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Thread: E-MonsterTorque

  1. #1
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    E-MonsterTorque

    I have a Stock 3905, and like to do something with it, without spending another small fortune.

    So I come up with the idea to make it a monster torque machine, not a crawler, don't want it to loose it's maxx identity, but plenty of power to crawl on very tough terrain and have enough puling power.

    So far I have:
    • 3905 stock E-MAXX
    • Dual tower pro MG995 servos (200oz each)
    • Yellow EVX2.
    • 4 six cell NiMh 4200 sxs
    • Gemini Talon tires.


    I'm getting:
    • Dual Novak 55T crawler motors.
    • 2 revo spools.
    • Longer shock rod ends to give it a little more travel (any ideas?)
    • A hummer or jeep body.
    • ...put your great idea here...


    The motors will be wired in parallel also 2 of the batteries to run 7.2v. It wont be fast, I know, i think 12/68 will pull a wealth of power.
    I'll leave the tires for another time, I'm not building this for any particular purpose, they can wait until i found one
    So Let me now what do you think.

  2. #2
    RC Turnbuckle Jr. rjm2519's Avatar
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    You would be better off IMO getting a slow torquey motor with more heft like a kershaw 970 or two. They have gobs of low end torque and if speed is not your thing smaller pinions are available. Also your going to need more suspension travel one way or another to be more capable of crawling up uneven surfaces possibly using longer shocks or 1/8th scale shocks.

    Also you may want to consider the two speed conversion to help with extra control and torque and also to be able to have short, quick blasts when necesary.

    http://banebots.com/pc/MOTOR-BRUSH/M1-RS550-120
    this motor may also be a good option and you can probably get away with stock pinions especially with the 2spd conversion.
    Donít handicap children by making life easy

  3. #3
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    Those 55t Crawler motors are awsome. They are terrible for a basher but AWSOME for a crawler. You will want the 2 speed conversion. With it you can get the wide ratio and gear it for both crawling and quicker speeds for bashing. No question about it, upgrade to 7 cell packs. If your running in parallel, 8.4v is pretty much necessary. Honestly, stock 21t Titans aren't terrible crawler motors when you gear them down and run 14 cells.
    The answer is no. And yes, mine is faster.

  4. #4
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    Thanks but i have a little dilemma, I don't want to spend more than the cost of a new vehicle ($300), this will keep my build as low as possible so the 2 speed conversion kit and the 7cells are out,I have to work with what i have.
    I think, not knowing, that the novak 55's are motors design for strong low end torque, and the KD for speed, also there is a KD 970 mounting issue, Novak's have standard mounting holes. I don't need another motor plate.

    I'm tired seeing my stock 3905 sit on the shelf all the time, so i started this project to see if I can get this truck to get some use. for speed and pure bashing i have my FLM-RPM MAXX and for racing the 1/10 buggy. So I needed something in the low end, so speed is not important, also don't want bashing speed. all plastic maxx wont last with my driving style
    Last edited by jefierro; 09-14-2008 at 10:51 AM.

  5. #5
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    It's Done.
    Ordered:

    • Traxxas Spool T-Maxx (I.ll use my old 3906 diffs, already have one spool)
    • HPI Jeep Wrangler Rubicon Body
    • 2 Novak Fifty-Five Crawler Brushed Motor
    • 2 Maximizer Zero Offset 12-Spoke Beadlocks Black 17mm
    • Maximizer 17mm Adapter Composite Maxx
    • Maximizer Rock Rings Circle/Slotted Red

    $195.67

    I almost ordered some dirt claws but the shipping price just got to high. maybe i'll find some at my LHS.

    Question, is it possible to unglue the talon to recover the tires by boiling them? or it will damage the rubber?, how about the foam inserts? will they survive?

  6. #6
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    Yes you can uglue youre talons that way.Youre chrome is more at risk then the rubber.They onely need to be in long enough to warm the ca up.Id say 1.5-2.5 min and that should do it.The chrome should be ok.But if you leave them in to long the chrome will fade/chip off.Wait for more replys about it though,I have never done it.But have read up on it a few times.Foams will be alright also.Just make sure theyre dry before reinstalling them.What gearing are you going to use?
    youre not offroading until you go muddin!

