I finally finished the motor mount and found some gears so I was able to mount it with proper mesh! Iīm currently geared a bit on the low side... 68/17 Stock e-maxx gearing, but that is good since I will be throwing around alot of the white stuff with the paddles.
I also modified my Geode wheels to accept my "normal" Pro-line mtr tires, since I stripped a hex on the rulux and it looked wierd to have half offset in the rear and non offset in the front. I also added some stickers to the truck I like stickers.
And some pics of the final version of the chassis, the esc will be mounted over the rear shocks:
No mistakes here :P:
Got the Lst diffs in now! I also have the rear centershafts and cups in steel. The whole drivetrain will be steel soon enough like Mcīs.
For the moment Iīm using Lst diffs, savage rear center dogbone and savage gearbox/diff cups in steel. Perfect fit for my chassis setup!
The Whole process was much easier then I thought it would be, I didnīt have to grind much material away, actualy I accidently removed too much, the area on the sides where it is small holes was totaly unnessacary to grind.. Donīt think it affects durability tho... Iīm always snapping my bulks between the centerskid and the rear skid, and since all the grinding is done under the rear skid I think it will be fine, and I will be using a hardcoreracing titanium skid later on so no worries then.
Look at that difference, twice the size and four spiders...:
I just took Mcīs tip and cutted some wheel axels in the right length:
I found out that the best gearmesh on my lst diffs were achieved by using one shim between the ringgear and the bearing, the pinion didnīt need any shims. It now has absolutley Zero play.
I grinded the top of the lst case by mistake...It wonīt affect durability but it doesnīt look that good..:
On this pic you can see the unnessecary hole I accidently made clearly:
Next time I will remove less material.....:
Beefy beefy beeefyy:
And this is the end station:
Canīt wait to get my hands on some Lst cvdīs, the summit shafts will have to do it for now.
What batteries and connectors are you useing? because with my ERBE i get about 10min of run time with 1 batterie
Hows that nitro taste on your electric?
I am using dual Rhino 3700mah 4s in parallel, they give me about 25-45minutes of runtime depending on surface and driving style.
The new esc is finally here!
It runs smoother than my mamba max in some wierd way Itīs really really easy to program with the programcard, and after about 7hours of use, Iīm still very happy with it! I turned the fan in it upside down so the air will be pushed away from the esc to make the snow blow away instead of getting sucked in to the esc.
Some before and after pics of the plastidipping:
Last edited by Manne; 12-13-2010 at 04:09 AM.
And this is how I finally mounted it:
I will add a enginehead bar from a Savage later on I think, you can never have enough protection something like this:
And yes, I have had the truck covered in snow several times and it works just like normal:
I plastidipped the esc three times, that made the trick I guess. I have driven the car with the snow half melted many times to really see if the plastidip does itīs job and the answer is yes, it works flawlessly. I wonīt submerge it like the old esc tho... I donīt want to play with the devil so to say
How much did the whole lst diff mod cost you?
35dollars for the rear and I assume that the front end will end up in about the same price class, really really worth it!
Hey, I have a few choices to make and I need help.
I have have Lst diffs front and rear, steel centershafts, cups etc front and rear, but I canīt decide if I should use Lst cvdīs or continue to use summit shafts from the diffs to the wheels.
I like the thought of having it "bulletproof" with steel cvdīs but I have some spare summit shafts and they have been holding up great so far ( only one have broke ), it feels like a waste to just let them sit there at the shelf. And it feels good to have a "easytochange" weak link, it feels forgiving to the drivetrain to have the summit shafts, then I wonīt have to be worried about stripping diffs or outputs.
It is also a problem that Iīm breaking the rear carriers/knuckels were the turnbuckle attatches, so I want to swap these to alloy as I did on my previous truck, If Iīm going to use cvdīs I have to get some to accept the bearings that the Lst cvdīs needs.
Mc used RD knuckels, but the bearings fit wasnīt perfect, he used gorillatape since it was only a test, but recommended a sleeve to get rid of the slope, I canīt get a sleeve and the tapeing isnīt up for it... That is a problem.
And now Iīm going 5s and I canīt decide if I should buy a 3s 1P 5000mah and 2s 1P 5000mah configration to use in series to keep it light, or just buy the same pack as I have now ( 3700mah 4s in paralell for 7400mah ) in a 5s configruation instead? I like loooong runtimes, but the truck wonīt be nowere near light with dual 3700mah 5s packs....
Last edited by Manne; 12-15-2010 at 05:09 AM.
