Unimog XP RTR to crawler

[martco78]

I had returned to RC buggies after many years off with a vintage Associated RC10 modification/rebuild.
Whilst browsing RC stuff one day I discovered a new Tamiya Unimog XP RTR at a knock-down price and as it had always held a soft spot for me decided to add it to the stable. It was only after purchase that I discovered I had bought myself a passport to the world of CC-01 upgrades and modification, this forum and rock-crawling in general.
I was lucky to come across a part-modded chassis which sorted out the brick mod, the rear suspension arms and gear-reduction/battery relocation issues so it was just down to endless hours of happy reading, sourcing new parts and and getting it up and running with virtually all the recommended mods from here.
The XP body is immaculately finished so that will be my shelf clothing, so just need something for bashing now.
I've put up some side-by-side comparison shots of the stock RTR and the modded mog as this is an uncommon scenario, but tells a story. I had planned that the RTR would be a part donor for the crawler, but in the end it has used new or scavenged parts so it will be sold complete and untouched (minus the body and mounts).
I can fill in the full specs for those interested, but it is still work in progress. You know how it is!

[martco78]

Decided to update the front suspension to get a little more steering movement and bling.

There was some occasional binding with the stock dogbones ( one bent!) so they were swapped out for the Tamiya Hop-up CV shafts which sorted that out completely.

Next up I ordered via eBay a set of alloy lower arms, hub knuckles and carriers and a set of upper arms. These were all cheap versions from China which turned out to be pretty good in assembly, though I did add a couple of Associated RC10 transmission shims to the top and bottom of the carrier pivot screws to take out a little slack.

The only real problem I encountered was that the pivot eye connecting the upper arm to the top of the hub carrier was way too big for a stock 3mm threaded bolt, creating a huge amount of slop in that area. Nothing was supplied with the arms and there was nothing in my parts box I could use as any kind of sleeving.
After an extensive trawl I found Tamiya's OP-1409 14x3 step screw set which seemed to fit the bill, though I had no precise dimensional data. On arrival though they were slightly too large for the upper arm eyes. Undeterred I fixed up my my £10 cheapo hobby 'dremel' as a mini-lathe and after a few sessions with a hand-held fine grinding attachment I managed to achieve a perfect fit. Full movement and zero slop.

This will all now go together along with a skid plate winging its way from China. More pictures as it happens.

[Zukiiholic]

Looking really good.
I like the modded chassis..
Nice mini-lathe .. ;) I'm gonna have to remember that..

[martco78]

All assembled with no further issues.
In the same order from China I included a set of cheap metal-bodied shocks to which I added a little 10w oil and some Associated shock springs from the parts box (as the delivered springs were hard and not very compliant). Not really sure until I do some serious crawling what springs will work best, so just trying these out for now.
The Jun-Fac bash plate arrived today as well, but that will require a larger cutout to clear the angle of the prop shaft when the Tamiya stroke extenders on the rear shocks come into play.

[martco78]

Not wanting to use my immaculate XB factory Unimog body I have been casting around for a cheap body to use.
I had been watching those yellow Jeep Rubicon bodies from China with interest and when one popped up for auction with cheap postage I snagged it for a bargain £26.

http://www.ebay.co.uk/itm/Body-Shell...EAAOSwgmJXzRQL

It took a couple of weeks to arrive, but the quality and detail is astonishing for the price. All the details are separate and mostly screwed in place, plus the front and rear lights are LED-ready.

I stripped it down, cleared most of what I could off the top of the Unimog rolling chassis and offered them up. First off the wheelbase is longer so I notched the rear axle back by 25mm using the long wheelbase fixings. Still waiting for a longer drive-shaft and axle arms to finish it, but it was at least enough to sort out the body position and mounts.

