nosram matrix evolution troubles

[mk1joe]

hi,

as sugested in the title im having trouble with my nosram matrix evolution, i have calibrated it whith my transmitter but when it enters full throttle it stops and the lights flash, about 5 seconds later it will start again but it wont go on full throttle. not sure weather this is a a problem with all esc or just the evolution but hopefully someone will know.

and also i am running it whith a brushless novak 4.5turn sensored motor.

thanks for the help

joe

[Walsall-Basher]

What battery are you using with it? Would need a pretty big lipo with a equally large C rating I'd have thought?

[mk1joe]

are there any recomended size and brand of lipo i should be using

[Walsall-Basher]

you need to check the ampdraw on your brushless system, its usually in the packaging somewhere, but at a guess i'd say 4.5t novak was pretty high.

then lipo wise you take the capacity in mAh/1000 * C rating to get the ampage

ie 4200mAh with a 40C rating would give you (4200/1000)*40=168amps

not easy to find a lipo with these big numbers in a stick pack style but there are some on evilbay from HK, i just ordered one branded as a 'silverback'

[TA-Mark]

The 7.5 Amp Tamiya battery plug is an issue, as discussed in the other thread here. The Ni-MH can supply more than 7.5 Amps and the 4.5 brushless will certainly draw more than that.

Over gearing can also be an issue as you have this in a DT02 with limited gearing options. Over gearing causes excessive current draw, which will cause the motor and battery to run very hot which will eventually kill both.

As mentioned in the other thread, when you can't match the gearing to the motor (because of limited options - 17 tooth or 19 tooth pinion) you have no choice but to match the motor to the chassis (lower motor Kv). It will be an expensive lesson, but you will learn it in the end. Excessive motor heat kills the magnets on the rotor. Excessive current draw from a Li-Po pack will cause it to swell or worse, catch fire and burn the buggy. Li-Po packs do burn well when mistreated. Plenty of videos of them going up on youtube.

[mk1joe]

im using a 5500mAh ni-mh at the moment i dont know the c rating though, the motor draws 413 watts. what is the importance of it being a lipo though because i know the esc can handle both. do lipos have more power?

if it is just the connector that is the problem than what conector is recomended to handle most current?

thanks

joe

[mb_c11]

Could be that the motor is too powerful for the battery. I had the same problem with a 7.5 turns and using NiMH; after switching to Lipo the problem went away.

[mk1joe]

did you use the same size battery?

[mb_c11]

No (3600 mAh), but if you give full throttle and the ESC cuts out, it's likely that the voltage drop caused by going full throttle makes the ESC go into failsafe mode because the battery drops below what the ESC considers as "safe". At least that's what happens with my LRP Sphere Competition, of which the Nosram Matrix Evolution is a rebadged version (so it likely behaves the same).

[Walsall-Basher]

Novaks website recommend their motors down to 8.5t for 2wd buggies with your gearing. Any lower turns you'll overheat it, lose your warranty and end up with a scrapped motor.

I learned the cheap way about overgeared motors as I only fried 2 mabuchi 540s before I decided to look up final drive ratio on a search engine

[Backlash]

Have you checked to see if the LiPo cutoff is turned off in the ESC? If the LiPo cutoff is turned ON, then the battery voltage is probably dropping below the cutoff voltage, and causing the ESC to shut down..

You could also try running a lower throttle profile in the ESC, as this will lower the maximum current drawn from the battery.. I am told that the Sphere comp TC ESC runs 20 deg dynamic timing on the highest throttle profile (profile 8 I think) so selecting profile 1 will make things a little more tame..

A 4.5 in a buggy is overkill... A 7.5 - 8.5 would be a handful in that car, and a 10.5 would still result in wheelstands..

I know of many people that have used 4.5 BL motors on NiMh batteries, and had no problems... However, these NiMh packs were "top of the line" race packs, so the problem still could be your battery packs, especially if thery are "no-name" eBay specials...

Cheers..

[mk1joe]

ok so in terms of power needed to run the motor is higher mah quite iportiant? or is being a lipo more importiant? there is a mode which disengages the lipo protection when using 4-6cell ni-mh, i asume you dont need lipo protection when not using lipo.

