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FTX Carnage Brushed - Brushless Mod Slipping?


turtletom100

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Hi again well as some of you know I am in the middle of taking out the standard brushed motor and replacing it with a sky leopard brushless well I have it all fitted but it sounds like it is slipping but not to sure why as I thought I had it lined up correctly. (The pinion may sit a little bit behind spur but not much. Well it sounds like it is slipping but before I strip it down and try to realign it again can someone just Co firm this. 

(I have filmed it using me phone in rubbish quality as was hoping to upload straight to here but couldn't find how so went on youtube if needed I will film it in hd and upload others)

 

Ftx carnage slip:

Ftx carnage slip 1:

Ftx carnage slipping 2:

Ftx slipping 3:

 

Any help would be appreciated. Or tips. :-) 

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Ouch, strip it Tom and look.  Sound quality is poor for me but i'm at work so have to have it really low.  Check the mesh and all the teeth (particularly the spur) but also the slipper clutch pads.

What I'll do is film it in hd and upload that to youtube. I think stripping it is the best a thing to do. But it is weird as as soon as you get past the initial acceleration it is fine no judder no grinding. And if I look at the spur and pinion it doesn't seem to be churning either/or. I will take pic of that aswell if I can.

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What I'll do is film it in hd and upload that to youtube. I think stripping it is the best a thing to do. But it is weird as as soon as you get past the initial acceleration it is fine no judder no grinding. And if I look at the spur and pinion it doesn't seem to be churning either/or. I will take pic of that aswell if I can.

 

 

Also slipper clutch pads are fine the car has only being in total since new between 4-5 hours with the brushed motor and about 5/10 minutes with the brushless

 

Ahh, I hadn't realised it ran ok after the initial juddering.  Sure it's not just the motor?  I'm new to brushless (nitro background) and only have one can in a motor - that too is a little 'notchy' if you try and run it at the slowest speed.

 

If the gears don't look like they've been chewed (and if it runs ok after the initial burst then prob not) then that leaves the slipper (prob wouldn't make that noise) or the motor.  Take the motor out and try and emulate the conditions - you might not get the same gear type noise (as the spur etc isn't in play) but it might show the motor.  

 

As to whether this is normal for a b/l can idk - others should be able to help. 

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Tighten the slipper clutch, pretty sure this is causing the issues...a bl motor is kicking out more power than the brushed can, so settings for the brushed could be a tad too loose for the bl.

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Ahh, I hadn't realised it ran ok after the initial juddering.  Sure it's not just the motor?  I'm new to brushless (nitro background) and only have one can in a motor - that too is a little 'notchy' if you try and run it at the slowest speed.

 

If the gears don't look like they've been chewed (and if it runs ok after the initial burst then prob not) then that leaves the slipper (prob wouldn't make that noise) or the motor.  Take the motor out and try and emulate the conditions - you might not get the same gear type noise (as the spur etc isn't in play) but it might show the motor.  

 

As to whether this is normal for a b/l can idk - others should be able to help.

Well I have took it out the front of mine for its first run, I haven't stripped it back down yet but as you can see it don't judder when it's going. Excuse me kid in the background (he was running up and down the path lol)

Brushless grind 1st run: http://youtu.be/88WZMNwrxzM

Brushless grind 1st run 2: http://youtu.be/XuCGAu6CzVE

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Tighten the slipper clutch, pretty sure this is causing the issues...a bl motor is kicking out more power than the brushed can, so settings for the brushed could be a tad too loose for the bl.

Ok will give this a go later, I have just uploaded 2 other videos of it going at almost full throttle but there is no judder when it's going with a bit more speed.

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to me that mesh is too tight. (though cant quit see on my crappy screen)

 

sensorless motors can cog (jittery at very low speed).  couple that with your tight mesh and thats usually the result.

 

slipper may also be a factor.

Edited by Deafty
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The mesh definitely looks too tight, try the "paper method" for the correct mesh.

I do mine by eye, just so that the spurs teeth "rock" inside the pinion.

Is your battery up to the job?

If you have low spec lipo, it might not be providing enough power for the motor.

This causes cogging on initial take-off.

Is your brushless esc set up correctly?

If your "punch" is set too high this can have the same effect as the last point.

If you have the programming card for the ESC, it's a 2 min job to sort it.

Just drop it down a touch.

Definitely get your slipper set right though, that's the only problem I have had.

Sort that, and you should be good to go!

Cheers

KingPin

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Well, that answers one of my questions about my BL conversion. I figured I was getting cogging so when my new pinnys arrive I'll back the punch off a bit. Might help keep the front wheels on the ground too. 

