getting. These are the rear Lesu tires:
https://photos.smugmug.com/Hobby-Stu...M-S1212S_1.jpg

Here's the wide fronts:
https://photos.smugmug.com/Hobby-Stu...M-S1212W_1.jpg

Rear wheels:
https://photos.smugmug.com/Hobby-Stu.../LM-W-2012.jpg

https://photos.smugmug.com/Hobby-Stu...M-W-2012_1.jpg

Front wheels: Gotta make sure to order the correct ones because standard fronts use bearings/bushings, not a 12mm hex drive like we're used to!
https://photos.smugmug.com/Hobby-Stu...M-W-2041-A.jpg

What it looks like installed. It's the closest I could get to the look I was after without spending an absolute fortune!
https://photos.smugmug.com/Hobby-Stu...O/W-2042_2.jpg

Re: 6x6 Peterbilt Semi Truck
 

i did something similiar, i bought two sets of rear alum dually wheels. then simply unbolted the outer wheel, leaving the inner wheel with the hex/pin drive to use on the front.

Re: 6x6 Peterbilt Semi Truck
 

Yep, that would work, as well! But for this build I wanted the extra grip and flotation of the wider front wheels/tires. I don't expect it to do "well" offroad, but I'd like it to have as much capability as it reasonably can while still being true to my vision of an "all conditions" hauler.

Kinda hoping some other folks in the area will get some semis (street or trail), but even if that doesn't happen, I'm really glad to have this thing. I've been wanting one for SO long and it's been a really fun build thus far. "thumbsup"

Re: 6x6 Peterbilt Semi Truck
 

Looks awesome, can't wait to see where this goes, that 2.5 million diff lube is interesting too! Giving it a military/utilitarian 'bed' or?

Re: 6x6 Peterbilt Semi Truck
 

Thanks! Plan is to keep it with a 5th wheel. I'll eventually pick up a flatbed trailer for it and I plan to challenge it with hauling heavy loads of bricks and such across various terrain. I can also put drifters on it when we're have a drift event. :mrgreen: I'm going to make it like a nice looking, well cared for truck that isn't quite a "heavy hauler", but is designed to haul just about anything.....anywhere. Hence the driven front axle. I may also consider building a removable flatbed for it.

For the final product, imagine a mix/match of these trucks:
https://photos.smugmug.com/Hobby-Stu...10f5122994.jpg

https://photos.smugmug.com/Hobby-Stu...DSCN2017-S.jpg

https://photos.smugmug.com/Hobby-Stu...ugClint1-M.jpg

Re: 6x6 Peterbilt Semi Truck
 

do they sell 1:12 scale trucker girl mudflaps?

Re: 6x6 Peterbilt Semi Truck
 

Nope.



But they do sell them in 1:14 scale. :flipoff:

Re: 6x6 Peterbilt Semi Truck
 

oops
nice 8)

Re: 6x6 Peterbilt Semi Truck
 

Awesome! I love me a good semi-build.

Re: 6x6 Peterbilt Semi Truck
 

I was trying to decide how far I wanted to go to make this look like a Peterbilt. Well, I guess I decided. :mrgreen:
https://photos.smugmug.com/Hobby-Stu...IMG_7325-L.jpg

My string method for cutting styrene needs a little help, but whatever. :ror: At a minimum, I plan to fill in the front fenders to make them smooth and maybe go with this grill/light assembly. It's a bit pricey, but I like the look. Hmm.....I wonder how LEDs/wires would look with this setup?
https://photos.smugmug.com/Hobby-Stu...%20%282%29.jpg

https://photos.smugmug.com/Hobby-Stu...%20%281%29.jpg

What I now need to decide is if I want to just stop there or if I want to just replace the fenders altogether. I've never bought anything from Shapeways, but these look rather promising. Curious if this may be easier than filling in the headlights and marker light openings on top of the fenders.
https://photos.smugmug.com/Hobby-Stu...1459354305.png

Re: 6x6 Peterbilt Semi Truck
 

whats the second grill for?
my fear with 3d printing is always surface finish, but could always be sanded smooth. what does it take to buy the printed fenders? ive always thought shapeways seemed pricey for what you get.

Re: 6x6 Peterbilt Semi Truck
 

Not sure (yet) on the second drill. There's a wire mesh behind the stock grill so maybe it gets sandwiched between the grills?

The Shapeways fenders are like $40, if I recall. Not cheap, but it would take me a few hours to fill/sand the headlight holes and marker light holes, plus these are more accurate to what a real Peterbilt fender would look like. So it could be worthwhile, depending on how they mount.

