PDA

View Full Version : First Rock Crawler attempt - "King 4x4"


MetalMan
06.03.2007, 07:34 PM
After having wanted a crawler for a couple years, I broke down and bought a Wheelie King a few weeks ago. Just for kicks I removed all of the electronics from it and installed a Johnson 550 12v motor, EVX, a 2s 6400mah Lipo, and my radio (so I can sell all the stock stuff as "brand new"). The thing did wheelie like a "King", but couldn't do anything else. At that point I took the whole truck apart, with the axles separated from the chassis. I will only be using the axles and possibly the shocks, as the chassis is quite worthless (except I will be using 4 holes from it as a template). Here's what I am planning to use:

-KMS 2826/06 (http://www.hobbypeople.net/gallery/108512.asp) 14pole 730kv brushless motor (I work there, so I got it for a better price)
-2s A123 mounted to the front axle (had a couple cells left over from my 4s2p pack)
-Wheelie King axles
-Mamba Max ESC (need to send 2 in for repair)
-axle-mounted servo (TowerPro MG995)
-custom short chassis
-custom links made from 3/8x1/8" polycarbonate tube with 1/8" carbon fiber rod down the center, and Revo rod ends
-Proline Masher 2000s on custom beadlocks
-Maxx slider shafts
-no tranny, just pinion gear to spur gear, and spur gear is mounted to the output shaft
-geared 9/52, diff ratio is 2.92:1, total top speed should be about 4mph

So far I have the servo mounted to the axle, and the lower links are finished. Next I will make the upper link mounts on the axles out of some aluminum u-channel, and after that it will be time to design and cut the chassis. I'll get pics up as I progress.

What's_nitro?
06.03.2007, 08:11 PM
Wow 14 poles? Can the MM handle that? Otherwise sounds sweet. I'm gonna build a crawler too OOTD. Maybe soon since I finished the Rustler.

BrianG
06.03.2007, 08:55 PM
Um, where are the required pics? ;)

MetalMan
06.18.2007, 01:02 PM
Ehh... Obviously I've been procrastinating a bit. I've had the chassis done for a week. Later last week I bought some Traxxas Maxx Big Bore shocks (split the 8-pack with a guy at work). And now I'm almost done with the spur gear/motor mount. After that's done, I will mount the electronics, and it will be running :). So pics should be up later tonight (after work, I get off at 8:45pm PST).

Maxxman
06.18.2007, 03:40 PM
can't wait to see the pictures sounds like it will be miles better than the stock wheelie king.

we all know why because itll be brushless!

MetalMan
06.19.2007, 02:39 AM
can't wait to see the pictures sounds like it will be miles better than the stock wheelie king.

we all know why because itll be brushless!

And it is lithium-powered, so it's even better :018:.

At work today I just about finished the truck. It's definitely in driving condition (I drove it after work). It's only missing the center skid plate, since I haven't gotten around to making it yet. I slapped in a Mtroniks Genesis Truck ESC since it's the only working one I had laying around, and I must say, it is quite smooth. In fact, everything about this rock crawler is smooth. The drivetrain is smooth, the motor spins very smoothly, the suspension acts smoothly, etc. At work all the guys were rather impressed, but half of them haven't seen it yet, and they're used to seeing this sort of work from me :004:.

I have dubbed this crawler the "King 4x4." You'll see why.

Now, I'll let the pics speak. If they don't tell you the answer to a question of yours, I will gladly answer it for you.

http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_5879.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_5892.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_5898.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_5905.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_5898.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_5911.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_5907.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_5916.jpg

MetalMan
06.19.2007, 02:39 AM
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_5917.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_5922.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_5923.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_5928.jpg

This truck is all custom, except the axles and the shocks. All parts were made with any combination of a scroll saw, drill press, file, and Dremel with fiber reinforced cutoff tool.

The articulation in the last pic is just an example, it can actually go past 90* :eek:. Some fuel tubing will be used to limit articulation to about 80*.

Maxxman
06.19.2007, 02:38 PM
wow.
Thats simply amazing i can see why you called it king 4X4
all you need to dod is put a winch on it and it would be even better (if thats possible.)

Maxxman
06.19.2007, 02:44 PM
wow.
Thats simply amazing i can see why you called it king 4X4 all you need to do is add a winch and it would be even better than it is now(if thats possible)

edit: sorry for posting this twice but my computer couldn't load the screen so i went back to do it again assuming it hadn't worked only to find that it did. Sorry once agai but it really is awesome

jdtmaxx
06.19.2007, 02:49 PM
maxxman. what kind of truck do you have?

Maxxman
06.19.2007, 03:08 PM
i have a brushless e-maxx:
All UE drive train,
G-maxx chassis, extension, single speed and motor mount,
strobe slipper, feigao 8xl quark 40 series wheels and tyres and stock.

i shorted a battery on the chassis braces and now hope do go to Lipo.