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The mesh definitely looks too tight, try the "paper method" for the correct mesh.I do mine by eye, just so that the spurs teeth "rock" inside the pinion.Is your battery up to the job?If you have low spec lipo, it might not be providing enough power for the motor.This causes cogging on initial take-off.Is your brushless esc set up correctly?If your "punch" is set too high this can have the same effect as the last point.If you have the programming card for the ESC, it's a 2 min job to sort it.Just drop it down a touch.Definitely get your slipper set right though, that's the only problem I have had.Sort that, and you should be good to go!CheersKingPin

Hi cheers for the reply I done the paper thing (slide in between teeth then pull out) it didn't rip at all and come out relatively smoothly had a few teeth marks on the paper which I thought would happen, but it was slipping so I thought it was to far apart so moved the motor/pinion in a bit more hence why it is now quite close.

I have tightened the slipper to almost it's limit but still got the slipping at low speed, I have used the program card and tried numerous settings and it still slips. I will move the pinion away a little bit tommorow now the slipper has being tightened and see if that helps any. When you say rocks do you mean the teeth are only just interlocking (if that's the right term) if possible do you have a picture of a ideal setup?

Well, that answers one of my questions about my BL conversion. I figured I was getting cogging so when my new pinnys arrive I'll back the punch off a bit. Might help keep the front wheels on the ground too.

I think the punch stops the car from full throttling straight away and kind of eases it in to the full throttle. I might be wrong though.

Edited by turtletom100
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I have just had a quick Google at cogging and apparently if it was cogging when I move the spur with my finger from the bottom of the chassis it would jump which it isn't it is moving reasonably freely. Does this suggest it's not cogging? I will make a video tommorow and upload it to y/tube with me using fingers to move the spur.

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Can you not move the pinion back on the shaft?    They really ought to line up better to spread the load, elsewise you risk wearing that spur too quickly.   Lots of info re mesh around - yours looks only a tad tight, kingpin's advice was good - by rock he means the pinion can rotate clockwise and anti a small amount before it engages (moves) the spur.  Too tight and any movement of the pinion will move the spur. 

 

Take a video of it running at various throttles, cogging - which is what I was trying to get at in post #5, seems likely.  Your explanation of cogging test isn't clear to me - but it is just past midnight.  Never mind the spur - push the car fwd and back and feel how it rolls.  If it's cogging (which it appears is a b/l issue) then it won;t feel smooth at slow speed.  As far as I can tell it isn't an issue.

 

Looks like your still using the included nimh?   From experience the batteries are a serious weak link in these budget kits.  I don't know if it affects cogging or not (to my layman mind a better battery only masks the issue more) but if so then that stock nimh isn't helping.  Time to go  lipo or at the very least get some better batteries - Overlander and Vapextech are both good cheap options in my experience - although it's prob wasted money when lipo is almost everywhere nowadays.  IIRC your esc is lipo ready (ie has a low voltage cut off).  

 

Ought to say if your still unsure take the motor out - turn the pinion by hand and feel that / run it under power (watch temps tough) and whilst out push the chassis and feel the drivetrain for smoothness.  Check that slipper clutch.

Edited by capri-boy
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Can you not move the pinion back on the shaft?    They really ought to line up better to spread the load, elsewise you risk wearing that spur too quickly.   Lots of info re mesh around - yours looks only a tad tight, kingpin's advice was good - by rock he means the pinion can rotate clockwise and anti a small amount before it engages (moves) the spur.  Too tight and any movement of the pinion will move the spur. 

 

Take a video of it running at various throttles, cogging - which is what I was trying to get at in post #5, seems likely.  Your explanation of cogging test isn't clear to me - but it is just past midnight.  Never mind the spur - push the car fwd and back and feel how it rolls.  If it's cogging (which it appears is a b/l issue) then it won;t feel smooth at slow speed.  As far as I can tell it isn't an issue.

 

Looks like your still using the included nimh?   From experience the batteries are a serious weak link in these budget kits.  I don't know if it affects cogging or not (to my layman mind a better battery only masks the issue more) but if so then that stock nimh isn't helping.  Time to go  lipo or at the very least get some better batteries - Overlander and Vapextech are both good cheap options in my experience - although it's prob wasted money when lipo is almost everywhere nowadays.  IIRC your esc is lipo ready (ie has a low voltage cut off).  

 

Ought to say if your still unsure take the motor out - turn the pinion by hand and feel that / run it under power (watch temps tough) and whilst out push the chassis and feel the drivetrain for smoothness.  Check that slipper clutch.

Yea i can move the pinion back further on the shaft but will have to remove the motor as I have used loctite for the grub screw so will have to heat it up a nd take it off then apply loctite and try to do this again.

I will film the car being pushed back and forth tommorow as it is getting a bit late and the brain is getting ready to hit the hay lol.