It looks like there's a couple mounting holes on the Shapeways fenders, but what would they attach to? With the old fenders cut away, you'd have to add some styrene to the hood sides. Or at least that's my best guess? :|

Re: 6x6 Peterbilt Semi Truck
 

Didn't have much time to mess with the truck until this evening and when I did I decided to focus on my gear reduction and transfer case solution. First things first I looked into how the tranny is going to interfere with a front driveshaft. Obviously, that's definitely got to be addressed! :ror:
https://photos.smugmug.com/Hobby-Stu...MG_7341-XL.jpg

I think I've narrowed down my drivetrain choices to these:
1. Use an Axial 2.6:1 trans as a transfer case and possibly a 2:1 planetary gear reduction in front of the Tamiya transmission.
2. Use a planetary gear reduction (probably 2:1) and add a t-case like the 2.18:1 RC4WD Disruptor or the 2:1 t-case from wtbcar.com:
https://photos.smugmug.com/Hobby-Stu...S/TFCB01-S.jpg https://photos.smugmug.com/Hobby-Stu...-600x600-S.jpg

In either of these solutions, the stock Tamiya tranny needs to be raised up fairly substantially....for two reasons. As mentioned, the tranny will prevent a driveshaft from reaching the front axle, but the 2:1 planetary will hit the steering/shifting servos because it'll push the motor forward. My best guess shows a height of 15-20mm is needed. Here's a rough approximation of the height required:
https://photos.smugmug.com/Hobby-Stu...MG_7344-XL.jpg

The floor will need to be trimmed, but I'm okay with that. I can always just build a simple cover for it so the trans is hidden from sight. My first estimation of where it'll need to be cut (everything within the white markings).
https://photos.smugmug.com/Hobby-Stu...MG_7343-XL.jpg

So before I order some standoffs I made some temporary 15mm spacers to see how that would work.
https://photos.smugmug.com/Hobby-Stu...MG_7346-XL.jpg

Driveshaft clearance should be okay with the trans raised 15mm, especially since the trans output will be fairly low.
https://photos.smugmug.com/Hobby-Stu...MG_7349-XL.jpg

Front view showing the height of the motor compared to the servo. It'll be reeeeally tight, but I can easily add a few more millimeters of spacers if need be.
https://photos.smugmug.com/Hobby-Stu...MG_7348-XL.jpg

Thinking this is what I'll need to cut away to accommodate the new trans height.
https://photos.smugmug.com/Hobby-Stu...MG_7351-XL.jpg

So now I need to decide what to do about the transfer case. I have an Axial trans so that's the cheapest solution. I'll just have to fab up a bracket for it. And it'll definitely get the outputs low enough to clear the stock trans. The wtbcar.com t-case looks like it would bolt in after drilling a couple holes so that'd be super easy, but it would cost me ~$50 and time to wait for shipping from (presumably) China. Not sure I'm patient enough to do that. Ha!

Re: 6x6 Peterbilt Semi Truck
 

Axial transmission (all metal internals, of course) ready to be used for the new t-case. I just need to trim off the excess on the input shaft.
https://photos.smugmug.com/Hobby-Stu...MG_7353-XL.jpg

Re: 6x6 Peterbilt Semi Truck
 

Use what you already have. Love it. Like this build a lot. Keep up the good work.
Ben

Re: 6x6 Peterbilt Semi Truck
 

I did exactly that on the Mean Green 6x6, raised the transmission. I also used an Axial trans for the t-case. However, I wanted a more centered input so I cut the top of the Axial trans and flipped it so it would be centered. I used JB weld to reattach it.

If it will help you, here's the build thread: http://www.rccrawler.com/forum/1-9-s...green-6x6.html


Edit: I just remembered that I flipped the transmission upside down to keep the motor weigh lower.

Re: 6x6 Peterbilt Semi Truck
 

Thought I posted earlier but i guess i didn't. Anyhow, good to see you building again and looking forward to seeing what you come up with!"thumbsup"

Re: 6x6 Peterbilt Semi Truck
 

Thanks, Ben and Dean!

Dean, I've very familiar with Mean Green. It was the inspiration for me to want to build a 6x6 or 8x8 years ago! I'm excited to be building again. The comp side of scalers is less appealing to me these days what with the extremes people are going to make "scale" looking trucks. Building something like this is a breath of fresh air for me! "thumbsup"

Got the rear wheels in the mail today! Only issue is that I don't have a hex driver small enough to fit the nuts to secure the wheels to the hub. The Tamiya multi-tool is too short to reach down in there. I'm guessing it's a 4mm or 4.5mm hex? Anyone know for sure? FYI, these are Lesu wheels.
https://photos.smugmug.com/Hobby-Stu...MG_7357-XL.jpg

Re: 6x6 Peterbilt Semi Truck
 

So whichever transfer case I end up with, I'm pretty sure I'm going to need a gear reduction. Using an Axial trans/t-case and a 2:1 gear reduction unit (GRU) would get me to 5.2:1 reduction over a stock setup. That's pretty darn low, but not sure if it'd be TOO low. However, I can't locate any 2:1 GRUs. Closest I can find is a 3:1 unit. It's cheap so I went ahead and ordered it.
https://photos.smugmug.com/Hobby-Stu...1VgogKH36L.jpg

Doesn't look to add much length to the motor.
https://photos.smugmug.com/Hobby-Stu...1EU8tVKYkL.jpg

Now I'm thinking the Axial t-case may be too low so I may consider a unit with a little taller ratio like 2:1. I have several options. I'm open to suggestions from those of you who've geared down your trucks. Knowing I plan to take this thing offroad and pull reasonably heavy loads with it, what kind of overall gear reduction should I look for? 3:1? 5:1? 7:1? 8)

Re: 6x6 Peterbilt Semi Truck
 

I think the 3:1 might be a bit much unless you run a 1:1 t-case. I ran the stock transmission and a cobalt 7t combined with the axial transmission as the transfer case, I was able to pull a trailer with an iron small block cylinder head on it. I think the motor was a Holmes Cobalt 10t on 7.2v.

