New project: "The Shop Rig", MRC based Jimny Mud Dragger

[89redranger]

Have been doing quite a few builds and repairs for customers lately and haven't had a lot of time to work on my stuff. For a while now I've bounced between build ideas for my current MRC. First a true scale Samurai...fought getting the narrow axles to work with a wide chassis. Then a Unimog...fought how the axles were going to end up sitting under the chassis amd driveline angles.

This time around I've got an itch to go a little faster. Just ordered the SJ30 body, cut my 1.9 Mud Slingers, and stripped and polished ALL my rock rashed billet parts. Will be based on an 8.5" wheelbase, which is a 2" stretch for the body.

Now, the good part...
To get a little more wheelspeed from this guy I will be using an HR trans case for a mini t, the mini t metal trans gear set, steel Pro locker, double disk slipper, and my MIPs into built comp worthy axles, overdriven in the front. Steering will be a mini servo with a saver, waterproof of course, instructed by my Airtronics MX Sport TX/RX for now. Motivation will come from my Mongoose Mini setup on 3s with the drag break and instant reverse turned off.

Chassis, links, and shocks still undecided and under construction. Sensored 4400kv 380 on 3s, tall gearing, and an RTR weight of around 2 lbs...she's gonna fly! Roughly 25mph. Should get there in a hurry.

Teaser pics for the evening-

And the body as ordered from Tower. Currently on back order, waiting.




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[89redranger]

Picking up either the BWD or DLux link/shock tabs to finish getting rid of any M2 hardware on the rig. Anybody know of a set of shocks around 45mm compressed, with bigger shafts and rod ends? I'm afraid the Losi stuff is just too small and flimsy. If a slow rock rig will pull the ball ends off my shocks, I know this thing will.

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[89redranger]

A few more pics of the electronics and rolling axles/mockup chassis all laid out as I try to gather ideas on where I'm gonna fit it all. The upper link plates and links aren't staying. I'll fab up something new to accommodate a mini servo and 4 links front and rear. This stuff is for a panhard/3 link. The skid will be based around the RTR skid dimensions, but cut in delrin and drilled for the mini t trans. I don't really want the motor hanging out in the open, and I want to be able to run a HR billet spur cover on the mini t trans.

Note the rubber cut from all 4 tires. That pile weighs as much as one whole tire. No wheel weights, and trying to cut every other gram I can. Rotating or not. Hoping for under 2 lbs RTR.







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[89redranger]

Also been considering running the Mini LST dual motor trans with dual Hobby Wing 5700KVs on 2s. I have 2 of the transmissions laying here, but it would raise the COG and overall weight considerably.

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[89redranger]

Canceled Tower order. RPP had the body in stock, and cheaper. Should be here by next week. Mockup, trim, then off to David of Crawllife Graphix to do his thing with the paint.

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[T_Tank]

Looking cool as for the shocks the closest I can think of off the top of my for shocks that compress that short would be rc4wd 70mm scaler shocks any of them anyways.

Do you have a way to mount the crawler center drives to the mini-T diff gear? the outdrives on the miniT diff is abit different then the mini cralwer same goes for the mini LST. Now the 1/16 traxxas mini revo transmission is compatible an you could theoretically go bonkers an toss a 540 motor into the build!

[89redranger]

The Pro steel locker drops right into the Mini T/LST trans'. The outdrives from the MRC trans slip right in as well, leaving my MIP driveshafts as a direct bolt up like stock. When I build the chassis I have to build a new skid as well though. The Mini T trans uses a different bolt pattern than the MRC. As for the Mini E Revo trans, I had considered it. As with the mini LST trans, the center of gravity would suffer. This thing is already gonna be a handful. With an HR case, Losi metal gear set, dual disk slipper, a GPM 62t Ti spur, and the steel Pro locker and outdrives it ought to be bulletproof. It won't be the trans that gives me trouble. I'm betting the ring and pinion let go.

Remember how I mentioned in another thread a certain hardened steel diff gear/no slop locker/deep engagement shaft setup? This will be the punishing testbed for a few things I have in mind...

