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  1. #1
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    Question Velineon 3500 Magnet loose

    Hi,

    I have a Traxxas slash with the slipper clutch locked very tight. After a while the magnet started spinning on the shaft. Took the motor apart used epoxy resin and fixed it. Two runs and it went loose again. Bought some JB weld and fixed it again but never tried it out because in the meanwhile i got the Novak Ballistic 550 6.5T sensored (which works fine with the VXL btw in sensored mode) and put that one in. Few runs and same magnet came off. I will rty the same fix anyway but is there anything that i could do to avoid this? Thinking of replacing the slipper with a center diff (hate the slipper very hard to get it right and only for short periods)
    PS Tires are IMEX 5.5 but the first time happened on 3 inchers (stock) and i run 12-13/54-nothing crazy
    -Ran on grass and tarmac
    If you had similar xp please advise
    Thank You
    RGS Syl

  2. #2
    RC Turnbuckle Jr. JimmyNeutron's Avatar
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    What does the motor temp out at while you are running it?
    Whatever it is I just typed... could be wrong.

  3. #3
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    I use a 550 radiator (no fan) and still can put my hand on it. I didnt measure it but i gues in the range of 80C-it should be OK. I know that high temps can affect the glue in between the shaft and magnet but i don't thik thats the reason. Motor mount plate and slipper cluck mount are all upgraded to aluminium which helps even more the cooling.
    Last edited by sylmarils; 02-08-2014 at 12:50 PM.

  4. #4
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    How old is the slipper? That could be why its not staying.

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  5. #5
    RC Turnbuckle Jr. JimmyNeutron's Avatar
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    If I understand your post correctly, two different motors had their magnets come unglued... chances of that happening due to motor manufacture issues on two different brands is very unlikely. This is why I am thinking it is an outside cause... but I am not sure what would cause it.
    Whatever it is I just typed... could be wrong.

  6. #6
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    A really tight slipper clutch puts a lot of stress on that motor.

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  7. #7
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    I think so also but not sure what exactly. As i said the clutch is blocked so im thinking that it could be usefull to upgrade to a center diff. Maybe forgot to mention is a Platinum build. Anyway thanks for all the advice

  8. #8
    RC Turnbuckle Jr. El Sob's Avatar
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    I have had slipper clutches locked down so far that the pin that holds them in place has bent. Heat is the only reason I have ever heard of motor shaft separation. Have you pulled your truck apart to see if something is binding? I have had hair behind the wheel hex that caused a lot of binding.
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  9. #9
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    I will have a look and take the diffs apart if needed. They seem to go smooth anyway-no more than normal.A 550 motor has alot of torque-was the reason to upgrade+sensored. I wonder if the core (magnet) is getting hot too quick and by the time the outher part of the motor gets hot to cool down its allready sepparating. Anyway ill give it the JB weld threatment. I understand it can withstand way over 250C. Definately going for the center diff-i suspect that the locked down slipper and big tires is a killer for any motor. I will update once i use the JB and see how it goes.

  10. #10
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    Not sure where you got those numbers lol but it is most likly that your stressing the motors with a tighted slipper it like running it just straight from wheel to motor stopping and hard accelating will deglue your motors and getting over 160 is ussaly bad but it is where you normally want to stay with your motor but hey i could be wrong!

  11. #11
    RC Turnbuckle Jr. El Sob's Avatar
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    I have had a Novak. It was a 5.5 SC.it is basically the same as the one you have. I never had any problems with heat with it. Do you think your gear mesh could be too tight? This has me thinking a lot.
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  12. #12
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    You said it was around 80C which would be around 180F which is running hot! Without a temp gun you really cant be sure of these numbers they could be anywhere from 160F to 200+

    You need a temp gun to access whats going on then you can proceed from there

  13. #13
    RC Turnbuckle Jr. El Sob's Avatar
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    180 is the danger zone! If you run your truck too many times at that temperature, the motor WILL fail! I didn't think to do a conversion of the temperature. How are you gearing the motors? That may be your problem.
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  14. #14
    RC Turnbuckle Jr. JimmyNeutron's Avatar
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    Guys... just to help reduce confusion, put a "F" or "C" behind your temps.

