HPI converts a WK to a crawler

[nirvana04]

Man those wheels look nice.

[1ra8der]

wow that is bad!!!!
i want one!!!!

great job on the ins-truck-sions!!!!

[Pete from Houston]

has anyone heard when the release date for the HPI crawler conversion will be? We're halfway into April and the HPI site still shows the kit as "out of stock".


I know, I know....make my own links. If I can't get the kit by the end of the month, I probably will.

[SubaruGLlifted]

I spent 42.00 to make mine a crawler and used alot less all thread and found better deals on links but I still followed the directions alittle and have a functioning crawler

[GhostRyder]

HPI has a lot of good intensions but not a lot of follow through. I.E. a stage two article promised over a year ago. The converion kit was announced as available months ago. You can get a few of the parts in the kit through the HPI site but not the whole kit. Overall it's pretty frustrating.

[fordman94]

Has Any One Herd Wen Stage 2 Is Coming Out

[Haziza]

Damn i want that Conversion kit now to my WK, any news when it will be out?

[pook]

Europe sight says there in stock now for conversion kit

[Haziza]

Are you sure?

[sigarms9]

ITS OUT!!! :-P:-P:-P:-P:-P:-P HPI Crawler Kit Is Here. Just ordered mine today from tower hobbies.

[Vanman]

nice, helps alot

[rockeater]

Anyone got one yet? How ya like/dislike it?

[peyton.]

thats pretty b.a!!!

[D.K.V]

so was there ever a stage 2 or 3?

[Jeep-Power]

Originally Posted by rockeater

Anyone got one yet? How ya like/dislike it?

I have one here that I've been working on-- my buddy got it with the idea that it would get him into RC Crawlin'.

My experience is with Axial based comp rigs-- I bought a built/used rig that was RTR & put a few ugrades into it after things broke/failed. I don't compete with it. It's pretty much bombproof now for the bashing I do.

With due respect to HPI, 'The Crawler King' certainly doesn't live up to it's name.

I had never seen a Wheelie King or Crawler King before this & have no idea what they share in common, other than the axles. After doing a little research here, it seems they share most of their parts.

The steering system is pathetic-- I mean PATHETIC! It requires making endless K-turns to get anywhere. It WILL NOT work while crawling.

The gearing is way too tall. It doesn't crawl AT ALL. The motor stalls constantly. Making any sort of climb requires a full-throttle assault, which usually result in a back-flip onto the roof. I find it amusing that in the article they switch out the WK 21/90 gears, but that's just what came in my buddys KK.

The ESC, while it does allow for *somewhat* precise control, does not allow for jamming it into reverse. In order to go quickly from forward to reverse, you have to hit reverse twice. Driving out of a back-flip situation (which happens AOLT -- see above) is just NOT happening. Maybe with a bit of practice, it will be attainable, but I haven't been able to save myself once. Is this option able to be programmed out?

The rear lockout system is flimsy as hell, just like the steering linkage. This does seem to give it some advantage, as it will not break, it just bends like crazy.

Again, I have NOTHING against HPI-- the misrepresentation is what gets me. It pisses me off that this thing is called "The Crawler King" and it is the far from that title. Someone is buying this thing, thinking they are ready to go crawling as soon as it is out of the box. They are going to be sorely mistaken, just as my buddy & I experienced.

The good news is that there is hope. I'm takin' photos and will post up all the mods I did to overcome the major faults. With a little time & investment, it has come around and is actually fun to crawl.

[Jeep-Power]

Mission Accomplished! I had a hard time putting the controller down. This thing definitely crawls now!

1st things first: The steering, it doesn't. Servo On axle (SOA) works well and was a no-brainer. The trick is mounting the servo. A quick trial shows the HPI servo was gutless-- I settled on a used Traxxas 2075 I had in the parts bin. It's waterproof (always a nice feature) and it has relatively high torque (around 100 Oz).

This was the hardest thing to do.

Thanks to HndsWthtShdws for posting the template!



I re-used the stock HPI servo saver because the 2075 has plastic gears. I shaved off the stub on the backside & then drilled it out to the size of one of the HPI pivot screws that I had removed elsewhere. This allowed it to pivot freely on the shaft of the screw.


Drilled a hole in the stock tie rod. I used the servo saver as a guide. I know it's a bit hack, but the tie rod is SUPER flexible, so it easily allows for any up & down movement of the pivot point. The steering now works 400% better then the stock 'system'.





NOTE-- in order to mount the servo here-- I had to move the upper control arm mount back. I did this by flipping the axle bracket. I shimmed it off the axle a hair with nylon washers. All this required that I cut about 3/8" off the end of the control 'wishbone' and then drilled the hole deeper. A washer was put on the outside to prevent the ball joint from pulling through.



The gearing was next--

THe OEM setup was a 90/21 tooth count with 48 pitch gears. That comes out to a 4.285 : 1 gear ratio. The parts bin had a Traxxas 66 tooth 32 pitch spur gear that I had to drill (using the OEM spur as a guide) to fit the hub. The parts bin also had a 8 tooth 32 pitch pinion. The 66/8 combo gives us a 8.25 : 1 gear ratio -- NICE! No more motor stall and MUCH more control in climbing-- woohoo!



Lasty was the tires. They were hard as a rock! My Chisels (I bought hem used, so I am not sure what foam is in them) flex like mad and have a bit of sidewall bulge even when the rig is not moving. These tirese looked like they had 35PSI in them & rode that way too! I was surprised to find that the rims were already vented. So what could be the problem? I took one apart and found that the foam was very stiff. OHHHH-- this is why folks cut thir foams! I went alittle easier than this on the first, and it wasn't flexable enough-- so I got more agressive with the rest. This is the last foam I cut.
OEM


half way done


done & they flex great!




I have to say the OEM shocks/springs are set up pretty well. This thing flexes great & is surprisingly stable! I drove it into place here and drove out of it. Note the reat tire compression... that's the way I like it.


Detail shot of the servo clearance in above shot.


I only have one crawler and it's a tuber. It is really cool to see a Jeep crawling around-- looks so much more like the real thing!

[Daddy NS]

Very very nice!!

[Daddy NS]

Originally Posted by phase10

i wish someone would post a thread with pictures on it. seems liek a really important part of making a WK a comp. crawler. wheres stage 2? i know: they are waiting for HPI to come out with the new parts. ( motor esc all that jazz) they dont wanna tell us to go buy an integy =P

Man I'm droooling over STRC and Integy parts for the CK just looking at them...

[Jeep-Power]

Originally Posted by Daddy NS

Very very nice!!

thanks!

[SOMD_BASHER]

very awesome ride