  7. #7
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    what about this motor? any good for rock crawling??

    http://banebots.com/pc/MOTOR-BRUSH/M1-RS385-72

    If not, why?
    I was anti-obama before it was cool!

  8. #8
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    Its too small.
    The answer is no. And yes, mine is faster.

  9. #9
    RC Turnbuckle Jr. rjm2519's Avatar
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    Donít handicap children by making life easy

  10. #10
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    CIM motors or Cascade Induction Motor are use in robotics and mission critical applications, for what I could understand googleing, "a reliable and controllable motor or generator."
    I don't have the slightest idea of their capabilities or applications in RC modeling.

    Nominal v: 12v
    No Load RPM: 5280
    Stall Current: 115A
    Kt: 3 oz-in/A
    Kv: 440 rpm/V
    Efficiency: 74%
    Last edited by jefierro; 09-16-2008 at 01:53 AM.

  11. #11
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    The build

    Okay to save 10 bucks I decided to use my old 3906 differentials, already had one spool so only need to buy one, also revo spools where out of stock at the time. and my FLM-RPM maxx needed new diffs.
    I removed the old diffs from my 3906 and notice the diff shafts where different lengths from the 3905, so a simple shaft swap did the trick.

    Here the shafts are already swapped to the left 3905 difs and 3906 to the right



    The only problem, the 3905 shaft in the 3906 housing didn't have enough room for the central half shafts yoke. Now enter the dremel.




    Now to make room for the yoke, cut 2mm of plastic



    Voila...




    Now I'm ready for the package to arrive.



    My wife is going to love this.



    Next I'll try to unglue the revo gemini's, but I noticed that the tire beds are different from normal, say proline tires, Actually they have no bead at all, just a long strip of tire rubber, I don't know if they'll fit in the new bead locks.

  12. #12
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    Well Made 3 out of 4, I failed to recover one of the gemini tires.
    boiled the tires and remove the wheels, all but one, my guess to damaged tires to begin with. so I'm off to the LHS.



  13. #13
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    Im' back from the hobbie shop and found a set of HPI Super Mudders. Very nice aggressive look. But only found them premounted, so I'll give the boiling another try.

    I'm starting to plan how I'll should connect the hole thing.

    Option 1
    Connect the motors in parallel as the original motor wiring of the evx2 and use 2 batteries also in parallel to give each motor 7.2v, Using the BEC side and a parallel harness for the batteries.(dual parallel batteries are for equal weight distribution and added weight for traction) Or

    Option 2
    Connect the batteries in serial for 14.4v, also the motors in serial to divide the voltage to 7.2v for each motor.

    which should yield better performance, or should I return to highschool?

  14. #14
    RC Turnbuckle Jr.
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    I'd stick to wiring the motors in parallel, and the batts also for more runtime and less speed.

    Im amazed how easily stock-type tires fall apart; my big fat jumbo tires have been torn off the rims so many times, yet they are in almost perfect shape....

    Im also highly interested in those 3905 pinion gear shafts from the diffs- they are alot shorter arent they, which is probably why so many people say their center cvds dont fit properly- if they switch to the longer 3906 pinion gear shaft, that should give them the extra few mm they need; or just buy longer drive cups I suppose (traxxas engineers, ya takin note I hope?)...
    READ THE FAQ!
    or else.....

  15. #15
    RC Turnbuckle Jr. rjm2519's Avatar
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    Wow that is a nice record of your build I had no idea what the diffs looked like inside and was a bit worried of taking them apart but seeing it open it really is quite simple. Please keep the pics coming they are very helpful for those of us who have not had the pleasure of digging into our maxx that deep yet.

    I second the motors wired in parallel your not going to split 14.4v as easily as you put it together.
    Donít handicap children by making life easy

  16. #16
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    Quote Originally Posted by Suicideneil
    Im also highly interested in those 3905 pinion gear shafts from the diffs- they are alot shorter arent they, which is probably why so many people say their center cvds dont fit properly- if they switch to the longer 3906 pinion gear shaft, that should give them the extra few mm they need; or just buy longer drive cups I suppose (traxxas engineers, ya takin note I hope?)...
    That is correct.The 3905 pinion works with the sliders,but cvds have clearance issues.I use 3906 pinions on my 3905 diffs.Lined it perfectly .
    I was worried about the mesh at first.If you look at the teeth on them both,you can tell the 3905 pinion is shaped a lil different.But I had no mesh issues using 3906 pinions.I had trouble finding longer cups,maybe I didn't look hard enough.