Will the center shafts that you used on your lst mod, work on the longer ERBE chassis or would I need a 3.3 chassis?
That is a good question, To use a 3.3 Chassis is a huge modification, but Iīm sure that you are aware of that. If you want steels in the center, you should consider to just get Traxxas own center replacement.
Now is there no one who can help me with my decisions?
Okay thank you.
Given the difficulties of fitting LST2 cvds, I would say stick with the summit shafts really. If you look around enough you may be able to locate some odd sized bearings to use the LST2 cvds without needing to shim them though, but its a tricky one all the same.
As for batts, I dont think a couple extra cells will add that much weight if you went with 5s2p; my Gmaxx runs 2s 5s 4000mah packs in parallel and it barely notices the weight with all that power ( might notice it if you crash but anyways... ).
Keeping the Mods busy is my specialty...
Thanks for shiming in AoD.
Yeah I found some 8x12 bearings that will fit in the knuckles without mods with the included sleeve that makes the hole for the outer bearing 12 like the old style knuckles instead of 13 like it is theese days. But I think a 8x12x3.5 bearing is going to blow each and every day, and it wonīt help me anyway since my problem is to make the inner bearing fit.... I can enlarge the outer hole to accept 8x16.
I didnīt think it trough enough before I started to bid on some cvdīs at ebay... Iīm currently the highest bidder and there isnīt much time left on the auction. I guess time will tell If Iīm going to use summit shafts or lst shafts.
Two 4000mah 5s packs!? Man you got to have runtime! I saw someone who ran a similar setup with some more mahīs and got one and a half hour of runtime in his maxx
Iīll go for the 5s 3800mah in parallel then. If I get some with bad cells I can just take some cells from my other packs since they are exactly the same brand/ c rating/ mah...... I know That mixīn match with used/brand new cells isnīt prefeered but I donīt want to bother sending them back when I can fix them myself... AND I havenīt got the batterys yet so no bad cells yet I shouldnīt be thinking of problems like this yet.
Iīll keep everyone posted about how this will end.
Well, I won one auction on some Lst cvdīs so I just bought another set to convert the whole truck. To solve my rear carrier issue I bough some rpm knuckels for the rear only. They will accept the 15x21 bearing without modifications and I will have to enlarge the outer hole 1mm, no biggie. For the front Iīm going to do like Mc and just press the 15x21 in without any mods and enlarge the outer hole. I will use the Stock drivecups on the XXL diffs.
I havenīt found any dogbones for the front yet that Iīm sure is the right length to fit.. But I think some non XXL losi center shafts should do it, some more meassuring will tell, In the meantime I will use summit shafts for the front-center, so the only weak link in my drivetrain will currently be the front center..... I can almost promisse that itīs going to break....
Still waiting on the cvdīs to arrive....
Iīve got the stuff! I will make this long story as short as possible, if there is something that someone is wondering, feel free to ask.
I decided to use the Stock outputs that comes with the Lst diffs, If you install everything like Mc did the driveshafts will be too short for my likening since the outputs will sit longer in on the diffs than if you have the stub axel mod with additional cups on for the cvds, To fix that I simply used a additional layer of bearings in each knuckle, A easier way to do it would be to use Tekno carriers, I will try that version later on.
Alot of 8mm shims.
4 Lst cvds.
2 lst differentials.
1 rear dogbone, savage.
1 drivecup, savage with 8mm bore.
1 drivecup, savage with 6mm bore.
2 grub screws from the center lst-cvd that came with the diffs.
1 drive cup ( or what to call it ) from the center lst-cvd that came with the diffs.
1 complete summit shaft with two diff output axels on it.
4 15x24 bearings for the rear rpm knuckles.
4 8x16 bearings for the rear rpm knuckles and front stock knuckles.
4 15x21 bearings for the front knuckles.
This is how I did:
I started to install the metallrings I had laying around from some stock knuckles on the rpm knuckles, itīs a good fit.
Then I enlarged the outer hole on the rpm knuckle to make the 8x16 bearing fit.
I took two of the four 15x24 bearings and put a layer of thin tape around them, the outer hole on the rpm bearing is about 24.8 so the fit is a bit loose without the tape, some 25x25 bearings would be perfect but I couldnīt find any...
And then itīs ready for the cvd install:
In the front I just removed a little bit material from the seats for the 15x21 bearings to make it easier to press in the bearings and get them out later on if they breake, I removed a very tiny bit of material with a knife. I used dual 15x21 bearings in each knuckle to make the shafts go really really deep into the drive cups when using LT rockers with P3 pushrods for that super high ground clearence. No binding have occoured.