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[89redranger]

This started out as a budget rig using up my old comp rig parts. I just ordered $150 more worth of parts, I still need to fab a chassis, I still need shocks, and then I have to wait for Novak to "hopefully" fix my junk or I'll be in it for another ESC/motor...

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[89redranger]

Another interesting piece for you scaler guys, the Losi trans is 6.64:1. Running a Mini t trans into a Mini LST trans is 5.64:1. Playing with the spur/pinion will get you lower or higher than stock crawl ratio.

Here is an MLST trans modded to function as a hanging t-case, with an MRC locker, outdrives, and MIPs.





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[T_Tank]

interesting by chance you have pictures of the outdrives on the mlst center diff?

[89redranger]

The stock MLST outdrives? They are a dog bone cup. Junk for anything in our world. Suspension would articulate and pull the driveshaft right out.

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[T_Tank]

so how did you mount the center drives to the mlst outdrives out of curiousity?

[89redranger]

38t bottom gear/16t top shaft/MRC outdrives/plastic MRC locker in this one for now. Everuthing drops right in. The Mini T and MLST use the same gears, shafts, bearings, different cases. 2.375:1 ratio.

Pulled apart-


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[89redranger]

Mini T/MLST on left, MRC bottom gear on right. Same center hole size and shape. MRC locker is a direct fit. Remove MLST diff gears and outdrives, drop in MRC locker and outdrives, reassemble. Back on topic with the SJ30 though, please.



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[89redranger]

Body in hand, rough trimming done, building chassis around it, then off to paint. Updates coming. No internet connection ATM.

[89redranger]

Still looking for shock options guys. Need some with bigger rod ends than the Losi stuff, but the body needs to be about the same OD. I have two sets of aluminum Mini Late Model shocks, two sets of aluminum Mini T's, two sets of aluminum MRC shocks, and they're all too flimsy feeling. The tiny M2 shafts and rod ends are the failure point. Most other shocks this size are for buggies/on road cars, and lack high misalignment ends. Not looking for scale, looking for performance and durability. I've got $200 in Losi aluminum shocks sitting here from when I crawled this rig, and don't mind paying for quality. Shocks are my one major nitpick...

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[daver18qc]

Integy has some nice looking shocks.
Don't know how tough they are, but they are 100% metal with internal springs, metal rod ends and no oil.
Seems most integy stuff is crap though, so yeah....

http://www.integy.com/st_prod.html?p...64&p_catid=374

[txbart]

So how is the chassis fitting underneath that body? I've got the Tamiya VW bus body waiting for a chassis & I believe your Sj30 has the same wheelbase.

[89redranger]

A few pics of the mockup phase. No real updates to speak of. Haven't had time. Also, I know I have PMs waiting. Gimme some time to catch up.











My daughter's rig. An Exceed Maxstone 16, fairly stock, putied up for a 5 year old girl. Just got an Xtreme 380 installed, fabbed up new electronics trays from polycarb, and sorted the wiring. Been putting some hours into this thing. Stock electronics with LiPo buzzer added, and doing well with new motor and 2s. Stock Exceed 14/60 gearing. Zippy!











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[89redranger]

Decided on the MLST trans for this build with a single motor, battery on the other side. Built the motor plate/rear hanger bracket to hang the trans. Now I need to finish up the front bracket. These two brackets will accomodate anything from a 25t pinion/62t spur down to a 9t pinion/54t spur for a VERY wide range of gearing options. The lower flanges on these brackets will be trimmed down to 1/4" wide, and be drilled for M3 hardware. With the front/rear mounts the trans/motor/battery mount will come out of the chassis from the top as one piece after removing 4 bolts. There will also be no skid in this chassis. Keeping everything as open as possible to avoid the chassis "plowing" in the mud. Wrenching and clean-up will be simple. Also (!!!), picked up a Castle CM-2054 (5400kv, 3s safe) for this rig. My Novak setup will be finding it's way into another comp rig.









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