    To anyone thats geting confused,this is about using 3905 diffs in a 3906 e-maxx stock chassis.I don't have any aftermarket chassis(FLM.HCR etc.) so I don't know how it works with them.
    Last edited by mudshredder07; 09-18-2008 at 02:10 PM.
    youre not offroading until you go muddin!

  17. #17
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    Yesterday a brown truck left this really big box in my office, oh! boy, oh! boy!!

    Installing the last spool.



    Building the bedlocks, didn't needed the spacers. for smaller beads.



    oh! may, what big tires you have!



    Now too the motors, twin novak's 55T





    First try of the Rubicon body, still deciding about the final color.



    Building the parallel harness, no biggy here just a parallel harness!
    without fear or regret I chop off the other evx2 battery input



    Last edited by jefierro; 09-19-2008 at 09:05 AM.

  18. #18
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    Almost done now.





    Finished late yesterday so only tried in the house, climbing my son's toys, books, and other stuff. indeed a torque monster, and ice cold. This is going to be a nice setup, I though it would be slower, but it has plenty of speed, just that the AM stock radio is glitching a bit.

    I might reconsider the 2nd speed kit for it, also will give a try at building 7cell batts from the 4 six cells. i don't think I'll be needing 4 batts 2 lasted over 30 min and didn't totally discharge them. so i should be good.

  19. #19
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    The monster is now crawling.

    It's Done, or at least is crawling. I Just have a blast with my son and nephew on a dry small river with the torque monster, definitely not a rockcrawler but much better performance than stock. I liked the scale looking performance.

    Is getting a bit hot, 145į but on a 45min long run running over obstacles, over obstacles continuously. definitely the 2nd speed is needed. also i'll like to use some lipos to see if it takes more amps.

    So here is the final product.







    And some video:

  20. #20
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    up close and personal. Here is a more detail video.


  21. #21
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    need more torque

    I plan on modding the tranny using parts from the 3905 second speed kit. not the hole kit as the drive dog carrier will create gear play between froward and reverse. and it's just $10.00 in parts
    I plan to do this

    this is the stock transmission.

  22. #22
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    Waouh I love the look of your EMT Original project !

  23. #23
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    thanks popoxx, actually I'm starting to like this maxx allot. is nice to slowdown sometimes.

  24. #24
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    Small big improvements

    Still waiting on the lower ratio gearings for the tranny, but made some mayor improvements with small upgrades. Amazingly this little upgrades did a big improvement over the ability to climb.

    I cut the tire foams in a gear pattern, didn't want to "flatten to much the tires with a star pattern as the crawler community does. it worked grate.
    Next I removed the 3905 servo saver and install an old steering horns from my 3906, this give by far the best performance, now the steering helps the climb.

    I'm really amazed how this project turn out, with some little upgrades I made a hole new and different performance maxx.







    The motors are still getting hot 164įF on a full hour of hard climbing so I put this heatsinks but without air flow they won't help much, I need to lower the ratio simply they are pulling to much amps. but at 68/12 the only solution is to modify the tranny

  25. #25
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    Update:
    Installed the wide gears, w/o the 2nd speed kit. needed a little dremeling the output gear




    Now at 68/12 it makes a stupid 81:1 reduction. So now is official I created a MonsterTorque. Lol this thing can pull me sited in my chair.
    Don't believe me? look what happed to the shaft when I went to the rocks.





  26. #26
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    I've seen the old 3906 Maxx axles turned into spaghetti, but never a 3905's. HOLY COW!
    Traxxas: Stampede, E Maxx
    Losi: Muggy

  27. #27
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    Awesome thread. Keep it up.
    Faster Higher Longer Harder
    youtube.com/BisMaxx ē

  28. #28
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    Quote Originally Posted by jefierro
    Update:
    Installed the wide gears, w/o the 2nd speed kit. needed a little dremeling the output gear




    Now at 68/12 it makes a stupid 81:1 reduction. So now is official I created a MonsterTorque. Lol this thing can pull me sited in my chair.
    Don't believe me? look what happed to the shaft when I went to the rocks.





    i haven't even done that with my hv 4.5 lol very impressive.
    Man i need more than 50 characters.

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