New picco .28 monster build!

[TK5310]

YAY!!!!

A bash session that ended with it still running & driving after chewing through 1/3 of a gallon in a couple of hours.

Maybe reliability in a BB revo is possible.

Couple of little issues - the new 1-2 shift dog clutch is a dud, adjusting screw unwinds itself within a minute or 2 & locks it in top gear. Doesn't make all that much difference really, still wheelstands from a standing start in top gear, but is a little sluggish untill the motor gets up to speed & doesn't wheelstand from a roll.
Blew a couple of tyres off the wheels, need to reglue them.
Clutch sometimes needs a few extra revs to engage, needs a little maintenence - it copped a hard time with the trans locked in top, still works but the shoes probably need a little clean up.
Needs a new pipe seal after a hard barrel roll that bent the pipe mount.
Another throttle servo died (2075), got a 2056 in there now which works just fine, but I'll have to get a decent servo for the throttle/brake.
Lost another rear shaft drive pin, forgot to loctite the retaining screw & it worked loose & the pin came out & gouged the chassis, new pin in & sorted pretty easy.

So I reckon I'm at the end of the struggle, just gave it a degrease & blast off with compressed air to get it clean for a tear down to fix the little issues tonight & a once over to check everything is coping ok & a few dabs of loctite on stuff that has a habit of working loose.

Now I'm settled on the driveline I'll locate the trans properly with a couple of extra screws, from here on it should just be maintenece (I hope).

 

[TK5310]

Casualty report for the weekend:

1x trx trans main shaft
2x sets diff spider gears
1x alloy diff cup
2x clutchbell bearings


Put my custom made 8740 steel main shaft back in, that seems to be holding, the trx shafts are just not up to scratch.
Diffs let go due to the alloy cup getting pounded out of shape, Erevo diffs are going to be the only option it seems, for now I'll borrow another different brand alloy diff cup, fit that to a fresh stock diff & shim the gears nice. Front diff is holding for now, I have to pull it down & make sure the cup is ok.
Clutchbell bearings disintegrated, not sure why, clutch shoes are also looking a bit second hand after only about 2 hrs run time - clutch is a losi 8ight 4 shoe. Looks like clutch shoes are going to be a consumable item.


I'm thinking the best plan I can come up with to keep the driveline in 1 piece is to gear it up a little to reduce the torque being fed through the driveline, currently has 17/38 gearing, stepping up to 19/38 will reduce torque through the driveline about 10%, combine that with running the slipper as loose as I can without it slipping too much to help save the clutch & diffs & it may hang together.
The taller gearing will give the clutch an even harder time, but I think I'll just have to look at it as a consumable, grab another clutch (or 2) & swap them out every couple of litres or so & rebuild them so I've always got a fresh spare.

 

[revo6929]

Try a 17/36 gearing, that works very well on my revo 28. And it will eat those shoes up fast, i have a losi 8T 4 shoe clutch in it and went to the all aluminum shoes and there doing okay for now.

 

[TK5310]

I'm stuck with the 38 spur - it's a robinson racing slipper conversion & only comes in 38t.
But 19/38 gearing will be pretty close to your 17/36.

What motor do you run? LRP or Picco or other?

I've got the all alloy shoes in the clutch, I killed one set stone dead - I figured they were fine & was busy sorting the trans & diffs, so I never looked at it. Probably if I'd given the shoes a touch up a bit more often it would have lived longer, once they transfer alloy to the bell they chew up fast.

One thing I am happy with - I put a hyper 1/7 250cc fuel tank in it, massive run time on it now.

 

[revo6929]

I run the LRP on mines and how difficult was that tank mod? The LRP is alwayz thirsty and i would love to have a longer run time.

 

[TK5310]

tekno conversion + hyper 1/7 tank.

Pretty easy, the tekno conversion mounts the RX battery pack right down low & shifts the RX box to where the RH steering servo would be, you shift the single steering servo to the left side.
The tank mounts above the battery pack.

Doubles the run time.

Don't fill the tank right to the brim tho, tune goes pig rich with the tank full right to the filler neck, leave it 1/4" down from the top & it's sweet.

i'll throw a couple of pics up when I get the car back together.

 

[revo6929]

Okay Thanks

 

[olds97_lss]

Please do. My LRP's are thirsty as well, which isn't something i'll have to worry about again until next year since I dropped in a 3.3, but would be nice to have the pics to see for next year.

 

[TK5310]

Hyper 1/7 tank conversion with tekno RX box/Battery/tank conversion:

 

[jamdude]

which 3 shoe clutch did you use?

 

[TK5310]

4 shoe - Losi 8ight.

