Another Gmaxx is born

[suicideneil]

Rotational mass, its an axle killer for sure, but I have spares...

Im looking at getting some 40series bowties or similar- they are still quite large, but alot lighter compared to what I have now, and should allow for a bit better handling on grass too.

Luckily the camera I killed was my old one, an amazing 4 MP 6x optical zoom item I've had for 6 years, recently replaced by a nice FZ28 ( I wont be strapping that to the truck in a hurry). Gonna replace it with a dirt cheap little digital camera for truck duties, something alot smaller and lighter that wont have a telescopic lens to damage.

Anyways:

http://www.youtube.com/watch?v=6T97wD1FgQ0



Enjoy

[suicideneil]

Originally Posted by Rivermaxx

Looks like you had fun though and we all know you did this because your bored and like to work on it just as much drive it lol. Try droping the camera again maybe it will fix itself. As far as the axle givin up the ghost it was bound to happen with that amount of power and those big ass tires. I had those same tires on my kids t-maxx because I didnt want him to break anything. Those tire just bounced off everthing without a scratch lol. I am really surprised you havent striped a hex yet, those are 14mm right?

True- its overdue a strip down ( ) and rebuild..

Camera is thoroughly borked though, and my efforts to 'fix' it made sure it stays borked No biggie, wasnt worth much.

14mm hex yeah- a few of them are getting a little bit stretched, but they are holding up quite well. I'll just glue the hexes inside the wheels at some point to strengthen em up again.

[Rivermaxx]

That vid was cool! too bad we live a world apart, it would be fun to have a bash session with you.

[OZ-RUSTLER]

Great vid Neil Had a little motion sickness after that

I didn't notice any Cricket pitch on that Rugby field. Fields down here a full of them, that have to be avoided at all costs

Looking forward to the new project.

[suicideneil]

Oh yes, we did just win the ashes didnt we

Not a cricket fan myself, too many middle aged men rubbing big red shiney balls up and down the inside of their legs...

[OZ-RUSTLER]

What are the Ashes?

[Kcaz25]

Originally Posted by suicideneil

Holy monkies....

So, not to be outdone by the Candyman I took the Gmaxx out today for a thorough bash session, and boy, did I bash that poor truck.

Damage report:

destroyed wheelie bar
destroyed rear-left drive shaft
bent Ti front skidplate
crippled slipper clutch
dented both 5s lipos
slightly bent whole front end of truck 1-2 degrees to one side
destroyed digital camera

The wheelie bar is great so long as you dont get to lively with the steering under power, the result of which is cartwheels that extert alot of leverage onto it. End result of some wicked-nasty large jumps was a wheeliebar bent upwards at 45 degrees, and 2 sheered screw heads holding the braces onto the bar.

Rear left driveshaft was on its way out as noted earlier, but I finally ripped it apart at the yolk. On the upside, this allowed me to experience what having a dodgey center diff must be like- no power to the rear wheels and massively ballooning front tyres. And I do mean massive, as in about 10inches diameter at full throttle, made an incredible sight and sound too, almost like a pulse jet-type grumble as the truck roared along trying desperately to get traction. No vid of that as the camera was dead by then saddly.

Whilst doing those large jumps and and down a 6-8" tall hill, I misjudged a jump and sent the truck straight into a little ledge, only about 2" high, but it hit hard enough to bend the skid right back- no damage to the chassis thankfully, just need to bend the skid back into shape.

Slipper clutch also decided it didnt want to be locked anymore, so I had to tighten that a couple times during each set of batteries. The last time it came loose I couldnt get it tight again, so had to call it a day- needs a bit of CA glue and a 2nd nyloc nut I reckon to hold it tight.

Lipo damage was annoying more than anything, seems they shifted forwards during one of my little bumps, causing the rear edge of servo plate to dig in a little bit; just made a little dent about 15mm wide and 5mm deep in the upper two cells in each pack. They still work fine.

The bad damage, slight as it is, came when I misjudged a turn and clipped the corner of a little metal framed dugout thing at the side of the rugby pitch, hit the metal pole just hard enough to bend the entire front end to one side. I think its damage to the FLM bulkheads rather than the chassis, just stretched or compressed on side a bit. Have hammer & vice, will fix

Saddly my old digital camera which was serving as the action-cam wasnt so lucky. During one big jump, the whole improvised mount it was bolted to flexed enough to allow the telescopic lens to smack against the top of the esc. Result is that it killed the little drive motor for the lens, and I just get a 'lens error' notice when I turn it on, and shuts itself off again. Even more annoying is that the video I was shooting when it died didnt get saved to the memory card , otherwise that would have made for an excellent end to the vid (grass-sky-grass-sky-grass-grass-grass-dead).

Performance:

Motor temps averaged around 130*F for most of the session, although I did reach 180*F on the last run using the A123s (forgot to stop for a break half way through the run to check temps).

Esc temps were hard to get as usual, but the highest I managed to record were 100-110*F around the caps & base of the battery and motor wires. Didnt help stuffing the fan full of dried grass like I normally do, so I will add a fine mesh over the fan grill before the next run.

Lipo temps were exellent, barely above ambient at 90-100*F, A123s temps were a bit higher, kinda nice to hold on a cool evening actually :lol, so around the 110*F mark.

