TMaxx conversion

[Traxxas2.5TMaxx]

Hello, I'm new into the electronic field of RC. Been running nitro for a while. I just got a Mamba Monster x 8s with a Castle 1515-2200kv for my old TMaxx 2.5. Other then mounts I'm wondering what else I may need to complete the conversion and battery recomendations. I've checked on their website a few time but not sure what voltage to get. It just says don't exceed 32v.

 

[pug]

I would not run more than 4s in it, even 4s may be pushing its limits.

 

[Traxxas2.5TMaxx]

I would not run more than 4s in it, even 4s may be pushing its limits.

I'm sorry, I'm not understanding. What is 4s?

 

[Bogda89]

I'm sorry, I'm not understanding. What is 4s?

Because everything will fall apart

 

[pug]

I'm sorry, I'm not understanding. What is 4s?

4 cells in a series for a LiPo. A 4s is 14.8v nominal and 16.8v fully charged. The T-Maxx Classic wasn't made to handle the torque of an electric system.

 

[Traxxas2.5TMaxx]

4 cells in a series for a LiPo. A 4s is 14.8v nominal and 16.8v fully charged. The T-Maxx Classic wasn't made to handle the torque of an electric system.

I'm not worried about the torque. It's 3.3 driveline upgraded with the alloy parts. I upgraded it years ago because I kept breaking the plastic stuff from crashes and stunts. Either way, run, break, fix, repeat. Right? I'm more worried about frying the esc or motor.

 

[pug]

I'm not worried about the torque. It's 3.3 driveline upgraded with the alloy parts. I upgraded it years ago because I kept breaking the plastic stuff from crashes and stunts. Either way, run, break, fix, repeat. Right? I'm more worried about frying the esc or motor.

The ESC is rated for 8s LiPos max, so you can run up to 8s LiPos. You can run stuff under that too.
Oh yeah, that motor is good up to 6s only.

 

[Traxxas2.5TMaxx]

The ESC is rated for 8s LiPos max, so you can run up to 8s LiPos. You can run stuff under that too.
Oh yeah, that motor is good up to 6s only.

Sorry for all the questions. Again I'm new to this electrical upgrading. I'm assuming it runs 1 battery at a time? I.E. 1 4s battery?

 

[pug]

Sorry for all the questions. Again I'm new to this electrical upgrading. I'm assuming it runs 1 battery at a time? I.E. 1 4s battery?

You can do 1 x 4s or 2 x 2s wired in a series,

 

[Greywolf74]

Sorry for all the questions. Again I'm new to this electrical upgrading. I'm assuming it runs 1 battery at a time? I.E. 1 4s battery?

Technically you can run up to 6S (or 22.2v) LiPos. The motor is the limiting factor here, at least in terms of the electronics. The suggestion to run it on 4S is probably a sound one although if you're not afraid to break parts and try to rebuild it stronger than before then your electronics can go up to 6S. Each LiPo cell is 4.2V fully charged but the voltage rating for LiPos tends to get spoken of by its "nominal" voltage which is 3.7V per cell. A 6S LiPo is a battery that has a total of 6 cells wired up in series which means all of the cell voltages are added together. Thats why a 6S LiPo is said to be 22.2V nominal. 3.7v x 6 cells = 22.2V for the whole pack. As for what brand to by Id look at Liperior (yellow packs), Liperior Pro, CNHL G+ series (Not their racing series), Zippy Compact, Turnigy, or SMC LiPos. Bear in mind that the dimensions of LiPos are not standardized so you need to make sure the size of the pack will fit in your particular battery tray.

As Pug mentioned it doesn't matter if you run a single 4S pack or two 2S packs wired up in series but the easiest thing to do starting out would just buy a single battery pack until youve learned a little more about electrics. Just bear in mind that when running two lipos wired up in series that they both need to be identical batteries and should be kept as "matched pairs". So for example if you wanted to run 6S with two batteries then it has to be identical so they both have to be 3S batteries, same brand, same mAh rating, same C rating, etc. If you're not familair with what a matched pair of batteries is then that just means you always run them in pairs and never by themselves. This keeps the usage the same roughly between batteies and wont stress one battery harder then the other battery.

Also if I were you, Id buy a LiPo charger like the HOTA D6 Pro that can measure the internal resistance (IR) of the individual cells in a LiPo when you charge it. The cell IRs are a general indicator of how "healthy" the cells are. If IRs start getting too high or one cell develops a much higher IR than the other cells then you know your LiPo is developing an issue. This is crucial to safe Lipo usage.

If you have the 3.3 tranny with all metal gears, metal drive shafts, and metal axles which if I understand your post clearly you do have, then you should be able to run on 4S. On 6S you may have to upgrade your differentials to Heavy Duty or metal diff housings. I'm assuming the 2.5 has metal diff gears?