    The glue used in most motors start to let go at around 200F(93C)... which is no where near 482F(250C). Most RC'rs, to keep their motors/electronics safe, target an after-run temp of 160F(71C). When pushing the limit they may allow 180F(82C)... but that is about as high as I would go. Constantly running at that temp will ruin a motor.
    Whatever it is I just typed... could be wrong.

  15. #15
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    I pushed the limit on my castle 2200 in one of my erevos. It was grossly over geared and I was driving it offroad with tons of wheel spin. Truck stopped running after 15 minutes and the motor was roasting. Didn't have a burning smell which was good.
    When I got home 15 minutes later, the temp was still a tad over 300*F.
    The next day it ran perfect. I sold it 8 months later and it was still running great.
    ERBE, ERBE, Summit, Slash 4X4, Bandit,

  16. #16
    RC Turnbuckle Jr. JimmyNeutron's Avatar
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    I can guarantee that the magnets lost at least some of their strength with that heat treatment!
    Wow that was hot!!
    Whatever it is I just typed... could be wrong.

  17. #17
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    They probably did, but it wasn't noticeable.
    I cooked my summit motor good, don't know how hot it was, spit would sizzle and dry up fast.
    It was a pain having to carry that truck through the woods to the truck about half a mile away.
    That motor didn't work the next day.
    ERBE, ERBE, Summit, Slash 4X4, Bandit,

  18. #18
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    Quote Originally Posted by Zepher View Post
    When I got home 15 minutes later, the temp was still a tad over 300*F.
    The next day it ran perfect. I sold it 8 months later and it was still running great.
    I was running my stock drive train on a 3s, got it over 180. Was feeling bad on that but not after hearing yours survived 300.

    That's hot but getting there is sometimes worth the pain.

    Watching mine running on asphalt with 3s and those grabby stock tires is fun and funny.
    ' .... she doesn't respect my craft.

  19. #19
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    Quote Originally Posted by RC-nightmare View Post
    Not sure where you got those numbers lol but it is most likly that your stressing the motors with a tighted slipper it like running it just straight from wheel to motor stopping and hard accelating will deglue your motors and getting over 160 is ussaly bad but it is where you normally want to stay with your motor but hey i could be wrong!
    Hi RC -Nightmare
    JB WELD Steel reinforced Epxy has a tensile strength of 3960PSI and sets to a hard bond overnight.It can withstand temperatures up to 550F (about 287C) from the packadging that came whith it. Its more than any other epoxy based i researched on the net. Maybe its only marketing but it states that the bond is almost similar to welding. If this doesn't do it i don't know what else would . PS I lost my shims from the motor and cannot find them otherwise i would post a feedback of this repair. Magnet is fixed and balanced perfect @50K rpm. It has the advantage that while is not cured tends to stick to the magnet towards the magnetic poles and excess can be easily sanded off . If this works it a heck of a tip !


    Edited for language abuse. If you see a starred out word in your post, you must edit it out to avoid earning warning points.
    Last edited by cooleocool; 02-11-2014 at 05:45 PM.

  20. #20
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    Quote Originally Posted by El Sob View Post
    I have had a Novak. It was a 5.5 SC.it is basically the same as the one you have. I never had any problems with heat with it. Do you think your gear mesh could be too tight? This has me thinking a lot.
    Hi El SOb,
    You might have a point there. I put the following gearing 13/54 and 14/54 and now going 12/54-nothing mad really and the usual paper in between before setting them up. I just realised that my problems started when i upgraded to 3S battery pack 40c Fusion (got a pair for a good price). They really deliver and pinions started wearing really bad (use a 54 steel spur).I got one that was really bold-should have post it but throw it out. Now i know there is a slight difference in metric in between 32p and 0.8M (.7938) and if this was machined metric that it could be the part of the problem, but also could be low quality pinion steel. Unfortunately the ebay seller didnt specify the pitch only that they are a replacement as per manual-which it was. The traxxas stock ones are fine on the velineon, but the 5mm bore from Novak are allready eaten slightly in 2-3 runs until magned got loose. When the velineon got loose i was on sand so no big torque but i wasn't surprised it really as it had 2 years of total abuse and 2 esc's burned with it. I ordered oil and will service the diffs but they run very smooth as is (someone suggested this on the thread). Ill get to the bottom of this.