The only place that there is a problem is over the steering servo arm and this was resolved by cutting out the foot-well at that area. The body is very sturdy, a good weight and of something like polystyrene so rewarding to cut if you have a dremel or similar. I added rear Tamiya post mounts inside to the back of the front seats and used the stock Unimog mounts for the front bonnet and I'm quite happy with the result.

Battery position is now my only real problem as the original bay is taken up by my reduction gearbox and the previous alternate position (running lengthways above the rear wheels) is blocked by the interior centre console and rear seats. But there appears to be loads of space under the Jeep bonnet so I may just experiment with attaching the battery to the (very rigid) bodywork, maybe crossways behind the dash bulkhead.





Once all the bits are sorted I'm planning on spraying it all military green , but I suppose there is the benefit of a self-coloured body which wont show the scratches too much.....

[martco78]

The extended driveshaft arrived and was fitted without any hitches which then gave me the chance to properly fit the skid-plate.
Decided not to cut it, just put the rear flange (with the driveshaft cut-out) in a vice and gently decrease the angle of it until the shaft cleared it on full articulation.

The battery went well into the body-shell behind the dashboard bulkhead, secured with a couple of adjustable cable-ties. Power connection is easy by reaching through the space within the wheel arch.

Last thing to do before painting the body is to reverse the rear body mounts so that the posts fit to the body facing downwards with the clips on the underside of the wheel-arch. (The clips would be inaccessible behind the front seats once the seat-backs and the hard-top are in place.)

[scalemadness]

Not trying to be a dick but those body posts through the hood look like sh*t get yourself some rare earth magnets and fill those holes in

[Ruud109]

Awesome looking Unimog body. Like the tires a lot too! I just got a 425 Unimog that i am starting to build once some hop up parts get in the mail.

[DaJester]

What length extenders are you using to widen the wheel width? I have to agree with the body post, will look so much better with magnets, should have done it on mine.

[martco78]

Originally Posted by DaJester

What length extenders are you using to widen the wheel width? I have to agree with the body post, will look so much better with magnets, should have done it on mine.

12mm extenders from eBay. Work well and cheap!

Wheel adapter joint Hex 12mm For RC Cross Truck RC4WD Tamiya 1/10 SCX10 D90 CC01 | eBay

Been working on other projects over Christmas, but have added even bigger wheels and cut the body/chassis more to get a better fit.

Happy enough with the posts whilst I'm modding as they give secure static mounting points whilst the job's in progress. Magnets for later for sure.

[Synister_Intent]

Very nice build sir. Any more pictures?

Sent from my SM-N920V using Tapatalk

[martco78]

Ok. A bit of an update...

4" wheels/tyres added, Tamiya alloy body shocks with barrel springs added and so major surgery on the chassis and body to clear the new tyres on full lock/articulation.

Looking better proportion now I feel.


...and good articulation.


Body showing new cuts and battery location.



Cuts to chassis.



A little more dremel work to the bumpers on the body plus some cover for the new holes perhaps and we should be ready for some paint.

[HCCrawler]

Slick Rig!!! What parts did you use to make the power shaft?

[martco78]

Originally Posted by HCCrawler

Slick Rig!!! What parts did you use to make the power shaft?

eBay, from China again. It is a complete item which fixes straight on the the CC01 gearbox output and axle connection. That and the varying lengths available for the axle links makes the wheelbase quite finely tunable to your choice of body.

Crawler Drive Shaft 178mm for AX10/SCX10/RC4WD/ CC01 | eBay

[OkinawaCrawler]

Do you have any pictures of the front flex not from under the truck?

[martco78]

The major downfall of the CC01 chassis for crawling is the front end. Poor suspension range and lack of steering lock limits its use as a proper crawler, but with all the other mods I will give it a go before I eventually give-in to a MST CMX chassis.

MST CMX 1:10 4WD High Performance Off Road EP RC Cars Crawler Kit #532143 | eBay

[OkinawaCrawler]

that is great flex out of a cc01. I don't see you getting much more with a cmx. Good job.