[another question relevant to the matrix evolution esc is when you change modes there isnt a way to keep it on the chosen mode, eg. there are 4 modes and if mode 4 is chosen you press "mode again" and it stays on mode 4, but if you want it to stay on mode 1,2,or3 you cant press "mode" again because it changes to the next mode. the only thing i can think of is turning it of when the chosen setting is reached but im not sure if this is right, the manual isnt very clear on this subject]

thanks

joe

[Backlash]

Yes that is correct... If you are not using LiPo batteries, then you leave the LiPo cutoff turned off...

LiPo batteries dont like to be run any lower than 3V - 3.2 Volts* per cell, and if you do it can cause the pack to fail, puff, or burst into flames the next time you try to charge it... (*depending on LiPo and who you are asking at the time LOL..).. NiMh batteries also dont like to be over discharged (i.e. do not run them completely flat) but if you do, they cannot be damaged in the same way that LiPo's can..

I am not that familiar with the Nosram Brushless ESC's. but from what I understand, they are only re-badged LRP Sphere ESC's.. Its been a while since I programmed my sphere, but what happens if you select mode 1, and then just let it sit for a few seconds... Does your ESC have one button or two? (mode and set?).. If it has a set button, have you tried pressing that to see if that will select that mode?

Cheers

[mk1joe]

i tried leaving it for a minute but it did not set, it has two buttons mode and set but the set button changes the value so when you press it it dose not lock the mode.

thanks

joe

[mb_c11]

i tried leaving it for a minute but it did not set, it has two buttons mode and set but the set button changes the value so when you press it it dose not lock the mode.

thanks

joe

Read the manual that came with your ESC and use the procedure described inside to set your ESC.

[mk1joe]

so if heat is the issue that will kill the motor it can be eliminated and the motor wont die? --->

http://cgi.ebay.co.uk/540-550-Water-Coolin...=item3363296e24

[Walsall-Basher]

so if heat is the issue that will kill the motor it can be eliminated and the motor wont die? --->

http://cgi.ebay.co.uk/540-550-Water-Coolin...=item3363296e24

its an amphibious buggy then?

[Backlash]

Joe..

FORUM RULES... Do not post links to eBay auctions unless they are your own.. May I suggest that you delete the link before a mod sees it and does it for you..

The heatsink is watercooled, so I would assume that it is more suited to a boat, unless of course you plan to fit a water pump, water tank and radiator to your car... If you search ebay you will find heatsinks that have small fans attached that may be more suited to your needs.. (although fitting them to a buggy may not be that easy..)

ESC Programming (from the LRP Sphere TC manual..)... With the battery connected and radio turned on (may I suggest placing the car on a stand so the wheels are off the ground when programming)...

Press and hold the mode button for 3 seconds (or more) to enter programming mode.. (You will now be in Mode 1, Lipo cutoff on or off... )

Count how many times the blue SET LED flashes.. 1 Flash LiPo cutoff is on, 2 Flashes LiPo cutoff is off... (Default is 1 flash, cutoff ON)... Press the set button to toggle up.. (i.e. press the set button once to turn the LiPo cutoff off)

Press the mode button to enter, and move to the next mode..

Mode 2 is Throttle / Motor profile.. Again count the flashes of the blue SET LED.. Profiles go from 1 to 8, so press the set button to toggle up until the SET LED flashes once.. Then press the Mode button again to lock it into Profile 1, and move to the next mode.. (Profile 3 is default)

Mode 3, Initial Brake force.. Default is 2-- Leave as it unless you want more brakes.. 0 setting is no brakes.. Press Mode again to enter next profile..

Mode 4, Drag brake... Default is 2 -- This mode adds a little bit of brake force when you release the throttle to simulate the effect given when using a brushed motor... 0 value is off, so car will free-wheel when throttle is released.. Press Mode again to enter value, and EXIT programming mode..

At this point you should be able to re-enter the programming mode (press and hold mode button for 3 seconds) and check the stored values by counting how many times the SET LED flashes in each mode.. Dont press the SET button at any time whilst doing this, otherwise you will change the value..

Goodluck..