    Thanks BR Syl

  21. #21
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    Quote Originally Posted by Jimmie Neutron View Post
    I can guarantee that the magnets lost at least some of their strength with that heat treatment!
    Wow that was hot!!
    Agree there Neodium Boron magnets loose their magnetic properties irreversibly at 302F or 150C.If its at 100C (water boiling point) you can get burned just by touching so thats a good give away.
    http://www.magmamagnets.com/permanent-magnet-stability
    Far as i know all these magnets are NeFeB but i could be wrong

  22. #22
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    PS: I wonder if the temperature is not being picked up by the VXL via the sensor harness. I know other ESC's shut down when the motor is hot!?

    All for a second less!

  23. #23
    RC Turnbuckle Jr. mwe-maxxowner's Avatar
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    The esc shuts down if the esc gets too hot, but it has no idea what the temp of the motor is. Sounds like you REALLY need a temperature gun. I got a duratrax IR temp sensor for 20$ usd. Money well spent.
    460, straightpipes, buried throttle, nuff said :D

  24. #24
    RC Turnbuckle Jr. El Sob's Avatar
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    The steel spur gear could be part of your problem. There is no need for anything other than a plastic spur gear. You said you could see wear on the gears? That is a big sign of improper gear mesh. Go back to plastic and readjust the mesh properly and I almost guarantee your temperature will be lower.
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  25. #25
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    Ordered the center diff upgrade and that comes with the plastic one anyway. I will give it a go. Thanks

  26. #26
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    That is true for the VXL itself but my motor is sensored and also has a temp sensor in it. I know other ESC's do shut down if the motor is too hot (i.e. Novak) not necessarily the esc, so the question is if the VXL does it or not.
    PS: Running the VXL in sensored mode with the Ballistic 550 6.5T
    Also noticed before the magnet came loose that the motor was shuttering so i wonder if the ESC was trying to cut off due to high motor temps-i guess this is a discussion for another thread.
    Have two guns also-one of them is more precise but remember outer temp (also cools faster on the outside if it has a heat-sink) is not the same to the core one so its just for approximation
    Last edited by sylmarils; 02-12-2014 at 08:29 AM.

  27. #27
    RC Turnbuckle Jr. mwe-maxxowner's Avatar
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    My old novak hv-maxx had no sort of motor sensing, but then again that is a pretty old setup. I'm pretty certain the vxl esc can't sense motor temp even with a sensored motor. I've never seen it mentioned as a feature anywhere.
    460, straightpipes, buried throttle, nuff said :D

  28. #28
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    Found the issue i think. The spurr its a 0.8m and i used 32p pinions. Some say it should be ok to use but maybe for plastic not metal.Got a few from a friend and put them on. Tried them on the spurr and the Novak ones get caught a bit while running them over with my fingher but very little (these are definately 32p). I guess that this little difference is causing alot of heat and the pinions to get blasted. I have loads of pinions and about half are not smooth while running over so i guess they are 32p and the rest 0.8M. Now if that is set i tried adjusting the clutch. I want a bit of punch for jumps so its just a bit tight but is there any right way to set it up or its really touch and go. I was holding the car while pushing half throtle and i set it up by the feel of the pull-could hear the clutch slipping 2-3 times. Motor and wires got hot quickly!!! I'm a bit worried about it as i would subject the car to a bit more than that. CUrrently i'm set 11/54 so i cant really go lower then that to reduce temps. Any advice is welcome. Thanks El SOb you gave me the right direction

  29. #29
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    Hello All
    Another final update! This must be the reason from the beginning. The esc burned out. The magnet fix did hold on the shaft with JB weld. WHen it burned out the motor was 100C-on the outside! but esc had a cappcitor burned out so bad that it melted the battery wire out and then went thru the receiver to get the high current and burned out the wire



    There must be a link in between the esc and motor temps!

    Thank YOu all for chipping in

    Syl

  30. #30
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    The thermal protect in the esc only lasts so long and continuing to overheat the esc will cause it to go up in smoke since the thermal protect circuitry eventually fails.
    ERBE, ERBE, Summit, Slash 4X4, Bandit,

  31. #31
    RC Turnbuckle Jr. El Sob's Avatar
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    I am a little late but you are welcome. When your esc goes into heat protection mode, do you let the esc cool down by itself until the light turns green on its own or do you turn it off and it will be green when you plug it back in? I am sorry about your esc, if you really need my advice you can pm me at anytime and I Will be sure to help you.
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