Re: 6x6 Peterbilt Semi Truck
 

Thanks, man, that's good to know! I sent a request to cancel my 3:1, but if it's too late that's okay. I'm sure I'll find a use for it eventually. ;-) So I guess it's time to move forward with the Axial t-case install. Jeez, it's been so long since I've done any RC fab work, I'm not sure I'll remember how to do it! :ror:

Re: 6x6 Peterbilt Semi Truck
 

Today I picked up a 4mm hex driver and it allowed me to finally put together my new rear wheels Love 'em!
https://photos.smugmug.com/Hobby-Stu...MG_7372-XL.jpg

Re: 6x6 Peterbilt Semi Truck
 

Since the fenders are on the way, I decided that I may as well start on the one thing that I've been dreading......bodywork. I'm okay with styrene, but it's been awhile since I've done any detail work with the stuff. And in an effort to make it as easy as possible to replace the hood sides I wanted nice, square cuts and edges. Eventually, I decided to just jump on in and make it happen.

I decided to remove the fenders first to make it easier to cut by the cowl area. First I outlined the cut areas with a thin Sharpie marker. Then I used string to cut through the fenders and removed them.
https://photos.smugmug.com/Hobby-Stu...MG_7376-XL.jpg

Next I measured the styrene of the body to be .060" (1.5mm) thick so I used my calipers and scribed a line at the .060" mark. Applying black ink beforehand made it easier to see. Then I used the string method to cut along the line as carefully as I could. Came out rather clean! That's encouraging!
https://photos.smugmug.com/Hobby-Stu...MG_7378-XL.jpg

Now with the fenders removed I was able to use my razor saw to get nice, straight lines along the cowl and the horizontal line near the top of the hood. Using a combination of sawing with the saw and scoring with the Xacto blade, I was eventually able to cut the sides out. Honestly, it went quite a bit smoother than I expected.
https://photos.smugmug.com/Hobby-Stu...MG_7379-XL.jpg

They look nice and square to me! Mocking up an uncut piece of styrene confirmed my suspicion: nice and square. Good stuff! :D
https://photos.smugmug.com/Hobby-Stu...MG_7381-XL.jpg

An update on other components....

The front wheels and all the tires should arrive to the States any day now. The posts to raise the motor/trans will be here Saturday along with a bunch of hardware in my goal to replace as much Philips head hardware as possible! And I was able to cancel my order for the 3:1 reduction unit. Sweet! :)

I've got to pack for a camping/offroading trip this weekend so time is tight, but if I get some time I may try to bond the new, uncut hood sides to the KH. It still has a long way to go, but progress is progress!

Re: 6x6 Peterbilt Semi Truck
 

Glad to see you building again. Dean's rig always had my interest and this one does too!

Interesting always cost me money...

Re: 6x6 Peterbilt Semi Truck
 

Thanks, man, I appreciate that. I was rather disinterested for a while, but happy to say my enthusiasm for building is returning. :)

Re: 6x6 Peterbilt Semi Truck
 

Looking good Tommy, very nice work with the string saw. "thumbsup"

Where are you going wheeling? Our weekend trip to Death Valley was cancelled due to mud. :cry:

Re: 6x6 Peterbilt Semi Truck
 

Thanks, Dean! I literally believe it's been since 2009 since I used string to cut styrene. LOL! It was for the stretched TJ I built many, many moons ago.

Bummer about your trip! We're going to the Llano, Texas area. It's part of the central Texas "hill country" and we're lucky to have several offroad parks out that way. It's anywhere from a 1-2 hour drive from Austin, depending on where you go. This time we're headed to a small park that isn't always open to the public called Stillwater Ranch. I'll post up a link to pics when we get back. "thumbsup"

Re: 6x6 Peterbilt Semi Truck
 

Tiny update...

Wanting this styrene work to be plenty stout I decided to take a couple minutes and build some plates and bonded them to the OEM plastic. This will give me a nice, flat surface(s) to attach the new hood sides and it will provide a lot more strength. I'll wait to get the fenders in before I bond the new hood sides. The reason being I want to make one side and trim it to fit the new fenders and then will use it to make a template so both sides are as symmetric as possible.
https://photos.smugmug.com/Hobby-Stu...MG_7383-XL.jpg

Passenger side cut and mocked up.
https://photos.smugmug.com/Hobby-Stu...MG_7384-XL.jpg

Re: 6x6 Peterbilt Semi Truck
 

Cool, looking forward to pics from your trip. I've seen a few videos of wheeling in Texas. Looks pretty good to me. Some day, I'd like to take a trip with the FJ40 and check out that area.