Serum
06.19.2007, 04:01 PM
Great work Travis! next thing we need is a movie..

jdtmaxx
06.19.2007, 05:06 PM
maxxman, sounds like a cool truck.

sven
06.19.2007, 05:20 PM
Very nice job. I love the 'transmission' it is nice and simple.

Maxxman
06.20.2007, 02:39 AM
jdtmaxx, i like it a lot.

i've got some others which are nitro or stock and are Savage (hopefully going to go brushless some time), twin detonator, e-maxx, hpi rush evo but none of the are as good as my brushless maxx.

the transmission is very simple and i like it. not a lot to go wrong.

MetalMan
06.20.2007, 11:51 AM
Great work Travis! next thing we need is a movie..

Well, the thing is, yesterday I would have gotten some video footage if this didn't happen:
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_5931.jpg

That gave me only 3wd. But besides that, the hexes were slipping in the wheels with the wheels all the way tight :026:. Now the hexes are glued to the wheels.

Serum
06.20.2007, 11:56 AM
must be smaller than a 6mm axle right? what's the length of the complete bone? what is the bearing size on that wheel axle? (outer/inner?) perhaps you can set with another set of CFD's, that flat spot is easy machined, perhaps a maxx CVD would do a better job. (got no idea about size)

MetalMan
06.21.2007, 12:14 AM
The shaft of the dogbone is 5mm. At the end of the dogbone before the ball you see a bit of a lip, that's where a bearing goes (to keep the dogbone stable inside of the axle). The axle shaft is 5mm, and is the same thing that is used on the HPI MT2. I already have replacements, and sometime in the future I hope to be able to make my own with a lathe in the machine shop class I am taking this summer (maybe using spring steel).

dabid
09.22.2007, 04:24 PM
Bah, my old TLT could take it....all hail the return of the knower of everything crawling: me! :wink: :lol:

MetalMan
09.22.2007, 11:44 PM
It could definitely have taken on the Wheelie King in the form seen in the pics. But now... It's totally different. For example, it's a droop setup, smaller/stiffer lower links, rotated lower link mounts, different gearing, soon-to-be 3s Lipo, custom (heavy) beadlocks, better-looking Bronco body, etc.
I just need to stop being lazy and take the pics I planned on taking about a month and a half ago :angel:.

dabid
09.23.2007, 03:42 AM
You only know about those things because I told you, or you read my thoughts during my sleep, where's my tin foil hat?!?!

It's finally cooling off out here, we're going to have to arrange a bash down by you and a crawling day out by me sometime.

MetalMan
11.06.2007, 01:00 AM
Ehh, about that update...

Here's what has changed over the past 5 months:
-CVDs in front after breaking tons of stock driveshafts
-Maxximizer WK diff lockers
-3s 2100mah 15C Lipo in the rear, mounted on a custom polycarbonate shelf
-custom 10cell 1100mah NiMh battery mounted to the front axle
-Hitec 5955TG servo (after stripping the metal gears in the Tower Pro servo)
-new lower links and steering link, made out of carbon fiber tube covered by thin-wall aluminum tube on the outside (to keep the carbon fiber from splintering)
-aluminum front knuckles, added because of too many broken stock knuckles (from the torque of the 5955TG)
-RC4WD aluminum rear-lockouts, added to help stabilize rear and eliminate knuckle break-age
-motor shaft was turned down to 1/8" from 5mm
-32p gears, 6/66 current gearing (despite the numbers, works very well)
-2.5oz. added to each wheel, 10oz added total
-droop suspension with internal springs, shocks mounted on custom lower link mounts
-custom bent plastic skid plate, removable in the blink of an eye, yet stays on very well to protect spur and lower link rod ends
-Mamba 25 ESC
-Chinese 3amp switching BEC (has cool blue and red LEDs that are bright at night)
-HPI 1973 Bronco body that's been beaten to hell (I've mastered somersaulting with this truck)

Pics:

http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6666.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6669.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6676.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6677.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6681.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6686.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6692.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6695.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6698.jpg

BP-Revo
11.06.2007, 01:14 AM
The servo isn't powerful enough...










:lol:

drkros3
11.06.2007, 01:28 AM
that looks pretty good man. what kinda chassis is that.

BP-Revo
11.06.2007, 01:39 AM
that looks pretty good man. what kinda chassis is that.

The chassis is custom.

This truck is all custom, except the axles and the shocks. All parts were made with any combination of a scroll saw, drill press, file, and Dremel with fiber reinforced cutoff tool.

espeefan
11.06.2007, 01:44 AM
Nice. See through 4 links! That's a first for me. What kind of springs are those on the big bores? I can't seem to find any in a different spring rate that actually fit the big bores. I am pretty desperate to find some for my Rustler, but I also need shorter ones for the front big bores.

drkros3
11.06.2007, 01:45 AM
ohhh ok very cool.

yo metalman you ever hear of using the mammoth shock towers as the chassis. a guy came in and he said he used 2 shock towers from the mammoth as is chassis for his tlt rock crawler.

i forgot to ask him if it was from the first or the second mammoth. i think it might of been from the first one.

