Mini-X with iWaver guts conversion….

[ph2t]

Mini-X conversion…

A while ago I got a mini-x from rcmart, the basic kits comes with a full chassis, shell and motor. Not to shabby for $16!!

http://www.rcmart.com/catalog/default.php?cPath=144_29_44_249

The chassis set is pretty full on. It is a shaft driven 4WD chassis with two well made ball differentials at each end. We’re talking proper balldifs that have an adjustable pressure plate with ball bearings as well, not just the diff plates. A lot like the RC18T balldiffs.

The chassis is made out of this clear plastic that whilst looks brittle it’s actually bloody strong! You also get a polycarbonate shell that you need to cut out (just like 1:10).

The motor is a direct drive system where the pinion attaches directly onto the ball diff spur gear. There is a slight issue here ’cause the mounting hardware needs to been secured well to put up with the stresses of the pinion/spur gear mesh. If this isn’t affixed well, you will strip the gears. It’s been documented before on microrccenter.com and ripper7racing.com.

You get bearings in the drive shaft and diff outdrives as part of the stock chassis kit. You will need to purchase two sets of extra bearings to get bearings in the wheel hubs, making the drive train fully bearing based. Just looking now it doesn’t appear as if rcmart stocks the bearings any more but if you look at the bushing set you can get the dimensions and go from there:

http://www.rcmart.com/catalog/product_info.php?cPath=144_29_46&products_id=87

The motor is a 70T, ferrite magnet, bushing can based motor. The magents are slightly stronger than your average stage 2 magnets. It has a typical, standard size plastic commutator. The motor is nothing to write home about……

You can get the RTR kit that includes a full hobby grade setup of RX module, ESC(with bec) and micro servo or you can put your own eletronics in there but it’s a bit tight on room and the servo needs a custom cover on it to affix to the mini-x chassis. You can get that here:

http://www.rcmart.com/catalog/default.php?cPath=144_29_44_249

I bought the RTR kit but the ESC was dead, I also heard from badwrench on AM’s forum of the same situation, he purchased a RTR mini-x kit from rcmart and the ESC arrived dead. So I would be cautious about getting it.

In in the end went with a iWaver PCB conversion.

The conversion was quite straightforward with these major steps.

1) Removed stock wires from iWaver pcb (servo wires too), shorted out the power switch.
2) Attached deans micro connector for power (+ and – on iWaver PCB)
3) Removed the controller circuitry from the micro servo.
4) Soldered micro servo motor the iWaver PCb.
5) Soldered micro servo feedback POT to iWaver pcb.
6) Soldered drive motor to motor tabs on iWaver pcb.

That’s it in the basic sense. The only thing is to watch the orientation of the wires for the feedback potentiomer. I’m using my mini-x perfex KT5 transmitter that doesn’t have a reverse switch for either channel (which gives me the shits btw).

Anyway, enough of the BS text, here’s some pics…

I converted the motor to a ball bearing can with neo magnets and carbon brushes. I also polished up the commutator and broke it in for an hour in the forward direction. It’s kicks arse now!

Here you can see the placement of the iWaver PCB affixed on top of the servo.

The whole thing is powered by a pair of 600mAh li-ions, aka the mini-z pro kit in the xmod world.

They just sit in the original AAA battery bays on the chassis.

Overall, I’m pretty happy with it. The top speed on this is quite fast, the bottom end torque isn’t the greatest but given that it’s Stock MOSFETS on the iWaver pcb and stock 70t winding on the motor, there is a lot of room for improvment.

The handling is pretty good. The chassis sits low and solid thanks to the placment of the motor and batts. The tyres are a hard compound with a tread on them. They work well for the 4WD setup this chassis runs. I run mainly on concrete so I wouldn’t know how it handles on typical micro indoor carpet/rcp tracks.

The next step is to put a nelly in it and get the motor rewound for a hotter setup. I’m getting flash-sp from xmodding.com to do a nice pattern wind, 35-45t deal. I’ve got one of his motors that I use in my mr02 and it’s bloody great!