The cvdīs have about 0.2mm of play from bottoming out in the drive cup when the suspension is compressed, but I like it that way, no cvdīs is popping out on my truck.
Last edited by Manne; 01-18-2011 at 12:00 PM.
Then I enlarged the hole on the hexes.
Itīs hard to explain how I installed the summit driveshafts drive cup on the lst diffīs output for the center without pictures, I assembled everything and forgott to take pictures... I will upload some pics If I have to deassemble it for some reason. All I can say is that I made the summit shaftīs output to fit in the Lst diffīs cvd output....
I also drilled up my pro-line 23mm hubs to fit the 8mm axels, Iīm just using a screw inside the stub axel ta make the hub stay on the shaft:
Iīm using a screw in the front too just to make sure that there is absolutley zero play:
Finally I added a savage engine head protector to really make sure that no electronics gets hurt on those upside down landings
I have now driven the truck for several hours and all I can say is that it was very well worth the time and effort. Iīm using a completly locked slipper ( not just tightned down the nut fully ) and Iīm doing drivetrain abusing stuff each and every day and itīs just keeps coming back asking for more. I have noticed that there is ALOT less slope in the drivetrain and the wheels so that is a big plus.
I donīt like the mods to the knuckles or the need of tape in the rear knuckles, I will try to use some tekno carriers instead since they use dual 8x16 bearings, that should do it.
:Edit: Just saw that each tekno carrier is using only one 8x15 bearing and then the stock 12x18.....But Iīll solve it.
I want to say thank you to Mistercrash for all the great info he has given us all here at the forum, that information made the whole process go alot easier.
So Thanks Mc.
Thats all for now
Last edited by Manne; 01-18-2011 at 12:50 PM.
Well, a few things have happend since last time I wrote. My thread has hopefully come back to life and hopefully all pages with all the information and pictures are here. Pleas send me a Pm If you see that something in the thread is missing or lost.
The truck has now lived trough about 35hours of ABUSE and the carnage list looks like this:
1 Stock knuckle split in half.
1 Lst cvd Bent like a banana.
1 set of Internals in the rear diff blown.
2 Escs smoked.
I must say tho, I am very very pleased with the result of the diff swapp, the stockers wouldnīt survive one hour of the type of driving that these babys has gone trough.
So, why did the rear internals go?
1, to thin diff fluid wich lets the diff unload one tire like crazy.
2, the unloading made the planetary gear nearest the outdrive inside the plastic cup eat some of the plastic in the cup.
3, The lack of "wearplates" ( see pic )
That made the mesh get a tad looser and the internals stripped.
What to do about it?
1. buy new stock internals, a new plastic cup, and thicker oil.
2. buy new stock internals and shim them.
3. buy savage internals wich has a thicker base on the big internal gears wich will make the gearmesh tighter.
I will ofcourse try the Savage route, I have already ordered the gears
The big "shims" is what I call wearplates, they are between the diffcup and the big internal gears:
About the bent cvd.. I think It got bent because I got a straight hit from a savage from the side right on the rear wheel. I think the a-arms flexed and the driveshaft bottomned in the diffs output and then had to take all the force from the impact. Itīs not a big deal, I drove it bent for a long while before I noticed it... I just bent it back, it will do until my new lst cvds arrives
About the escs...sad story.. The esc itself is great! The first one worked for around 25hours, the second one about 3hours... And I have now driven about 7hours on the last one wich is still working fine, the first two were killed by moist and water. When I removed the plastidip on both of them after they smoked I found alot of water inside the plastidip layer...
So now Iīm using a new better method :
Ofcourse I have made some Improvements to the truck too
I thought that the battery "boxes" was nice and durable but waaay to heavy ( almost 800grams..) So I decided to moke up some new ones. I made them out of plastic cuttingboards. It turned out great and the weight difference is like day and night!
I also bought a new body, I donīt really like the looks of the summit body but Itīs durable...And that is whats most important to me
And here are the pics I talked about in the lstdiff install section before of how I attatched the summit shaft to the lst diffs:
That is pretty much everything for now, Iīm going to place the 5s order the 26th when I get my payment
Happy bashing everyone!
Great thread you got going here Manne!