ClodMaxx
11.06.2007, 09:16 AM
that's awesome, metalman. looks like she's seen some good use. :great:

MetalMan
11.06.2007, 01:30 PM
Nice. See through 4 links! That's a first for me. What kind of springs are those on the big bores? I can't seem to find any in a different spring rate that actually fit the big bores. I am pretty desperate to find some for my Rustler, but I also need shorter ones for the front big bores.

I'm guessing you are looking at the pics on the first page, which don't resemble the truck in its current stage at all.
Only the front upper links are currently polycarbonate (see-through).
The orange springs are the stock Wheely King springs cut down. But now I'm using internal springs, which you can't see.

ohhh ok very cool.

yo metalman you ever hear of using the mammoth shock towers as the chassis. a guy came in and he said he used 2 shock towers from the mammoth as is chassis for his tlt rock crawler.

i forgot to ask him if it was from the first or the second mammoth. i think it might of been from the first one.

I haven't heard of it being done, but I don't see why it wouldn't work. My guess would be the shock towers from the original Mammoth, too.

that's awesome, metalman. looks like she's seen some good use. :great:

She certainely has. This truck can take a lot of abuse. For example, sometimes I'll let it roll off of rocks and fall 4 feet before landing, at which time it's already back on it's wheels :whistle:.

My only real complaint with the truck is the body. It's big and square, so it likes to cause the truck to get stuck on rocks. But, it's not that big of a deal.

jokerjustin
11.08.2007, 10:33 AM
it still looks great though... now i want to make a crawler!

dabid
11.09.2007, 05:06 PM
I can't find the one where a guy used the original Mammoth towers, but found this one (http://www.rccrawler.com/forum/showthread.php?p=787012) where a guy uses Mammoth ST towers for a $10 chassis, looks quite good too.

MetalMan
11.09.2007, 06:32 PM
Jeez, and I thought my chassis was of minimalist style! I bet that Mammoth ST shock tower-chassis would work well with a droop setup...

dabid
11.09.2007, 09:35 PM
Maybe, droop has only just gotten popular in the last 6 mos or so, before then it was just a novelty.

I believe the guy that made the original Mammoth shock tower chassis used TLT axles, but I might be wrong. One thing I know, they were the standard blue anodized ones, and did look pretty sweet.

MetalMan
02.07.2008, 03:10 AM
It's time for an update, since a lot has changed.

Behind the axle (BTA) steering has been custom-made for the front. This helps remove the steering link clearance issue, and it will also keep aluminum servo horns from bending when the hit an object.

New bent rear links give A LOT more clearance in the rear.
This was accompanied by relocation of the rear shocks, you can see how/where they were relocated in the pics.

NiMh battery removed from the front, and a new battery tray was made for the rear. This keeps the battery out of the way, but doesn't really raise the CG.
I might need to add some weight to the right side of the front axle, since there isn't much weight there anymore.

NARROWED AXLE housings. With the MSD Top Gun beadlocks, the truck was as wide as it could be without wideners. I basically cut almost an inch off of the front and rear axles, and used fiberglass and epoxy to hold them together:
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6849.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6850.jpg

And now for the rest of the pics:
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6905.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6910.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6912.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6914.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6916.jpg

MTBikerTim
02.07.2008, 05:15 PM
That thing is hideous :lol:.


I like it. It looks tough. Those linkages and wheels aren't going to break in a hurry.

suicideneil
02.07.2008, 05:57 PM
Thats something abit different, interesting setup and mods.

MetalMan
02.07.2008, 06:13 PM
That thing is hideous :lol:.


I like it. It looks tough. Those linkages and wheels aren't going to break in a hurry.

I call it function over form :whistle:. And a limited budget...

ClodMaxx
02.07.2008, 11:46 PM
good stuff - i like it a lot!

did you decrease the width for comp-worthiness, or was it just too wide with the new wheels?

MetalMan
02.07.2008, 11:51 PM
Both. If I were to ever go to a comp, it would help, but just for general crawling it also helps.