Im very pleased at how well the truck stood up to the abuse, but Im thinking if I want to jump it like I was doing, then a much cheaper purpose built beater-truck will be in order, like those cheap chinese ebay items you see around, I cant justify trashing the Gmaxx for when Im in one of those 'f*ck it, lets go for it!' kind of moods- that was fine when I had the madbull that was made of rubbery plastic that would-not-break, but its not fine for an all metal 13lb truck.

So, a new project shall be beginning soon.... *dun dun dun*

Video will be uploaded once its been edited.

YAY finally another video! WOW sorry to hear about the carnage!

I can see how the wheelie bar would act as a nasty leverage device in a torquey turn. How funny would it be to land on it in soft grass? Lawn dart!

The slipper problem sounds grievous, I hope it is a simple problem. I hope the input gear isn't doing something funny. I guess you've checked for slop/play?

I can't believe you bent a bulk with those Strobe braces on! I might hope it was the chassis.

My TRX CVDs have a quite a few hours on them and are still going strong. Withstanding standing backflips and all. HEHE definently stronger than 3905 plastic. But heavier and more expensive.

[suicideneil]

Yeah, slipper problem isnt anything serious, just needs more glue

Im about to tear the truck down so I'll be able to see exactly where the damage is- it looks like the bulk has bent where it attaches to the chassis (upper and lower plates), so the strobe braces woudnt have prevented it.

I dont worry too much though, its all part & parcel of the hobby...

[swiftneed]

Ok, I checked several sites and cant seem to find a g4 for my build who is hiding them and if gorillamaxx is saying they are still fabricating them, why arent they available from rcmonster or should i use Fastlane Machine or am i 2yrs to late in finishing my build LOL

[Rivermaxx]

Heres some info http://www.rc-monsters.com/forum/sho...d.php?p=281636 They supposedly are still going to make the g4 chassis. I guess the machinest is behind.

[DwightSchrute]

Originally Posted by swiftneed

Ok, I checked several sites and cant seem to find a g4 for my build who is hiding them and if gorillamaxx is saying they are still fabricating them, why arent they available from rcmonster or should i use Fastlane Machine or am i 2yrs to late in finishing my build LOL

they were in stock briefly about 3 weeks ago. those G-4's go FAST.

[suicideneil]

Anyways, after the bash session, came the tear down and inspection:













I owe an apology to someone- seems that the steel idler did indeed eat into the aluminium output gear. Its not as bad as it looks though, seems like its just worn down one half roughly of each tooth's face, creating a little burr along the edges. Reluctantly then, I've decided to swap over the idler for one of the rc4wd items- I'll open up the tranny again after a few more runs and see how it looks.



Pebble dashed lower A-arms. I could put some dirt guards over them like some guys are doing on their buggies and truggies, but Im not really bothered as such- battle scars are sexy



I even opened up the rear diff for an inspection, and was happy to see zero wear on the ring & pinion gears. The only slight wear to report is on the output shafts- the hole for driveshaft yolk retaining screw pin has been slightly elongated into an oval shape. Not a big issue really, and its better that the metal has a bit of stretch to it rather than sheering unexpectedly- it may snap one day, but it wont be for a while, and is easily replaced.

I also fixed the slipper- a few bits of sandpaper super glued to the spur and onto the slipper plates creates alot of friction that will be hard to budge- I'll have to test that theory though.

Beyond that, the Gmaxx will live to fight another day.

[Rivermaxx]

I brought the fact up that a steel gear will eat up an aluminum one. No apology needed, how many run did you have on it since you lubed it last?. Now with the new setup, the steel input gear is going to eat up the aluminum idler gear. Aluminum does not make good gears for sure, when it wears it turns into alumminum oxide which is used for sandpaper. I wonder if we could find a delrin gear we could make work. I also read you can boil the stock plastic gear for 10 minutes and it would last longer but I have no way to confirm this. I would just run the steel idler with a stock plastic gear mine seem to be holding good on 6s. When it lets go just buy a new one for ~$5 shiped. Maybe put smaller lighter tires and rims to free up some rotational mass.

[Chadworkz]

Who made that aluminum output gear? It's not an Ultramaxx GenIII gear is it? If not, there is no wonder that steel idler chewed it up...if it is, it can only be run with the other Ultramaxx gears (idler and input).

Anyway, the larger the gear, the less stress it receives due to its larger diameter, so the stock nylon output gear will be fine when run with the hardened-steel idler gear and steel input gear, even on high-powered brushless systems.

The ultimate single-speed E-Maxx transmission is one with all aluminum gears that have been titanium nitride (Ti-Ni) coated! The aluminum is more than strong enough, it just can't be run against other aluminum gears, so coating them in Ti-Ni would be perfect, since Ti-Ni is currently the best wearing surface in RC right now.

[Rivermaxx]

Hey Chad, I dont think you can put that ti-ni coating on aluminum, only steel but I could be wrong. Plus I have never seen one. As far as Ultramaxx gen III gears the idlers are made out of the same bronse alloy that was used in the otb gears input gear. I am almost positive the 1st and second gen Ultramaxx gears had the same issues with wear thats why there is 3 generations, the latest is the greatest and almost impossible too find.