So I previously posted this in the pic thread;
So the car has sat around needing a few bits and pieces. Steering servos work but the clicking sound given by them indicates there are some teeth likely missing, the torque with the Big Joes is also lacking. Sick of the toe rod ends coming out. Hinge pins are all bent which prevents arms moving freely. It's all been annoying me a bit so I went to buy some parts to repair it but being in Australia and parts taking forever to get in I figured stuff it, I'm going to hit the whole thing in one go.
On order now;
FLM Hybrid bulks with 1/8 diffs
FLM Aluminium chasis (non-LCG, I don't like the way the batteries sit in the LCD)
Savox Brushless 'Monster Torque' servo (2270SG from memory) (444oz/in @ 7.4v)
Castle Creations 10amp BEC
Lunsford Titanium hinge pins
4 x Black RPM A-Arms
Front and Rear Traxxas Aluminium Toe Links
I'll be getting some new pics as I do this also.
like the wheels
Nice list! Spent a few bucks there!
what are you using for a servo saver? those big tires and torque will eat the stock plastic one, I keep wearing mine out and the steering gets sloppy.
Yeop the stock servos are pretty well toast, they barely move the tyres. The stock servos are adequate for the car in standard form but not after a few upgrades as the car gets a bit heavier and the tires themselves get heavier as well as having more surface contact to deal with.
The stock uses 2 servos rated at 125oz/in. The servo that will be going in will be a single brushless servo rated at 444oz/in @ 7.4v. So I'm going to be running a BEC this time around.
[Edit]Oh sorry servo saver, I will cross that bridge when I get to it. I have never really bothered to get into the steering linkages and components. I will suss it out when I have it all apart and look for the weak / potential problems and go from there.
Did you have to adjust your steering endpoints with those rims to avoid them hitting into the suspension arms?
Always get a 2nd Opinion!
Suteki...nice to see you back. Hows Gladstone treating you? I've just built myself an eSlayer...SC race truck are a bunch of fun .
Rock n Rolla !
Mugs - never had a problem with them hitting the rims. I did adjust the end points when I switched over from the standard receiver to the Futaba but they've never been a problem to be honest. Mind you I have 6mm offset on each side of the truck because of the extra length of the axles from the Losi XXL cvd's. Rather than machine a new hole back toward the tekno carriers, I just shimmed the 6mm difference to the hexes. Gives the tires more room and a wider track for the car over all; the truck doesn't tractional roll at all anymore, it either kicks up the inside back wheel or slides. Before that it would just roll all the time but with the extra wide tracking plus the width added by the extra offset of the 40 series big joes themselves, it's never been an issue.
Craig - ****ed busy. I work 5-6days a week, 11hrs a day so while I have more more to put into the car (which I didn't before) I don't actually have a lot of time to do anything. Member at the local 1/8 offroad track so I can use it anytime I want and the major class is 1/8 buggy, both EP and IC, so I picked up a Mugen Eco with Tekin combo and have started racing that. Only one race a month unfortunately but that's probably enough with work. Took the Emaxx down there once but thats when I stripped the a-arm / pillow ball and the constant rod ends coming out just got worse especially over the jumps, hence why I'm not jumping on getting it all done.
No real short course class though so I dunno whether to sell or keep it. Runs beautifully, can beat some of the 1/8 buggy guys with it. But yeh, no actual short course class except younger ones with 2wd brushed and and mild brushless, so a 4wd with 4 pole 4600kv isn't really a fair comparison.
Nice build! Those wheels are sweet! I had the same problem with my rear links that you mentioned. Have you considered going with the RPM true-track for the rear? One less thing to worry about. You are going to love the FLM goods!
Slash BL-Pede-E 4Tec-FLM EMAXX-Wraith-AX-10-SCX-10
Considered the true track but I can't be bothered modifying another set of axle carriers to fit the LST XXL driveshafts so I will just stick with the toe links, worse case scenario if the rod ends start coming out again, I'll glue the stupid things in.
Might make a video of the conversion as well that just covers some of the basics. Always seems to be a 'bought my Emaxx, what do I need to upgrade?' so I will film some of the work I do and explain some of the things I've done and why I've done them etc to make it easier for others.
I've got my a-arms, toe links, servo and BEC so now I'm just waiting on the lunsford hinge pins and FLM stuff before I get going. Unfortunately the last lot of FLM parts I ordered took a while to get from memory so I am hopinh they arrive faster this time.
Alright so all the parts have arrived. The parts I ordered all came a few weeks ago (mid Jan) but the FLM hybrid bulks and chasis didn't show up till this week so last night was the first chance I got to really work on it, started around 9ish, finished up around 1am and been at it since about 4 this arvo till 10 tonight.
Biggest problem so far has been the differentials which I pretty well expected. I really do not like the way Hot Bodies (I assume these are the hot bodies they use for the diffs) are assembled. They don't feel anywhere near as solid, smooth or are as easily put together as the ones in my Losi SCTE or my Mugen Eco. Having to use the paper gaskets to get the right amount of clearing on them to get the gears to mesh correctly was a real pain. Even at it's best the diffs still felt a little notchy, yet too many would result in the gears not contacting or contacting every now and then while too little and you couldn't even turn them. My ECO's and the Traxxas diffs were / are much smoother. I eventually got it sorted but still not as good as other diffs I have had to work on which was very trying as I A: hate working on diffs because they are so fiddly and B: taking the crown gear on and off the diff cup so much got old really quickly.
