XTM XST Electric Conversion
 

I have a XTM XST truggy that I am wanting to convert to brushless, but i noticed nobody makes and sells a conversion kit for it or any XTM vehicle. I have a Tekno 42mm Universal Mount but its not a direct bolt up. I just want to see if someone makes a mount for the XTM vehicles. I would rather not have to make an adapter to just use the mount. I noticed that somebody makes clamp style mounts for the XTM's but i dont completly trust those mounts. So does anybody have any ideas for what I can do.


The setup I am trying to do is a Mamba Monster Max 2650kv combo, with a 5000mah 4S1P pack, 14T pinion, no mechanical brakes.

Thanks Matt

You could shoot RC-Monster Mike (the owner) an email, it's likely he has the drawings for what you need already. Your mount would be the same as for the Mammoth ST, XLB, and XT2, except it would need to be optimized for the 53t spur gear.

Also, you may want to reconsider your setup. That gearing on that motor will be quite stressful on the motor (50+mph), and typically the 2650 is used for buggies. You would be much better off with the 2200 and a 14-15 tooth pinion.

And welcome to RC-Monster!

Thanks for the quick reply. I just sent Mike an e-mail, hopefully he can help me out with this. So if I am to go with the 2200kv system, should i go with a 5s and a 14T. Also I was wondering if it was worth it for the electric clutch system Tekno RC makes, to act as a slipper in a way, but I know im not going to have much room for that, if I do the center bulkhead mount that the clutch is out of the question right?, and if I stick with the Tekno 42mm mount I have now I would have to mount it back far enough to fit the clutch on. Also thanks for the welcome, I really like this forum so far.

Thanks,
Matt

You can use the Speed Calculator made by BrianG to help with gearing:
http://scriptasylum.com/rc_speed/_top_speed.html
Generally it is best to gear 1/8 for no more than about 45mph to keep temps and controllability in check.

For you:
-1/8 buggy typical ratio (43/13)
-1:1 transmission ratio (direct drive)
-53t spur
-5s Lipo @ 3.6v/cell (I use this value to account for voltage drop)
-6in. tall tires (this is what I use to account for ballooning)

Plugging those values in, a 14t pinion would yield 55mph+, which IMO is too much. An 11t pinion would be optimal.

Alright so I used that speed calculator and plugged in some stuff, I figured that the 2200kv system, with 14T pinion and a 53T spur, and a 4S battery pack would get it going around 45MPH, which is what I'm looking for. Any other suggestions or ideas?

Thanks,
Matt

If you can swing 5s, that will be a better performing setup. Any reason why you seem stuck on a 14t pinion?

I like the stock gearing thats on it right now, but I can try a 11T pinion with the 5s. I'm just trying to keep the cost down as much as possible.

Wait, I'm confused. Are you planning on using a RC-Monster mount or the Tekno mount?

4s will still provide great performance, a lot better than the stock 24.7 engine.

If Mike can make that mount for me, then its the RCM mount I'm gonna use. He said he made one for another customer before, just waiting for him to reply to my e-mail now. I may end up going with the 4s for lower cost. Also the 4s would me smaller and better to fit in the truggy. If you recomend anything else please tell me, I would like the best setup I can get.
Thanks,
Matt

Do you have a particular battery in mind? I think you'll need at least 5200mah with 4s to get decent runtime. My truggy runs 5s 5000mah and provides roughly 15mins of play time.

I was going to get a Zippy 5000mah pack, but if there are any other packs out there that are really good for a decent price then I might change. Only 12 min runtimes? I got a guy that has a E-Revo with a MMM 2200kv and 5000mah packs and he gets 30 min runtimes going full speed almost all the time.

Matt

30mins, is that on 4s? He must have a light trigger finger...

You can go with 5000mah, I personally wouldn't but I also know my driving style (and I don't know yours).

30min on a 6s, I was kinda puzzeld at first, but I found out he changed the settings on the esc. I'm going to race it so I wouldn't be hitting full speed too much, since the straight aways are short. What battery would you recomend using for maximum runtimes for just fooling around on the track with some other guys.

Thanks,
Matt

If you want max. runtimes then you'll want to maximize available energy - 6s 5000mah is a good size battery without weighing too much, and they can still be gotten for pretty cheap. But you won't be able to properly gear your XST with that battery and the 2200 motor, so that means 5s is pretty much the maximum. The capacity you get will depend on how much weight your care for your truggy to carry around, and how deep your pockets are. 5s 5000mah is my personal choice.

I get 30 minutes of hard runtime with my E-Revo as well on 4900mah packs. In the Erevo there is a transmission and the extra gear reduction helps out on battery drain as well. Same reason why I only get 3-5 minutes of runtime with my boats, its a direct drive with no reduction...