I’m not going to put an uber hot motor in this for a few reasons. The motors as it is currently gets very hot! It is wedged in the plastic with no room for ventilation so that is an issue longterm that I’m going to have to deal with. Also, the li-ions aren’t made for high current draw applications. I may put some lipoly in it instead, we’ll see….

More to come….

ph2t.

[Admin]

Cool, I dig it. Looks like a good solid little 4wd. I might have to pick one of those up to do some messing around. The only thing I don’t really like about it is the motor setup. The direct drive is cool, but having the single long arm to catch the front diff is kinda limiting. It’d be really cool if you could make it twin engine, but that looks like it would involve some really funky gear linkage or relocation of the steering servo.

Nice work!

J.

[ph2t]

Yeah, the drivetrain is a hassle, but so far so good. I actually did this a while ago and it’s been sitting here, waiting to be posted…..With everything else going on at the moment I’m lucky to get this info up, lol….

ph2t.

[merc-blue]

Ph2t,
hows she go on ride height i was looking at these back in the day, but they always looked far to low for 99% of surfaces

[rcs2die4]

Hey Ph2t,

I got one of the (not listed as!!) pre-release kits from RCMart back in the day !! back when RCmart were still DINBALL.. They sold some to the public which I later found out from Express they should never have done !!!

The pre-release was the biggest load of S#@T I’ve ever seen !!! nothing lined up, nothing meshed, the diff’s would not differential and the front end was also very bad, cause if you dialed in any camber or the castor, the drive cups at the wheel end hits the ball screws on the swing arms !!!!! I was getting about 3 min runs with it and it was very slow !! it was 4 cell then, I think the chassis is now for 5 cell packs!!!

It cost me $200 for chassis, cover and radio (no TX) !! I was not happy !!! and neither DINBALL (rcmart) nor Express would do anything about it !!!

After allot of modding I finally got the chassis to sort of roll and the diff’s to sort of differential … I then installed the RX and ESC and it cooked the ESC !!:angry:

so after about a year, stupid me decided to try again !!! so I purchased a new RX kit from US ebay and had another go at it !!! which also turned out to be a waste of money as now the RX and ESC where much better quality but the chassis was still crap !!! so now I was up to 260-270 and only had some 1/24 size radio gear to show for it !!!…

I’ve been thinking for about 6 months now “SHOULD I GET THE NEWER CHASSIS AND TRY AGAIN !!!”… The thing that S@#TS me the most is that you can now buy the chassis for about $20aus.grrrr :angry:

I think the chassis could have been really good if the quality was there cause the independent suspension, ball diffs and AWD was way before it’s time but the quality was way behind the likes of a MINI Z’s…

Anyway, I suppose my question to you is !!!

What is the quality like now !!! IE’ plastic, diffs, alignment/ mesh of everything and also the front end ?? Or would I just be wasting more money ??

L8R

[ph2t]

@merc, ride hieght is similar to mini-z’s mate, a bit more clearance though. It’s adjustable on the suspension arms, the usual screw adjust will do it. I’ve left min riding high. Works well over your typical concrete. I’ve run it up and down my driveway with no problems. Also run it at Betty’s with no issues there either.

@rcs2die4, plastic is VERY strong man. Very strong. I’ve head butted a few things with it and the OTHER part comes out worse, lol… the gear mesh is OK, I can see it still wearing out in the long term. ie: the pinions are crap moreso than the diff. I ‘ve found that the problem is in the mounting post, it’s just one screw with no alignment buttress on it, ie: the mount will twist with the screw when tightening it! Strengthen the mount and it will help.

ph2t.

[betty.k]

mini x’s are made from polycarbonite, like lexan:topstuff: :8ball:

[rcs2die4]

Thanks PH2T !!

So what do you reckon !! Try again or give up ??

[Admin]

I’m gonna have to give one of these a try. I’ll get the chassis from RCMart, and I have some extra Etec Li-po’s. Where to find an Iwaver EP ?

J.

[ph2t]

get them here mate:

http://www.rcmart.com/catalog/product_info.php?cPath=144_21_150&products_id=14328

let me know when you go ahead, I’ll post some detailed pics of the servo/servo pot connections….

ph2t.

[Author]

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