One last piece of advice. Get yourself an infra red temp gun and when you first start running keep tabs on your motor and ESC temps. You really dont want the motor getting hotter than 170F and I dont like my ESCs to get hotter than 160F. Regardless if your running 4S or 6S if either the ESC or motor starts getting within a couple of degrees of those numbers shut it down and let it cool off. If it gets close to the overheating point then youll need to adjust your gearing. Either put a smaller pinion on it or a larger spur gear. I usually adjust by 2 or 3 teeth and try again. by using your temp gun eventually you can get your gearing dialed in so that the electronics will get within 5 or 10F of the target numbers without going over. If its not the middle of the summer when you dial this in make sure you keep tabs on temps during the summer. Also the cooler it runs the longer it will last so you may choose to gear it so that everything is running 15F cooler than max temps. Thats a personal preference call. Once you can run a couple of packs back to back through it without overheating then youve reached your optimized gearing, at least for bashing. Oh and your LiPo shouldnt go over 150F either. If your LiPo is getting too hot then either the specs are too low on it or it may be damaged/defective. You will want packs that are at least 5000mAh and 40C or higher generally speaking. The higher the better though for both of those numbers.

I hope this helps.

 

[tntpoof]

6 cells is 25.2 not the lower voltage mentioned above.

 

[Traxxas2.5TMaxx]

Technically you can run up to 6S (or 22.2v) LiPos. The motor is the limiting factor here, at least in terms of the electronics. The suggestion to run it on 4S is probably a sound one although if you're not afraid to break parts and try to rebuild it stronger than before then your electronics can go up to 6S. Each LiPo cell is 4.2V fully charged but the voltage rating for LiPos tends to get spoken of by its "nominal" voltage which is 3.7V per cell. A 6S LiPo is a battery that has a total of 6 cells wired up in series which means all of the cell voltages are added together. Thats why a 6S LiPo is said to be 22.2V nominal. 3.7v x 6 cells = 22.2V for the whole pack. As for what brand to by Id look at Liperior (yellow packs), Liperior Pro, CNHL G+ series (Not their racing series), Zippy Compact, Turnigy, or SMC LiPos. Bear in mind that the dimensions of LiPos are not standardized so you need to make sure the size of the pack will fit in your particular battery tray.

As Pug mentioned it doesn't matter if you run a single 4S pack or two 2S packs wired up in series but the easiest thing to do starting out would just buy a single battery pack until youve learned a little more about electrics. Just bear in mind that when running two lipos wired up in series that they both need to be identical batteries and should be kept as "matched pairs". So for example if you wanted to run 6S with two batteries then it has to be identical so they both have to be 3S batteries, same brand, same mAh rating, same C rating, etc. If you're not familair with what a matched pair of batteries is then that just means you always run them in pairs and never by themselves. This keeps the usage the same roughly between batteies and wont stress one battery harder then the other battery.

Also if I were you, Id buy a LiPo charger like the HOTA D6 Pro that can measure the internal resistance (IR) of the individual cells in a LiPo when you charge it. The cell IRs are a general indicator of how "healthy" the cells are. If IRs start getting too high or one cell develops a much higher IR than the other cells then you know your LiPo is developing an issue. This is crucial to safe Lipo usage.

If you have the 3.3 tranny with all metal gears, metal drive shafts, and metal axles which if I understand your post clearly you do have, then you should be able to run on 4S. On 6S you may have to upgrade your differentials to Heavy Duty or metal diff housings. I'm assuming the 2.5 has metal diff gears?

One last piece of advice. Get yourself an infra red temp gun and when you first start running keep tabs on your motor and ESC temps. You really dont want the motor getting hotter than 170F and I dont like my ESCs to get hotter than 160F. Regardless if your running 4S or 6S if either the ESC or motor starts getting within a couple of degrees of those numbers shut it down and let it cool off. If it gets close to the overheating point then youll need to adjust your gearing. Either put a smaller pinion on it or a larger spur gear. I usually adjust by 2 or 3 teeth and try again. by using your temp gun eventually you can get your gearing dialed in so that the electronics will get within 5 or 10F of the target numbers without going over. If its not the middle of the summer when you dial this in make sure you keep tabs on temps during the summer. Also the cooler it runs the longer it will last so you may choose to gear it so that everything is running 15F cooler than max temps. Thats a personal preference call. Once you can run a couple of packs back to back through it without overheating then youve reached your optimized gearing, at least for bashing. Oh and your LiPo shouldnt go over 150F either. If your LiPo is getting too hot then either the specs are too low on it or it may be damaged/defective. You will want packs that are at least 5000mAh and 40C or higher generally speaking. The higher the better though for both of those numbers.

I hope this helps.

That helpped a lot actually. It did come with metal gear diffs. As for the gear ratio are you talking about the trans gears them selves or the spur gear off the front of the trans and the pinion gear off the motor?

 

[Greywolf74]

6 cells is 25.2 not the lower voltage mentioned above.

25.2V is the max volatge, 22.2V is the nominal voltage. No one refers to a 6S pack as a 25.2V pack. I would think youd know this as long as youve been in the hobby

That helpped a lot actually. It did come with metal gear diffs. As for the gear ratio are you talking about the trans gears them selves or the spur gear off the front of the trans and the pinion gear off the motor?

Spur and motor pinion. Those are generally the only gears you can change. not many kits (if any) have a choice of transmission gears.

That helpped a lot actually. It did come with metal gear diffs. As for the gear ratio are you talking about the trans gears them selves or the spur gear off the front of the trans and the pinion gear off the motor?

BTW, you may want to re-read my post again. I kept going back to it and adding info. I'm not sure if you saw it all or not