Eventually sorted it out. Front diff was a perfect fit once inside the bulkhead, no additional shimming was required, mesh was excellent. Rear diff was another story, heaps of play from side to side and the ring / pinion gear were barely touching leaving a lot of slack. Being that getting a shim (especially such an off sized one) would basically have required ordering from the states and I was sick of waiting. Thankfully I did have some nylon washers, 8mm ID / 15mm OD / 1mm thickness. I was able to dremel the inside of them out to about 10mm ID which let it sit on top of the hot bodies out drive just enough up that I was still able to fit the outdrive through the diff cup and put the capture pin in. With that washer on one side, and the supplied shim on the other, I got a really good mesh with zero side to side play.
Thus far that has been the hardest part, simply making sure the diffs have fit snug and are assembled to spin as freely as possible while eliminating any play. Actually hard is probably not the word, maybe it's 'trying' part as it's very time consuming to get it all done correctly and needs a lot of trial and error particularly as the diff cup needs to come apart every time to check the mesh when changing the number of diff gaskets to get the internal gears to mesh well. In the end it all came up brilliantly. Went with 10k front and 5k rear.
I hear you on the diffs. I just spent hours and hours building some for my roadmaxx. It can be quite time consuming. I Used a bunch of different parts so everything had to be modified. Grinding gears ect. to fit. Your truck is definetly a monster. Looks Nice!
Yeh it's getting there. Front half of the truck is done so far as bulkheads / diffs on, steering linkages, axle carriers and arms, front bumper are all put together, transmission is in.
Tomorrow I will fit the arms and carriers to the rear bulkhead and attach it to the chasis. Then I have to get the electronics up and running then it's small things like body posts and battery straps. Will be running the monster torque savox servo via CC 10amp BEC so I can output at 7.4v giving the servo 444oz/in torque. Shall be interesting to see how it moves the big joes compared to the 2 x 2075 traxxas servos which had 250oz/in from memory.
I would order the right shims as I think nylon might compress over time. Kyosho 96647 10x12mm
Sounds like a lot of work!
Last edited by 50togo; 02-09-2013 at 10:14 AM.
Yeh I will probably order them at some point but I don't think the nylon will compress, I'm more worried abour friction heating it up and causing it to explode in the bulkhead case.
Will find out at some point I suppose.
Then you can upgrade the diffs if your not happy with them
Lot of force against them but I would have thought flm was more precise. Mine was a pain from the beginning.
They told me I needed their thick aluminum shims and extended shafts. So I waited for those -finally arrived one side needed one the other side it was too thick. Put their extended shafts in and wouldn't work with the newer axles. Had to open up drain the oil and make my own from traxxas 5454 shafts
If down the road you do decide on different diifs the stock diffs are wider than newer diffs
How are you going to wire the bec. I ran 6v to the esc and 7.4 to the servo
Last edited by 50togo; 02-09-2013 at 10:27 AM.
So it's pretty well done mechanically, just most have to get the BEC all soldered up to the power.
50togo: BEC comes with - / + connections to power from ESC / Battery connection. Then power from that straight into the RX. Orange or in some cases White from ESC goes in normal but you don't run the - / + to the RX from ESC, just the information cable as the power comes direct from battery, to BEC, to RX as opposed to Battery to ESC to internal BEC to RX.
If that makes sense.
I was just wondering if you are planning on running 7.4v to the esc and servo. Or just to the servo
You know I'm not sure now.
I had 'assumed' (and you know what they say about assumptions) that if I ran the BEC from the battery to the RX @7.4v (via Castles instructions), that it would send 7.4v to the RX (Futaba R614FF) which would pass that onto the servo to the servo going at high voltage but I'm not so sure now......I need to make sure the RX won't some how adjust that voltage down to 6v. I can't imagine why it would but I'm not as positive about it as I was.
Running 7.4v straight from BEC to receiver and onto servo. Works great. Got it together and got some shots.
........and that's where the good news ends.
Tried to take it for a drive and there is something very wrong with those diffs. They were cracking really bad. When I turn one wheel it binds up badly.
Before I assembled the diffs it was a problem, eventually I got it to a point where it would move smoothly in my fingers but for whatever reason it's not locking them up, so I am pretty well expecting to pull the diff apart and find nothing but shredded metal.
I used half of the gaskets that were provided when I put them together but maybe it needed all of them, however when I did use all of them it didn't seem to make enough contact. So I dunno, these gears in the diff cup are the most painful ones I've ever had to work on. Never had this problem with other gears, cup and gears didn't need extra gaskets etc to mesh correctly, these apparently do and they seem fickle about it.
I believe I have found the problem, ride height.
With the ride height I have, coupled with the out drives, the dog bone was binding up in the out drive and I believe this is what caused my problem. Basically one of three things was bound to break;
A. Dog bone
B. Out drive
C. Differential gears.
As I would have guessed, the differential gears were the weak link. I pulled the rear diff apart and checked the inside gears. Absolutely had it. 1 tooth missing from the larger gear of diff cup attached to outdrive, while other larger gear in diff cup attached to the other out drive is missing 2. Both floating around somewhere in the cup nurling up the smaller planetary gears. No need to pull down the front diff to guess what has happen with that one either.
I used the provided diff cups with the FLM instead of the traxxas ones because it did fit more snugly and allowed me to screw the pillow balls in further to the arms, which no doubt increased the problem however I did this because one of the reasons I had to buy new arms to begin with was that one had A-arm had been stripped from the pillow ball.
Looks like I'll go back to the traxxas out drives as they have a more curved outter rim allowing the dog bone to articulate more.
Basically I want to try and keep the ride height as I prefer the stance like that but looks like I may need to drop it down if I can't get the articulation right.
Also, does anyone know what the part number is for the differential gears inside the diff cup? Looking everywhere but can't find it and RC Monster I can't post on until they activate my account which who knows when it will be.