And yea i have got the stock battery which I think I did use but also have a 3500mah, 2 X 4600mah nimh battery's aswell just the 1800 was charged and only takes half hour to charge. I have got a turnigy 5000mah 2s lipo just got to solder deans to it and buy the overlander rc-6 charger. But even the bigger battery's still makes the grinding noise. I would say it has being run for a 5 oral of 40/50 minutes today and mid way decided to stick the motor timing up to full just to see how hot the motor gets and it was quite warm but could still hold my finger on it and I think i have read that if I can hold my finger on the motor for 5 seconds or more it's fine.

With regards to the slipper clutch it has being tightened to its limit almost and still makes the grinding noise (don't seem to have got better or worse) so nor sure what the noise is still I will take the motor back out tommorow and take that pinion off and put it back on a bit further back and re align it using the paper method just for peace of mind (in the long run I am looking at getting one of the rt.6 pinions I think they were called) so will be taking the pinion off again at some point. Sucks that ftx don't sell a metal spur gear though as I would have thought this would have being tougher than the plastic spur gear it has.

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Metal spurs are all well and good but it doesn't hurt to have a weak link in the drivetrain ;)  I still haven't looked but sourcing a metal spur from another model shouldn't be impossible.

I think it can be replaced with one from another car, I have spoke with CML and they said 5 hey haven't got a metal spur "at the moment" so whether it is something they will bring out is another question on a different note I though balls to it *couldn't resist a little early morning rc car stripping*

Well after having a closer look it appears where the pinion was sitting a little bit in front of the spur the grub screw has being knocking against the spur it has caused a bit of damage to the spur hopefully will be alright for the minute though (I have uploaded a photo)

344azjn.jpg

I have just sat here taking the motor back out took the grub screw out (it's not like it was 1:30 am using a heat gun to help loosen the loctite on the grub screw) and re aligned the pinion and used loctite put it back on the shaft from the motor. I will put it back in the car in about 15 and re align the spur with the pinion using the paper trick (can you just explain how it should be done) I was just tearing paper strips and moving the car forward so the paper went in between the two then pulled the paper back out.

Also I have took a picture of what the current settings are on the car via the programmable car and they are these:

qnkwns.jpg

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Further update to this is that the pinion is in the correct position to my knowledge but whilst trying tobput the motor back in to align the mesh properly, i thought it was in the correct place tightened the 2 screws and turned it on and it appears the car is not respinsive and has got response issue as in pull throttle then a fe mw ms the motor spins but then carries on spinning im hoping its because me battery needs charging so going to leave it for the minute and charge me batterys and try again, if it isnt one thing its another *doh*

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You can't check for cogging by rolling the car backwards and forwards.

Sensored motors have little or nothing to do with the timing marks round the can.

 

Cogging is when the ESC doesn't know exactly what position the rotor is in the motor, so the firing order of the motor is *slightly* wrong, making it jump around under smaller throttle openings, once it gets up to speed, the slightly poor timing is all but invisible, as the inertia of the car masks it. A sensored motor has a sensor which tells the ESC exactly what position the rotor is in, so the firing order and timing is all but perfect at all throttle positions.

 

You'd know if it was a sensored set up as you would have a sensor cable (flat thing, 6 or 8 wires, plug on each end) connecting the ESC and the motor.

 

It even says at the bottom of your program card, "Motor Type"

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You can't check for cogging by rolling the car backwards and forwards.

Sensored motors have little or nothing to do with the timing marks round the can.

 

Cogging is when the ESC doesn't know exactly what position the rotor is in the motor, so the firing order of the motor is *slightly* wrong, making it jump around under smaller throttle openings, once it gets up to speed, the slightly poor timing is all but invisible, as the inertia of the car masks it. A sensored motor has a sensor which tells the ESC exactly what position the rotor is in, so the firing order and timing is all but perfect at all throttle positions.

 

You'd know if it was a sensored set up as you would have a sensor cable (flat thing, 6 or 8 wires, plug on each end) connecting the ESC and the motor.

 

It even says at the bottom of your program card, "Motor Type"

I thought sensored cans had timing numbers around one end of the can. And I don't know what the issue u have but at rolling speed it sounds like it grinding I have moved the pinion so it is more in line with the spur but still males the noise have tightened the slipper but still the same I'm stumped to be honest

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Right I have re aligned pinion as can be seen in video it is now sitting level but I still have this crappy grinding noise is this damaging my spur and/or pinion or is this cogging?

Grinding/slipping noise.

What is going on:

And also a video showing paper being pulled up through the spur and pinion and not ripping (so I think alignment is fine, correct me if I'm wrong)

Mesh alignment:

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