Build Thread DXtreme1 TMaxx Dual Builds

[DXtreme1]

The stock 21TM is pretty decent in my revo. Was a nice bump up from the 3.3. Not nearly as gnarly as the LRP28 in my other revo.

Originally I wanted to do a big block on the TMaxx but upon thinking about it further I think it would be better if I do a 1/8 scale buggy with a .21 race motor and I'm thinking either getting a Revo and do the big block conversion or do a Savage XL with the realy big block. Since the buggy and the Savage are meant to take the abuse of the true big blocks I think I'm better served doing it this way financially.

 

[DXtreme1]

I've been researching and looking for an electric based RC project. I like speed but I have no plans to run in the 100s. I'll be happy with high 60s to mid 70 mph speed. I also wanted an onroad style but higher clearance. This modified Slash fits the bill for me. This would be perfect for parking lot running. I'm gonna end up putting a 1:8 scale touring or road car lid on it for more realism.

 

[DXtreme1]

The stock 3.3 Tmaxx steering servo that I took from my 3.3 Tmaxx that I installed on my sons 2.5/3.3 hybrid grenaded. I took it apart. Gears are all good and motor works just fine however the top motor cover has a built in endpoint stop which broke off. There was no way to salvage it since I had no servos that had the compatible top to fit. I needed to find a budget servo for the meantime since my budget is tied up for something else. I ended up ordering the attached servo from Amazon. If this proves to be a really good servo I may order one more for brake/throttle duties for my 3.3.

 

[olds97_lss]

I have a servo similar to that... it's slow and not overly stout. Figured I'd give it a try too back when I got my brushless revo. I had ordered a couple others as well just in case.

Took a couple videos of it next to other servos:

 

[DXtreme1]

Wow that is definitely on the slower side. I'm glad it's cheap enough to serve as an emergency spare one later. It looks like I'm gonna have to get a better one sooner than I thought.

 

[DXtreme1]

I installed the servo on my sons TMaxx and tested it. It was very dissapointing. There is not way that this servo can push 277 oz/in. I don't even think it pushes more than 100 oz/in. I could deal with the slow speed but the steering would only steer less than 90 degrees from one point to another so if you turn it from dead lock from one corner it will only return barely 90 degrees. The servo cannot turn the steering 180 degrees as advertised. This won't do at all. I proceeded it for return right away. It's a waste of money even though it's only less than $20. You really do get what you pay for on this one. My 15 yr old JR servo with 112 oz/in can turn my sons steering more than the new servo.

 

[olds97_lss]

Could try out a savox 0231MG, but might want to get a glitch buster cap to go with it. It's a pretty cheap and stout servo.

 

[DXtreme1]

Is the Savox proned to glitches? I have a Futaba 4PV. I heard the Savox glitches were an issue when paired with a Spektrum reciever/radio thats why a lot of EBay vendors sell Savox servos with the glitch buster since Spektrum is the most popular radios out there. They offered it free to minimize returns. I was thinking of waiting a few weeks and spring for another Spektrum S6230 since I was very happy with that servo.

Could try out a savox 0231MG, but might want to get a glitch buster cap to go with it. It's a pretty cheap and stout servo.

 

[olds97_lss]

They aren't prone to "glitches" per say, but they are high current servos and tend to cause brown outs (low voltage) which causes the receiver or other servos to get weird. The glitch buster is just a capacitor that hooks into an open channel of a receiver (or a Y connector). It supplies a secondary surplus of current when needed which seems to be all that the savox servos need.

 

[DXtreme1]

So they're just like any capacitor. I've never used one for any of my servos but have used capacitors in different applications especially in car audio and brushed motors on RCs back in the day.

 

[olds97_lss]

Yep. Can't remember the v/f rating though. I picked up a cap or two at radio shack (when they still sold that stuff) and made my own for a few bucks. It's just a simple can cap that's wired in parallel with the power rail on the receiver so the battery pack doesn't get overwhelmed by current draw. Less of an issue with high amp esc's in electric, but I did have brown outs on my nitro revo using a 1600mah NiMH receiver pack with the 0231 in it until I put the cap in. I run a hitech 985MG servo for the t/b and when I'd steer, it would flutter a bit. With the cap, it holds solid.

 

[cbaker65]

Yep. Can't remember the v/f rating though. I picked up a cap or two at radio shack (when they still sold that stuff) and made my own for a few bucks. It's just a simple can cap that's wired in parallel with the power rail on the receiver so the battery pack doesn't get overwhelmed by current draw. Less of an issue with high amp esc's in electric, but I did have brown outs on my nitro revo using a 1600mah NiMH receiver pack with the 0231 in it until I put the cap in. I run a hitech 985MG servo for the t/b and when I'd steer, it would flutter a bit. With the cap, it holds solid.

That could be the reason my throttle servo keeps burning up in my baja ,it gets too much power from the 7.2 batts.!...

 

[DXtreme1]

Yep. Can't remember the v/f rating though. I picked up a cap or two at radio shack (when they still sold that stuff) and made my own for a few bucks. It's just a simple can cap that's wired in parallel with the power rail on the receiver so the battery pack doesn't get overwhelmed by current draw. Less of an issue with high amp esc's in electric, but I did have brown outs on my nitro revo using a 1600mah NiMH receiver pack with the 0231 in it until I put the cap in. I run a hitech 985MG servo for the t/b and when I'd steer, it would flutter a bit. With the cap, it holds solid.

I think I need to pick a couple of them up and install them into each truck. I haven't experienced any glitches on my TMaxx but I did experience it on my son's truck using the Traxxas Link controller and receiver.

 

[Certified Mike]

@cbaker65. As much as I hate to say it, there is actually such a thing as too much power!

 

[cbaker65]

@cbaker65. As much as I hate to say it, there is actually such a thing as too much power!

The 1/4 scale steering servo isn't effected by it ,its only the standard size throttle servo.
I went through 4 servo's.

I think that I need a servo that is rated for more power in amps!

So I think that one would not only have to look out for the torq. ,speed ,they will have to look out
for how much amps that it can handle an how much it is needed ,some can suck up a lot
an may need more to power them.
So ,rather than buying a cheap servo ,ya need to check all specs to work with your application!

In my case ,it is a manufacture error that they use a cheap throttle servo to begin with!...

 

[Certified Mike]

As long as there isn't any binding or a throttle return that's maybe a lil too strong, I'm sure there's a servo out there that could,be used to meet the need and not blow up... Hopefully not too pricey too!

 

[DXtreme1]

I'm thinking of cannibalizing one good housing and swapping the motor and board and keep the gearing for the one with the housing if I can find a set that fits. I have 4 different servos of various brands so I'm hoping a couple of sets will eventually fit. If this works out it will buy me some time to gather additional funds for the Spektrum servo or a Savox servo.

 

[Certified Mike]

I have done similar in the past. I found that because the servo sizes have to be more or less the same, many of the parts (although all made by futaba in my case), with different part numberz, I was able to build a couple funtioning servos from the pile of smash and bashed units that I had kicking around. Its Def worth a shot. There is no downside that I can see.

 

[DXtreme1]

Looks like the servo with the strong motor cannot be saved. The motor is good but the control board is toast. It would be useless to use the strong motor with another control board since the control board will just provide the same torque and speed as to what it was originally designed for. I guess just need to sideline the other truck until I can get the funds to get another Spektrum servo.

 

[Certified Mike]

It's entirely possible that the board is used to control the speed and torque. However, the motor and the gearing could also be responsible for that. If I were in your shoes, I'd prob give it a go and see what happens. What have you got to loose really?