---------- Post added at 11:04 PM ---------- Previous post was at 11:03 PM ----------

Oops - you mean the 1st one?

Hobao (hyper 8 I think?).

 

[ausher]

Question for you big block guys....

I bought a new era bb mount thinking it would work with with the picco .26 red dot, but apparently it won't so I think I'll go with the picco .28 with a pull start. Will a pull start fit In the revo? And I plan on replacing the top shaft gears with the Robinson racing. Or should I go all steel gears?

Basically what are the must have drive line parts to make a big block revo reliable? And what parts can I get by with using?

 

[TK5310]

Go for an LRP .28, picco is a bit much & will kill everything in the driveline.
Clearance for a pull start/rotostart will be close - but should fit with the new era mount.

Use a Losi 8ight clutch, go straight to a robinson racing (RR) slipper conversion (stock slipper won't cope) & RR all metal gear set (any plastic gears will get chewed up).
You'll also need steel front & rear driveshafts, stock axles will cope for a while.
I'd suggest going straight to E-Revo diffs, stockers will last for a little while on dirt, but will die sooner or later & they are a PITA to replace all the time.

 

[ausher]

OK thanks I will do all you suggested. The Lrp also cheaper. What drive shaft brand do you recccomend? Trx ones up to the.challenge of a big block? I read the summit drive shafts are stronger.... plan on gearing it high. Like 18/36 or 20/36.... how's the dynamite 053 side exhaust set up?

 

[olds97_lss]

I run full RRP in the trans with standard gear ratio. Stock axles all around and stock diffs. I'm running an LRP28 with 15/40 gearing and 1/8 scale clutch/flywheel/bell with alloy shoes.

I find with much taller gearing, the clutch slips and overheats. Granted... that was with teflon/carbon shoes and I was running 16/38 I believe. However, with 15/40, the LRP doesn't rev too high in top gear unless I have a lot of room like a park.

I spend 80% of my time in grass, 20% on concrete in a skate park, so not a lot of legroom to wind it out anyway.

 

[ausher]

Will the 8ight clutch bell work with the revo RR spur? Same pitch? Plan on ordering the motor tomorrow and exhaust when funds are finally available in my PayPal account. Next Friday RR wide ratio gear set.
Ordered the lrp .28 and the losi 8ight clutch. This one is the one that was reccomended right?

Now I need a compatible 16-18 clutch bell that will work with the RR 38 tooth steel slipper spur #7738 Gen 3...
I'm assuming I need a hardened steel clutch bell....

With this clutch bell work with the 8ight 2.0 clutch and revo spur gear?
http://www.teknorc.com/shop/tkr4117...mod-1-17t-for-2-shoe-system-traxxas-vehicles/


http://www.rcplanet.com/ProductDeta...dftrk=gdfV23720_a_7c1734_a_7c7525_a_7cTKR4126
Thanks for all the help and info. I read this thread 3 times already absorbing all the info I can.

 

[TK5310]

Well, I cracked the sh|t's with this just a couple of weeks ago after another round of broken stuff:
Smashed 2nd gear in the RR gear set, destroyed the RR slipper & hoBao bell, sprayed finely ground metal through the trans & killed a bunch of bearings.
I've also just about chopped out the drive hubs for the rear steel drive shafts & have smashed the front bulkhead.

I think I'm ready to fix the dang thing again, so I just sent RR an email to find out why they reckon the bits have failed & get a recommendation on a clutch bell to work with their slipper & the losi clutch.

The failed slipper could have been due to a couple of reasons, either a trans alignment issue or a clutch bell compatability issue, to rule out the alignment I'm gonna grab a new carbon fibre chassis, with any luck RR can advise on the clutch bell.

So it's rebuild time with new chassis, new bulkheads, new body mounts, a few new gears, new clutch bell & slipper gear & new driveshafts.

Dang.

My new integy (yeah yeah I know - but not many choices) bead lock 40 series rims with 23mm hubs have arrived, but my GRP tyres I was going to put on them don't fit, may have to use the big joe's again, if so I'll see if I can get some harder foam for them.

 

[ausher]

What carbon fiber chassis? The vantage one? I'm thinking of ordering the extended one, but they have no contact information... what kind of driving were you doing when this all happened? I'm using an ofna 18t hardened steel clutch bell and so far no problems.... I also broke a bulkhead. Keep us posted on why your spur and bell failed along with the 2nd gear. Think maybe a rock got between the spur and bell?

 

[Ckeithnitro]

my picco .28 monster build, its a slayer pro with lots of upgrades
to see videos of the build and others goto..
www.youtube.com/user/ckeithnitro

 

[lesclaypool]

That is one hell of a truck....bit of a handful I'd imagine.