MetalMan
03.26.2008, 04:16 AM
Another update:

I grew out of the first chassis, and with the design of a chassis from Offroader5 on RC Crawler, I was able to modify it and build what's called a body-less crawler - think of a tube chassis, but without tubes. The chassis and motor/spur gear mount took at least 8 hours to make, and then all of the suspension added another 4-5 hours. The crawler has awesome clearance now, and should crawl well especially with the delrin center skid. The addition of a Sidewinder ESC over the Mamba 25 should also help smooth out the delivery of torque.

http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6978.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6983.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6993.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6999.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_7005.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6984.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6988.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6989.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6985.jpg
http://img.photobucket.com/albums/v132/4x4pede/King%204x4/IMG_6990.jpg

MTBikerTim
03.26.2008, 05:36 AM
That looks awesome. Looks capable too. A question though, the centre drive shafts, how do they cope with the articulation without binding. I've seen lots of these and I'm impressed that the full articulation can be reached without the drive shafts binding.

MetalMan
03.27.2008, 01:53 AM
The driveshaft angles don't really change much when the crawler articulates. But even if they changed more than they do, it wouldn't be an issue since they're slider shafts.

Thanks for the comments!

MTBikerTim
03.27.2008, 02:30 AM
I suppose they wouldn't change too much would they. That is really a sweet looking chassis metal man. I'm surprised you haven't made it 4 wheel steer.

MetalMan
03.27.2008, 02:53 AM
Some day it would be nice if I could enter this crawler into a competition, so I tried to build it around those rules. Unfortunately rear steer isn't legal, but I'd have a hell of a time mounting another servo. This chassis really makes it difficult to mount everything!

crawler max
06.22.2008, 09:57 AM
nice work metalman. you got skillz.

MetalMan
06.22.2008, 03:52 PM
Thanks!

Soon I'll be throwing an AX-10 front axle on because my front narrowed Wheely King axle can't take the abuse, and the AX-10 axle is only 1/4" wider than my narrowed WK axle.

lincpimp
10.28.2008, 06:34 PM
A bit off subject, but I was wondering what it takes to use maxx sliders as center driveshafts? Main issue is that the ax10 axle and the pede tranny have 5mm output s and the maxx sliders are 6mm... I have seen it done and wonder what people did to make it work...

I like the body-less crawler, looks cool!

MetalMan
10.28.2008, 09:40 PM
Thanks!

Obviously it's been a while since I updated this thread, but the crawler is now running AX-10 axles front and rear with an Airtronics 780 steering servo. The front diff gears are the hardened ones for the HPI MT2 (same ratio as stock) and the rear diff ring gear is stock, while the rear diff pinion gear is from a Wheely King.

These diff pinion gears look like this:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&W=000279724&I=LXJYM2&P=K
There is a hole in the diff pinion gear for a screw pin to go through it, just like you will find on the Maxx/Revo/Savage/Rustler/etc. The shaft diameter is 5mm.
Now see here:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXDDT2&P=7
That T-Maxx transmission output yoke has a 5mm inner diameter, as you will find here:
http://www.traxxas.com/PDF-Library/4910-08_tranny.pdf
The yoke is made to fit shafts with flats on them, so you have to drill out the yoke with a 5mm drill bit to make sure it will fit onto a 5mm round shaft.
Then you can use a regular Maxx driveshaft (4951X if my memory serves correctly).

As for the transmission, you can use the same yokes, but you'll have to shave down the end so it won't interfere with the transmission case.

lincpimp
10.28.2008, 09:59 PM
Thanks!

Obviously it's been a while since I updated this thread, but the crawler is now running AX-10 axles front and rear with an Airtronics 780 steering servo. The front diff gears are the hardened ones for the HPI MT2 (same ratio as stock) and the rear diff ring gear is stock, while the rear diff pinion gear is from a Wheely King.

These diff pinion gears look like this:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&W=000279724&I=LXJYM2&P=K
There is a hole in the diff pinion gear for a screw pin to go through it, just like you will find on the Maxx/Revo/Savage/Rustler/etc. The shaft diameter is 5mm.
Now see here:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXDDT2&P=7
That T-Maxx transmission output yoke has a 5mm inner diameter, as you will find here:
http://www.traxxas.com/PDF-Library/4910-08_tranny.pdf
The yoke is made to fit shafts with flats on them, so you have to drill out the yoke with a 5mm drill bit to make sure it will fit onto a 5mm round shaft.
Then you can use a regular Maxx driveshaft (4951X if my memory serves correctly).

As for the transmission, you can use the same yokes, but you'll have to shave down the end so it won't interfere with the transmission case.

Good info, thanks!

MetalMan
10.28.2008, 10:16 PM
Comparing the Maxx shafts to 'Pede/Rustler or stock AX-10 driveshafts, Maxx driveshafts win hands down :yes:.

lincpimp
10.28.2008, 10:26 PM
I figured that, I have had some issues on my cr-01 with both the stock driveshafts (redefine the word "suck") and pede sliders. I have some homemade brass collars that work well, but the cr-01 has steep driveshaft angles, is geared for 10mph, and runs a novak 13.5... bit too much power!

I will see if the lhs has the 4927x yokes. Hope so, as that would make my like simple...