Your really need to film some of that crazy driving of yourse
this is alot of good stuff to use when i break stuff, im usually to lazy and just buy new stuff, sucks because my truck just sits as i wait for parts
Manne I love your truck and that you make due with what you have at hand. When I first seen all the steel on it I didnt like that too much but you redeamed your self with the cutting board. The next best thing would be some 1mm carbon fiber, ya it seems thin but carbon fiber is ultra strong for its propraties it should hold up even to your bashing standards.
Im with Ola we need some vids!!!
Cads, Insane RC, PWC,and BOAT CORNUCOPIA
Thanks alot guys Iīm getting excited to do more when I get comments
this is alot of good stuff to use when i break stuff" That is the main thing with this thread, to let other people see what fails on the truck and show how to fix it.
About vids, I will do some filming with the rest of the "crew" as soon as the snow goes away right now we have about three feet of snow... So Iīm not able to do some good driving in the sandpits right now..But there will be vids later on.
About the carbon, I have really thought about it but Iīm not sure if Iīm up to it, maybe I should get some and try... it would be nice to have!
Besides the carbon, what is my next step in modifying? I canīt really see anything that has to be modified, I just see a few parts that I should buy..
Since the Hcr fullskids are really hard to get I will get this stainless steel one:
And then some Rpm knuckels with steelrings for the front.
Titanium hingepins ( just because they are lighter )
Some 1/8 23mm hubs from cen or something similar instead of my drilled revo hubs.
Is it finished then?
But itīs no biggie Correctly shimmed and no full throttle landings with a screwlocked slipper will prevent this
Fantastic thread, fantastic pics, fantastic write up
Hey I love everything your doing and you creativity is bar none awesome. But I would like to say something in regards to you breaking ring gears and diffs so often. Its absolutely 100% happening because you are running different size tires up front and back. Those paddles in the rear are spinning slower(because they are larger) then the tires up front causing a great amount of pressure to be exerted on your drivetrain. The motor may not see any result of the tire size difference but your diffs seem to be taking the brunt of it. Its the same reason why you have to run same size tires on a four wheel drive truck or SUV or AWD car or two same size tires on the rear of a rear wheel drive vehicle etc. For example if you have a front wheel drive car and you get a flat tyre up front and you use your spare, the spare is of course smaller in size then the stock tire. Do not put that spare on the front, you'll have to go through the headache of taking a rear tire off thats the same size and installing it on the front and installing the spare in the rear where there is no power from the drivetrain(front wheel drive). Same applies to an AWD RC car like the E revo, especially one with a high powered brushless system running on LiPos. Try using 4 of the same size tires for a day of real hard bashing and see how your diffs hold up
Last edited by crf450ish; 02-24-2011 at 10:21 PM.
Thanks alot! And thanks for the input, but here is the thing:
I am well aware of drivetrain issues related to running different sized tires, I only use paddles in the winter and Iīm using slightly bigger tires in the front, this makes the front and pull a little bit more then the rear.
The pro-line paddles are "onedirection" paddles, wich means, they only have traction in one direction, they are like slicks if you break or try to go reverse, they or so "nogrippy" that I canīt go in reverse with only rear wheel drive...
And my front tires are worn out mtrīs so they arenīt grippy either. I canīt see how this possibly could affect the drivetrain bad in any way, I have been running this setup in the winters for many years and havenīt had any problems .
If this was bad for the drivetrain, then the front diff would go bad since itīs pulling more due to the bigger tires in the front, but itīs not, itīs always my rear diff .
And nine of ten diff failurs have happend with either my truggy tire setup wich is exatly the same front and rear, my mtr setup wich is also the same front and rear, or my stock tire setup .
BUT! It was a good call, If I was running this tire setup on tarmac it would be bad
Manne, how do you like that esc? Temps?
I did EXACTLY the same today.. But on a front diff... Rpm arms, XXL diffs, XXL axles.
I was jumping 35-40ft long, 10-15ft high and took some hits at acouple of bad landings hehe..
I think it might be due to axles being TO deep into the cups.. When the A-arms flex alittle, on a sideway hit, the axle pushes into the bottom of the cup and break the gear inside the diff.. Not 100% sure though.
I like it alot, itīs cheap, itīs durable, keeps performing each and every day, temps are good. Itīs rated for 6s usage, I wouldnīt run it on 6s tho..But I wouldnīt run a MMM on 6s either so..
Oh man that totally sucks...... Itīs possible that itīs the cvds bottoming in the cups making the gears to break BUT I think my gear cracked when I just landed on full throttle during a backflip, It was in my front too, and my gears was totally overshimmed at that moment, they were shimmed so tight that the diff was completly locked...
How ever, here is my small "recipie" of my internals that has worked well so far .
Iīm using four 0.1x3x10 shims and one 0.2x6x15 shim ( didnīt have the bag for the small shims..):
I use the four small shims behinde each of the four small gears of the internals:
And Iīm using the single big shim between one of the big internal gears inside the diff on the bottom of the plastic cup:
Everything in the cup:
And Iīm Skipping the blue gasket in order to get the gears to have a tighter mesh:
The reason of why Iīm not using the blue gasket and why I shim behind the four small gears is the fact that you canīt fit any more shims under the big internals, the outdrives just wonīt allow it, they are too short and you wonīt get the small pin in the outdrives that goes inside the two big internal gears..
You might be wondering, "why doesnīt he use a shim under the big internal on the ringgear side?" well... Same thing there, there isnīt enough space since Iīm using a shim on the outside of the ringear between the ringgear and the bearing to get proper mesh between the ringear and the pinion.
The best case scenario would be to have slightly longer shafts on the outdrives ( maybe hpi has some, I will check as soon as my new truck comes in ) to just shim behind the big internal gears.
I donīt like to shim the small gears ( 0.1 is fine tho ) because the gearmesh will get really really bad even on 0.2 behinde them due to the "edge" on them that will go into the big internal gears if you shim the small ones too far in.
Itīs also important that you have that Big shim in the bottom of the plastic cup because it will help the cup from wearing down, this was what had happend the frist time my internals went, on hpi diffs, ( even in the aluminium cups ) these "wearplates" comes as a standard from factory.
Now good luck everyone with Lst diff troubles!
I`m having alittle problems understanding why this shimming will keep the sun gear from breaking? If it was stripping i would understand the shimming.. But a sun gear that breaks in half, together with the hex pin behind it, sort of tells me otherwise..
I rebuilt mine to stock specs (with traxxas stubs and rcm cups) again, so it will be interesting to see how long they last this time. And for the experiment of it, i left them both as tight shimmes as they came from factory (ring/pinion), even though it feels alittle on the tight side.
Lucky thing i got a Flux on the way, as a second truck.. This way i can keep up the crazy driving, while waiting for new parts for one of them hehe.. Got one used, with a big box of spare parts and some hop-ups done to it..
So am I understanding correctly that the lst diffs are busting bc the steel axles are binding on large jumps and getting slammed against the diff? Would using the summit shaft keep this from happening?
I'm about to do the mod. . . If it works correctly.
Thats my theory atleast. And the summit axles would prevent that indeed..
But i THINK this goes under the category "_everything_ can break".. So it might not be a big problem, i dont know yet.
Iīm with ola on this one, but donīt get scared, the diffs will hold up 100 times longer then the stockers. I can promisse you, Itīs worth all the effort.
You are right, I got fooled by my own brain . I thoght that you also had the problem of the gears stripping...My bad.
In my case the gear snapped due to the overshimming as I said before, when the gears was forced to move ( landing slightly on one wheel on full throttle ) It just had to let go and work like a unlocked diff and "snap" there goes the gear. I had them overshimmed because they slipped before and I didnīt have any shims in the right size...And really wanted 4wheel drive. It lasted long enough for my spares to come so it was worth it
Nice! Show it to us on Rcm when you get it!
Haha isnīt it funny? I also ordered a flux last week Not a complete truck tho, Iīm building it up from something that looks to be a bit less then a roller. I will use some stuff from the E-revo: gearbox, 23mm hubs, wheels/tires, reciever, esc etc, should be fun
Ola, how much slope do you have between the rcm drivecup and the bearing on the diff? I just thought... If you have a mm or two (even less might do it) might be the reason of your cracked gear? Pleas tell me that you have slope, Then I could just get the rcm cups, cut some stubs, shim the diff internals like I want them and then shim the outside of the bearing, between the rcm cup and the bearing, and your problem would also be solved by shimming between the drivecup and the bearing.
If we did that the plastic cup itself would crack ( one of mine actualy gave up in a way like that.. the metal insert in the plastic cup was pressed loose and pushed further inside the cup and made me snap one of these little pinns.... Iīm glad the pin snapped and not the gears again..), Then we would just get some 7075 alu cups and problem ALMOST solved....
We still have to deal with the issue that the driveshafts will look like bananas....... So the next impossible step after that would be to make the lst shafts into slidershafts
Gaah, itīs always something that is impossible to cure with the revo......
Last edited by Manne; 03-14-2011 at 06:54 PM.
sweet thread .. keep em coming dude